Howto:Know if the ISDN line is point to point or point to multipoint: Difference between revisions
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1) Make an incomming call | 1) Make an incomming call | ||
2)Look for the Isdn Setup Message - | 2)Look for the Isdn Setup Message - this is the format: | ||
- 4 Byte: Layer-2 Information | - 4 Byte: Layer-2 Information |
Revision as of 15:40, 1 August 2007
Applies To
This information applies to
- IP 6000
- IP 3000
- IP 800
- IP 400
- IP 305
- IP 302
- IP 202
all Builds
More Information
Assuming that a call is comming from the ISDN to the innovaphone Gateway , then you can find out if it´s an Point to Point (Ptp) or Point to Multipoint (PtMp) connection.
example trace:
PtP, Incomming call
22:1844:747:2 - ISAC.2 -> LAPD.2 : PH-RECV-RESULT data(46),ISAC 02 01 30 ae 08 01 01 05 04 03 80 90 a3 18 01 89 ..0............. 6c 0c 21 83 33 30 39 32 32 35 38 35 34 32 70 0a l.!.3092258542p. c1 38 39 30 34 34 39 38 37 33 7d 02 91 81 .890449873}...
exapmple trace:
PtMp, Incomming Call
15:0526:685:6 - IPAC-TE.0 -> LAPD.0 : PH-RECV-RESULT data(45),IPAC-TE 02 ff 03 08 01 01 05 a1 04 03 80 90 a3 18 01 89 ................ 6c 0c 21 83 33 30 38 39 30 34 34 39 38 30 70 09 l.!.3089044980p. c1 39 32 32 35 38 35 34 32 7d 02 91 81 .92258542}...
The procedure:
Activate the Traceflag Diagnostics/Tracing/Interfaces/TELx or BRIx or PPP
so that Layer-2 informations get traced -
empty trace
1) Make an incomming call
2)Look for the Isdn Setup Message - this is the format:
- 4 Byte: Layer-2 Information - Der Wert '08': Protocol Discriminator=Q.931 Protocol for Layer-3 Call Control. - Der Wert '01': Length of Call Reference Value - 1 Byte: Call Reference Value - 1 Byte '05': Message Type=SETUP
3) According to 2) you know that it is a ISDN SETUP Message.
Now you can look for the 4 byte of the Layer 2 Information, there look at the second Byte whre the Tei is quoted.
Important, the TEI takes only the upper 7 Bits, the lower 8 Bits are set to '1'
- 02 01: Here is the TEI Tei=0 - 02 ff: Here is the TEI=127
4) Now you have to differ
- Bei Tei=0 there will be only one fixed Terminal addressed .So it is an ISDN point-to-point connection. - Bei Tei=127 tehre will abe all Terminal Endpoints addressed.Si it is an ISDN point-to-multipoint connection.