Media5 Mediatrix 4104, Reference Manual

Page: 254 / 466

Chapter 15 - Voice Transmissions Packetization Time
232 Mediatrix 4104
2. If you have enabled one or more of the G.726 codecs, set the G.726 actual RTP dynamic payload
type used in an initial offer in one or more of the following variables:
• voiceIfCodecG72616kbpsPayloadType: The default value is 97.
• voiceIfCodecG72624kbpsPayloadType: The default value is 98.
• voiceIfCodecG72632kbpsPayloadType: The default value is 99.
• voiceIfCodecG72640kbpsPayloadType: The default value is 100.
The payload types available are as per RFC 3551. The values range from 96 to 127.
3. Restart the Mediatrix 4104 so that the changes may take effect.
Packetization Time
The packetization time (also called packetization period or ptime) is the duration, in ms, of the voice packet.

To set the packetization time:
1. In the voiceIfMIB, set the packetization time of the codec(s) as required ( voiceIfCodecTable ).
Available values vary from one codec to another.
G.723.1 voiceIfCodecG723Enable g723-53kbs
g723-63kbs
G.726 at 16 kbps voiceIfCodecG72616kbpsEnable enable
G.726 at 24 kbps voiceIfCodecG72624kbpsEnable enable
G.726 at 32 kbps voiceIfCodecG72632kbpsEnable enable
G.726 at 40 kbps voiceIfCodecG72640kbpsEnable enable
G.729.A voiceIfCodecG729Enable enable
Table 147: Enabling Voice Codecs (Continued)
Codec Variable Set to...
Note:
When selecting the dynamic payload type, make sure that the value is not already used by another
dynamic codec. If a value between 96 and 127 is refused, this means it is already used by another dynamic
codec.
Note:
If you set the voiceIfDtmfTransport variable to outOfBandUsingSignalingProtocol ( “DTMF
Transport Type” on page 235 ), you cannot configure a dynamic payload type to 111 because it is already
used by the DTMF out-of-band using signalling protocol.
Table 148: Packetization Time Settings
Variable Definition Values (ms)
PCMU (G.711 u-Law)
voiceIfCodecPcmuMinPTime Shortest packetization period allowed for the
PCMU codec. Authorized values start at
10 ms and come in discrete steps of 10 ms up
to the one specified by the
voiceIfCodecPcmuMaxPTime variable.
Default Value : 10
10-100, with increments
of 10