Packet flow for voice between endpoints.

[Tommer Catlin]

Hi all -

Im trying to grasp the concept of how packets for voice traverse the network for this scenario:

- Hub location with CUCM cluster

- Remote location with PSTN H323 to CUCM

- Remote location SIP Gateway with SIP endpoints

- Incoming call from PSTN routes to CUCM---Route Pattern to SIP Trunk to SIP gateway at Remote location

Question, does the RTP traffic flow the entire path on a PSTN call or will it flow from router to router and signalling will flow through CUCM (keeps track of the call).

Thanks!

[Brandon Buffin]

RTP flow will be between the endpoints (gateways) unless you are using an MTP.

Hope this helps.

Brandon

[Tommer Catlin]

Ok, so if I have MTP configured in CUCM, then the RTP packets will flow through the trunks.   Trying to calculate my bandwidth requirement for this scenario.   I may try and put dial peers between the routers and a SIP trunk between the routers.... not sure yet.

Thanks much!

[Brandon Buffin]

Right, the MTP anchors the call so that the RTP flow goes through CUCM instead of endpoint to endpoint.

Brandon

[Tommer Catlin]

Thanks Brandon.  The MTP is what I missing on where it anchors or not.

Cheers!