RTP/RTCP – Real Time Transport Protocol/ Real Time Control Protocol
description
Transcript of RTP/RTCP – Real Time Transport Protocol/ Real Time Control Protocol
RTP/RTCP – Real Time Transport Protocol/ Real Time Control Protocol
Presented by
Manoj Sivakumar
Overview
Motivation RTP/RTCP description
Motivation
TCP/IP Not suitable for real-time
Retransmissions can lead to high delay and cause delay jitter Does not support multicast Congestion control mechanism (slow start) not suitable for
AV media UDP/IP
No defined technique for synchronizing Streams from different servers may collide A feedback channel must be defined for quality control
RTP/RTCP
A session consists of an RTP/RTCP pair of channels
Usually works over UDP/IP End-to-end protocol
RTP/RTCP
RTP Features Multicasting Payload type identification Time shaping Sequencing Delivery monitoring
RTP/RTCP
RTP Issues No QoS guarantees No guarantee of packet delivery
RTP Timestamp (TS) and Sequence Number (SN) TS used to order packets in correct timing order SN to detect packet loss For a video frame that spans multiple packets –
TS is same but SN is different
RTP/RTCP
RTCP Synchronize across different media
streams Provide feedback on the quality of data
using lost packet counts Identify and keep track of participants Retransmission requests
RTP/RTCP
Media Application
RTCP
RTP
UDP
IP
RTP/RTCPRTP HEADER
Reference
www.cs.columbia.edu/~hgs/rtp/papers.html