; General Description ................................. 39
7.2 RTCP Processing in Translators ...................... 41
7.3 RTCP Processing in Mixers ........................... 43
7.4 Cascaded Mixers ..................................... 44
8. SSRC Identifier Allocation and Use .................. 44
8.1 Probability of Collision ............................ 44
8.2 Collision Resolution and Loop Detection ............. 45
9. Security ............................................ 49
9.1 Confidentiality ..................................... 49
9.2 Authentication and Message Integrity ................ 50
10. RTP over Network and Transport Protocols ............ 51
11. Summary of Protocol Constants ....................... 51
11.1 RTCP packet types ................................... 52
11.2 SDES types .......................................... 52
12. RTP Profiles and Payload Format Specifications ...... 53
A. Algorithms .......................................... 56
A.1 RTP Data Header Validity Checks ..................... 59
A.2 RTCP Header Validity Checks ......................... 63
A.3 Determining the Number of RTP Packets Expected and
Lost ................................................ 63
A.4 Generating SDES RTCP Packets ........................ 64
A.5 Parsing RTCP SDES Packets ........................... 65
A.6 Generating a Random 32-bit Identifier ............... 66
A.7 Computing the RTCP Transmission Interval ............ 68
Schulzrinne, et al Standards Track [Page 2]
RFC 1889 RTP January 1996
A.8 Estimating the Interarrival Jitter .................. 71
B. Security Considerations ............................. 72
C. Addresses of Authors ................................ 72
D. Bibliography ........................................ 73
1. Introduction