RTP, RTCP and Jitter Buffer

jitter bufferIn this blog article we continue to analyze RTP and RTCP and we will see why Jitter Buffer is important and how it affects call quality.

As we saw in the previous article — SDP is not able to transfer media–this task is delegated to protocols such as RTP or RTSP.

RTCP (or Real Time Control Protocol) provides different levels of feedback about the ongoing RTP Stream.

The goal of RTCP is to provide information to the remote endpoint about the quality of service of the ongoing communication.

This is done by providing regular statistics about the amount of packets received, jitter, and packets lost (either via network or discarded by the jitter buffer). Continue reading “RTP, RTCP and Jitter Buffer”

Media transfer in Unified Communications – SDP protocol

SDP-protocolMedia is another vital component of a Unified Communication system. Once signaling is in place and working between two endpoints, information about media capabilities can be transferred, eventually allowing for streaming audio, making video calls, or exchanging other information.

In this blog article we will analyze what technologies are used to transfer information about available media between endpoints.

SDP

SDP (Session Description Protocol) is a format for describing streaming media initialization parameters standardized by IETF in 1998.

What follows is the Session Description fields usage and an example:

Continue reading “Media transfer in Unified Communications – SDP protocol”