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. 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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]