Integrate Nortel OPT 11C with Cisco CUCM 6.0 using MGCP gateway

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Aug 19th, 2008
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I need to integrate my clients Nortel opt 11C with CUCM 6.0. I configured mgcp at cisco 2812 router and it is registered with cucm 6.0 successfully.

Then i interfaced my mgcp gateway to Nortel using QSIG E1 signalling. QSIG was configured at Nortel by the client.

Due to availability of only 16 PVDMs at cisco router i configured timeslots 1-16 while timeslost at NOrtel was configured to 1-30 by the client. Below is my router configuration.

controller E1 0/0/1

pri-group timeslots 1-16 service mgcp





interface Serial0/0/1:15

no ip address

encapsulation hdlc

no logging event link-status

isdn switch-type primary-qsig

isdn timer T310 120000

isdn protocol-emulate network

isdn incoming-voice voice

isdn bind-l3 ccm-manager

no cdp enable


Now this mgcp gateway interface is not registering with cucm 6.0. Below is the status of the ISDN

2821-GW#show isdn status Global ISDN Switchtype = primary-net5

%Q.931 is backhauled to CCM MANAGER 0x0003 on DSL 0. Layer 3 output may not apply

ISDN Serial0/0/1:15 interface

******* Network side configuration ******

dsl 0, interface ISDN Switchtype = primary-qsig

**** Master side configuration ****

L2 Protocol = Q.921 0x0000 L3 Protocol(s) = CCM MANAGER 0x0003

Layer 1 Status:


Layer 2 Status:

TEI = 0, Ces = 1, SAPI = 0, State = TEI_ASSIGNED

Layer 3 Status:

0 Active Layer 3 Call(s)

Active dsl 0 CCBs = 0

The Free Channel Mask: 0x00000000

Number of L2 Discards = 0, L2 Session ID = 1

Total Allocated ISDN CCBs = 0

Is this the issue with TIMESLOT mismatch or something else.

Thanks in Advance.

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iptuser55 Wed, 08/20/2008 - 03:47
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I would say it is a cabling problem a Layer 1 is not up and so D channel info re timeslots is even sent. Remove the isdn bind-l3 ccm-manager from the Dial-peer and add the default application servcie commend ? so to force it to use H323 as a drop back when it can not see CCM. This will bring up the Link without CCM and so prove you can connect to the Op11

iptuser55 Wed, 08/20/2008 - 08:28
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WhetherWhether Fractional is supported is another question however it is configurable- depending on the number of DSP`s you have effects how you maintain the Fractional aspect of the MGCP

If you have installed the number of DSP for the number of channels i.e 8 DSP for 8 Channel then you can keep the CCM-MANAGER CONFIG commend and you do not need to busy out the channels in the CCM Parms however if you have more DSP available then channels then keeping the CCM-MANAGER CONFIG commends will mean CCM will overwrite the gateway config. and if you have enough DSP for the full E1/T1 then the timeslots will show the full amount after the config downward

sfurqanli Wed, 08/20/2008 - 23:28
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Its done.

I asked the client to configure PRI to channel 1-15 as B channel and 16th channel as D-channel, while Nortel opts 11C defaults to 31st channel as D-channel. As Cisco gateway defaults to 1-15 b-channel, 16th is D-channel and 17-31 b-channel.

After that my isdn went up, below is the staus:

Now I can call from pots at PBX to IP Phone at CUCM and vice versa. And MGCP is taking care of it.



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