Reference:DHCP client
innovaphone devices include a DHCP client which allows the IP interface to be configured from a DHCP server.
In addition to that, telephone devices allow configuring a number of settings via special DHCP vendor options.
Here is how the DHCP client works.
[ This article has been converted from the previous "howto" document in the V5 predoc folder and is intended to replace this ]
Applies To
This information applies to
- All innovaphone devices,
V5.01 Build 04-5679 and V6
More Information
Problem Details
The innovaphone devices do support auto configuration via standard DHCP options.
They additionally support some innovaphone vendor specific options to effect some VoIP specific configuration.
Some of them are generic; some of them are specific to the IP200.
These configurations include
− H323 Gatekeeper
The IP addresses of the main and alternate gatekeeper. IP200 only.
− H323 Gatekeeper ID
The ID of the gatekeeper taking care of the device. IP200 only.
− POSIX Time zone
The time zone string defining the time zone the device lives in (see the “VoIP Gateways 5.0” Manual, chapter 9.1.3 for more details about time zone settings)
− Default coder
The coder the device will try negotiate during media stream setup. IP200 only.
− Language
The user interface language of the device. IP200 only.
− Location
The location information (country code, area code etc.). IP200 only.
− VLAN ID
The VLAN ID for voice traffic
− VLAN Priority
The VLAN Priority for voice traffic
− TOS Bits
The value for the IP TOS field in the IP header of voice traffic
− Enbloc dialling
Overlapped sending disabled. IP200 only.
− Dialtone type
The type of locally generated dial tones. IP200 only.
− Faststart
Disable/Enable the H245 faststart procedure
− H245-Tunnelling
Disable/Enable H245 tunneling
− Clock type
Format of date and time display. IP200 only
− Static routes
Additional static routes
− Configuration parameters for the update server
URL to retrieve update commands from and poll interval
− LDAP directory configuration
Parameters to access an external LDAP directory. IP200 only
System Requirements
To use vendor specific DHCP options, a DHCP server that supports such options is required.
Most popular DHCP server implementations such as the Microsoft Windows DHCP service and the Linux dhcpd do so.
Installation
For the DHCP server to support vendor specific options, the options must be made known to the server.
Consult the accompanying documentation which comes with your DHCP server implementation how to do this.
In this section, the installation of innovaphone vendor options is demonstrated using a Microsoft Windows 2000 DHCP server.
First you need to create a new vendor class.
Use the “Define Vendor Class…” / ”Herstellerklasse definieren” menu entry on the DHCP server’s context menu
Add a new vendor class as follows:
Anzeigename / Display name innovaphone
Beschreibung / Description innovaphone VoIP Options
Kennung / ID (ASCII) 1.3.6.1.4.1.6666
Add the innovaphone options. Use the “Configure predefined options” / “Vordefinierte Optionen einstellen” entry in the DHCP server’s context menu
Select the innovaphone option class and add the innovaphone specific options
Name--- Data type--- Array--- Code
H323 gatekeeper-- IP address--- Yes--- 200
H323 gatekeeper id--- String--- No--- 201
POSIX TZ[1]--- String--- No--- 202
Default coder--- String--- No--- 203
Language--- String--- No--- 204
Location[2]--- String--- No--- 205
VLAN ID2--- Word (16bit)--- No--- 206
VLAN Priority2--- Byte (8bit)--- No--- 207
TOS Bits2--- String--- No--- 208
Enbloc dialling--- Byte (8bit)--- No--- 209
Dialtone type--- Byte (8bit)--- No--- 210
Faststart--- Byte (8bit)--- No--- 211
H245-Tunnelling --- Byte (8bit)--- No--- 212
Clock type--- Byte (8bit)--- No--- 213
Static Routes--- String--- No--- 214
Update URL--- String--- No--- 215
Update Poll Interval--- Word (16bit)--- No--- 216
LDAP directory--- String--- No--- 217
Configuration
To configure innovaphone vendor specific options for a specific scope, use the “Configure options” / “Optionen konfigurieren” entry in the scopes context menu.
Select innovaphone in the Advanced / Erweitert tab sheet.
Tick the options you want to provide and edit the respective values.
The following table lists the available options and their meaning.
Option
Meaning How to code
H323 gatekeeper
Defines the IP address of both the primary and the alternate gatekeeper for the device. This is only required, if gatekeeper discovery is not feasible This is an array of IP addresses. Put the primary gatekeepers IP into the first entry, the alternate gatekeepers IP into the second entry. Further entries are ignored.
H323 gatekeeper id
The gatekeeper id of the gatekeeper the device likes to register with. Usually required only if several gatekeepers are running and a particular one must be chosen during gatekeeper discovery Type the gatekeeper id as configured in the gateway or PBX configuration into the string field.
POSIX TZ
Defines both the time zone and the daylight saving time information. Enter the correct TZ string into the string field as you would configure it in the devices configuration applet. See chapter 9.1.3 of the VoIP Gateways Version 5 manual
Default coder
Defines the preferred coder for H.245 coder negotiation, as well as the packet size when sending RTP packets and the use of CNG and VAD. This string option must contain the value of the “/coder” option in the IP200’s configuration file, e.g. “G729A,40,sec”
Language
Defines the user interface language This string must contain the value of the “/lang” option in the IP200’s configuration file, e.g. “eng”
Location
Defines the various PBX access numbers (country code etc.) for the device. This string must contain the /cc, /ac, /ntp, /itp, /col and /pbx options in the IP200’s configuration file, e.g. “/cc 49 /ac 7031 /ntp 0 /itp 00 /col 0 /pbx 7”
VLAN ID
The 802.1q VLAN ID for traffic sent and received by the device Enter the numerical ID into the 16bit edit field
VLAN Priority
The 802.1p VLAN priority for traffic sent by the device Enter the numerical priority into the 8bit edit field
TOS Bits
The value for the IP TOS field in the IP header of voice traffic sent by the device Enter the numerical priority into the string field. You may prefix with 0x to specify hexadecimal numbers (or 0 to specify octal numbers)
Enbloc Dialling
The number of seconds dialled digits are kept in the IP200 before they are sent en-bloc to the gatekeeper Enter the number of seconds into the 8bit edit field. A value of 0 indicates that en-bloc dialling is turned off and digits are sent to the gatekeeper as they are dialled
Dialtone type
The type of dialtone to generate locally Enter the numeric dialtone type (0 - german PBX, 1 – german PSTN, 2 – US)
Faststart
Disable/Enable the H245 faststart procedure To disable enter 0, otherwise enter 1 into the 8bit edit field
H245-Tunnelling
Disable/Enable H245 tunneling To disable enter 0, otherwise enter 1 into the 8bit edit field
H245-Tunnelling
Define format of date and time display Enter the numeric clock type (0 – dd.mm.yy hh:mm, 24 hour clock; 1 – mm/dd hh:mm xm, 12 hour am/pm clock)
Static Routes
Static routes to be added to the routes already defined in the device configuration The string (max 127 characters) must contain comma separated route definitions in the form address:mask:gateway
address, mask and gateway are expected in dotted decimal notation, mask (but not the colon) can be left off in a host route
Update URL
URL to retrieve update commands from. This is identical to the /url option parameter of the UP1 module Complete URL as in http://192.168.0.10/file.txt. No symbolic host names are supported
Update poll interval
Standard poll interval in minutes. This is identical to the /poll option parameter of the UP1 module Interval in minutes
LDAP directory
Defines the various Parameters required to access an LDAP directory Configure an IP200 to access the LDAP directory in question (for details see “How to use LDAP with the IP200”). Then in the browser address field enter “<ip address>/!mod cmd PHONEDIR0 ldap-config”. The string returned in response to this input is the LDAP directory configuration you have to enter here.
Determining LDAP options
To determine a proper configuration for option 217 (LDAP), you best proceed as follows:
· Take a phone and configure it with static IP address
· Tweak the LDAP settings (Registration 1 / Directories / Extern) as desired
· Look at http://x.x.x.x/!mod cmd PHONE DIR ldap-config
· Set option 217 to the string shown
Determining LDAP options To determine a proper configuration for option 217 (LDAP), you best proceed as follows:
· Take a phone and configure it with static IP address
· Tweak the LDAP settings (Registration 1 / Directories / Extern) as desired
· Look at http://x.x.x.x/!mod cmd PHONE DIR ldap-config
· Set option 217 to the string shown
Disabling the DHCP client
In certain circumstances, it is convenient to partly disable the DHCP client. This way, the device still gets its IP address from the DHCP server, however, additional settings possibly supplied by the DHCP server are ignored. This especially useful if in a given setup, some devices are to be configured differently but the majority is still configured by DHCP.
This can be achieved using the following config file options
config change UP1 /no-dhcp
the update server uses the config files configuration even though there is a configuration supplied from DHCP (innovaphone vendor options "Update URL [215]" and "Update Poll Interval [216]" are ignored).
config change DHCPn /no-vlan
the VLAN settings use the config files configuration even though there is a configuration supplied from DHCP (innovaphone vendor options "VLAN ID [206]" and "VLAN Priority [207]" are ignored)...
config change DHCPn /no-vendor
all innovaphone vendor options are ignored.
Known Problems with lengthy options The minimum space available for options in a BOOTP/DHCP record is 312 byte. There are some extension mechanisms but only a few DHCP servers support it. The Windows 2000 DHCP server for example does not but silently truncates options not fitting in this 312 byte space. Thus it’s nearly impossible to distribute the LDAP directory configuration with a Windows 2000 server but it’s no problem with the DHCP Server built into each innovaphone device.
Known Problems with VLAN Configurations The handling of the 802.1q VLAN ID is a bit tricky. If not hard configured otherwise, the IP200 will request a DHCP lease using the Ethernet switch ports default VLAN ID (that is, it will not send any VLAN header). It will thus receive a DHCP offer dedicated to devices on that VLAN. If this offer includes a VLAN ID option, the IP200 will not accept the offered lease, set the VLAN ID to the value received in the otherwise disregarded offer and start the DHCP process all over again. Now, the DHCP request will be issued on a new VLAN ID. Therefore, the DHCP server will now send an offer dedicated for devices on that new VLAN. This will most probably be a different DHCP scope.
As a consequence, DHCP options of IP200’s on a non-default VLAN must be configured twice. The VLAN ID option itself must be configured in the default VLANs DHCP scope. All other options must be configured in the new VLANs DHCP scope.
Be sure to configure the VLAN in both scopes identically. If not, the DHCP client process will never terminate, since it will always detect a changed VLAN ID, set the VLAN ID and restart the DHCP process.
Here is how DHCP leases are handled in detail:
First Boot
The client will broadcast a DHCP DISCOVER, expecting an OFFER from the server including all requested parameters. If the client intends to use the offered lease, it will issue a request for the offered lease. Once it receives an ACK for the lease requested, it will configure itself accordingly. All lease information is stored in the devices config file using the /laddr option (unless suppressed using /no-keep).
Re-boot
If there is lease information (in the /laddr config file option), the client will broadcast requests for the same lease again. If there is no answer within 30 seconds, the device will configure itself using the parameters in /laddr. It will nevertheless continue to request this lease from the DHCP server again (every 30 seconds, a broadcast will be sent).
If the server acknowledges the old lease, the client will check for changes in the DHCP options and re-configure itself accordingly. Changed options will be saved in the config file.
If the server rejects the lease using a NAK, the client will forget about the lease and continue to operate like it does for the first boot.
First boot with VLAN ID option received
If an offered lease includes the VLAN-ID option and the ID proposed differs from the VLAN ID the devices currently operates with (that is, from the id configured in the devices configuration), the device will change its VLAN ID to the one received in the VLAN-ID option. It will not request the lease though. Instead, it will continue to send DISCOVER requests on the new VLAN ID. If a lease is obtained there, all lease information is stored in the config file as usual.
You can disable the VLAN-ID processing using the /no-vlan option.
Reboot with VLAN ID
If the device finds lease information in the config file at boot time and if there is a VLAN ID different from the devices current VLAN-ID, it will re-configure itself to the new VLAN ID and try to request the saved lease as usual. If the lease is rejected with a NAK by the server, the device will re-configure itself to the pre-configured VLAN ID and try to DISCOVER a new lease as usual.
Changing configuration options set by DHCP options
If a device has been configured by DHCP, you cannot change those parameters. Any attempt to do so will issue a “Reset required” message.
[1] This option is in fact identical to the standard DHCP option number 88 (TZ). However, various DHCP servers do not support this option, so it is provided as a redundant vendor specific option. If your DHCP server supports option 88, the vendor specific option is not needed.
[2] These options are only implemented in firmware 03-5467 and later
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