Configuring Rtp And Rtcp; Configuring Rtp Header Compression - Avaya G350 Administration

Configuring VoIP QoS

Configuring RTP and RTCP

Configuring RTP and RTCP
VoIP uses the RTP and RTCP protocols to transmit and receive digitally encoded voice data. RTP and
RTCP are the basis of common VoIP traffic. RTP and RTCP run over UDP and incur a 12-byte header on
top of other (IP, UDP) headers. Running on PPP or Frame-Relay, these protocols can be compressed.
Use the
ip rtp port-range
NOTE:
This range should match the range configured in the IP_network region to which the G350
is assigned in the ACM.

Configuring RTP header compression

Use RTP header compression to reduce the amount of bandwidth needed for voice data. The G350 RTP
Header Compression process is based on the following:
•
The packet order on a PPP and Frame Relay link is preserved.
•
After transmitting full headers, usually only the deltas from the full packet's header need to be
sent, and not the full header itself. This is due to the IP, UDP, and RTP header structure.
•
Since the deltas are often constant, the second order delta is 0 and does not need to be transmitted.
You can configure how often the full header is transmitted, either as a function of time or transmitted
compressed packets.
RTP Header Compression can reduce the size of all three headers (IP+UDP+RTP~40 bytes) to 2-4 bytes.
The G350 can only compress RTP packets. Any UDP packet with an even destination port within a user-
configurable range of ports, is considered an RTP packet.
The G350 can decompress any type of compressed packets. Decompression is enabled whenever RTP
compression is enabled.
Use the following commands to configure RTP header compression:
•
Use the
either for all enabled interfaces or for a specific interface. To clear RTP compression statistics for
all enabled interfaces, do not enter an interface type and number. There is no renegotiation of
parameters.
•
Use the
supported on this interface. Use the
command also sets the number of connections in the non-TCP space, not just RTP.
NOTE:
This command automatically enables TCP header decompression on this interface.
•
Use the
be sent between full headers.
•
Use the
62
command to configure the range of UDP ports for RTP.
clear ip rtp header-compression
ip rtp compression-connections
command to set the maximum number of compressed headers that can
ip rtp max-period
command to set the maximum number of seconds between full headers.
ip rtp max-time
command to clear RTP header compression statistics
command to control the number of RTP connections
form of this command to restore the default. This
no
Administration of the Avaya G350 Media Gateway
June 2004