Patent ID: 7362707
Filing Date: 2008-04-22
Classification: H04L,H04M

Abstract:
1. A method for determining latency for a real-time transport protocol (RTP) data flow between a first call endpoint and a call second endpoint, said RTP data flow transiting through a media router, comprising the steps of: intercepting a first RTCP sender report sent from the first call endpoint to the second call endpoint, and a first RTCP receiver report sent from the second call endpoint to the first call endpoint, each first report transiting through the media router, wherein intercepting a first RTCP sender report comprises the steps of: intercepting a second RTCP sender report sent from the second call endpoint to the first call endpoint, and a second RTCP receiver report sent from the first call endpoint to the second call endpoint, each second report transiting through the media router; and determining, in the media router, a round-trip delay between the first call endpoint and the second call endpoint based on a plurality of interception times, each interception time corresponding to the time of intercepting one of the RTCP reports; recording a last session report (LSR) timestamp when the first RTCP sender report transits through the media router; marking a first timestamp in the media router when the first RTCP receiver report transmits through the media obtaining a delay since LSR (DLSR) representing processing delay in the second call endpoint; and determining the round-trip delay based upon the LSR timestamp, the DLSR, and the first timestamp.