Aastra Telecom SISIP 57I CT - Manual (Page 365)

Operational, Basic, and Advanced Parameters
41-001160-00, Rev 01 Release 2.0 A-23
Configuration Parameters
Appendix A
Parameter –
sip nat rtp port
RTP Port Base
(in IP Phone UI)
NAT RTP Port
(in Web UI)
IP Phone UI Options->SIP Settings->RTP Port Base
Aastra Web UI Advanced Settings->Network->
Advanced Network Settings
Configuration Files aastra.cfg, <mac>.cfg
Description Indicates the port through which the RTP packets are sent. This value
must specify the beginning of the RTP port range on the gateway or
router.
The RTP port is used for sending DTMF tones and for the audio stream.
Your network administrator may close some ports for security reasons.
You may want to use this parameter to send RTP data using a different
port.
Format Integer
Default Value 51720
Range Not Applicable
Example sip nat rtp port: 51730