Page 80 of 378 ITG Engineering Guidelines553-3001-202 Standard 1.00 April 2000Table 6Silence suppression disabled T-LAN Ethernet and WAN IP bandwidth usage per ITG port
Codec type
Codec
Multi -
frame
duration
in ms
(payload)
(one way)
Voice/fax
payload
Multi -
frame
in bytes
(one way)
IP voice
packet in
bytes
(one way)
Ethernet
voice
packet in
bytes
(one way)
Bandwidth
use on
T-LAN in
kbit/s
(two way)
Bandwidth
use on
WAN in
kbit/s
(one way)
WAN with
Frame
Relay
overhead
in kbit/s
(one-way)
WAN with
ATM
overhead
in kbit/s
(one-way)
G.711
(64 kbit/s) 10 80 240 292 233.6 96.0 102 .4 127.2
20 160 400 452 180.8 80.0 83.2 106 .0
30 240 560 612 163.2 74.6 76.6 98.9
G.729AB/
G.729A
(8kbit/s)
10 10 100 152 121.6 40.0 46.4 84.8
20 20 120 172 68 .8 24.0 27.2 42.4
30 30 140 192 51 .2 18.6 20.8 28.3
G.723.1
(5.3
kbit/s)
30 20 120 172 45 .8 16.0 18.1 28.3
G723.1
(6.3
kbit/s)
30 24 128 180 48 .0 17.0 19.2 28.3
T.30/T.38
G3 Fax
Modem
14.4
Kbit/s
16.6 30 7 0 96 46.3 33.7 37.5 50.9
25 30 70 96 30.7 22.4 25.0 33.9

Note 1:

Based on voice multi frame encapsulation for Realtime Transport Protocol per H.323 V2.

Note 2:

The bolded rows contain the default payload/packet size for each codec in the MAT.

Note 3:

T-LAN data rate is the effective Ethern et bandwidth consum ption.

Note 4:

T-LAN kbit/s for voice traffic = 2*Ethernet frame bits*8/frame duration in ms

Note 5:

WAN kbit/s for voice traffic = IP p acket bytes*8/frame durati on in ms

Note 6:

24 ports per ca rd for all codecs

Note 7:

Overhead (RTP/ UD P he ade r + I P head er ) o f p ac k e ts o v e r the voice payload m ul tif r a me is 4 0 bytes;
overhead of Ethernet frame over IP packet is 26 byte s.

Note 8:

An Interframe gap is not i nc lude d in t he abo ve bandwidth calcul ati on , beca us e o f the lo w p r oba bil it y
of occurring in this type of application.