Aastra 9000i Series Administrator's Manual page 260

Aastra Web UI
Step Action
Click on Advanced Settings->Line <N>->RTP Settings.
Per-Line Settings.
2 Enter an RTP Port Base in the RTP Port field. Default is 3000.
The RTP Port 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.
Note: The phones support decoding and playing out DTMF tones sent in SIP INFO requests. The
following DTMF tones are supported:
• Support signals 0-9, #, *
• Support durations up to 5 seconds
3 The "Force RFC2833 Out-of-Band DTMF" field is enabled by default. Disable this field by
unchecking the box.
Enabling this parameter forces the IP phone to use out-of-band DTMF according to RFC2833.
4 Select a method to use from the "DTMF Method" list box. Valid values are RTP, SIP Info, Both.
Default is RTP.
Note: You can configure the DTMF Method on a global or per-line basis.
5 Select the type of RTP encryption to use from the "RTP Encryption" list box. Valid values are SRTP
Disabled, SRTP Preferred, or SRTP Only. Default is SRTP Disabled.
Note: You can configure RTP Encryption on a global or per-line basis.
41-001343-01 Rev 02, Release 3.2.2 4-97