incoming calls fail to CME router

[sampath9614]

Hi all,

I am having issue with cisco cme. Am able to get calls from cucm to cme and successfully call routing is happening. 

But calls from PBX (PRI Trunk) are not coming to CME.. Only a single digit of the total number is coming and then receiving a disconnect message. (RX <-- Disconnect) 

I have told them that its the issue with their PBX only, and they are working on it. 

Just want to ensure that any configuration issue in CME or not.

Configuration:

in interface serial

isdn overlap-receiving t302 2000

dial-peer voice 10 pots

incoming called-number .

direct-inward-dial

port <serial interface port>

dial-peer voice 10 voip 

destination-pattern 81...

session target ipv4:x.x.x.x

session protocol sipv2

there aren't any overlapping dial-peers.

customer from pbx should dial 81333

but the cme is receiving only '8' and then disconnecting.

plz help

[Jonathan Unger]

Hi There,

A few points:

1. Is the PRI dedicated to the connection to the other PBX? Or is it used for other purposes like general PSTN access?

2. I noticed the following command under your serial interface.

isdn overlap-receiving t302 2000

Are you sure that the other PBX is using overlap sending and receiving (sending the digits to you after the call has been routed to your PRI)? This configuration looks off to me since you have direct-inward-dial configured on your inbound dial-peer.

3. Can you please attach the output of a debug isdn q931 when a call comes in from that PBX?

[sampath9614]

Hi jonathan,

1. PBX is dedicated to CME

2.Am not sure but, when i remove that command am seeing missing mandatory information element and in the pbx also some error of same kind is showing.

I understand overlap-receiving command as matching the digits one by one in the destiantion pattern and when a perfect match is made it will route the calls without matching any further digits, please correct me if am wrong. I am confused by ur words "(sending the digits to you after the call has been routed to your PRI)?" please let me know how it works..

3. debug isdn along with ccapi inout is attached please check...

[Jonathan Unger]

Based on the debug it does look like you need the isdn overlap-receiving command in there since the called number is not transmitted in the initial ISDN SETUP message.

Can you try increasing the the t302 timer on the serial interface to see if that will make a difference?

isdn overlap-receiving T302 12000

There is another post on the forums which states that you have to disable "direct-inward-dial" on the incoming POTS dial-peer. You can try that as well.

https://supportforums.cisco.com/document/105866/overlap-receiving-issues

[sampath9614]

sure i have tried removing the did..still its the same...

i will try increasing the timer though.. 

[Jonathan Unger]

Hi There,

Any luck with increasing that timer?

[sampath9614]

hi jonathan, 

there some issue at the pbx end and resolved by replacing its pri card..

no issues in CME