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diff --git a/doc/rfc/rfc6332.txt b/doc/rfc/rfc6332.txt new file mode 100644 index 0000000..7c3c9fc --- /dev/null +++ b/doc/rfc/rfc6332.txt @@ -0,0 +1,899 @@ + + + + + + +Internet Engineering Task Force (IETF) A. Begen +Request for Comments: 6332 E. Friedrich +Category: Standards Track Cisco +ISSN: 2070-1721 July 2011 + + + Multicast Acquisition Report Block Type for + RTP Control Protocol (RTCP) Extended Reports (XRs) + +Abstract + + 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 or 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 diagnostic 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 the + Multicast Acquisition (MA) report block, within the framework of RTP + Control Protocol (RTCP) Extended Reports (XRs) (RFC 3611). This + document also defines the necessary signaling of the new MA report + block type in the Session Description Protocol (SDP). + +Status of This Memo + + This is an Internet Standards Track document. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Further information on + Internet Standards is available in Section 2 of RFC 5741. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc6332. + + + + + + + + + +Begen & Friedrich Standards Track [Page 1] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + +Copyright Notice + + Copyright (c) 2011 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 + 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 + 2. Requirements Notation . . . . . . . . . . . . . . . . . . . . 4 + 3. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 4 + 4. Multicast Acquisition (MA) Report Block . . . . . . . . . . . 4 + 4.1. Base Report . . . . . . . . . . . . . . . . . . . . . . . 5 + 4.1.1. Status Code Rules for New MA Methods . . . . . . . . . 6 + 4.1.2. Status Code Rules for the RAMS Method . . . . . . . . 6 + 4.2. Extensions . . . . . . . . . . . . . . . . . . . . . . . . 6 + 4.2.1. Vendor-Neutral Extensions . . . . . . . . . . . . . . 7 + 4.2.2. Private Extensions . . . . . . . . . . . . . . . . . . 10 + 5. Session Description Protocol Signaling . . . . . . . . . . . . 10 + 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11 + 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 + 7.1. RTCP XR Block Type . . . . . . . . . . . . . . . . . . . . 11 + 7.2. RTCP XR SDP Parameter . . . . . . . . . . . . . . . . . . 12 + 7.3. Multicast Acquisition Method Registry . . . . . . . . . . 12 + 7.4. Multicast Acquisition Report Block TLV Space Registry . . 12 + 7.5. Multicast Acquisition Status Code Space Registry . . . . . 13 + 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14 + 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 + 9.1. Normative References . . . . . . . . . . . . . . . . . . . 15 + 9.2. Informative References . . . . . . . . . . . . . . . . . . 15 + + + + + + + + + + + + +Begen & Friedrich Standards Track [Page 2] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + +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]. + + In most RTP-based multicast applications such as the ones carrying + video content, the RTP source sends inter-related data. + Consequently, the RTP application may not be able to decode and + present the data in an RTP packet before decoding the data in one or + more earlier RTP packets and/or before acquiring some Reference + Information about the content itself. Thus, RTP receivers that are + randomly joining a multicast session often experience a random + acquisition delay. In order to reduce this delay, [RFC6285] proposes + an approach where an auxiliary unicast RTP session is established + between a retransmission server and the joining RTP receiver. Over + this unicast RTP session, the retransmission server provides the + Reference Information, which is all the information the RTP receiver + needs to rapidly acquire the multicast stream. This method is + referred to as the Rapid Acquisition of Multicast RTP Sessions + (RAMS). However, depending on the variability in the Source + Filtering Group Management Protocol (SFGMP) processing times, the + availability of network resources for rapid acquisition, and the + nature of the RTP data, not all RTP receivers can acquire the + multicast stream in the same amount of time. The performance of + rapid acquisition may vary not only for different RTP receivers but + also over time. + + To increase the visibility of the multicast service provider in its + network, to diagnose slow multicast acquisition issues, and to + collect the acquisition experiences of the RTP receivers, this + document defines a new report block type, which is called the + Multicast Acquisition (MA) report block, within the framework of RTCP + XR. RTP receivers that use the method described in [RFC6285] may use + this report every time they join a new multicast RTP session. RTP + receivers that use a different method for rapid acquisition or those + that do not use any method but rather do a simple multicast join may + also use this report. This way, the multicast service provider can + quantitatively compare the improvements achieved by different + methods. + + + + + + +Begen & Friedrich Standards Track [Page 3] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + +2. Requirements Notation + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and + "OPTIONAL" in this document are to be interpreted as described in + [RFC2119]. + +3. Definitions + + This document uses the acronyms and definitions from Section 3 of + [RFC6285]. + +4. Multicast Acquisition (MA) Report Block + + This section defines the format of the MA report block. The base + report is payload independent. An extension mechanism is provided + where further optional payload-independent and payload-specific + information can be included in the report as desired. + + The OPTIONAL extensions that are defined in this document are + primarily developed for the method presented in [RFC6285]. Other + methods that provide rapid acquisition can define their own + extensions to be used in the MA 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). + + It is better to send the MA report block after all the necessary + information is collected and computed. Partial reporting is + generally not useful as it cannot give the full picture of the + multicast acquisition, and it causes additional complexity in terms + of report block matching and correlation. The MA report block is + only sent as a part of an RTCP compound packet, and it is sent in the + primary multicast session. + + The need for reliability of the MA report block is not any greater + than other report blocks or types. If desired, the report block + could be repeated for redundancy purposes while respecting the RTCP + scheduling algorithms. + + Following the rules specified in [RFC3550], all integer fields in the + base report and extensions defined below are carried in network-byte + order, that is, most significant byte (octet) first, also known as + big-endian. Unless otherwise stated, numeric constants are in + decimal (base 10). + + + +Begen & Friedrich Standards Track [Page 4] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + +4.1. Base Report + + The base 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=11 | MA Method | Block Length | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SSRC of the Primary Multicast Stream | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Status | Rsvd. | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Figure 1: Base Report Format for the MA Report Block + + o BT (8 bits): Field that denotes the type for this block format. + The MA report block is identified by the constant 11. + + o MA Method (8 bits): Field that denotes the type of the MA method + (e.g., simple join, RAMS, etc.). See Section 7.3 for the values + registered with IANA. + + o Block Length (16 bits): The length of this report block, including + the header, in 32-bit words minus one. + + o SSRC of the Primary Multicast Stream (32 bits): Field that denotes + the SSRC of the primary multicast stream. + + o Status (16 bits): Field that denotes the status code for the MA + operation. + + This document defines several status codes and registers them with + IANA in Section 7.5. If a new vendor-neutral status code will be + defined, it MUST be registered with IANA according to the + guidelines specified in Section 7.5. If the new status code is + intended to be used privately by a vendor, there is no need for + IANA management. Section 4.2.2 defines how a vendor defines and + uses private extensions to convey its messages. + + To indicate use of a private extension, the RTP receiver MUST set + the Status field to zero. A private extension MUST NOT be used in + an XR unless the RTP receiver knows from out-of-band methods that + the entity that will receive and process the XR understands the + private extension. + + o Rsvd. (16 bits): The RTP receiver MUST set this field to zero. + The recipient MUST ignore this field when received. + + + +Begen & Friedrich Standards Track [Page 5] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + + If the multicast join was successful, meaning that at least one + multicast packet was received, some additional information MUST be + appended to the base report as described in Section 4.2.1. + +4.1.1. Status Code Rules for New MA Methods + + Different MA methods usually use different status codes, although + some status codes (e.g., a code indicating that multicast join has + failed) can be common among multiple MA methods. The status code + reported in the base report MUST always be within the scope of the + particular MA method specified in the MA Method field. + + In certain MA methods, the RTP receiver can generate a status code + for its multicast acquisition attempt or can be told by another + network element or RTP endpoint what the current status is via a + response code. In such cases, the RTP receiver MAY report the value + of the received response code as its status code if the response code + has a higher priority. Each MA method needs to outline the rules + pertaining to its response and status codes so that RTP receiver + implementations can determine what to report in any given scenario. + +4.1.2. Status Code Rules for the RAMS Method + + In this section, we provide the status code rules for the RAMS method + described in [RFC6285]. + + Section 11.6 of [RFC6285] defines several response codes. The 1xx- + and 2xx-level response codes are informational and success response + codes, respectively. If the RTP receiver receives a 1xx- or 2xx- + level response code, then the RTP receiver MUST use one of the 1xxx- + level status codes defined in Section 7.5 of this document. If the + RTP receiver receives a 4xx- or 5xx-level response code (indicating + receiver-side and server-side errors, respectively), then the RTP + receiver MUST use the response code as its status code. In other + words, the 4xx- and 5xx-level response codes have a higher priority + than the 1xxx-level status codes. + +4.2. Extensions + + To improve the reporting scope, it might be desirable to define new + fields in the MA report block. Such fields are to be encoded as TLV + elements as described below and sketched in Figure 2: + + o Type: A single-octet identifier that defines the type of the + parameter represented in this TLV element. + + + + + + +Begen & Friedrich Standards Track [Page 6] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + + o Length: A two-octet field that indicates the length (in octets) of + the TLV element excluding the Type and Length fields and the 8-bit + Reserved field between them. Note that this length does not + include any padding that is needed for alignment. + + o Value: Variable-size set of octets that contains the specific + value for the parameter. + + In the extensions, the Reserved field MUST be set to zero and ignored + on reception. If a TLV element does not fall on a 32-bit boundary, + the last word MUST be padded to the boundary using further bits set + to zero. + + In the MA report block, the RTP receiver MUST place any vendor- + neutral or private extension after the base report. + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Type | Reserved | Length | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + : Value : + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Figure 2: Structure of a TLV Element + +4.2.1. Vendor-Neutral Extensions + + If the goal in defining new TLV elements is to extend the report + block in a vendor-neutral manner, they need to be registered with + IANA according to the guidelines provided in Section 7.4. + + This document defines several vendor-neutral extensions. First, we + present the TLV elements that can be used by any RTP-based multicast + application. + + o RTP Seqnum of the First Multicast Packet (16 bits): TLV element + that specifies the RTP sequence number of the first multicast + packet received for the primary multicast stream. If the + multicast join was successful, this element MUST be included. If + no multicast packet has been received, this element MUST NOT exist + in the report block. + + Type: 1 + + o SFGMP Join Time (32 bits): TLV element that denotes the greater of + zero or the time difference (in ms) between the instant the SFGMP + Join message was sent and the instant the first packet was + + + +Begen & Friedrich Standards Track [Page 7] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + + received in the multicast session. If the multicast join was + successful, this element MUST be included. If no multicast packet + has been received, this element MUST NOT exist in the report + block. + + Type: 2 + + o Application Request-to-Multicast Delta Time (32 bits): OPTIONAL + TLV element that denotes the time difference (in ms) between the + instant the application became aware it would join a new multicast + session and the instant the first RTP packet was received from the + primary multicast stream. If no such packet has been received, + this element MUST NOT exist in the report block. + + Type: 3 + + o Application Request-to-Presentation Delta Time (32 bits): OPTIONAL + TLV element that denotes the time difference (in ms) between the + instant the application became aware it would join a new multicast + session and the instant the media was first presented. If the RTP + receiver cannot successfully present the media, this element MUST + NOT exist in the report block. + + Type: 4 + + We next present the TLV elements that can be used when the RTP + receiver supports and uses the RAMS method described in [RFC6285]. + However, if the RTP receiver does not send a rapid acquisition + request, the following TLV elements MUST NOT exist in the MA report + block. Some elements may or may not exist depending on whether or + not the RTP receiver receives any packet from the unicast burst + and/or the primary multicast stream. These are explained below. + + o Application Request-to-RAMS Request Delta Time (32 bits): OPTIONAL + TLV element that denotes the time difference (in ms) between the + instant the application became aware it would request a rapid + acquisition and the instant the rapid acquisition request was + actually sent by the application. + + Type: 11 + + o RAMS Request-to-RAMS Information Delta Time (32 bits): OPTIONAL + TLV element that denotes the time difference (in ms) between the + instant the rapid acquisition request was sent and the instant the + + + + + + + +Begen & Friedrich Standards Track [Page 8] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + + first RAMS Information message was received in the unicast + session. If no such message has been received, this element MUST + NOT exist in the report block. + + Type: 12 + + o RAMS Request-to-Burst Delta Time (32 bits): OPTIONAL TLV element + that denotes the time difference (in ms) between the instant the + rapid acquisition request was sent and the instant the first burst + packet was received in the unicast session. If no burst packet + has been received, this element MUST NOT exist in the report + block. + + Type: 13 + + o RAMS Request-to-Multicast Delta Time (32 bits): OPTIONAL TLV + element that denotes the time difference (in ms) between the + instant the rapid acquisition request was sent and the instant the + first RTP packet was received from the primary multicast stream. + If no such packet has been received, this element MUST NOT exist + in the report block. + + Type: 14 + + o RAMS Request-to-Burst-Completion Delta Time (32 bits): OPTIONAL + TLV element that denotes the time difference (in ms) between the + instant the rapid acquisition request was sent and the instant the + last burst packet was received in the unicast session. If no + burst packet has been received, this element MUST NOT exist in the + report block. + + Type: 15 + + o Number of Duplicate Packets (32 bits): OPTIONAL TLV element that + denotes the number of duplicate packets due to receiving the same + packet in both unicast and primary multicast RTP sessions. If no + RTP packet has been received from the primary multicast stream, + this element MUST NOT exist. If no burst packet has been received + in the unicast session, the value of this element MUST be set to + zero. + + Type: 16 + + o Size of Burst-to-Multicast Gap (32 bits): OPTIONAL TLV element + that denotes the greater of zero or the difference between the + sequence number of the first multicast packet (received from the + primary multicast stream) and the sequence number of the last + burst packet minus 1 (considering the wrapping of the sequence + + + +Begen & Friedrich Standards Track [Page 9] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + + numbers). If no burst packet has been received in the unicast + session or no RTP packet has been received from the primary + multicast stream, this element MUST NOT exist in the report block. + + Type: 17 + +4.2.2. Private Extensions + + It is desirable to allow vendors to use private extensions in TLV + format. The range of [128-254] of TLV Types is reserved for private + extensions. IANA management for these extensions is unnecessary; + they are the responsibility of individual vendors. + + Implementations use the structure depicted in Figure 3 for private + extensions. Here, the private enterprise numbers are used from + http://www.iana.org. This will ensure the uniqueness of the private + extensions and avoid any collision. + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Type | Reserved | Length | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Enterprise Number | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + : Value : + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Figure 3: Structure of a Private Extension + +5. Session Description Protocol Signaling + + A new unilateral parameter is defined for the MA report block to be + used with the Session Description Protocol (SDP) [RFC4566]. In the + following ABNF [RFC5234], xr-format is used as defined in [RFC3611]. + + xr-format =/ multicast-acq-ext + multicast-acq-ext = "multicast-acq" + + Refer to Section 5.1 of [RFC3611] for a detailed description and the + full syntax of the 'rtcp-xr' attribute. + + + + + + + + + + +Begen & Friedrich Standards Track [Page 10] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + +6. Security Considerations + + The security considerations of [RFC3611] apply in this document as + well. + + The information contained in MA reports could be stolen as with any + other RTCP reports if proper protection mechanism(s) are not in + place. If desired, similar to other RTCP XRs, the MA reports MAY be + protected by using Secure RTP (SRTP) and Secure RTP Control Protocol + (SRTCP) [RFC3711]. + + Malicious sniffing or otherwise obtaining MA report blocks can reveal + performance characteristics of the RTP service and underlying + network. This information is mostly available to an observer with + the ability to capture RTP and RTCP session traffic. The contents + and value of any private extension need to be studied when + considering the necessity to secure the MA reports since application- + level performance data might be present that is not otherwise + available to an attacker, as with the required fields and vendor- + neutral extensions. + + Using the MA reports to provide feedback into the acquisition of the + multicast streams can introduce possible additional security + implications. If a forged or otherwise modified MA report is + received for an earlier acquisition attempt, invalid data can be used + as input in later rapid acquisition attempts. For example, + incorrectly small SFGMP join times could cause the unicast burst to + be too short, leading to gaps in sequence numbers in the approach + discussed in [RFC6285]. Additionally, forged reports could give the + appearance that rapid acquisition is performing correctly when it is + in fact failing, or vice versa. While integrity protection can be + achieved in different ways, we RECOMMEND the use of SRTCP [RFC3711]. + +7. IANA Considerations + + The following contact information is provided for all registrations + in this document: + + Ali Begen + abegen@cisco.com + +7.1. RTCP XR Block Type + + Type value 11 has been registered with IANA for the "Multicast + Acquisition Report Block" in the RTCP XR Block Type Registry. + + + + + + +Begen & Friedrich Standards Track [Page 11] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + +7.2. RTCP XR SDP Parameter + + The SDP [RFC4566] parameter 'multicast-acq' for the 'rtcp-xr' + attribute has been registered in the RTCP XR SDP Parameters Registry. + +7.3. Multicast Acquisition Method Registry + + A new IANA registry for the MA methods has been created. The + registry is called the "Multicast Acquisition Method Registry". This + registry is to be managed by IANA according to the Specification + Required policy of [RFC5226]. + + The length of the MA Method field is a single octet, allowing 256 + values. The registry is initialized with the following entries: + + MA Method Description Reference + --------- ------------------------------------ ------------- + 0 Reserved [RFC6332] + 1 Simple join (No explicit method) [RFC6332] + 2 RAMS [RFC6285] + 3-254 Unassigned Specification Required + 255 Reserved [RFC6332] + + The MA Method values 0 and 255 are reserved for future use. + + Any registration for an unassigned value needs to contain the + following information: + + o Contact information of the one doing the registration, including + at least name, address, and email. + + o A detailed description of how the MA method works. + +7.4. Multicast Acquisition Report Block TLV Space Registry + + A new IANA TLV space registry for the MA report block extensions has + been created. The registry is called the "Multicast Acquisition + Report Block TLV Space Registry". This registry is to be managed by + the IANA according to the Specification Required policy of [RFC5226]. + + The length of the Type field in the TLV elements is a single octet, + allowing 256 values. The registry is initialized with the following + entries: + + + + + + + + +Begen & Friedrich Standards Track [Page 12] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + + Type Description Reference + ------- -------------------------------------------------- --------- + 0 Reserved [RFC6332] + 1 RTP Seqnum of the First Multicast Packet [RFC6332] + 2 SFGMP Join Time [RFC6332] + 3 Application Request-to-Multicast Delta Time [RFC6332] + 4 Application Request-to-Presentation Delta Time [RFC6332] + 5-10 Unassigned Specification Required + 11 Application Request-to-RAMS Request Delta Time [RFC6332] + 12 RAMS Request-to-RAMS Information Delta Time [RFC6332] + 13 RAMS Request-to-Burst Delta Time [RFC6332] + 14 RAMS Request-to-Multicast Delta Time [RFC6332] + 15 RAMS Request-to-Burst-Completion Delta Time [RFC6332] + 16 Number of Duplicate Packets [RFC6332] + 17 Size of Burst-to-Multicast Gap [RFC6332] + 18-127 Unassigned Specification Required + 128-254 Reserved for private extensions [RFC6332] + 255 Reserved [RFC6332] + + The Type values 0 and 255 are reserved for future use. The Type + values between (and including) 128 and 254 are reserved for private + extensions. + + Any registration for an unassigned Type value needs to contain the + following information: + + o Contact information of the one doing the registration, including + at least name, address, and email. + + o A detailed description of what the new TLV element represents and + how it is interpreted. + +7.5. Multicast Acquisition Status Code Space Registry + + A new IANA TLV space registry for the status codes has been created. + The registry is called the "Multicast Acquisition Status Code Space + Registry". This registry is to be managed by the IANA according to + the Specification Required policy of [RFC5226]. + + The length of the Status field is two octets, allowing 65536 codes. + However, the status codes have been registered to allow for an easier + classification. For example, the values between (and including) 1 + and 1000 are primarily used by the MA method of simple join. The + values between (and including) 1001 and 2000 are used by the MA + method described in [RFC6285]. When registering new status codes for + the existing MA methods or newly defined MA methods, registrants are + + + + + +Begen & Friedrich Standards Track [Page 13] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + + encouraged to allocate sufficient continuous space. Note that + because of the limited space, not every MA method can be assigned + 1000 different values for its status codes. + + The status code 65535 is reserved for future use. The registry is + initialized with the following entries: + + Code Description Reference + --------- ------------------------------------------------ --------- + 0 A private status code is included in the message [RFC6332] + 1 Multicast join was successful [RFC6332] + 2 Multicast join has failed [RFC6332] + 3 A presentation error has occurred [RFC6332] + 4 An unspecified RTP receiver internal error has + occurred [RFC6332] + 5-1000 Unassigned + 1001 RAMS has been successfully completed [RFC6332] + 1002 No RAMS-R message has been sent [RFC6332] + 1003 Invalid RAMS-I message syntax [RFC6332] + 1004 RAMS-I message has timed out [RFC6332] + 1005 RAMS unicast burst has timed out [RFC6332] + 1006 An unspecified RTP receiver internal error has + occurred during RAMS [RFC6332] + 1007 A presentation error has occurred during RAMS [RFC6332] + 1008-65534 Unassigned + 65535 Reserved [RFC6332] + + Any registration for an unassigned status code needs to contain the + following information: + + o Contact information of the one doing the registration, including + at least name, address, and email. + + o A detailed description of what the new status code describes and + how it is interpreted. + +8. Acknowledgments + + This specification has greatly benefited from discussions with + Michael Lague, Dong Hsu, Carol Iturralde, Xuan Zhong, Dave Oran, Tom + Van Caenegem, and many others. The authors would like to thank each + of these individuals for their contributions. + + + + + + + + + +Begen & Friedrich Standards Track [Page 14] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + +9. References + +9.1. Normative References + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [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. + + [RFC3711] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. + Norrman, "The Secure Real-time Transport Protocol (SRTP)", + RFC 3711, March 2004. + + [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session + Description Protocol", RFC 4566, July 2006. + + [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax + Specifications: ABNF", STD 68, RFC 5234, January 2008. + + [RFC6285] Ver Steeg, B., Begen, A., Van Caenegem, T., and Z. Vax, + "Unicast-Based Rapid Acquisition of Multicast RTP + Sessions", RFC 6285, June 2011. + +9.2. Informative References + + [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an + IANA Considerations Section in RFCs", BCP 26, RFC 5226, + May 2008. + + + + + + + + + + + + + + + + + +Begen & Friedrich Standards Track [Page 15] + +RFC 6332 MA Report Block Type for RTCP XR July 2011 + + +Authors' Addresses + + Ali Begen + Cisco + 181 Bay Street + Toronto, ON M5J 2T3 + Canada + + EMail: abegen@cisco.com + + + Eric Friedrich + Cisco + 1414 Massachusetts Ave. + Boxborough, MA 01719 + USA + + EMail: efriedri@cisco.com + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Begen & Friedrich Standards Track [Page 16] + |