Title
An integrated NTP-RTCP solution to audio skew detection and compensation for VoIP applications
Abstract
The circuit switched POTS (plain old telephone system) preserves the timing relationship between media samples from sender to receiver through use of a common clock. For PC-based Internet multimedia, the existence of separate audio and system clocks on either end-host can introduce significant complications. Much work has taken place in recent years that addresses the issue of system clock skew and its effect on precise delay measurement. In a voice over IP (VoIP) environment, where adaptive buffering techniques are employed, system and audio clock skew can distort both delay measurement and playout control as well as lead to poor buffer performance. This paper presents a high level mechanism to measure and compensate for the skew relationships between system and audio clocks at each end of a multimedia session. The mechanism utilises both the network time protocol (NTP) and the RTP (realtime transport protocol) control protocol or RTCP. Preliminary and positive results are presented from a testbed system and plans for further work are outlined.
Year
DOI
Venue
2003
10.1109/ICME.2003.1221672
Multimedia and Expo, 2003. ICME '03. Proceedings. 2003 International Conference
Keywords
Field
DocType
realtime transport protocol,network time protocol,integrated ntp-rtcp solution,plain old telephone system,audio clock skew,voip application,system clock skew,control protocol,audio skew detection,audio clock,common clock,system clock,testbed system,voice over ip,audio signal processing,clock skew,transport protocol,internet telephony,transport protocols,circuit switched,real time systems,adaptive control
Network Time Protocol,RTP Control Protocol,Circuit switching,Computer science,Computer network,Clock skew,Skew,Digital clock manager,Audio signal processing,Voice over IP
Conference
Volume
ISBN
Citations 
2
0-7803-7965-9
1
PageRank 
References 
Authors
0.37
8
2
Name
Order
Citations
PageRank
Melvin, H.110.37
Murphy, L.210.37