hp-ux multimedia streaming protocols white paper

 

December 2004

protocol overview

Real Time Protocol (RTP)

 

Real Time Protocol (RTP) is a transport protocol that provides end-to-end

 

network transport functions for applications transmitting data with real-time

 

properties, such as interactive audio and video. These services include payload

 

type identification; sequence numbering; time stamping and delivery

 

monitoring. Applications run RTP on top of UDP.

 

RTP consists of Real-Time Control Protocol (RTCP), a closely linked protocol,

 

which provides a mechanism for reporting feedback on the transmitted real-

 

time data.

 

RTP can be used in the following scenarios:

 

Multicast audio conference

 

Audio and video conference

 

Mixers and translators

 

Real Time Streaming Protocol (RTSP)

 

Real Time Streaming Protocol (RTSP) controls the transfer of real-time media

 

data and serves as a network-remote-control for multimedia services. The client

 

requests a selected media file from the server using RTSP. The server, in

 

response, returns information required by the client to transfer the media data.

 

Applications, which use HP-UX MSP libraries, run RTSP on top of TCP.

 

Session Description Protocol (SDP)

 

Session Description Protocol (SDP) describes the general real-time multimedia

 

sessions. A multimedia client uses SDP to announce a conference session by

 

periodically multicasting an announcement packet to a familiar multicast

 

address and port using Session Announcement Protocol (SAP).

 

SDP conveys information about media streams in multimedia sessions and

 

allows the recipients of a session description to participate in the session. The

 

primary use of SDP is in an Internetwork, but it is sufficiently general that it can

msp on hp-ux

describe multimedia conferences in other network environments.

The MSP framework for HP-UX multimedia streaming servers includes libraries

 

required for implementing the multimedia streaming protocols (RTP, RTSP, and

 

SDP) and transmitting real-time data over remote networks. These libraries use

 

underlying transport mechanisms, such as TCP and UDP, to deliver multimedia-

 

streaming services.

 

The MSP implementation on HP-UX offers greater benefits in terms of high

 

performance, ability to take advantage of scalability, reliability, and high

 

availability of the HP-UX operating system.

 

MSP is available as a web release on the HP-UX 11i v1 and HP-UX 11i v2

 

operating systems.

library features

The following lists the features that the MSP libraries support:

 

RTP/RTCP

 

Payload identification

 

Sequence numbering

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