CUCM: Interconnecting two overlapping IP networks

[dfokin]

Hi all!

Currently we need to establish a VoIP link between our CUCM and CUCM of one of our partners. We plan to use

an intercluster trunk, but there is one problem: our IP addressing overlaps with IP addressing of our partner, so there is a problem with RTP traffic.

Is is possible to establish IP connectivity between two clusters without change of IP addressing?

TIA.

[barry]

Hi

If you configure your ICT with Media Termination Point (MTP) required, then your IP address overlap shouldn't matter as CUCM will terminate the RTP.

HTH. Barry

[dfokin]

Hi, Barry and thank you for reply.

As far as I know, this solution will envolve additional CPU resources on call processing nodes, and it must be avoided in situations with high call rate. May I accomplish this task using external HW, a 28xx router, for example?

[barry · Accepted solution]

Hi

I think if you configured each CUCM with a 28xx or 29xx SIP gateway and configure dial peers on these gateways, then this should probably achieve the same thing.

I haven't actually tested this, however generally when you configure CUCM to connect via a CUBE router over SIP, the CUBE router terminates the RTP streams unless you explicity tell it not to.

HTH. Barry