Courseware:IT Plus - IP-DECT

This book describes the how to set up a DECT system.

Start configuration

Before you start this book please make sure you have a working App Platform on the SSD of your IP411LEFT. If not set up an Application Platform as described in the book.

So don't proceed if you don't have an AP running on your IP411LEFT.

In this topic we will focus on how to set up a DECT system. This means that we need more devices as the usual training equpiement. You need 2 IP1202(or IP1203) base stations, one IP64 and one IP65 for this course. If you have not already done so, please enter the MAC addresses in your  Training Setup Device Definition.

In this topic, we won't need an IP222, so you can unplug it if you haven't already. As a result you should have two free ports left on your switch. Please connect your two IP1202/IP1203 to these ports.

As a next step please click the setting_up_dect load button.

If you are using an IP1203 for this course, please complete the following steps before you proceed with the book:

• Change the admin password of both your IP1203s to ip1202, otherwise your IP1203 cannot be accessed by moodle. You can find this option at General / Admin.
•  Add the default update URL (https://config.innovaphone.com/init) to your IP1203, otherwise your device will not be able to connect to moodle and provisioning will fail. This is a consequence of the missing default update URL in the shipped firmware and is described in  this wiki article.

To ensure that your base stations (IP1202A and IP1202B) start with a new configuration, please perform a factory reset. Resetting to factory settings can be done by pressing  the reset button on the back of the IP1202 until the LED is steady yellow/orange. Afterwards you can power cycle the base station or in other words, you can power it off by unplugging the LAN port and powering it on again.

Device-specific information on the possible  LED color indications can be found in the Wiki.

This book also has a start configuration for your AP. So don't forget to click on the  Load initial lesson configuration to your Application Platform button once it appears. This may take a while, so bear with us and keep trying

To log into myApps use ckl and ip411 as password.

Use this address: https://hq-dvl-ckl2.training.innovaphone.com

 

Admin menu

All innovaphone DECT handsets have a hidden admin menu for system administrators. This admin menu can be useful for a variety of a tasks, such as:

• Retrieve software and hardware information of the DECT handset
• Retrieve the IPEI and user ID
• Perform a Factory Reset
• Error logging
• Manage Site Survey tools
• Retrieve DECT link and System Information
• Configure System parameters although user protection is active

As said before this function is hidden, so you have to navigate to Menu->Call list->Call time and press the following combination on the keypad of your DECT handset.

> * < < * <

• > means to press the right direction on the control pad of your DECT handset.
• < means to press the left direction on the control pad of your DECT handset.

If your handset is not reset to factory settings, please enter the admin menu as described above and select the Factory reset setting, which is the last entry in the list. After you confirm the factory reset, the handset will restart and ask you for a language.

WinPDM

WinPDM is a software application for Microsoft Windows to manage your DECT handsets and chargers. To be more precise, it allows you to perform firmware updates, apply configuration templates or change advanced settings of the handset. A programming charger (DP1-UAAA in case of an IP64 and IP65) is needed to connect your DECT handset to your PC.

You can find the WinPDM installation files together with a detailed explanation on how to use the software, inside the WinPDM download folder located at the software segment on  store.innovaphone.com: release/download.htm.

 

DECT overall Design

Before we start with the configuration, we will take a closer look at the logical building blocks of a DECT system and the relevant terms you have to be familiar with. The graphical representation helps us to put the terms into context.

RFP

RFP is the shorthand for Radio Fixed Part and describes the radio part of a DECT base station.

RFPI

Every RFP repeatedly transmits the RFPI (Radio Fixed Part Identity), which contains the PARI and a RPN. The RFPI is therefore used to identify the RFP and is the basis for granting or denying access to the DECT system.

• RPN: RPN is short for Radio Fixed Part Number and specifies the number of the base station within a DECT system
• PARI: The Primary Access Rights Identity is a unique ID to identify the RFP. The PARI master automatically assigns this ID to an IP1202 in the DECT system.
  

DECT Handsets

A DECT Handset, like an IP64 or IP65, needs to be subscribed to a DECT system. As soon as it is subscribed, it listens to the signal strength of DECT radios within range and selects the radio with the best signal strength to establish a connection.

Radio

The DECT radio is responsible for converting signalling and voice data between DECT radio signals and IP packets. The radio registers at the DECT master and H.323 is used as IP based signalling protocol. Each IP1202 has a radio part built-in that can be activated and handle up to 8 simultaneous calls for DECT handsets connected to this radio.

PARI Master

The PARI master is a function of the IP-DECT master which has to be activated specifically. The PARI master is responsible for assigning PARIs to all RFPs of the DECT system. It can manage up to 1023 radios. The PARI master has a database of all RFPIs and the matching MAC addresses. This way the PARI master knows each radio. Since this function is centralized there can only be one PARI master per site (except for a standby instance).

IP-DECT Master

The IP-DECT master is responsible for maintaining an H.323 registration for each user with a handset subscription to the PBX. Since the radio registers at the IP-DECT master the IP-DECT master works as a Gatekeeper for the radios. Furthermore it routes H.323 signalling traffic from the PBX to the proper radio and vice versa.

The IP-DECT master maintains a database (Home Location Database - HDB) which contains the authentication information for each DECT handset. The IP-DECT master can handle up to 1000 DECT users. A DECT system can have more than one IP-DECT master but in that case you need a mobility master which is explained in the next chapter.

In addition, the IP-DECT master is responsible for handling DTMF Feature Codes.

Voice traffic

Once the call is established, RTP traffic is sent from IP endpoint to IP endpoint. In a DECT system the radio is the IP endpoint. A bidirectional radio channel is then used to transmit voice over the air to the DECT handset. These calls on the DECT link are encrypted by a cipher key. Depending on your configuration, voice traffic on the IP link can be SRTP encrypted.

Features

Handover

The process of moving a DECT handset from one base station to another during an active call is called Handover. In such a case the PARI master notices that the IP endpoint of DECT handset has to change. Since the PARI master manages the base stations, it notifies the base station that originally established the RTP connection to act as an RTP proxy and to forward RTP traffic to the new base station the handset has traveled to. The remote party does not notice any change and keeps the RTP connection to the radio that established the call in the first place.

Roaming

The process of moving the handset from one location to another and still being able to make and receive calls is known as roaming.

Early Encryption

If you activate the Early Encryption feature, data such as the caller ID or dialed digits are protected before the encryption of the handset's private cipher key on the DECT link can start. As soon as the handset subscribes, it receives a token from the IP-DECT master which enables it to calculate a key which is used for encryption. For security reasons we recommend to activate this feature which is available at DECT / Config / System on your active IP-DECT master. Keep in mind that you need a Crypto Master as well as a Mobility Master for this function, in case you have multiple IP-DECT master.

DECT System Layouts - One Master

Single Site

This layout is intended to be used for customers installing a Single Site.

In a single site installation, one of your Basestations will act as the active Master and PARI Master, and optionally as a Radio. All other IP1202/IP1203 are used as radio only. One of the Radios has to be the Air Sync Master.

The system capacity for this layout is:

• Up to 1000 users (Note: Up to 500 users if TLS is used for the registration)
• When the number of system IDs used in the installation is between 1 to 36:
• Max. 1023 IP1202 / PARI Master
• When the number of system IDs used in the installation is between 37 to 292:
• Max. 127 IP1202 / PARI Master

Multiple Sites

If you have multiple sites but want to keep the configuration as simple as possible you can use this layout. If the WAN connection between the remote site and site with IP-DECT master is down, the remote site is without DECT support.

In this layout, each site can have one or more IP1202/IP1203. The PBX and the PARI Master and Master are located centrally. Each site has a Base Station as Air Sync Master with its own Sync Region.(We will discuss Sync Region a litte latter in this book)

With this solution the handset will be able to roam to a different site and it will be possible to receive incoming and make outgoing calls.

The system capacity for this layout is:

• Up to 1000 users (Note: Up to 500 users if TLS is used for the registration)
• When the number of system IDs used in the installation is between 1 to 36:
• Max. 1023 IP1202 / PARI Master
• When the number of system IDs used in the installation is between 37 to 292:
• Max. 127 IP1202 / PARI Master

Distributed PBX Systems

In a PBX System with a Master PBX and one or several Slave PBXes, the single IP-DECT Master points to the Master PBX. The registrations to the User Objects belonging to Slave PBXes will be redirected by the Master PBX. This enables to maintain single IP-DECT Master in the System of multiple Master-Slave PBXes.

Note that in this case the registrations of all DECT users will have the master PBX as their physical location. This can be a problem if you have a local tunk at each site.

DECT System Layout - Multiple IP-DECT Master

Before we go into the Layouts if you have multiple IP-DECT master we have to explain two more terms.

Mobility Master

The Mobility Master enables handover and roaming in a multiple IP-DECT master system. The Mobility Master has its own Home location Database (HDB) which it receives from each IP-DECT master in the Installation. This way it has the authentication information of each DECT handset from every IP-DECT master in the system.

It could be even necessary to have multiple Mobility Master in case you need to distribute load. In such a case the Mobility Masters need to be interconnected to each other.

Crypto Master

You need to configure a Crypto Master if you activated Early Encryption and you are using a Mobility Master. Each handset has to have a unique crypto token in the system. The Crypto master ensures there is no conflict of the Crypto token although you have multiple IP-DECT master.

Single Site

If your system design requires you to have multiple IP-DECT masters because you have more than a 500(TLS based) or 1000 users, you should aim for this layout. You to have a Mobility Master in your DECT system which connects both IP-DECT master. Please note that you can have only one PARI master in a single site installation although you have multiple IP-DECT masters. It will be possible to do roaming and handover between all radios.

The system capacity for this layout is:

• Up to 1000 users / Master (Note: Up to 500 users / if TLS is used for the registration)
• When the number of system IDs used in the installation is between 1 to 36:
• Max. 1023 IP1202 / PARI Master
• When the number of system IDs used in the installation is between 37 to 292:
• Max. 127 IP1202 / PARI Master
• Max. 100 Masters / Mobility Master

Multiple Sites

This layout is chosen if you have multiple sites and each site should be able to operate independently if the WAN connection between the sites is down. One of the sites must have a Mobility Master and both IP-DECT Masters must be able to connect to it.

The system capacity for this layout is:

• Up to 1000 users / Master (Note: Up to 500 users / Master if SIP over TLS is used.)
• When the number of system IDs used in the installation is between 1 to 36:
• Max. 1023 IP1202 / PARI Master
• When the number of system IDs used in the installation is between 37 to 292:
• Max. 127 IP1202 / PARI Master
• Max. 100 Masters / Mobility Master

More on Roaming

In the last chapter, we talked about the system layout of a multi-site setup. When a handset moves from one site to another, the handset's subscription should still work. When a handset is turned on at the remote site, it will attempt to contact the IP-DECT master at its home site. This connection (remote base station -> IP-DECT master) uses H323/UDP, so you cannot use a reverse proxy to route traffic from one site to another because the reverse proxy will only listen to TCP-based H.323. A VPN connection is required between the sites.

In other words, it is important that each IP-DECT master is able to reach all base stations from both sites. This will only work if you create a VPN tunnel between these sites.

Note that the H323 registration of the IP-DECT master to the PBX can be configured to use H323/TCP or H323/TLS, so the PBX can be located in the cloud.

DECT Master

We will start to configure our IP1202A  by selecting a mode for the IP-DECT master. For now, we will use the Active mode for our IP1202A. This option can be set atDECT / Config / Master. Restart the device afterwards.

The IP-DECT master can run in the following modes:

• Off - You probably guessed it, this mode turns off the IP-DECT master feature of your IP1202. This is the default value.

• Active - This mode turns on the IP-DECT master, allowing you to use all functions of your IP1202.
  

• Standby - A nIP1202 in standby mode takes over as soon as the active IP-DECT master fails. You cannot subscribe handsets to a standby IP-DECT master even if the standby has taken over. This mode is deprecated and we recommend to use the mirror mode instead.
  

• Deployment - This mode allows us to test our voice quality and measure signal strength. Outgoing calls are forwarded back to the handset.
  

• Mirror - If you configure two IP-DECT masters in mirror mode, you always have one active IP-DECT master. Even if the active IP-DECT master fails, the other IP-DECT master in mirror mode will switch to active which allows you to maintain normal operation. We will discuss this feature in more detail later in this book.

DECT System

You have to create a DECT system object in the PBX for each IP-DECT master in your system. This means if you have more than one IP DECT master, you need a DECT system object for each of them. Fortunately, the PBX is capable of handling multiple DECT system objects, so you can create them all in the same PBX. To create a DECT system object we need to go back to our PBX PBX / Objects and select a  DECT System object in the drop down menu and  assign a Long Name to the object.

Please choose the Long Name of the DECT system object carefully because it will be used throughout your DECT system and is even visible on the screens of the DECT phones. We therefore recommend to use a System name that identifies the physical location of this IP-DECT master. It would be advisable to call it Dect-headquarters or Site-Sindelfingen. Furthermore, you can define a PBX location in the drop-down menu of the DECT system PBX object. If you have a master-slave scenario, you would select the PBX where the DECT system is located.

The purpose of the DECT system object is easily explained. It stores system parameters such as the preferred codec or the authentication method of the DECT system within the PBX.

Please go ahead and create a DECT system object at PBX / Objects and use hq-dect as Long Name for the object.

Afterwards we have to define our DECT system name at the IP-DECT master as well. Therefore we will go to DECT / Config and  configure the system name. Note that  the system name you configured here has to match the Long Name of the DECT system object in the PBX you created before.

As a result please set the system name to hq-dect.

You are probably wondering which password to use as system password. As soon as we create an LDAP replication between PBX and IP-DECT master, the PBX will share user data, like the user password with the IP-DECT master. Such data is communicated in encrypted form consequently both sides need to share a secret to encrypt and decrypt the data. The secret in this case is the PBX password. The equivalent to the PBX password is the system password at the IP-DECT master. As a result we need to set the system password equal to the PBX password. If you remember back on the first day of the training we set the PBX password at PBX / Config / Security.

Please set the password to ip411 and reset your IP1202A again.

LDAP replication

The IP-DECT master needs to know all user objects that should be capable of using a DECT phone. In the next chapters we will establish an LDAP connection between IP-DECT master and PBX. LDAP is used to replicate all DECT capable user objects to the IP-DECT master and to write information from the IP-DECT master back to the DECT system object we created earlier.

User object settings

The next step is done  in the DECT tab of the user object.

• Gateway: This parameter is mandatory, otherwise the object will not be replicated to the DECT master. You must set the DECT system name here.
• IPEI: In the course of the book we will discuss two different methods to subscribe a DECT handset to an IP-DECT master. We can either preconfigure this value with the IPEI, the serial number of the DECT handset, or we can leave this value empty and use a feature code to assign the handset to a user.
• Idle Display: You can enter a text to be shown on the display of the handset.
• AC: You can define a personal access code that protects the user object from an unauthorized subscription at this object.

The IPEI of the DECT handset is printed on the box the handset was delivered in and under the handset battery. It is also possible to use the  Service Code *#06# to determine the IPEI.

If you configure the IPEI in the user object, the last digit should be omitted. Although the IPEI is a 13-digit number, you should only enter 12 digits and skip the last digit. The last digit is used as a check digit and can be a special character like a *. If you enter the 13-digit IPEI, the registration will fail.

Please go to the DECT tab of John Doe's user object.

• Set the Gateway value to hq-dect
• Configure the first 12 digit of the IPEI  of your IP65.
• Please configure a simple personal access code for John Doe, like 1234

Please go to the DECT tab of Richard Roe's user object.

• Set the Gateway property to hq-dect

Powering on a virgin DECT handset

If you receive a virgin DECT handset, we have to prepare your handset to be able to use it.

• Remove the battery cover. In case of an IP64 you better remove the clip to be able to slide down the battery cover.
• Pull off the foil.
• On an IP64 you need to plug in the battery connector.
• Reattach the battery cover.
• Press and hold the disconnect button at your handset to turn it on.
• You are going to be asked for a System name, PARK and AC. You can skip this for now because we talk about the subscription of a handset later in the book.

Subscription vs Registration

A common misunderstanding is the difference between subscription and registration. When we talk about subscription, we talk about adding the DECT handset to the DECT environment in order to become known to your IP-DECT master. If the subscription was successful you will see  an indication at your IP-DECT master. As long as the DECT handset is not assigned to a user, a subscribed handset will be listed as anonymous. When the IP-DECT master learns which IPEI corresponds to which user object, the IP-DECT master will try to establish a registration on the behalf of the DECT subscription.

LDAP server

As a next step we will  create new LDAP credentials on the LDAP server of the PBX. This is necessary because the DECT master replicates its user objects from the PBX. Therefore the DECT master needs access to the user database of the PBX. It is important to set Write Access for this LDAP connection, because the DECT master has to be able to store information on the DECT system object and PBX user objects.

It important to not set the Apply Hide checkmark for this LDAP connection because the DECT system object is marked hidden by default. As a result, as soon as you activate this checkmark the DECT system object could no longer be seen from the DECT master which would lead to the error message No Sys-Object at the DECT master.

Please  create LDAP credentials at Services / LDAP for the LDAP replication.

• Set the user to hq-dvl-ckl2.training.innovaphone.com\dect
• Use ip411 as password
• Tick the Write Access checkmark
  

LDAP Replicator

As a next step, we complete our LDAP replication configuration because we finally want to see some objects at DECT / Users. More specifically, we want to see John Doe and Richard Roe because these are DECT capable user objects and only these objects should be replicated. Therefore we will have to set up an LDAP replicator at Services / LDAP / Replicator.

The first decision we have to make is the choice of a Replication Type. We select Full Replication which is used when replicating objects from an innovaphone PBX. The Active Directory Replication option is selected if you need to replicate users from a Microsoft Active Directory. But this is currently not what we are looking for.

Please make sure that you selected Full Replication. Afterward we configure the following parameters:

• Tick the enable flag to activate the replication

• The server property has to be set to the DNS name of the PBX (hq-dvl-ckl2.training.innovaphone.com)

• The PBX only allows LDAPS connections. As a result we have to activate the TLS checkbox next to the Server property to enable LDAPS. This automatically adds the default port 636 to the server property.
  

• We do not need to configure an Alt. Server (Alternate Server) at the moment. This option is used in case we want to have a backup source to replicate from if the PBX is down.
  

• You have to configure a search base as the DN property. To replicate objects from the PBX database, the configuration option should be cn=PBX0

• Since we only want to replicate user objects with a DECT configuration, we set the Filter Type option to DECT Gateway Name

• Set the DECT Gateway Name to the Long Name of the DECT system object in the PBX. In our case it is hq-dect

• Set the user property to the LDAP user name we previously defined in the PBX LDAP server. In our case the correct user is called hq-dvl-ckl2.training.innovaphone.com\dect

• The password must match the password we defined for the LDAP user configured on the PBX LDAP server. Of course, as always, we will use ip411

To see if your configuration worked, you can switch to  the replicator status screen Services / LDAP / Rep-Status. If everything worked as it should, you will see the state Completed next to the Full replication information. If your configuration generated an error, you will find an error message in the Last messages section.

Finally, when you click show on your DECT / Users screen, you will see the  replicated users John Doe and Richard Roe.

Setting up the IP-DECT master

In this chapter we will focus on further configuration options of the IP DECT master.

Please note that you need to have an active LDAP replication before you configure the IP-DECT master. If this is not the case, the IP-DECT master cannot write the configuration into the DECT system object. If the IP-DECT master is rebooted, configuration options such as the SARI are lost if they are not present in the DECT system object.

Master ID

You have to assign an  ID to the master. This ID has to be unique for each IP-DECT master in a DECT System with multiple IP-DECT masters. In other words, if you have more than one IP-DECT master, each of these IP-DECT masters must have a different Master ID. The default value of the Master ID is 0. To avoid errors, a one-digit number would be advisable in most cases although you may choose the value freely.

It is important that a Standby master has the same ID as the master.

For training purposes we will use 1 as our master ID at DECT / Config / Master .

PARI Master

As already discussed, the PARI master is a function of the IP DECT master.  You can activate this function by checking Enable PARI function at DECT / Config / Master. After activating and restarting your device, you have further configuration options available in your IP1202, such as setting a system ID or SARI.

To activate the PARI master function please tick the Enable PARI function check mark and restart your IP1202A afterwards.

System ID

As we talked before the PARI is part of the RFPI. A unique System ID is part of the PARI. The System ID is created randomly and assigned automatically as soon as you enable the PARI master. If more than one IP-DECT system operates in the same coverage area the System ID has to be unique in order to differentiate the systems. The system ID has to be unique as well in a system with two physical sites operating with the same SARI. As a consequence you can set the System ID manually to a value between 1 and 296 at DECT / Config / PARI. Depending on the value, the number of radios per PARI master is limited.

If you use a System ID between 1 and 36, you can connect up to 1023 radios for one PARI master.

If you use a System ID between 37 and 292 the maximum number of radios for one PARI master is reduced to 127.

In large systems you can also set the System ID between 293 and 296. In this case, the PARI master can handle up to 2047, but all other functions such as radio, crypto-master or mobility master should be deactivated.

If you are doing the training in a group, please make sure that your fellow trainees are using a different System ID than you.

SARI

The SARI (Secondary Access Rights Identity) is a unique ID and used to identify an IP-DECT system and a mandatory configuration of the PARI master. Each DECT system requires its own SARI, which must be purchased for each productive DECT system. It is possible to enter more than one SARI. This can be useful if you want to join two different IP-DECT systems and allow roaming between those. The first entered SARI is later used as PARK, which must be entered to subscribe to a handset.

Please add one of the following SARIs to your configuration. The SARI can be set at DECT / Config / SARI. If you are doing the training in a group, please make sure that each participant has a different one.

31100654271708	31100654272203
31100654271745	31100654272240
31100654272049	31100654272304
31100654272102	31100654272341
3110065427214*	31100654272405

These SARIs are for training purposes only. Usage within productive systems is prohibited.

PBX connection

One of the tasks of the IP DECT master is to keep a registration for each subscribed handset and forward the signalling data from and to the PBX.  Consequently we need a VoIP signaling protocol to achieve such a task. In our case we will use H.323/TLS to encrypt traffic from and to the IP-DECT master.

• Gatekeeper - The IP-DECT master needs to know the address of the PBX to be able to route traffic to the PBX. Therefore a Gatekeeper is used.
  
• Alt. gatekeeper - If the PBX fails, a standby PBX should take over. The address of the standby PBX is defined here.
  
• Gatekeeper ID - If you want to route the signalling traffic through a reverse proxy. The routing decision is made via the gatekeeper ID, which is configured here.
  

Back at DECT / Config / Master please configure an IP connection between your IP-DECT master and the PBX.

• Select H323/TLS as protocol.
• Configure the Gatekeeper hq-dvl-ckl2.training.innovaphone.com
  
• Reboot your IP1202A afterwards.
  

Registration

Throughout this book we will subscribe and register our 2 DECT handsets to Richard Roe and John Doe. These two will be our DECT users. In order for them to register, we need to do some groundwork.

In the first part of the training we discussed that a phone is not registered to a user, but to a device defined in the user object. As a result, we had to create a hardware ID for this phone. We will do the same for our DECT phones but in order to configure it correctly, we need to know which name a DECT phone uses for the registration. The answer is simple, it uses the name of the object which was replicated to the IP-DECT master. For example, John Doe will use his name john.doe for the registration, which means  we need to add this hardware ID to the user object.

Please create a hardware ID for John Doe and Richard Roe that matches the name of these objects

Since the IP DECT master manages all registrations to the PBX, the IP DECT master must ensure a trustworthy registration. Activating H.323/TLS does not work in this situation because you cannot map the base station certificate to a user object.  The CN of the certificate will simply contain the MAC address of the IP1202, which is unknown in the PBX. However, you still have two different registration methods that you can use. You can either use the PBX password or the user password for the authentication. Both are valid options, but you must make a choice. You cannot use the methods simultaneously.

Registration with user password

We recommend using the user password for registration. Since this is the default method of the IP DECT master, you do not need to configure anything for it to work. The IP DECT master automatically uses the password of the user to authenticate the registration.

If you are afraid that the user can change the user password and then the registration will not work anymore. I can ease your concerns in this regard. Due to the LDAP replication between IP-DECT master and PBX, the IP-DECT master is always up to date with the user password, even if the user changed it.

As we mentioned before, the IP DECT master will use the object name to register to the PBX. This probably sounds familiar to you. The reason is that we already used the name of the object as a hardware ID when we created a hardware ID for ad-hoc registrations. A hardware ID must be unique in the PBX, which means that you must use the same hardware ID for both DECT and hotdesking. It also means that you should use the user password to authenticate the DECT registration because the user most likely doesn't know the PBX password.

Registration with PBX password

Of course you could also use the PBX password for the authentication of the registration. If you remember back the IP-DECT master already knows the PBX password. We had to set the password of the IP-DECT system to the PBX password because the PBX password is used as shared secret to encrypt the user passwords. The IP-DECT master can be told to use the system password for the authentication of the registration if you activate  the checkmark Registration with system password at DECT / Config / Master.

On the PBX side, you need to enable  the PBX Pwd option at the hardware ID of the DECT handset inside the user object. This option is necessary, because otherwise the PBX does not know to match the received password with the PBX password.

Radio

To proceed with our configuration we will now add radios to our DECT system. Fortunately, there is a really easy way to do this. We just have to go to DECT / Devices Overview at our PARI master and we  already see a list of radios.

Every virgin base station will use the Gatekeeper Discovery protocol to find his Gatekeeper, or in this context, the PARI master. It sends a gatekeeper request as an IP multicast message and hopes to discover a PARI master. As a result, this mechanism only works if the radio and the PARI master are in the same broadcast domain of the network. When they find each other, the radio will be included in the above-mentioned list.

Please add the radio of your IP1202A and IP1202B to your PARI master, by clicking the Add button.  A new window appears allowing us to specify a name and an alternative PARI master for the device. You can also add the radio to a Kerberos realm, but since we use the Devices app, this is no longer necessary. As soon as you click OK, the radio is registered with the PARI master and the configuration is done automatically.

You can also configure the radio manually at DECT / Config / Radio. You will need to configure the following components.

• Name - The system name must be entered here. We defined this name when we created the Long name of the DECT system object.
  
• Password - This password must match the password of the DECT system.
  
• PARI Master IP Address - The IP address of the PARI master has to be configured here.
  
• Standby PARI Master IP Address - You can define the IP address of a standby PARI master so that the standby PARI master will take over all H323 registrations of radios if the PARI master fails. This configuration is optional.

Since an IP address is used to connect the radio to the PARI master, you should give the PARI master a fixed IP address or create a reservation on your DHCP server so that the IP address always remains the same.

Air Sync

DECT in Europe operates in the frequency range from 1880 MHz to 1900 MHz and is divided into 10 channels with a bandwidth of 1728 kHz each. Each of these channels is divided into 24 timeslots with a duration of 10 milliseconds. These time slots must be synchronized on all radios in the same sync region, so that each radio has the same clock rate. To achieve synchronization, one radio must be an active sync master to dictate the clock rate.

Timeslots are used for the uplink and downlink between handset and radio. All of these 24 timeslots result in 12 bidirectional channels, 8 channels for speech and 4 for synchronization.

As long as the IP1202 is flashing blue, the base station is not in sync, which means that it cannot operate. If the LED of the base station is constantly blue, the base station is in operation.

But who decides which base station is active sync master? Radios configured as sync master will report to the PARI Master that they want to be the active sync master. The PARI Master will select one of them to be the active sync master. The remaining candidates act as sync slaves until the active sync master fails. In this case, one of the other candidates becomes the new active sync master.

All IP1202s in sync mode slave scan their coverage area to find radios in range. They send a list of received sync candidates to the master. The master tells each sync slave which radio to sync to. This can be the air sync master itself or another air sync slave.

As a result, radios form a sync chain of air sync slaves leading to the air sync master. To keep the sync chains as short as possible, we recommend placing the air sync master and its backup in the center of the DECT coverage area.

In case you configure a radio as a restricted slave, it can't be used as a synchronization source, it can only retrieve sync from another radio. This option is used when a base station cannot be considered a reliable source for synchronization. This may be the case if there is a door between two base stations and the synchronization is lost when the door closes. In such a case the connection can be considered unreliable.

Please set both of our IP1202s  from Sync Mode Slave to Master, because we will later test a fail-over that only works if both base stations can be the active sync master (DECT / Config / Air Sync and DECT / Config / Air Sync.

Sync region

There are two main examples why you would want  to split a DECT system into multiple sync regions.

• If the visibility of the base station used for synchronization is constantly changing, e.g. due to a door opening and closing or moving objects, you can divide the coverage area into sync regions, each sync region being independent of the other.
• If you have separate buildings far away from each other between which synchronization is not possible, you can define multiple sync regions. Also in this case the synchronization is independent from another sync region, but the radios still connect to the same PARI master

In other words, sync regions are used when all radios use the same PARI master, but the coverage between radios is not good enough for stable synchronization or the radios are simply out of range of each other. In this case, we can divide a site into several sync regions. Each of these sync regions has its own sync master, which dictates the clock in that sync region. This way, a handover within this sync region is possible. To enable handover between two sync regions, you must configure a reference sync from another region. If a region loses its reference sync, handover within the region still works, but handover between regions does not work.

Do not forget that the radios use H.323/UDP to talk to the PARI master. This means that the distance between the sync regions does not matter as long as the radio can reach the PARI master via IP. There could even be a VPN tunnel between the sync regions and the communication between the radio and the PARI master will still work. Since the reverse proxy only listens to TCP based traffic, a connection between a radio and the PARI master via the reverse proxy is not possible.

Sync region is a configuration option you can find at DECT / Config / Air Sync and has to be set to a value between 0 and 249 on all radios in the same sync region. As long as the value is within the specified range, you can select any value.

Please make sure that our two IP1202 are part of the same sync region.

As soon as you configure a radio as a sync master  you will get additional configuration options. One of these actions can be defined to be executed in case of a synchronization failure with its reference RFPI. You can set the resynchronization to a specific day and time, or it will only be executed on command, but note that all calls will be dropped during the resynchronization. The reference RFPI can be configured at DECT / Config / Air Sync  The RFPI value of your radios can be found at DECT / Devices Overview / Radios of your PARI master. Since our setup is quite simple at the moment and we only use one sync region, we do not need to configure a reference RFPI.

For synchronization to work, it is not allowed to configure the reference synchronization in a ring.

Handset subscription

Before we can subscribe our DECT handsets to our DECT system we need to talk about Subscription Modes and Authentication Codes.

For security reasons, we can define a subscription mode and a matching Authentication code to reject any unknown DECT handset that could be a malicious threat. You have three possible options to choose from.

• Allowed - Any handset may subscribe as long as the Authentication code is correct.

• If the user's IPEI is already known to the DECT master, like the IPEI of our John Doe, you only have to turn on your DECT handset. It will automatically search for a DECT system, subscribe to it and the IP-DECT master will create a registration on its behalf.

• If the IPEI of the handset is unknown, you need to use  the system Authentication code defined at DECT / Config / System to subscribe the handset. After a successful subscription,  the IPEI of the handset is listed as anonymous at DECT / Anonymous and has to be assigned to a user object. We will discuss this in the next chapter.
  

• With Activation - The handset subscription requires manual activation.

• If the IPEI of the user is already known to the DECT master, you must enter the personal user Authentication code. However, the subscription works only  if you click on the user's IPEI at DECT / Users. If you click on it, a subscription with this IPEI is allowed for two minutes. After a successful subscription, the DECT master automatically creates a registration at the PBX on behalf of the handset.

• If the IPEI is unknown to the DECT master, you can  add the IPEI to the anonymous screen (DECT / Anonymous). To subscribe the handset, you must click on the IPEI you just created and use the system Authentication code. In the next chapter we will learn how to connect an anonymous handset to a PBX user.
  

• Disabled - no new DECT handsets can be subscribed. This option can be used if all handsets are already subscribed and no further handsets should be able to be subscribed.

We advise against using the Allowed Subscription mode in a productive system to protect your system from unwanted subscriptions. This mode should only be used in the deployment phase. Please use With Activation or Disabled in a productive system.

Subscribing Handset in mode allowed

We will first subscribe our IP64 as if we are simulating the deployment phase. Therefore  please set the Subscription mode to Allowed. You can either use  the suggested system Authentication code or configure a new one. If you use the suggested Authentication Code you need to press OK or otherwise the Authentication code isn't saved in the configuration.

Before we subscribe our IP64, we need to discuss the options that needs to be entered.

• System name - You need to enter the DECT system name here to identify the DECT system. This configuration is not mandatory.
• PARK - You will find the PARK at DECT / Users and it serves to identify the DECT system. This configuration is not mandatory.
  
• AC - You need to enter either the personal or system Authentication code depending on the subscription method we discussed earlier.
• Protection - By turning on Protection the user is unable to unsubscribe the handset by himself. While this is a useful setting in real life, we will not use it in training, because we do not want to lock ourselves out.

You have to identify the DECT system either by the system name or PARK unless you are sure that no other DECT system is in range. In this case you can leave these options blank.

Please power on your  IP64. When you switch on your brand new DECT handset or a DECT handset that has been reset to the factory settings, it asks you (after selecting a language and canceling the searching) for the System name, PARK, Access Code (AC) and protection mode. You can also subscribe the handset by navigating to Menu/Settings/System/Subscription at the phone's user interface. We will enter the following values.

• System name: Please enter hq-dect
• PARK: Please enter your PARK which  can be found at DECT / Users
• AC: Please enter the previously configured system Authentication code
• Protection: No

If you want to enter the system name for the subscription, please note that the input mode is automatically set to "Abc"mode, which means that the first letter is entered as uppercase. You can switch this mode to "ABC", "abc" or "123" by pressing the * key on your phone's keypad.

If the subscription was successful you will see a pop up information on the display of the DECT handset and the DECT system name will appear on the DECT main screen together with the information "Please login". Additionally, you will see the IPEI of the device at the Anonymous screen (DECT / Anonymous).

Mapping a subscription to a PBX user

As soon as a handset is subscribed to the IP-DECT master as anonymous, we can assign the handset to a user object. This can be easily achieved by dialing this number from the anonymous handset:

*<Master-ID>*<User-Number>*<Access-Code>#

• Master-ID - When configuring the IP-DECT master, we previously set the master ID to 1 at DECT / Config / Master.
  
• User Number - We need to dial the number of the user to be mapped to.
  
• Access-Code - If you configured a personal authentication code in the DECT tab of your PBX user object, you have to also dial it, otherwise it could remain empty.

This means that we dial the following number from our IP64 (Keep in mind that we didn't configure a personal authentication code in the user object of Richard Roe):

*1*13*#

The IP-DECT master will create a registration on behalf of the handset. If the registration was successful, you can call any user number in the PBX.

Subscribing Handset in mode With activation

Please switch the Subscription mode to With activation, because we will use this method to subscribe our IP65.

If your IP65 is already registered, you turned it on while the subscription mode was set to Allowed. If the IPEI is already known, the subscription and registration process is performed automatically in this case. To proceed with the next task, you need unsubscribe your handset at Menu/Connections/System/Unsubscribe.

Please start your  IP65 and go to Menu/Connections/System/Subscribe. Please enter the following parameters

• System name: Please enter hq-dect
• PARK: Please enter your PARK which  can be found at DECT / Users
• AC: Please enter the previously configured personal Authentication code
• Protection: No

Do not forget to allow subscription  by pressing the IPEI on the IP DECT master since we switched the Subscription mode to With Activation. After successful subscription, the IP-DECT master creates a registration for the handset. Afterwards you can call any of our 4 desk phones.

Phone App

Of course you can also control your DECT handset with a phone app. The configuration is rather easy, you just have to add the word phone as App to the devices entry of your DECT handset. You can do this either  in the user object in the advanced UI or the user can do it by himself  in his profile app. As soon as you entered the name phone,  your phone app will appear.

Over the Air Update

It is possible to update the firmware of IP64, IP65, Ascom d81 and d83 handsets without the need of a programming charger and WinPDM. You can update the firmware over the air without physically touching the handset.

Defining the Versions to be used

To do this you have to define the firmware to be used.

To do this, open your Devices app, navigate to  your domain/Update, and click the Update Settings option. The devices app will retrieve 4 different .json files that contain update definitions. In the case of the DECT handset update, the software.json file is important because the software.json tells us which DECT handset version is available in the App Store.

If new versions are available (which is the case in our sceanrio), please tick the Apply available versions option and then Apply.

Creating an update job for DECT handsets

The next step is to create an update job.

Click on the Add update job option and a new dialog will appear.

This dialog let's you define:

• a Description of the update job
• the Date and Time when the update should begin
• the Major Version for the update
• a Category. Only devices within this category will be affected by the update
• an Exclude category. You can exclude devices in a certain category from this update.
• due to the fact that we want to update our DECT handset you need to enable the Update DECT handsets(IP64,IP65,D81,D83) option.

Please  create an update job to update our IP64 and IP65 firmware. Select the category hq DECT and do not forget to press Ok after defining the above mentioned settings.

Each handset downloads the firmware individually because the firmware is not cached anywhere. Each downloaded firmware packet is immediately copied to the handset memory. You can download a maximum of 10 firmware files at a time. Depending on the connection and the call status of the handset, the download will take between 10 minutes and 2 hours. There is no progress bar to show the progress of the download. You will only see the progress if you run Wireshark on the IP-DECT Master.

After downloading the firmware, the handset must be restarted. An active call will not be disconnected. The handset will wait for the call to be cleared before rebooting.

Feature Codes

Feature Codes

Feature codes are used to call up a specific function on the IP-DECT master via DTMF tones. Which means that you can easily set up a call forwarding or number restriction by simply calling the corresponding feature code from your DECT handset. The IP-DECT master is responsible for interpreting the incoming DTMF tones to activate the desired function for the called user.

These feature codes can be set on DECT / Config / Features and are enabled by default. All feature codes can be changed and the change affects all DECT users.

As a little exercise, let's activate the call waiting feature for Richard Roe by calling *43# from your IP64. You will see an Executed information on the handset display and if you open the user object on your IP-DECT master, you will see all  activated features for this user.

R-key handling

In addition to the feature codes, you can also activate features during the call by pressing the R-key (Right function key). So if you are in a conversation, you have the possibility to use either of these options.

• R-key: Puts the active call on hold. Press the R-key again you retrieve the call on hold.
• R-key + any number: Puts the active call on hold and calls the dialed number.
• R-key + 0: An incoming call will be rejected while call waiting is enabled.
• R-key + 1: Disconnects the call currently on hold
• R-key + 2: Toggles between an active call and a call on hold.
• R-key + 3: Initiates a 3-party conference. (This does not work out of the box. We will come to this option later in the book Conferencing and DECT)
• R-key + 4: Connects the active call with the call on hold.

Let's test this feature

• Call Richard Roe(13) from Jane Doe(IP112)
• Connect the call with your IP64
• Call Richard Roe(13) from Edward Hyde(IP232)
• You will hear a ringing sound on your IP64, which means that call waiting is working
• Take the call by pressing the R-key and then 2 on your IP64.
• Richard can now talk to Edward while Jane listens to the MOH

DECT Handset - Device Configuration

You can distribute configuration option to your IP64 and IP65 (this feature is not for an Ascom d81 or d83) through the Devices app. When you  go to your domain/Device configuration in the Devices app, you have the possibility to select a new device configuration (DECT handsets) from the drop-down menu.

Please note that your IP64/P65 must have at least firmware version 4.3.2. Otherwise the configuration is not pushed to the devices. If this is not the case please update your handset as explained in the chapter IP-DECT: Over the Air Update.

As with any device configuration, you configure a description and select a category.

You can set the following options in this dialog:

• Language: Select the language you prefer. The phone menu will be displayed accordingly.

• Date format: You can select a date format to display on the handset.

• Voicemail number: Enter  the voicemail prefix followed by the variable N. Press and hold 1 on the handset keypad to make a call to the voicemail number. N is replaced by the extension number of the user at the beginning of the call. This allows each user to call their own voicemail box. If you want to learn more about voicemail, check out our  voicemail topic in the Plus Training.

If you change the configuration parameters here, the phones will not be updated immediately. By default a phone will ask for a new configuration every 60 minutes. This timer can be changed as explained in  our wiki article.

Please create  a DECT handset device configuration and configure the description IP64/IP65 Handset and select the category hq DECT, which includes our IP1202/IP1203. Configure all other values as you like.

Phonebook

Now we are going to configure a phone book at DECT / Config / Phone Book to be able to search for names aka forward lookup. The phone book will use LDAP as a protocol to find contacts in the PBX, contacts app service database or a third-party directory service. This will allow us to use the Central Phonebook function of the DECT handsets.

General Settings

Phone Book Number

The Phone Book Number is not allowed to overlap with an existing number in the PBX. The default value is 999999 and it's not recommended to change it. You can still use the number 9 or 99999 in your PBX. This will not result in a conflict.

Discarded Results Text

If too many matches are found in the LDAP search, the result is discarded and the configured text is displayed.

Result Format

This option allows you to decide in which format a search result should be displayed at the handset. Imagine your Display/Sort Attributes value of your external LDAP server configuration is set to: givenName,sn,city,email. In this regard the results are mapped to variables: A=givenName, B=sn, C=city, D=email.

A B C D E and B A C D E will display all found attributes separated by blanks either starting by A or B.

E.g: A B C D E = Erika Müller Sindelfingen your@email.com

A, B C D E and B, A C D E will display all attributes separated by blanks expect the first one which is also separated by a comma. Again you can choose if you want start the list with A or B.

E.g: B, A C D E = Müller, Erika Sindelfingen your@email.com

(A or B) C D E and (B or A) C D E will only display A or B and then the rest of the attributes. In case the first attribute is not found the second one is displayed.

E.g: (B or A) C D E = Müller Sindelfingen your@email.com

PBX search

To find contacts in the PBX we will configure a PBX search on the IP-DECT master.

Server settings

For the PBX search to work, we first need to configure the server side. You probably guessed it, the server side for the PBX search is the PBX.

We will create new LDAP credentials on the LDAP server (Services / LDAP / server) of the PBX.

• Set the username of the LDAP account to hq-dvl-ckl2.training.innovaphone.com\phonebook

• Set the password of the LDAP account to ip411

• Set the Apply Hide flag because we don't want to find hidden objects.

Client settings

As a second step we need to configure the PBX search parameters on DECT / Config / Phone Book.

To  configure client side of the PBX search for your DECT handsets, you need to do the following steps.

• Tick the Enable flag

• Enter hq-dvl-ckl2.training.innovaphone.com as Server property because the LDAP search request should be sent to the PBX

• We need to use LDAPS for this connection therefore we have to activate the Use TLS check mark

• You do not need to tick the Validate TLS Certificate check mark.

• Set the User of the PBX search to hq-dvl-ckl2.training.innovaphone.com\phonebook

• The password should be ip411 again because this should be the password the LDAP server account
  

Let's try it. Therefore please go to Menu/Contacts/Central Phonebook and search for j as first name. You will find Jane and John Doe. You can call both directly from the phonebook.

External LDAP search

As a next step we establish a LDAP connection to our contacts database which we will use as directory service.

Server side

Once again we are going to configure the server side first. As a result we will do the following steps which most likely sound familiar to you because we did the same steps when we discussed the contacts chapter.

• start Contacts

• When you type fen in the search window, you should see the  entry for Renée-François Fenêtre
  
  
• Open the contacts  Settings plugin and click Change configuration.

• type a secure password into the Password (LDAP) field
  In this course, we will use ip411 again.

• tick the Enable LDAP check mark to start the LDAP server if not already active.

Client side

To complete our configuration we will configure the following steps  on the client side.

• Tick the [[:input Enable|nocopy] check mark.

• Set the server property to the DNS name of your App Platform ( inputapps-dvl-ckl2.training.innovaphone.com)

• Tick the Use TLS check mark to use LDAPS

• You do not need to tick the Validate TLS Certificate check mark.

• Set the User to a name in the domain\user format. The domain is apps.dvl-ckl2.net in this case. User is the name of your Contacts App service (contacts). So in this case, you end up with  inputapps-dvl-ckl2.training.innovaphone.com\contacts

• Set the Password to ip411 which is the matching password in our contacts app

• Set the Search Base to dc=entries

• Leave the Search Filter attribute empty because we don't want to filter our search results

• Set the Search Attributes to givenName,sn
  

• Set the Number Attributes to telephoneNumber

• Set the Display/Sort Attributes to cn


• Set the Meta Name Attribute to metaSearchText

Once again we will configure  the Dialing Location. This resembles the Prefix for Intl/Ntl/Subscriber and Country-Code/Area-Code/Subscriber property in PBX/Config/General, however, the format is slightly different. The Dialing Location is used to put the number in a dialable context.

• set Country Code to the country code of your trunk line, 49 in your case

• set Area Code to the area code of your trunk line
  If there are no area codes in your country, this field must be left empty. So for you, set it to
  

621

• set National Prefix to the prefix you need to dial to reach a national number but without the trunk access prefix (this is the difference to the setting in PBX/Config/General).
  Again, if there are no area codes in your country, this field must be left empty. So for you, set it to
  

 

input0

• set International Prefix to the prefix you need to dial to reach an international number but without the trunk access prefix (this is the difference to the setting in PBX/Config/General).
  

00

• set External Line to the trunk access prefix of your trunk. In your case, this is

0

If you go to Menu/Contacts/Central Phonebook and search for r, you will find Renée-François Fenêtre from the external contacts and Richard Roe from the PBX.

Please note that the LDAP client of the IP-DECT master cannot access a personal phonebook directory in Contacts, as this would require permissions that are not currently configurable.

Reverse lookup

As we learned in the chapter about contacts, the reverse lookup of a number is done in the PBX, in a central place. This means you don't have to configure a separate reverse lookup at your IP-DECT master. This is already taken care of.

You may wonder about the LDAP directory search configuration at DECT / Config / Master. This configuration became obsolete with the introduction of the reverse lookup URL in the PBX. As long as the PBX is already sending a name, which it does when you configure the reverse lookup URL, the LDAP directory search in the IP DECT master will not be performed, even if you have activated it. You can configure the LDAP directory lookup to ask a third-party LDAP server (not the contact database) in case no name was delivered by the PBX, but this is somehow useless because you could enter this server as a reverse lookup anyway.

DECT Redundancy

Now that we have a working DECT environment, we want to strengthen the robustness of our DECT system against sudden failures. For this reason, we are creating a redundant IP-DECT system.

Redundant DECT master

At the beginning of the book we talked about which mode to select for our IP-DECT master. We decided to put the device into active mode. But as we discussed before, we want to make sure our system is working even if the active IP-DECT master fails. To do this, we add another IP-DECT master to our system, but this IP-DECT master should work in standby mode. A standby takes over all responsibilities of an active IP-DECT Master if it fails, without the possibility of subscribing handsets.

We no longer recommend creating a master/standby scenario because it is outdated. Instead of an active/standby scenario, an IP-DECT master in mirror mode can work as both active and standby, but it has to work in pair with another IP-DECT master in mirror mode. So if you put one IP-DECT master in mirror mode, you must also put another one in mirror mode. In other words, it is not possible to mix an IP-DECT master in mirror mode with an IP-DECT master in another mode.

One of the IP-DECT master in mirror mode will start in the active role, while the other one becomes the standby. When the active mirror fails, the standby automatically becomes the active mirror. When the failing IP-DECT master recovers, it becomes the standby mirror and the active mirror remains active.

This already explains the advantages of the mirror mode compared to a master/standby scenario. You can still add/edit/delete users and subscribe handsets in mirror mode, which you cannot do when in active/standby scenario when the standby takes over. Furthermore, if the failing master recovers in a master/standby scenario, all active calls will drop. This is not the case in a mirror mode scenario.

As a next step we have to configure the same system parameters at our IP1202B so that the configuration of our IP1202A and IP1202B is identical.

• Please set your IP1202A and your IP1202B to master mode mirror at DECT / Config / Master and DECT / Config / Master. Reboot both of your IP1202 afterwards.

• Please configure the same DECT system name (hq-dect) and password (ip411) for your IP1202B as well. A reboot of your IP1202B is necessary afterwards.

• The next step is to establish a relationship between our two IP-DECT masters in mirror mode. To do this we need to configure  the following parameters on both of our base stations and promote one of our base stations to active IP-DECT master.

• Mirror Master - We have to configure the IP address of the other IP-DECT master in mirror mode here.
• Mirror Status - You can see the current status of this base station, whether it is the active master or not. In addition, we have to decide which of our IP DECT masters starts as the active master in mirror mode. This is done by clicking the Activate mirror link.

Afterwards you will see that one of your IP-DECT master in mirror mode  is active and the other is not. Both are connected to each other.

Before we can test the mirror mode we have to set several parameters identical on both IP1202s.

• Set the Master ID to 1 at DECT / Config / Master so that both IP-DECT masters in mirror mode share the same master ID.

• Choose the H.323/TLS as protocol and configure the Gatekeeper (hq-dvl-ckl2.training.innovaphone.com) at DECT / Config / Master

• Create an LDAP replication at Services / LDAP / Replicator for your IP1202B as well. Please use the same credentials as described in the LDAP replicator chapter in this book.

You must create the LDAP replication from/to the PBX although you already see the desired user objects at DECT / User. The reason for this is that an implicit LDAP replication is created between your IP-DECT masters in mirror mode. It is important that both base stations can write and read from/to the PBX in their active state. When both base stations are online, one of the two LDAP replicators is auto disabled, the other keeps the LDAP replication to the PBX alive and the auto disabled replicator replicates only from its mirror mode counterpart. This way, no conflict in the LDAP replication can occur.

Redundant PARI master

The PARI master is a function of the IP-DECT master. Consequently you can only set this function if your IP1202 is an IP-DECT master. Since the PARI master manages all radios you need one PARI master per site. If the PARI master fails you can define a standby PARI master that takes over if the PARI master fails.

To configure a standby PARI master you need to set the following parameters.

• Enable the PARI function at DECT / Config / Master and reboot your IP1202B afterwards. Your IP1202B will be the standby PARI master from now on.

• Configure a Standby PARI Master IP Address at DECT / Config / Radio and DECT / Config / Radio which should point to our IP1202B. A reset is required afterwards.

Redundant Air sync master

To ensure that all radios are in sync, there must be a sync master that dictates the synchronization. If this sync master fails, there must be another sync master in the same sync region to take over. We therefore recommend having more than one sync master in the region.

Fortunately, we do not need to configure anything at our two base stations, since both are already sync masters.

Trying it

Now we can test our configuration.

• Unplug one of our base stations. The other one will be active. (This will take a few minutes)
  
• Start a call between your DECT phones.
• Plug your IP1202 back in. Your call won't be dropped.
  

Site Survey

When planning a new IP-DECT system, we need to conduct a site survey at the installation site to determine the number of base stations required to provide satisfactory coverage of the area.

With a site survey we need to find answers to the following questions:

• Determine the customer's specific requirements for coverage and call capacity.
• Determine the number of IP1202/IP1203 required.
• Determine base station locations for the best possible air sync and voice coverage.
• Avoid/remove any radio interference at the site for best performance/stability and call quality.

Without a site survey, we cannot guarantee that the IP-DECT system will work properly for the customer's needs because different environments have different requirements.

As a result the site survey has to be a mandatory step for any IP-DECT implementation.

Please be aware that you could have a good Air Sync coverage but bad call speech coverage because Air Sync between base stations could be established at higher distances than handset calls.

We must always check the overlap of speech coverage between IP1202s to avoid creating no-coverage zones.

Please consider the following guidelines for an optimal deployment:

• When placing the base station, aim for a clear view of the users.
• Do not place the base station closer than 30 cm to a metal structure.n
• Analyze the voice quality to check if it's a reflective environment.
• Use the IP1202/IP1203 in deployment mode to determine the distance between base stations.
• Good documentation of measurements.
• Avoid unsynchronized foreign DECT systems.

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A site survey is required to determine the number of IP DECT Base Stations and their optimal placement.

After performing the site survey, you will know:
• Where to place the base stations
• the coverage areas for the handsets
•Areas with interference caused by reflective environments or rogue DECT systems

Speech and Air Sync Coverage

On a site survey we must determinate two different types of coverage:

• Speech coverage - the radius of the circle (circular radiation patterns of the IP1202/IP1203 antennas are assumed for reason of simplicity), around particular base station, in which portable parts can communicate with that IP1202, see figure below.
  
• Air Sync coverage - the radius of the circle, around a particular IP1202/IP1203, in which other IP1202/IP1203 can synchronize with that base station with a given probability of synchronization loss. This means that the size of the sync radius depends on the desired synchronization loss probability, see figure below.

• Speech coverage higher -68 dBm - Area where a call can be done with a good voice quality.

• Air sync coverage higher -83 dBm - Area where a sync slave can synchronize to another base station.

Adjacent cells must have a good overlap to ensure a proper handover and speech without disturbances (value less than 6 dBm).

Effects of different signal strengths:

• -30 dBm, handset very close to the base station
• -68 dBm, handset will start roaming (looking for better base station)
• -75 dBm, speech affected
• -90 dBm, risk of dropped calls

Base Station Coverage

This section describes how architecture, building elements, and special areas affect the coverage and the placing of the base stations.

The radio environment, or the cell covered by a base station, is not spherical as it is often depicted in diagrams. If a snapshot of its shape could be taken, it would be clear that its shape is much more irregular. The actual size and shape depends on the material the walls and floors are made of, the location and material of furniture, machines, air conditioning, and the location of the base station in such an environment.

Because of these unpredictable conditions, it is not possible to give hard and fast rules for calculating the number of base stations in a given situation.

• The indoor cell size in offices can have a radius between 10 and 30 meters, see example of base station locations in a building. The cell size in exhibition or production halls can have a radius of up to 200 meters.
• The free space (outdoor) cell radius can be up to 300 meters.
• Base stations can partially cover the floors immediately above and below. The useful range through floors and ceilings varies from 0 to 8 meters (2 floors) radius; see example of base station locations in a building.

Architecture

This section describes how the building's architecture can affect coverage.

• Central areas with access to stairs and elevators may require additional base stations due to heavier construction.
• Coverage in elevators may require base stations closer to or in the elevator shaft.
• Corners and irregularities in construction such as partial renovations, additions to older buildings, etc. will have an impact.
• Concentration of air conditioning ducts or other technical installations can affect the field pattern and thus the coverage.

Building Elements

This section describes how different building elements can affect the coverage.

• The size of the cell depends on the material that the walls, ceilings, and floors are made of.
• Plain, light or reinforced concrete, wood and plaster absorb and transmit radio waves in different ways.
• Metal walls and large rows of metal cabinets reflect all signals, resulting in greatly reduced coverage in areas behind these objects.
• X-ray rooms in hospitals protected by lead walls and computer rooms in bank buildings protected from unwanted interference do not allow radio signals to penetrate.
• Exhibition halls or manufacturing facilities can cause reflections due to large metal structures. This causes interference that reduces the capacity and range of the base station.

Walls

Walls, ceilings, and floors have a large impact on the range, and different types of walls have a different impact on the signal range. For a list of the most common types and the approximate range achieved by these materials, see the table below.

Type	Examples	Range in meters
Stud wall	Plaster	30-60
Concrete		10-30
Reinforced concrete	Fire wall	0-10
Stone/brick		30-50
Metal	A panel on brickwork	0-10
Wood		30-60
Wired glass	Fire protection	0-10
Surface coated float glass	Only of importance for coverage outside if the base station is installed inside	30-50
None	Open-plan office or outdoors	150-300

The values in this table are estimated values. Furniture (cabinets, etc.) and the amount of movement in the area to be covered, such as cranes in a production hall (see also Reflective Environment), are other factors that affect the coverage area.

Ceilings and Floors

The difference between ceilings and floors and walls is in the materials used. Concrete and reinforced concrete are the main materials and it is important to determine the coverage of a base station on the floor above and below. For "normal" concrete, this coverage extends to a radius of approximately 15-20 meters, providing coverage for the floors above and below. In some cases, an open stairwell or atrium can be used to provide coverage to two floors simultaneously, see Base Station Covering Two Floors.

Fire-resistant walls/doors

Firewalls follow the same principles as normal walls described in the section above. However, since the fire doors are usually open during the site survey, it is important to close the fire doors before taking the final site survey measurement and before finalizing the base station plan. If a fire occurs and the doors are closed, there must still be adequate coverage.

Outdoors/car park

Outdoor coverage is usually not a problem as there are few or no obstructions. The location of the base station depends on the customer and the size of the area to be covered. If the customer wants as few base stations outdoors as possible (due to the cost of the outdoor housing), it is possible to install one or more base stations with the antennas in front of a window.

The base station must be able to 'see' as much of the outdoor area to be covered as possible (i.e. there must be as few obstacles as possible between the base station and the area to be covered). Make sure that a measurement is taken to check how much coverage a base station provides to the outdoor area; the intention is not to install all base stations in front of windows, as this is not the ideal position for indoor coverage (usually 1-2 base stations are sufficient).

Type of glass	Range in meters
Normal glass	150-300
Surface coated float glass	30-50
Wired glass (fine-mesh)	0-20

Lift

If coverage in elevators is desired, the base station should be placed near the elevator, preferably at the front so that the base station can "see" the front. This is because an elevator is usually surrounded on three sides by a reinforced elevator shaft, with the only opening at the front. Placing a base station in front of an elevator is usually not the most ideal position for the overall design. It is usually the case that one or more additional base stations are required to provide coverage for an elevator. The base station will generally also provide coverage for the floor above and below the floor on which it is installed.

Stairwell

The main problem with stairwells is that they are often located in a corner of the building. Coverage is not a problem in itself, but it must be considered in the context of the overall design. There are several ways to provide coverage in a stairwell. Either the base station is installed directly in the stairwell as a dedicated stairwell base station, or it is installed in the immediate vicinity of a stairwell. The method depends on the type and location of the stairwell (is it an open or closed stairwell; is it in a corner of the building or in the center, etc.).

Toilet Rooms

Restrooms are typically in awkward locations for a site survey: behind or next to elevators, in or next to stairwells, or in a corner of the building. Installing the base station in the restroom itself can be considered. If placed outside the restroom, it should be placed near the restroom in a location where the base station can "see" as much of the restroom as possible (preferably the entrance, as doors are usually made of wood and will attenuate the signal less than the walls).

If the base station is placed near the toilet room, it should be placed so that it covers as much of the rest of the floor as possible.

Maintenance Shaft

In larger buildings, there is usually a requirement for coverage in maintenance rooms. The most common are the elevator and ventilation rooms. The elevator service room is often located on the roof or in the basement. The ventilation maintenance room is usually located on the roof. These rooms should be discussed with the client to avoid surprises. A well-positioned base station on the top floor (20 to 30 meters or less from the room to be covered) will usually provide sufficient coverage for the rooftop maintenance rooms.

Basement and Indoor Car Park

It can be difficult to provide adequate coverage in basements and parking garages due to the heavy construction.

Use Site Survey Tool on IP65

We should use handset IP65 Site Survey tool function to make our site surveys and measure the Air Sync and Speech coverages of the IP1202 on the site.

How to use it:

First we should make subscription of the Handset on the IP1202 we are using, then Press *#77#.
This will give us the Site survey tool menu that have some options.

The most important to use will be Link, this option give us full details regarding the subscribed DECT system.

In the example:
C5 S9 - Current Carrier channel and TimeSlot
-25dBm - Received Signal Strength ( Should be less than -68 dBm to ensure good voice quality).
Error rate - show the amounts of bad frames per second which are received by handset (downlink).
Q2 Error rate - Shows the amounts of frames per second that Bad frames that are received by base station (uplink).
Bad frames occur when the received strength is low (<-68dBm) or in a reflective environment even if the signal strength is good.

Other information's are about the system and type of connection made so they are not relative to measure the coverage and signal quality.

Possible disturbances

We could have disturbances on our Dect system caused by many factors. One of them is an alien DECT (other DECT system in the area, i.e. residential DECT) and reflective environments.

• Alien and Residential DECT Effect
• Unynchronised Alien DECT systems consume twice as much radio capacity compared to a synchronized system.
• Difficulty for DECT users in all systems to make a call.
• If possible, remove all Residential DECT sets (ie. Gigaset).
• If other DECT system is present in the same coverage area a stronger sync signal is required (at least 6 dB stronger).

• DECT in Reflective Environments
• Characteristics
• Large open halls
• Metal walls and ceiling
• Metal machinery
• Impact on DECT system
• Bad speech quality despite high field strength, i.e. close to base station
• High frame error rate
• Dropped calls
• Many hand-over attempts
  
• Necessary to decrease the distance between base stations to have less bad frames.

Step by Step Site Survey

Now that we know all the possible disturbances and the values we need to get good speech and air sync coverage, and we have the tools, we can begin the site survey.

Prepare the Base Station and Site Survey Kit

Before starting a site survey, prepare the Site Survey Kit and an IP1202/IP1203 gateway. The basestation must be configured as usual with IP-DECT Master, PARI Master and Radio - only the mode for the IP-DECT Master must be set to "Deployment". This mode allows us to register handsets without a PBX, make loopback calls by dialing any number to analyze the voice quality and measure the signal strength. Also make sure to configure a static IP address on the ETH0 interface.

Prepare DECT Handsets

Subscribe one IP65 in Base Station and select Link on Site Survey tool options.

Optionally we can subscribe other IP64 with Headset to analyze speech quality doing loopback calls or just use the same IP65.

Perform Site Survey

The following steps must be performed when performing a site survey:

1. Place the deployment base station in the center of the deployment area and in sight of it to get the most useful coverage area.

2. Determine the maximum distance from the base station to the IP65 where the signal strength is -68 dBm and mark the radius. This will be the voice coverage.

3. Determinethe maximum distance from the base station to the IP65 where the signal strength is -83 dBm and mark the radius. This will be sync coverage. Make sure to use different marker colors for Sync and speech radius.
   

4. Move the IP1202/IP1203 to a new position within the previously marked sync coverage, following the same principles of the middle area with the best view.

5. Determine the sync and speech coverage. Make sure that the speech coverage overlaps the previous position.