Which Router to Use?

[chuck-larrieu]

1) hub and spoke topology. DS3's at hub site. Multiple T1's at spoke sites.

2) spoke sites may have anywhere from 10 to 200 telephones, and 20 to several hundred data ports.

3) the requirement is 4 FXO for local PSTN access / failover plus one port to connect to local paging systems

4) centralized Call Manager. Conference calling is essential, so a Conference Server has been specified.

5) the WAN router at the spoke sites will provide various QoS functions, local DSP resources, SRST, etc

My question for this forum - given that I have no real information about call volume, at what number of phones would people think it prudent to up the router from the lower end pair ( 1760+2651 ) to something like a 3745?

a) at a site with 2xT1 and PPP multilink - 20 phones? 50 phones?

b) at a site using 3xT1 and PPP multilink - 30 phones? 60 phones?

Any general guidelines, any general thoughts are welcome.

[rkeblusek]

One consideration will be if you plan to use cRTP compression. If so stick with the 2691, 3725, 3745 or 7000 series. The 7000 series has raw speed but the other three have zero impact on performance with and without cRTP. In this size network this is important to save bandwidth. 2691 as WAN edge router for example can hangle 90 concurrent voice streams with cRTP enabled. I would probably lean 2691 on all sites with 2 T1, 3725 for the others. Another option is 3745 with the 16 or 32 port 10/100 Ethernet in the network module. You will have to crunch the numbers to see what works best form a price standpoint.