Cisco Systems ATA187I1ARF manual GL-5

Glossary

Proxy Server	An intermediary program that acts as both a server and a client for the purpose of making requests on
	behalf of other clients. Requests are serviced internally or by passing them on, possibly after
	translation, to other servers. A proxy interprets, and, if necessary, rewrites a request message before
	forwarding it.
PSTN	Public switched phone network

Q

QoS

Quality of Service. The capability of a network to provide better service to selected network traffic over various technologies, including Frame Relay, Asynchronous Transfer Mode (ATM), Ethernet and

802.1networks, SONET, and IP-routed networks that may use any or all of these underlying technologies. The primary goal of QoS is to provide priority including dedicated bandwidth, controlled jitter and latency (required by some real-time and interactive traffic), and improved loss characteristics.

R

Redirect Server

Registrar Server

router

RTP

A redirect server is a server that accepts a SIP request, maps the address into zero or more new addresses, and returns these addresses to the client. It does not initiate its own SIP request nor accept calls.

A registrar server is a server that accepts Register requests. A registrar is typically co-located with a proxy or redirect server and may offer location services.

Network layer device that uses one or more metrics to determine the optimal path along which network traffic should be forwarded. Routers forward packets from one network to another based on network layer information. Occasionally called a gateway (although this definition of gateway is becoming increasingly outdated). Compare with gateway.

Real-Time Transport Protocol. One of the IPv6 protocols. RTP is designed to provide end-to-end network transport functions for applications transmitting real-time data, such as audio, video, or simulation data, over multicast or unicast network services. RTP provides services such as payload type identification, sequence numbering, timestamping, and delivery monitoring to real-time applications.

S

SDP		Session Definition Protocol. An IETF protocol for the definition of Multimedia Services. SDP
		messages can be part of SGCP and MGCP messages.
SIP		Session Initiation Protocol. Protocol developed by the IETF MMUSIC Working Group as an
		alternative to H.323. SIP features are compliant with IETF RFC 2543, published in March 1999. SIP
		equips platforms to signal the setup of voice and multimedia calls over IP networks.
SIP endpoint		A terminal or gateway that acts as a source or sink of Session Initiation Protocol (SIP) voice data. An
		endpoint can call or be called, and it generates or terminates the information stream.
		Cisco ATA 187 Analog Telephone Adaptor Administration Guide for SIP (Version 1.0)
	OL-21862-01		GL-5