Internet DRAFT - draft-jayaprabhu-xrblock-rtcp-xr-viewership
draft-jayaprabhu-xrblock-rtcp-xr-viewership
INTERNET-DRAFT R.N. Jayaprabhu
Intended Status: Standards Track HCL Technologies
Expires: June 20, 2014 December 17, 2013
Viewership reporting block for
RTP Control Protocol (RTCP) Extended Reports (XRs)
draft-jayaprabhu-xrblock-rtcp-xr-viewership-00
Abstract
This document defines a new report block type within the framework of
RTP Control Protocol (RTCP) Extended Reports (XRs) that allows the
reporting of the usage pattern of a receiver in a RTP session. This
document also defines the signaling of the Viewership report block in
the Session Description Protocol(SDP).
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts. The list of current Internet-Drafts is at
http://datatracker.ietf.org/drafts/current/
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
This Internet-Draft will expire on June 20, 2014.
Copyright and License Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Jayaprabhu Expires June 20, 2014 [Page 1]
INTERNET DRAFT Viewership Report Block Type for RTCP XR December 2013
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Viewership Report Block . . . . . . . . . . . . . . . . . . . 3
3 Session Description Protocol Signaling . . . . . . . . . . . . 5
4 Security Considerations . . . . . . . . . . . . . . . . . . . . 5
5 IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
6 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 6
7 References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1 Normative References . . . . . . . . . . . . . . . . . . . 6
7.2 Informative References . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6
Jayaprabhu Expires June 20, 2014 [Page 2]
INTERNET DRAFT Viewership Report Block Type for RTCP XR December 2013
1 Introduction
The RTP Control Protocol (RTCP) is the out-of-band control protocol
for applications that use the Real-time Transport Protocol (RTP) for
media transport [RFC3550]. In addition to providing minimal control
functionality to RTP entities, RTCP also enables a basic-level
monitoring of RTP sessions via sender and receiver reports. More
statistically detailed monitoring as well as application-specific
monitoring are usually achieved through the RTCP Extended Reports
(XRs) [RFC3611].
As the number of IPTV deployments continue to increase, it becomes
necessary for the operator to collect various information on the
streams that are being delivered to the user. This document defines a
new report block type for the Extended Report (XR) packet type of the
RTP Control Protocol (RTCP) which allows IPTV clients to report to a
server on the usage pattern of the stream that is being delivered to
them. For example the RTP data received by them may be used for
viewing purpose and/or recording purpose.
The new block type defined in this document is the Viewership report
block. The data reported by a client is intended to be useful in
understanding the usage pattern of a particular client over time and
also can collect detailed information on how many users used a
particular stream and for what purpose.
1.1 Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. Viewership Report Block
This section defines the format of the viewership report block. The
packet format for the RTCP XR is defined in Section 2 of [RFC3611].
Each XR packet has a fixed-length field for version, padding,
reserved bits, payload type (PT), length, synchronization source
(SSRC) of packet sender as well as a variable-length field for report
blocks. In the XR packets, the PT field is set to XR (207).
The viewership report block is only sent as a part of an RTCP
compound packet, and it is sent in the primary multicast session.
Following the rules specified in [RFC3550], all integer fields in the
base report and extensions defined below are carried in network-byte
Jayaprabhu Expires June 20, 2014 [Page 3]
INTERNET DRAFT Viewership Report Block Type for RTCP XR December 2013
order, that is, most significant byte (octet) first, also known as
big-endian. Unless otherwise stated, numeric constants are in
decimal (base 10). The report format is shown in Figure 1.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BT=TVM | ver=0 | rsvd | block length = 3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of the Primary Stream |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V| time watched (cumulative) - seconds |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|R| time recorded (cumulative) - seconds |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Format for the Viewership Report Block
o block type (BT): 8 bits
A Viewership Report Block is identified by the constant TVM.
o version(ver=0): 4 bits
The currently defined version is 0
o resd: 4 bits
This field is reserved for future definition. In the absence
of such definition, the bits in this field MUST be set to zero
and MUST be ignored by the receiver.
o block length: 16 bits
The length of this report block, including the header, in 32-
bit words minus one. The block length is equal to 3 for the
viewership report block. The block MUST be discarded if the
block length is set to a different value.
o SSRC of the Primary Stream: 32 bits
The SSRC of the RTP data packet source being reported upon by
this report block.
o time watched (cumulative) - seconds: 31 bits
Jayaprabhu Expires June 20, 2014 [Page 4]
INTERNET DRAFT Viewership Report Block Type for RTCP XR December 2013
This field denotes how much time was spent watching the primary
session. This is a cumulative counter expressed in seconds.
The receiver should keep track of this value using a local
representation as this will wrap beyond (2^31 - 1) seconds
o time recorded (cumulative) - seconds: 31 bits
This field denotes how much time was spent recording the
primary session. This is a cumulative counter expressed in
seconds. The receiver should keep track of this value using a
local representation as this will wrap beyond (2^31 - 1)
seconds
o Viewing flag (V): 1 bit
This field should be set to "1" in case if there were "any"
seconds during RTCP reporting interval, if the primary session
was used for watching i.e. if "time watched" field increased
during this interval and "0" otherwise.
o Recording flag (R): 1 bit
This field should be set to "1" in case if there were "any"
seconds during RTCP reporting interval, if the primary session
was used for recording i.e. if "time recorded" field increased
during this interval and "0" otherwise.
3 Session Description Protocol Signaling
This session augments the SDP attribute "rtcp-xr" defined in Section
5.1 of RFC 3611 by providing an additional value of "xr-format" to
signal the use of the report block defined in this document. The ABNF
[RFC5234] syntax is as follows.
xr-format =/ vqe-viewership
vqe-viewership = "vqe-viewership"
4 Security Considerations
The new RTCP XR blocks in this document do not introduce any new
security considerations beyond those described in [RFC3611].
5 IANA Considerations
Jayaprabhu Expires June 20, 2014 [Page 5]
INTERNET DRAFT Viewership Report Block Type for RTCP XR December 2013
New block types for RTCP XR are subject to IANA registration. For
general guidelines on IANA considerations for RTCP XR, refer to RFC
3611. The contact information for the registrations is:
Jayaprabhu Nadarajan
janadara@cisco.com
49-50, Nelson Manickam Road,
Chennai, Tamil Nadu - 600029, India
6 Acknowledgments
The author would like to thank the members of the VQE Team, Rob
Drisko and Michael Lague for their inputs and suggestions.
7 References
7.1 Normative References
[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V.
Jacobson, "RTP: A Transport Protocol for Real-Time
Applications", STD 64, RFC 3550, July 2003.
[RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control
Protocol Extended Reports (RTCP XR)", RFC 3611,
November 2003.
[RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008.
7.2 Informative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
Authors' Addresses
Jayaprabhu Nadarajan
HCL Technologies,
49-50, Nelson Manickam Road,
Chennai,
Tamil Nadu - 600029,
India
EMail: r.n.jayaprabhu@gmail.com
Jayaprabhu Expires June 20, 2014 [Page 6]
