[Asterisk-Users] g729 and latency measures

[Erick Perez]

Hi, we have set up a small project in a school the following way:
SITE_A(4 port analog to ip
g729)------ADSL_ISP1-------ISP2--------Asterisk-----PSTN
Site A has 1 Megabit of bandwith (up 512kilobit down 1 megabit)
The asterisk box gets internet service via a wireless antenna. 1 Mbit
of up/down bandwith

Comments:
So far, this means that I will need licenses for the 729.
asterisk only supports 20ms sampling on g729 so 4 channels will need
96 kilobits at 20ms sampling (or is it kilobytes??) for the internet
bandwith.
i cannot use CRTP because i cant be sure if the ISP's routers are CRTP aware.
Installing ADSL from ISP1 on the asterisk place will give a clear advantage

Please correct any of my prior statements if wrong.

should I maintain packet latency below 300ms or 150ms?

How can I measure this latency all the way to the asterisk? Should I
ping from SITE_A to the asterisk box with 8k packets?
If I can't install ADSL for the moment, will the above setup work?

thanks in advance for all your help.

Erick.