NEC Univerge SV9100 Manual page 437

8-46
Bandwidth Calculation
( [ Layer 2 overhead + IP/UDP/RTP header + Voice Payload ] /
Voice Payload ) * Default CODEC speed = Total Bandwidth
Example of a G.711 call over Ethernet using a 20ms packet size and not
using RTP header compression
(.020 * 64000) / 8 = 160 Bytes for Voice Payload
([ 18 + 40 + 160] / 160) * 64000 = 87200bps
If VAD is not enabled each side of the conversation would be streaming
87.2kbps in one direction for a total of 174.4kbps.
The following chart shows the supported CODECS for IP phones with different
packet sizes over PPP and Ethernet.
CODEC
G.711
G.711
G.711
G.711
G.722
G.722
G.722
G.722
G.729
G.729
G.729
G.729
G.729
G.729
Packet Size
10 103.2 kbps
20 83.6 kbps
30 77.1 kbps
40 73.9 kbps
10 103.2 kbps
20 83.6 kbps
30 77.1 kbps
40 73.9 kbps
10 47.2 kbps
20 27.6 kbps
30 21.1 kbps
40 17.8 kbps
50 15.9 kbps
60 14.5 kbps
PPP Ethernet
110.4 kbps
87.2 kbps
79.5 kbps
75.6 kbps
110.4 kbps
87.2 kbps
79.5 kbps
75.6 kbps
54.4 kbps
31.2 kbps
23.5 kbps
19.6 kbps
17.3 kbps
15.7 kbps
IP Multiline Station (SIP)
Issue 2.0