1. RTP/RTCP – Real Time Transport Protocol/ Real Time Control Protocol Presented by Manoj Sivakumar

2. Overview Motivation RTP/RTCP description

3. 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

4. RTP/RTCP A session consists of an RTP/RTCP pair of channels Usually works over UDP/IP End-to-end protocol

5. RTP/RTCP RTP Features  Multicasting  Payload type identification  Time shaping  Sequencing  Delivery monitoring

6. 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

7. 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

8. RTP/RTCP Media Application RTCP RTP UDP IP

9. RTP/RTCP RTP HEADER

10. Reference www.cs.columbia.edu/~hgs/rtp/papers. html