IP-phones at remote site

[immadov]

Dears

I need the experts advice.

I am going to install 32 IP-phones in a remote site without installing any Media Gateways there. we have 2 Mb/s WAN link and Qos is well configured to give prority to the voice traffic. call admission controll will be configured to allow only 6 simultinous calls over the WAN link with G729a commpression for extra domain calls.

our provider advises me to install MG for remote sites that include more than 10 IP-phones but i didn't find any reason prevent me from installing extra devices without installing M-Gateway.
I am wondering here if there is any document or recomendation from alcatel about the number of IP-phones that can be installed at remote sites without installing MG.

In my case i need all external calls to go in/out through the central site and i can't imagin what extra benefites that i will get from installing MG other than the signaling backup.

note: i have 3 remote sites, each of them enclose 14 IP-phones. no MG and untill now i didn't face any problem.

[krzysioD]

Maybe it's a economic suggestion: buy more MG :>

but for situation that you describe (no Telco external lines in branch offices) then well, that will give you
MG+T0:
Backup link to main MG (note one MG can rescue one MG, so if 2 WAN points go down... )
Monthly rate for T0.
MG + PCS:
local communication by ip-phones, possibility to survive big crash of WAN.
MG + PCS + T0/APA:
local + remote communication by ip-phones, surviving crash of WAN and/or CPUs at main site (or 2 sites if spartial redundancy)
monthly rate, but you could go with one APA

Note: often provider of your WAN is very same (as cable/fibre goes) provider of your PSTN/APAor ISDN/T0 line... so you backup for router failure not the big J.C.B. (aka Jacob) doing some ground-work.

What i would do is to say, have in big branch offices a GSM gateway (2-4 SIM card / 1-2 T0) + PCS + GD (MADA8) and a router with GSM inertnet gateway as backup for your DATA. Then negotiate with GSM provider :>

As for 10-15 IP-phones, how much does it cost for your company to reach key persons in each office by GSM? Maybe everyone in your company have a GSM with smalles monthly rate that could be used to reach them if they are needed?
Or this is key for your company to have this 10-15 people "in touch", i think this is correct question.

[frank]

We have over 300 remote workers, each of them in a different state, different town.. Nobody use a remote gateway.. They all work good, as long as the bandwidth can support the traffic.

The only time they don't have phones is when their internet goes down

For the branch offices, we use PCS