Aastra Telecom SISIP 57I CT - Manual (Page 127)

Advanced Network Settings
41-001160-00, Rev 01 Release 2.0 4-61
Network Configuration of the IP Phones
Configuring the IP Phones .
Aastra Web UI
Step Action
1 Click on Advanced Settings->Global SIP->RTP Settings.
2 Enter an RTP Port Base in the RTP Port field. Default is 3000.
3 Enable the "Basic Codecs (G.711 u-Law, G.711 a-Law, G.729)" field by checking the check box.
(Disable this field by unchecking the box). Enabling this parameter allows the IP phone to use the
basic Codecs when sending/receiving RTP packets.
4 Enable the "Force RFC2833 Out-of-Band DTMF" field by checking the check box. (Disable this field
by unchecking the box). Enabling this parameter forces the IP phone to use out-of-band DTMF
according to RFC2833.