[asterisk-users] Re: Bandwidth requirements

[Benny Amorsen]

>>>>> "h" == hugolivude  <hugolivude at gmail.com> writes:

h> I wasn't sure what "Packet Duration to select so I took the default
h> 20ms (2 samples) - whatever that means. I plugged in 5 for the BHT
h> (20 customers, each getting 3 X 5 minute calls/hour = 5 Erlangs)
h> and the default 0.01 for the Blocking. It worked out to 264 kbps.
h> Does this sound reasonable? If so great! A business DSL could
h> support this.

DSL has excessive overhead for small packets, due to ATM. No matter
which codec you pick, you probably won't get below 2 ATM frames per
voice packet. So for G.729 and 20ms frames, that means
50 packets/sec * 2 frames/packet * 48 bytes/frame * 8bits/byte =
38.4kbps per voice call, per direction. A bit worse if you include the
ATM overhead, then it's 50 * 2 * 53 * 8 = 42.4kbps.


/Benny