German ISDN Voice

[jdsalminen]

I have a 2821 router in Germany configured as a H323 gateway and is attached to an ISDN PRI line. The E1 PRI line is configured with primary-net5 ISDN switch type.

The problem is that about 5 inbound calls from the German ISDN network arrive with one digit short in the 'called number' field and more specifically the missing digit is the last digit in the number which makes it unique and routable to a specific destination. As a workaround I put in a dial peer that has a wildcard to catch these calls and send them to office main number, but unfortunately some of these calls that come in with the last digit missing are fax machines.

Does anyone currently have Cisco voice routers in place in any part of Germany? What ISDN switching type are you using? Have you ever encountered inbound calls with the most significant digit missing?

Any advice is appreciated. Thank you.

[paolo bevilacqua]

It is indeed an overlap call, see below the digit 9 sent via info IE. Please send output of "show run int se0/3/0:15" to verify the command "isdn overlap-receiving" is present.

Note after you have it you need to remove whatever translation you had put as workaround.

Mar 26 07:51:50.368 CET: ISDN Se0/3/0:15 Q931: RX <- SETUP pd = 8 callref = 0x0227

Bearer Capability i = 0x9090A3

Standard = CCITT

Transfer Capability = 3.1kHz Audio

Transfer Mode = Circuit

Transfer Rate = 64 kbit/s

Channel ID i = 0xA18383

Preferred, Channel 3

Progress Ind i = 0x8083 - Origination address is non-ISDN

Calling Party Number i = 0x2183, 'XXXXXXX'

Plan:ISDN, Type:National

Called Party Number i = 0xC1, '523033'

Plan:ISDN, Type:Subscriber(local)

Mar 26 07:51:50.372 CET: ISDN Se0/3/0:15 Q931: TX -> SETUP_ACK pd = 8 callref = 0x8227

Channel ID i = 0xA98383

Exclusive, Channel 3

Mar 26 07:51:50.416 CET: ISDN Se0/3/0:15 Q931: RX <- INFORMATION pd = 8 callref = 0x0227

Called Party Number i = 0xC1, '9'

Plan:ISDN, Type:Subscriber(local)

[jdsalminen]

Ah, I do see the second iteration of 'Called Party Number' with the missing digit.

Here is my serial config.

interface Serial0/3/0:15

no ip address

encapsulation hdlc

isdn switch-type primary-net5

isdn overlap-receiving

isdn incoming-voice voice

no cdp enable

[jdsalminen]

In conjunction with overlap receiving here is my dial peers. Note that I created a new dial-peer at 1003 to catch all. The originals I left in place, but shutdown.

dial-peer voice 1001 voip

shutdown

destination-pattern 52303.

progress_ind setup enable 3

voice-class h323 1

session target ipv4:10.8.101.10

dtmf-relay h245-signal h245-alphanumeric

codec g711ulaw

no vad

!

dial-peer voice 1002 voip

shutdown

destination-pattern 52303..

progress_ind setup enable 3

voice-class h323 1

session target ipv4:10.8.101.10

dtmf-relay h245-signal h245-alphanumeric

codec g711ulaw

no vad

!

dial-peer voice 1003 voip

destination-pattern 52303T

progress_ind setup enable 3

voice-class h323 1

session target ipv4:10.8.101.10

dtmf-relay h245-signal h245-alphanumeric

codec g711ulaw

[paolo bevilacqua]

I think DP 1002 is more correct.

[jdsalminen]

I believe this long standing issue has finally been solved. I am noticing this a few seconds after the 6th digit is received 'Sending Complete'. Thereafter the call appears to be routed directly to the recipient.

[paolo bevilacqua]

Good, please remember to rate useful posts, I've rate the one above that made the solution to come back to my mind.