Voice-only with different codecs

Experimental Setup

In order to gain inside in the bandwitdh usage when SIP-phones use different codecs, the following experimental setup is used. A voice-call has been established between SIP-phone 201, which uses the GSM-codec and SIP-phone 301, which uses the G711u-codec.

Legenda:

• Blue: Traffic between the Asterisk-boxes.
• Red: Traffic to and from SIP phone 301.
• Pink: Traffic to and from SIP phone 202.
• Green: Traffic to and from SIP phone 201.

Voice-call between 201 (GSM-codec) and 301 (G711u codec)

Used filters in I/O-graph:

Filter-Black: proto=sip
Filter-Red  : ip.addr == 192.168.1.3   && ip.addr == 192.168.1.106
Filter-Green: ip.addr == 192.168.1.189 && ip.addr == 192.168.1.101
Filter-Blue : ip.addr == 192.168.1.106 && ip.addr == 192.168.1.101
Filter-Pink : ip.addr == 192.168.1.100 && ip.addr == 192.168.1.101

This does not tell us which Asterisk box makes the conversion between the GSM codec and the G711u codec. Therefore we made another graph with the traffic meassured only in one direction.

Used filters in I/O-graph:

Filter-Black: ip.src == 192.168.1.101 && ip.dst == 192.168.1.106
Filter-Red  : ip.src == 192.168.1.3   && ip.dst == 192.168.1.106
Filter-Green: ip.src == 192.168.1.189 && ip.dst == 192.168.1.101
Filter-Blue : ip.src == 192.168.1.106 && ip.dst == 192.168.1.101
Filter-Pink : ip.src == 192.168.1.100 && ip.dst == 192.168.1.101