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Interdigit timing problem for inbound ISDN calls on H323 Gateway


I'm experiencing an interdigit timing problem with incoming calls after a configuration change. 
The environment: ISDN is going into a H323 gateway, that send the calls to a CUCM 8.6

the original configuration on the H323 gateway was

voice translation-rule 1
 rule 1 /^\([1-9]\)/ /0\1/ type subscriber Subscriber
 rule 2 /^\([1-9]\)/ /00\1/ type national national
 rule 3 /^\([1-9]\)/ /000\1/ type international international

voice translation-profile PSTN-in
 translate calling 1


controller E1 0/1/0
 pri-group timeslots 1-31


interface Serial0/1/0:15
 no ip address
 encapsulation hdlc
 isdn switch-type primary-net5
 isdn overlap-receiving
 isdn incoming-voice voice


voice-port 0/1/0:15
 translation-profile incoming PSTN-in
 bearer-cap 3100Hz

dial-peer voice 200 pots
 description ** Inbound from PSTN **
 incoming called-number 555
 port 0/1/0:15

dial-peer voice 300 voip
 description ** Outbound to CUCM **
 preference 1
 destination-pattern 555T
 session target ipv4:
 dtmf-relay h245-alphanumeric
 no vad

Everything worked, but I wasn't happy with the 555T Dialpeer so I put another translation on the voice-port

voice translation-rule 2
 rule 1 /555.$/ /555100/
 rule 2 /555..$)/ /555100/
 rule 3 /555...$/ /\1/

voice translation-profile PSTN-in
 translate calling 1
 translate called 2

(Same translation was done on CUCM before)

and I reconfigured the Dialpeer to CUCM

dial-peer voice 300 voip
 description ** Outbound to CUCM **
 preference 1
 destination-pattern 555...$
 session target ipv4:
 dtmf-relay h245-alphanumeric
 no vad

In testing everything worked fine, but in the real environment sometimes a call eg. 555123 seems to arrive only as 5551 or 55512 on the Voiceport and is translated to 555100. I think there must be an interdigit timing problem, but I do not understand why it had worked before. 

I will have to change a parameter on voice port and I first thought of "timeouts interdigit"  or "timing interdigit" but they seem do be for outside direction only. I know, I can apply the translation to the inbound PSTN dialpeer too, but I want to keep it on the voiceport.

Has anyone a hint for the correct solution - thanks.


The gateway will try voice

The gateway will try voice translations on every digit received. If it receives 5551 it will be translated to 555100. 555100 does perfectly match on 555...$ and the calls is routed directly.

Use another dial-peer for too short numbers and put the translation (^555.$ and ^555..$ to 555100) outgoing on the dial-peers instead of the voice-port.

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