Is it possible to run CME on an existing CUCM MGCP Gateway?

[Matthew Michaluk]

Hello all,

Is it possible to run CME for about 16 SIP Clients on a existing CUCM MGCP Gateway?  I need to setup these SIP clients separately from the CUCM cluster for security reasons.  Currently I am running CUCM 8.5 with 2 nodes with two MGCP voice gateways.  The hardware is 2921 for each gateway.  Thank you.

[Chris Deren]

Sure, you can.  What will these clients use for outbound calling?  This GW? If so since you are using MGCP you will have to hairping the calls to CUCM first, ideally you can convert the MGCP GW to either SIP or H323 and use it nativvely by both CUCM and CME.

HTH,

Chris

[Matthew Michaluk]

I was going to create a SIP trunk on CUCM to CME for outbound calling.  Would that be the same thing?  I was also going to set CME on the secondary gateway and not primary for obvious reasons.

[Chris Deren]

Well, it would be extra config since now to make an outbound PSTN call from the CME phones you will always need to route them to CUCM via the SIP trunk.

If you remove MGCP and simply create SIP trunk between CUCM and CME then you can use this for the integration, i.e. dialing between phones and also share it for inbound/outbound calling for both systems, this way if SIP phone on CME dials out it no longer needs to be hairpinned to CUCM it just goes out locally.  PSTN calls from CUCM would use this SIP trunk instead of MGCP GW for inbound/outbound calling. 

HTH,

Chris

[Matthew Michaluk]

Could I also setup some H.323 dial-peers for the CME to dial out locally?

[Chris Deren]

Sure, but what type of trunks are you using?

If it is PRI then the by using MGCP you are backhauling the D-channel to CUCM and this would not work. If this is simply POTS lines then it should work fine.

If I was in your shoes I would definitely thing strongly about replacing MGCP with either SIP or H323.

Chris

[Matthew Michaluk]

PRI Trunks. 

[Chris Deren · Accepted solution]

Then as I said with MGCP the D-channel is backhauled to CUCM which means that to use it with CME devices you will need to first send the call to CUCM, so your H323/SIP dial-peers would need to be voip dial-peers pointing to CUCM where you would need to ensure the GW is defined to accept all significantDigits and allow sending these back to the MGCP GW via Route pattners, so CSS assigned to the GW would need to have access to the route pattner Paritions.

With SIP/H323 controlled PRI you would simply have pots dial-peers to send these calls out to the PRI, and these dial-peers would be shared between CUCM and CME, alot cleaner and easier.

HTH,

Chris

[Matthew Michaluk]

Thanks Chris.