Polycom DMA SIP trunk with CUCM - using E1 PRI of CUCM
I understand that we can have a SIP trunk between DMA & CUCM and route calls back & forth from both sides. My question is, can my endpoints (HDX, group series, RPD) registered on DMA route (send & receive) calls to/from the external participants using the E1 PRI (external trunks) of CUCM (we don't want to have E1 PRI on RMX).
As per my understanding it should be possible, as I can choose the prefix from DMA & CUCM to route calls both sides. Let say, I have prefix 100xxxx from DMA to route calls from DMA to CUCM. hence, If I have to make a call from HDX to CUCM endpoint I dial 1003333 (3333 be an extension). from CUCM if i have to dial out (offnet) I use "9" as prefix. So to dial an external number I dial "9xxxxxxxx" (xxxxxxx be an external number). So, to do the same from DMA I should be able to dial "1009xxxxxxx" - where "100" will be stripped when routing the call to CUCM and "9xxxxxxx" will be treated by CUCM as it did in a local scenario?
Re: Polycom DMA SIP trunk with CUCM - using E1 PRI of CUCM
This can be done. I have done this with another customer. The problem I had was the gateway device was not registering to the DMA instead it was registering with the CUCM server. This caused a breakdown in communication because the alias was being denied by the DMA. We created H323 trunk to the CUCM server. The dial rule was created to strip the prefix and add a gateway prefix. You have described the process correctly. Here is an example postliminary that you can use on the DMA dial rule to strip the prefix: