Rtp Parameters - Linksys 900 Series Administrator's Manual

Chapter 5 900 Series phone Field Reference

RTP Parameters

Field
RTP Port Min
RTP Port Max
RTP Packet Size
Max RTP ICMP Err
RTCP Tx Interval
No UDP Checksum
Symmetric RTP
Document Version 3.1
Description
Minimum port number for RTP transmission and reception.
<RTP Port Max> should define a range that contains at least 4 even number
ports, such as 100 – 106.
The default is 16384.
Maximum port number for RTP transmission and reception.
The default is 16482.
Packet size in seconds, which can range from 0.01 to 0.16. Valid values must be a multiple
of 0.01 seconds.
The default is 0.030.
Number of successive ICMP errors allowed when transmitting RTP packets to the peer
before the 900 Series phone terminates the call. If value is set to 0, the 900 Series phone
ignores the limit on ICMP errors.
The default is 0.
Interval for sending out RTCP sender reports on an active connection. It can range from
0 to 255 seconds. During an active connection, the 900 Series phone can be programmed
to send out compound RTCP packet on the connection. Each compound RTP packet
except the last one contains a SR (Sender Report) and a SDES.(Source Description). The
last RTCP packet contains an additional BYE packet. Each SR except the last one contains
exactly 1 RR (Receiver Report); the last SR carries no RR. The SDES contains CNAME,
NAME, and TOOL identifiers. The CNAME is set to <User ID>@<Proxy>, NAME is set
to <Display Name> (or Anonymous if user blocks caller ID), and TOOL is set to the
Vendor/Hardware-platform-software-version (such as Linksys/900 Series
phone-1.0.31(b)). The NTP timestamp used in the SR is a snapshot of the 900 Series
phone's local time, not the time reported by an NTP server. If the 900 Series phone
receives a RR from the peer, it attempts to compute the round trip delay and show it as the
<Call Round Trip Delay> value (ms) in the Info section of 900 Series phone web page.
The default is 0.
Select yes if you want the 900 Series phone to calculate the UDP header checksum for SIP
messages. Otherwise, select no.
The default is no.
Enable symmetric RTP operation. If enabled, the SPA3102 sends RTP packets to the
source address and port of the last received valid inbound RTP packet. If disabled (or
before the first RTP packet arrives) the SPA3102 sends RTP to the destination as indicated
in the inbound SDP.
References to the SPA3102 also apply to the AG310.
The default is yes.
<RTP Port Min> and
Linksys 900 Series IP Phone Administrator Guide
SIP Tab
5-13