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Common Channel Signalling over IP

I have two NEC systems that I need to connect over a frame relay circuit. The systems will have T1 interfaces and use CCIS, or common channel inter-office signalling. It's similar to a PRI. Here is what I plan to do, but i need some help with dial-peer configurations.

Create 2 channel groups; one with a single channel, and one with the remaining 23 channels.

The single channel group contains the control channel, which will be configured G.711 and needs to be "nailed up". The second channel group will have trunks assigned dynamically, and be configured G.729(a). I understand how dial peers work with dialed numbers, but what about a peer in which no numbers are dialed and only signalling is used? How can I make sure that the single channel group on each end finds the proper session target?

14 REPLIES
Silver

Re: Common Channel Signalling over IP

We have made NEC number 7 signalling work across IP networks many times in the past.

The G711 codec will not work for passing the signalling traffic. You need to use clear channel codecs on timeslot 24 and the Transparent CCS features -

http://www.cisco.com/warp/public/788/voip/trans_channel_signal.html

The voice timeslots use G729 codecs and are nailed down using permanent connection trunks.

Another option is to use STUN to pass the signalling traffic via a channel group configured for timeslot 24. Either way the voice timeslots are nailed down with connection trunks.

If you want some working configs post your email address and I will send them to you directly.

New Member

Re: Common Channel Signalling over IP

Are you saying that the G729 timeslots are nailed down on the interface or across the link?

Also, this is a frame connection (512k). Is there an MTU concern with regard to the signalling channel? We are using a fragmentation and interleave configuration.

I have updated my profile to show my email address. Please send me any working configs you have.

Thanks!

New Member

Re: Common Channel Signalling over IP

hello there,

I know this is very very old topic.

But we are going for the STUN for connecting the NEC PABX across IP network. I got some configuration but it is for the fixed channel mapping with the fix extesnsions on either side. We want to route the calls across the E1 using STUN.

Can you please share the working configuration as you have mentioned in your post. You can send mail on sachin@emircom.com.

Appreciate your any help on this subject.

BR,

Sachin

Hall of Fame Super Gold

Re: Common Channel Signalling over IP

As the other poster correctly indicated, if the protocol is really not ISDN (nnlikely), you should use T-CCS, not STUN.

New Member

Re: Common Channel Signalling over IP

Thanks Paolo  for the reply.

I may sound novice but I just want to know, when you "nailed down" the channels and configurr one dial-peer each for the destination numbers, how can we dial more than 30 numbers in this case.

I may be interpreting wrongly. But what I get from the above discussions and the configuration examples is that, you get 30 dial-peers each with destinatoin pattern for the other side extension numbers and vice versa, so if i need to dial more than 30 numbers, how can I configure that? In other words, how can I route the calls?

Sorry but this is bit confusing for me.

BR,

Sachin

Hall of Fame Super Gold

Re: Common Channel Signalling over IP

You said it, you have 31 DPs and each one relates to a specific number, and channel.

New Member

Re: Common Channel Signalling over IP

Do you mean to say, I CAN NOT route more than 31 numbers which are predefined, on a single E1 ?

If that is the case, how can we use this technology to connect the PABX in effective manners? Because practically we will always have much more than 31 extensions across another PABX.

Hall of Fame Super Gold

Re: Common Channel Signalling over IP

For an E1 with T-CCS, you only use 31 numbers, never more.

The router will never know or care about how many extensions you have.

New Member

Re: Common Channel Signalling over IP

Do you mean to say, these 31 numbers are used only by the router for the Configuration purpose and it has nothing to do with what extensions you have on PABX?

And we can use any 31 numbers for this configuration purpose irrespective of the dialing plan of the PABX.

Hall of Fame Super Gold

Re: Common Channel Signalling over IP

Yes.

Please remember to rate useful posts clicking on the stars below.

New Member

Re: Common Channel Signalling over IP

Thanks Paolo.

Hall of Fame Super Gold

Re: Common Channel Signalling over IP

Thanks for the nice rating and good luck!

New Member

Re: Common Channel Signalling over IP

We're using it for the NEC PBX CCIS between two sites.

However, we can't keep the d-channel stable, the pbx throws traps stating the cch link is down/up.

We can see the link light on both ends go out and no calls can be established.

Also experience call disconnects when this is happening.

brad

Hall of Fame Super Gold

Re: Common Channel Signalling over IP

Possibly a clock issue, you should look at show controllers E1.

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