Configuring Rtp Base Udp Port - AudioCodes Mediant 3000 User Manual

User's Manual

15.3.5 Configuring RTP Base UDP Port

You can configure the range of local UDP ports for RTP, RTCP, and T.38 media streams.
The range of possible UDP ports that can be used, depending on configuration, is 6,000
through to 64,000. The device assigns ports randomly to the traffic within the configured
port range.
For RTCP and T.38 traffic, the port offset from the RTP port used for the voice session
(channel) is one and two, respectively. For example, if the voice session uses RTP port
6000, the RTCP port and T.38 port for the session is 6001 and 6002, respectively.
However, you can configure the device to use the same port for RTP and T.38 packets, by
setting the T38UseRTPPort parameter to 1.
Within the port range, the device allocates the UDP ports in "jumps" (spacing) of 10
(default). For example, if the port range starts at 6000 and the UDP port spacing is 10, the
available ports include 6000, 6010, 6020, 6030, and so on.
The port range is calculated using the following equation:
BaseUDPPort to (BaseUDPPort + number of channels*10)
Where, BaseUDPPort is a parameter for configuring the lower boundary of the port range
(default is 6000) and number of channels is the maximum number of channels purchased
from AudioCodes (included in the installed Software License Key).
For example, if the base UDP port is set to 6000, the port range for 20 channels is:
6000 to (6000 + 20*10) = 6000 to (6000 + 200) = 6000 to 6200
You can also configure specific port ranges for specific SIP entities, using Media Realms
(see Configuring Media Realms on page 319). You can configure each Media Realm with a
different UDP port range and then associate the Media Realm with a specific IP Group, for
example. However, the port range of the Media Realm must be within the range configured
by the BaseUDPPort parameter.
The following procedure describes how to configure the RTP base UDP port through the
Web interface.

To configure the RTP base UDP port:
1. Open the RTP/RTCP Settings page (Configuration tab > VoIP menu > Media >
RTP/RTCP Settings). The relevant parameter is listed under the 'General Settings'
group, as shown below:
Figure 15-7: RTP Based UDP Port in RTP/RTCP Settings Page
2. Set the 'RTP Base UDP Port' parameter to the required value.
3. Click Submit.
4. Reset the device for the settings to take effect.
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