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Bandwidth Calculation on SIP Trunk


I know SIP utilizes Bandwidth , and there is no concept of channels like T1,E1 .

I need to now if i need 100 calls coming IN & OUT from my Organization .how much bandwidth will be required for SIP Trunk .?

To accomplish this requirement do we need more than 1 SIP Trunk ? 

Given G.711/G.729 will be used on SIP Trunk .




5 Replies 5


Dear Prakash,


You don't require additional SIP trunk, one SIP trunk can handle as many calls depending upon the bandwidth of the connectivity.


Regarding the bandwidth consumption G.729 will consume 32 kbps and G711, will consume 87kbps per call. 

Chris Deren
Hall of Fame
Hall of Fame

In addition to great answers by others, you contract how many concurrent SIP sessions (calls) you will be able to deliver with your SIP provider as typically they charge for #calls you get, plus you would need to match that number with CUBE licenses you get from Cisco.  As to the bandwidth that is already answered, you also need to me make sure that the handoff to your network/CUBE supports the bandwidth you will need, but with 100 calls that is never an issue.

Thanks everyone for the kind reply .

i am learning SIP and have some more queries.


lets say there are 3 CUCM clusters and for calling between the cluster we create SIP Trunk .

do we require dial peers along with sip trunk in order to reach from one cucm to the other two cucm ?or RP/RL will do only ?


and how to collect logs for SIP calls between the two CUCM clusters ?




If you have 3 clusters on the same IP network you do not need CUBE (thus no dial-peers) to integrate them, you can use the SIP trunk along with either route patterns/route list/route groups or enabling GDPR to route calls between them. 

You would collect CCM SDL logs by getting them via RTMT like you do for all other tracing in CUCM.

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