Voice bandwidth over T1 (g.720 and CRTP)

[jrhofman]

I am planning on running 80 concurrent voice calls over a dedicated T1 using g.729 and cRTP. These are agents that are up all the time. Based on my calculations 80 agents will us 960K BW. 12K per call x 80 agents. I will be using 2621M routers to terminate the T1s. My questions are;

Is my math correct on BW utilization of 960K? No data on this T1. Just voice.

Is a 2621XM suffecient for 80 calls doing cRTP or should I move up to a bigger box?

[santoshk]

Case study by Avaya using Cisco 2621

http://www1.avaya.com/enterprise/whitepapers/r300cisco.pdf

I guess 12K per call is fine.

Hope this helps.

Santosh

[m.fleming]

You won't get 80 concurrent calls on a 2621xm. Cisco

state 60 but I would think that with cRTP it'll be a lot less. I'd be looking at something bigger.

http://www.cisco.com/en/US/partner/products/hw/routers/ps259/prod_bulletin09186a008014a9b9.html

[jrhofman]

Thanks for the feedback. I'm thinking the 60 calls their talking about are PSTN type calls. The max Digital voice port density you can only get is a 2 port NMHDV network module (2 PRIs) which would net you 60 calls max.

I also think it makes sense to move up. I'm going with the 3725 or 3745.