Technical Summary
In most RTP-based multicast applications, the RTP source sends inter-
related data. Due to this interdependency, randomly joining RTP
receivers usually cannot start consuming the multicast data right
after they join the session. Thus, they often experience a random
acquisition delay. An RTP receiver can use one ore more different
approaches to achieve rapid acquisition. Yet, due to various
factors, performance of the rapid acquisition methods usually varies.
Furthermore, in some cases the RTP receiver can do a simple multicast
join (in other cases it is compelled to do so). For quality
reporting, monitoring and diagnostics purposes, it is important to
collect detailed information from the RTP receivers about their
acquisition and presentation experiences. This document addresses
this issue by defining a new report block type, called Multicast
Acquisition (MA) Report Block, within the framework of RTP Control
Protocol (RTCP) Extended Reports (XR) (RFC 3611). This document also
defines the necessary signaling of the new MA report block type in
the Session Description Protocol (SDP).
Working Group Summary
There was nothing contentious about this document.
Document Quality
Are there existing implementations of the protocol? Have a
significant number of vendors indicated their plan to
implement the specification? Are there any reviewers that
merit special mention as having done a thorough review,
e.g., one that resulted in important changes or a
conclusion that the document had no substantive issues? If
there was a MIB Doctor, Media Type, or other Expert Review,
what was its course (briefly)? In the case of a Media Type
Review, on what date was the request posted?
At the moment the shepherd is not aware of any protocol implementations,
and no vendors have directly indicated they plan to implement, although he
assumes that all RAMs implementations will ultimately include this, as it is
essentially a mandatory part of RAMs. The reviewers are listed elsewhere
in the PROTO writeup. There were no external reviews of the types mentioned,
because there is no material requiring such review.
Personnel
Keith Drage is the document shepherd
Gonzalo Camarillo is the responsible area director.