![](/images/new-backgrounds/1295159/295159237x1.webp)
Chapter 5 Linksys IP Phone Field Reference
SIP Tab
Field | Description | |
|
| |
RTCP Tx Interval | Interval for sending out RTCP sender reports on an active connection. It can range from | |
(not applicable to SPA901) | 0 to 255 seconds. During an active connection, the Linksys IP 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 | |
| ||
| ||
| phone’s local time, not the time reported by an NTP server. If the Linksys IP 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 Linksys IP phone web page. | |
| Defaults to 0. | |
|
| |
No UDP Checksum | Select yes if you want the Linksys IP phone to calculate the UDP header checksum for | |
(not applicable to SPA901) | SIP messages. Otherwise, select no. | |
Defaults to no. | ||
| ||
|
| |
Symmetric RTP | Enable symmetric RTP operation. If enabled, sends RTP packets to the source address and | |
(not applicable to SPA901) | port of the last received valid inbound RTP packet. If disabled (or before the first RTP | |
packet arrives) sends RTP to the destination as indicated in the inbound SDP. | ||
| ||
| Defaults to yes. | |
|
| |
Stats In BYE | Determines whether the Linksys IP phone includes the | |
(not applicable to SPA901) | a BYE message. The header contains the RTP statistics of the current call. Select yes or | |
no from the | ||
| ||
| ||
| received>,PL=<packets lost>,JI=<jitter in ms>,LA=<delay in ms>,DU=<call duration in | |
| s>,EN=<encoder>,DE=<decoder>. | |
| Defaults to no. | |
|
|
SDP Payload Types
The configured dynamic payloads are used for outbound calls only where the Linksys IP phone presents the SDP offer. For inbound calls with a SDP offer, the Linksys IP phone follow the caller dynamic payload type assignments.
The Linksys IP phone uses the configured codec names in its outbound SDP. The Linksys IP phone ignores the codec names in incoming SDP for standard payload types (0 – 95). For dynamic payload types, the Linksys IP phone identifies the codec by the configured codec names. Comparison is
| Field | Description | |||
|
|
| |||
| AVT Dynamic Payload | AVT dynamic payload type. Ranges from | |||
|
|
|
| Defaults to 101. | |
|
|
|
|
| |
|
|
| Linksys IP Phone Administrator Guide | ||
|
|
| |||
|
|
|
|
|
|
|
|
| Firmware Version 5.1 |
| |
|
|
|
|