Cisco 7800 Series Administration Manual page 57

Step 3 Click Submit All Changes.
Configure the RTP Parameters
Procedure
Step 1
In the phone web user interface, navigate to Admin Login > advanced > Voice > SIP.
Step 2 In the RTP Parameters section, set the Real-Time Transport Protocol (RTP) parameter values.
Step 3 Click Submit All Changes.
RTP Packet Contents
During an active connection, the Cisco IP Phone sends out compound RTCP packets. Each compound RTP
packet, except the last one, contains a sender report (SR) and a source description (SDES). The last RTCP
packet contains an additional BYE packet. Each SR, except the last one, contains one receiver report (RR);
the last SR carries no RR.
The SDES contains CNAME, NAME, and TOOL identifiers:
• CNAME—User ID@Proxy
• NAME—Display Name (or Anonymous if user blocks caller ID)
• TOOL—Vendor/Hardware-platform-software-version.
Configure the SDP Payload Types
Configured dynamic payloads are used for outbound calls only when the Cisco IP Phone presents a Session
Description Protocol (SDP) offer. For inbound calls with an SDP offer, the phone follows the caller's assigned
dynamic payload type.
The Cisco IP Phone uses the configured codec names in outbound SDP. For incoming SDP with standard
payload types of 0-95, the phone ignores the codec names. For dynamic payload types, the phone identifies
the codec by the configured codec names (comparison is case-sensitive).
Procedure
Step 1 In the phone web user interface, navigate to Admin Login > advanced > Voice > SIP.
Step 2 In the SDP Payload Types section, set the value as specified:
• AVT Dynamic Payload—Any nonstandard data. Both sender and receiver must agree on a number.
Ranges from 96 to 127. Default: 101.
Step 3
Click Submit All Changes.
Cisco IP Phone 7800 Series for Third-Party Call Control Administration Guide
SIP and NAT Configuration
43