Re: SIP Trunk connections to GW

josjackson · ‎03-04-2020

Have a new site I just deployed. Our call flow is CUCM>>SIP Trunk>>GW>>PRI>>ISP

I have tested good inbound and outbound with our new DID Range.

We use 10 digit dialing on our CUCM deployment site. When testing inbound I noticed in the GW debugs that the SIP invite was using 4 digits instead of 10 and failing. So I made some trunk update and only required 4 digits as significant and added some prefix DN settings. Calls work fine now.

My question is, we will have a second DID range that will be cutover that is a complete separate range. I cant create more than one trunk to the same GW with the same name, so how can I fit in this other DID range and use the same trunk?

Would I use a translation rule on the GW?

Roger Kallberg · ‎03-04-2020

I would recommend you to do the number manipulations in the gateway with voice translations rules instead of doing it in CM on the trunk. But yes you could in theory create multiple trunks in CM to the same gateway, please note that for this you'd need to use different ports per trunk as you can't have multiple destinations to the same IP and port. You'd also need to configure dial-peers with different ports towards/from CM in the gateway.

Maren Mahoney · ‎03-04-2020

I'm with @Roger Kallberg on this.

It is common practice to "normalize" digits (put them into a standard format) on the SIP-speaking router using voice translation profiles prior to the router sending the call in towards CUCM. This gives you a lot of flexibility and power on the router to make the inbound digits conform to your CUCM dial plan.

And, no, you can't acquire the same gateway (SIP or H323) using the same IP address (or FQDN) twice in CUCM. I've acquired the same SIP-speaking router twice in CUCM using different IPs on the router, but that was a special case in a lab environment.

Maren

TONY SMITH · ‎03-05-2020

@josjackson wrote:
My question is, we will have a second DID range that will be cutover that is a complete separate range.

How many digits does the provider supply in their inbound call setup message? If it's only four, then your new DDI range will need to avoid conflict with those four digits in some way.

I agree with the previous comments, I would configure the gateway and dial peers to forward 10 digits to CUCM. How you make that conversion will depend in the number of digits presented, how you can distinguish the ranges, and how the gateway is currently configured.