Cisco Ip Phone 8800 Series Administration Guide For Cisco Unified Communications Manager - Cisco 8811 Administration Manual

Network protocol
Link Layer Discovery
Protocol-Media Endpoint
Devices (LLDP-MED)
Real-Time Transport Protocol
(RTP)
Real-Time Control Protocol
(RTCP)
Session Description Protocol
(SDP)
Purpose
LLDP-MED is an extension of the LLDP standard for voice
products.
RTP is a standard protocol for transporting real-time data,
such as interactive voice, over data networks.
RTCP works in conjunction with RTP to provide QoS data
(such as jitter, latency, and round-trip delay) on RTP streams.
SDP is the portion of the SIP protocol that determines which
parameters are available during a connection between two
endpoints. Conferences are established by using only the SDP
capabilities that all endpoints in the conference support.

Cisco IP Phone 8800 Series Administration Guide for Cisco Unified Communications Manager

Network Protocols
Usage notes
The Cisco IP Phone supports
LLDP-MED on the SW port to
communicate information such as:
• Voice VLAN configuration
• Device discovery
• Power management
• Inventory management
For more information about
LLDP-MED support, see the
LLDP-MED and Cisco Discovery
Protocol white paper:
http://www.cisco.com/en/US/tech/
tk652/tk701/technologies_white_
paper0900aecd804cd46d.shtml
Cisco IP Phones use the RTP
protocol to send and receive
real-time voice traffic from other
phones and gateways.
RTCP is enabled by default.
SDP capabilities, such as codec
types, DTMF detection, and
comfort noise, are normally
configured on a global basis by
Cisco Unified Communications
Manager or Media Gateway in
operation. Some SIP endpoints
may allow configuration of these
parameters on the endpoint itself.
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