Installation guide

Global SIP Settings
4-74 41-001561-00 REV00 – 10.2014
Silence Suppression
In IP telephony, silence on a line (lack of voice) uses up bandwidth when sending voice over a packet-switched system.
Silence suppression is encoding that starts and stops the times of silence in order to eliminate that wasted bandwidth.
Silence suppression is enabled by default on the IP phones. The phone negotiates whether or not to use silence suppres-
sion. Disabling this feature forces the phone to ignore any negotiated value.
You can configure silence suppression on a global-basis using the configuration files or the Mitel Web UI.
Option to Include/Remove Silence Suppression Attribute from SDP Offer
The parameter sip remove silence suppression offer is available allowing administrators the ability to control whether
or not the silence suppression attribute should be included in the Session Description Protocol (SDP) offer.
If enabled (1), the silence suppression attribute will be removed from the SDP offer. If disabled (0), the attribute will not
be removed from the SDP offer. This parameter is disabled by default and requires a reboot if the value of the parameter
has changed. You can configure this parameter using the configuration files only.
Configuring RTP Features
Use the following procedures to configure the RTP features on the IP phone.
Configuration Files
For specific parameters you can set for RTP features in the configuration files, see Appendix A, the section, “RTP, Codec, DTMF Global Settings” on
pageA-97.
IP Phone UI
For the 6863i/6865i:
1.
Press on the phone to enter the Options List.
2. Select Administrator Menu.
3. Select SIP Settings.
4. Select RTP Port Base to change the RTP port base setting. Default is 3000.
5. Press Done (2 times) to save the change.
Note:
The session prompts you to restart the IP phone to apply the configuration settings
6. Select Restart.
For the 6867i/6869i:
1.
Press on the phone to enter the Options List.
2. Press the Advanced softkey.
3. Enter the Administrator password using the keypad. Default is “22222”.
4. Select SIP > Call Server.
5. In the RTP Port Base field, enter an RTP port base setting. Default is 3000.
6. Press the Save softkey.
7. Restart the phone for the change to take affect.