Hi,

Thank you for your reply. I have tried to establish static NAT, but unfortunately, this works in wrong way. I have no problems with signaling, but have problems with RTP, because RTP traffic goes between IP phones and external GW and I need to somehow establish dynamic NAT rules to forward RTP traffic to IP phones, instead CUCM.

Hi

I'm not sure how your topology looks like, but i have a lab setup below that works, allowing the CUCM IP phones to call the CME phones and vice versa.

CUCM+IP phones -- NAT router --- h323 GW --- CME router --- CME phones

The CUCM+IP phones are in the "inside" network, and NAT router does static NAT for the CUCM and PAT for the IP phones. CUCM is configured with a route-pattern pointing to the h323 GW for the CME phone numbers. while CME has a dial-peer pointing to the H323 GW for the CUCM IP phone numbers. The h323 GW is effectively an IPIPGW and is configured with the appropriate dial-peers.

You may want to try to configure PAT for the IP phones, static NAT for the CUCM in the inside network to see if that works.

Hi,

Topology is the same. I will try to do PAT, as you have suggested. Thanks.