Q: 15 site deployment with shared WAN-VPN, recommendations?


#1

Hi all. I’ve been digging for a while and had trouble getting any specific comments on deployment recommendations that are appropriate for the setup I’m likely looking at (details below). Any feedback is appreciated. I’m in EARLY planning stages here (1yr lead time at least) but want to do this correctly.

GIVEN:

-Assume ~15 geographically distinct sites (across Canada)
-Each site is to have ~10-20 phones
-All sites will be on a common WAN/VPN infrastructure (computers at all 15 sites can ping each other via the VPN-WAN)
-WAN-VPN connectivity is via T1 or greater bandwidth (large academic sites)
-all sites will be making outbound calls to both (a) regular phone network and (b) other phones in the 15 sites
-I’m assuming we’ll simply use an external service provider to provide dial-in routing as well as outbound termination to PSTN network. (no PBX/PSTN bridge(s) in my asterisk box(es) - purely IP based).

QUESTIONS:

-Should I assume we need an asterisk server at each site for routing? Or can we simply have one (or two for redundancy) hosted centrally, and let IP traffic go from [all phones]–>viaWAN/VPN–>AsteriskServer–>Route to either internal phone clients or external termination service provider

-what kind of bandwidth are we to anticipate chewing with this kind of deployment (approx 20k/s up-and-down per active phone line …?) Should we expect too many latency issues if using central asterisk server vs distributed servers?

-clearly fewer centralized servers would be easier to setup/maintain than having such rigs at all sites … hence the query.

… many thanks for your assistance with this …

—Tim Chipman


#2

If you have full T1’s you should have enough bandwidth. Assuming that you aren’t going to have all 10~15 phones active at once. you could setup an * server at each site and maintain the configs at a single site using DUNDI or Swithcing. However, In this type of an installation I think I would use multiple central servers. Depending on the latency(Which should be negligable with Point-to-Point T1’s) echo/lag should be minimal.

The issues you might have is setting up the trunks with your Voip provider. you want to ensure you get one that supports voip
I use sellvoip.net and don’t have an issue with multiple simultaneous channels.

Jag5x5


#3

Hi jag5x5, Thanks for your response. After reading, I realize maybe I need to clarify: there will be ~15 sites with ~10-20 users per site, ie, between 150 and 300 phones in the total deployment. Not sure if this alters the ground enough to merit further concern/consideration.

Thanks,

–Tim