--- 1/draft-ietf-mmusic-media-loopback-15.txt 2011-09-15 22:16:45.000000000 +0200 +++ 2/draft-ietf-mmusic-media-loopback-16.txt 2011-09-15 22:16:45.000000000 +0200 @@ -1,28 +1,28 @@ Internet Draft K. Hedayat - Expires: September 11, 2011 EXFO + Expires: March 6, 2012 EXFO N. Venna Saperix P. Jones Cisco Systems, Inc. A. Roychowdhury Hughes Systique Corp. C. SivaChelvan Cisco Systems, Inc. N. Stratton BlinkMind, Inc. - March 11, 2011 + September 6, 2011 An Extension to the Session Description Protocol (SDP) for Media Loopback - draft-ietf-mmusic-media-loopback-15 + draft-ietf-mmusic-media-loopback-16 Status of this Memo This Internet-Draft is submitted to IETF 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. @@ -32,24 +32,23 @@ 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/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. - This Internet-Draft will expire on Septembre 11, 2011. + This Internet-Draft will expire on March 6, 2012. Copyright Notice - Copyright (c) 2009 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 @@ -78,68 +77,61 @@ means for measurement of more advanced VoIP, Real-time Text and Video over IP performance metrics. Table of Contents 1. Introduction .................................................. 3 1.1 Use Cases Supported ....................................... 4 2. Terminology ................................................... 6 3. Offering Entity Behavior ...................................... 6 4. Answering Entity Behavior ..................................... 6 - 5. SDP Constructs Syntax ......................................... 7 - 5.1 Loopback Type Attribute ................................... 7 + 5. SDP Constructs Syntax ......................................... 6 + 5.1 Loopback Type Attribute ................................... 6 5.2 Loopback Mode Attribute ................................... 7 - 5.3 Generating the Offer for Loopback Session ................. 8 + 5.3 Generating the Offer for Loopback Session 5.4 Generating the Answer for Loopback Session ................ 9 5.5 Offerer Processing of the Answer ......................... 11 - 5.6 Modifying the Session .................................... 12 - 5.7 Priming the loopback pump ................................ 12 - 6. RTP Requirements ............................................. 13 - 7. Payload formats for Packet loopback .......................... 13 - 7.1 Encapsulated Payload format .............................. 14 - 7.2 Direct loopback RTP payload format ....................... 16 - 8. Payload format for Priming the Loopback Pump ................. 18 - 8.1 Usage of RTP Header fields ............................... 18 - 8.2 Usage of SDP ............................................. 18 - 9. RTCP Requirements ............................................ 18 - 10. Congestion Control .......................................... 19 - 11. Examples .................................................... 19 - 11.1 Offer for specific media loopback type .................. 19 - 11.2 Offer for choice of media loopback type ................. 20 - 11.3 Offer for choice of media loopback type with loopback - primer ....................................................... 21 - 11.4 Response to INVITE request rejecting loopback media ..... 22 - 11.5 Response to INVITE request rejecting loopback media with - loopback primer payload type ................................. 23 - 12. Security Considerations ..................................... 23 - 13. Implementation Considerations ............................... 24 - 14. IANA Considerations ......................................... 24 - 14.1 SDP Attributes .......................................... 24 - 14.2 MIME Types .............................................. 25 - 15. Additional Authors and Acknowledgements ..................... 39 + 5.6 Modifying the Session .................................... 11 + 5.7 Establishing Sessions Between Entities Behind NAT ........ 11 + 6. RTP Requirements ............................................. 11 + 7. Payload formats for Packet loopback .......................... 12 + 7.1 Encapsulated Payload format .............................. 12 + 7.2 Direct loopback RTP payload format ....................... 15 + 8. RTCP Requirements ............................................ 16 + 9. Congestion Control ........................................... 16 + 10. Examples .................................................... 17 + 10.1 Offer for specific media loopback type .................. 17 + 10.2 Offer for choice of media loopback type ................. 17 + 10.3 Response to INVITE request rejecting loopback media ..... 18 + 11. Security Considerations ..................................... 19 + 12. Implementation Considerations ............................... 19 + 13. IANA Considerations ......................................... 20 + 13.1 SDP Attributes .......................................... 20 + 13.2 MIME Types .............................................. 21 + 14. Normative References ........................................ 30 1. Introduction The overall quality, reliability, and performance of VoIP, Real-time Text and Video over IP services rely on the performance and quality of the media path. In order to assure the quality of the delivered media there is a need to monitor the performance of the media transport. One method of monitoring and managing the overall quality of VoIP, Real-time Text and Video over IP Services is through monitoring the quality of the media in an active session. This type of "active monitoring" of services is a method of proactively managing the performance and quality of VoIP based services. The goal of active monitoring is to measure the media quality of a VoIP, Real-time Text or Video over IP session. A way to achieve - this goal is to request an endpoint to loop media back to the other + endpoint and to provide media statistics (e.g., RTCP and RTCP XR information). Another method involves deployment of special endpoints that always loop incoming media back for sessions. Although the latter method has been used and is functional, it does not scale to support large networks and introduces new network management challenges. Further, it does not offer the granularity of testing a specific endpoint that may be exhibiting problems. The extension defined in this memo introduces new SDP media attributes that enable establishment of media sessions where the @@ -308,24 +301,21 @@ The loopback-mode values are loopback-source and loopback-mirror. loopback-source: This attribute specifies that the entity that generated the SDP is the media source and expects the receiver of the SDP message to act as a loopback-mirror. loopback-mirror: This attribute specifies that the entity that generated the SDP will mirror (echo) all received media back to the sender of the RTP stream. No media is generated locally by the - looping back entity for transmission in the mirrored stream unless - the loopback primer payload type (described in Section 8 of this - document) is requested by the loopback-source or included in the - response by loopback-mirror. + looping back entity for transmission in the mirrored stream. is a media format description. The format description has the semantics as defined in section 5.14 of RFC 4566[RFC4566]. When loopback-mode is specified as loopback-source, the media format corresponds to the RTP payload types the entity that generated the SDP is willing to send. When loopback-mode is specified as loopback-mirror, the media format corresponds to the RTP payload types the mirror is willing to receive. The "m=" line in the SDP MUST include all the payload types that will be used during the loopback session including those specified in the loopback-mode @@ -488,59 +478,26 @@ not supported by the target UA. 5.6 Modifying the Session At any point during the loopback session, either participant may issue a new offer to modify the characteristics of the previous session. In case of SIP this is defined in section 8 of RFC 3264 [RFC3264]. This also includes transitioning from a normal media processing mode to loopback mode, and vice a versa. - 5.7 Priming the loopback pump + 5.7 Establishing Sessions Between Entities Behind NAT ICE/STUN/TURN provide a general solution to establishing media sessions between entities that are behind NATs. Loopback sessions that involve one or more end points behind NATs SHOULD use these - general solutions wherever possible. In scenarios where - ICE/STUN/TURN is not available and where the loopback-mirror is - behind a NAT and the loopback-source has a public IP address, the - following solution MAY be adapted. Note that this solution - addresses only a small subset of all possible use cases but - addresses the expected dominant use case for the loopback - application. - - If only the loopback-mirror is behind a NAT, it is possible that - the media transmitted by the loopback-source is blocked by a - network element until the loopback-mirror starts transmitting - packets. One example of this scenario is the presence of an RTP - relay in the path of the media. RTP relays exist in VoIP networks - for purpose of NAT and Firewall traversal. If an RTP relay is - present, the loopback-source's packets are dropped by the RTP relay - until the loopback-mirror has started transmitting media and the - media state within the RTP relay is established. This results in a - chicken and egg scenario as the looback-mirror cannot transmit any - media until it receives the media packets from the loopback-source - but for the loopback-mirror to receive any packets it needs to send - one first. In order to resolve this dilemma, Section 8 introduces a - new media format whose sole purpose is to establish the media state - in the intermediate devices. In the presence of this media format, - the loopback-mirror will transmit media according to the payload - description until it receives media from the loopback-source. The - loopback-mirror MAY include this media format in the answer if it - is not present in the offer. This may be necessary if the - loopback-mirror is aware of NATs, firewalls, or RTP relays on the - path of the call. In this case the loopback-source MUST accept - media corresponding to this media format. After the first media - packet is received from the loopback-source, the loopback-mirror - MUST terminate the transmission of media for this payload type and - MUST start looping back media as defined by the other loopback - attributes present in the offer. + general solutions wherever possible. 6. RTP Requirements A loopback-mirror that is compliant to this specification and accepting a media with rtp-pkt-loopback loopback-type MUST loopback the incoming RTP packets using either the encapsulated RTP payload format or the direct loopback RTP payload format as defined in section 7 of this specification. An answering entity that is compliant to this specification and @@ -739,86 +698,51 @@ type assignment for the stream, so dynamic payload type numbers MUST be used. The binding to the name is indicated by an rtpmap attribute. The name used in this binding is "rtploopback". The following is an example SDP fragment for direct loopback RTP format. m=audio 41352 RTP/AVP 112 a=rtpmap:112 rtploopback/8000 - 8. Payload format for Priming the Loopback Pump - - The sole purpose of the payload format described in this section is - to prime the loopback pump in cases where the loopback process - cannot start because of intermediate devices in the network as - described in Section 5.7. The loopback-mirror MAY send payload data - of any length and any content as it desires and the loopback-source - MUST NOT interpret the payload data. This payload format MUST NOT - be used for any purpose other than priming the loopback pump. - - 8.1 Usage of RTP Header fields - - Payload Type (PT): The assignment of an RTP payload type for this - packet format is outside the scope of this document; it is either - specified by the RTP profile under which this payload format is - used or more likely signaled dynamically out-of-band (e.g., using - SDP; section 8.2 defines the name binding). - - All other fields are set as described in RFC 3550 [RFC3550]. - - 8.2 Usage of SDP - - The payload type number for the loopback primer stream can be - negotiated using a mechanism like SDP. There is no static payload - type assignment for the loopback primer stream, so dynamic payload - type numbers MUST be used. The binding to the name is indicated by - an rtpmap attribute. The name used in this binding is - "loopbkprimer". - - The following is an example SDP fragment for loopback primer RTP - stream. - - m=audio 41352 RTP/AVP 112 - a=rtpmap:112 loopbkprimer/8000 - - 9. RTCP Requirements + 8. RTCP Requirements The use of the loopback attribute is intended for monitoring of media quality of the session. Consequently the media performance information should be exchanged between the offering and the answering entities. An offering or answering entity that is compliant to this specification SHOULD support RTCP per [RFC3550] and RTCP-XR per RFC 3611 [RFC3611]. Furthermore, if the client or the server choose to support RTCP-XR, they SHOULD support RTCP-XR Loss RLE report block, Duplicate RLE report block, Statistics Summary report block, and VoIP Metric Reports Block per sections 4.1, 4.2, 4.6, and 4.7 of RFC 3611 [RFC3611]. The client and the server MAY support other RTCP-XR reporting blocks as defined by RFC 3611 [RFC3611]. - 10. Congestion Control + 9. Congestion Control All the participants in a loopback session SHOULD implement congestion control mechanisms as defined by the RTP profile under which the loopback mechanism is implemented. For audio video profiles, implementations SHOULD conform to the mechanism defined in Section 2 of RFC 3551. - 11. Examples + 10. Examples This section provides examples for media descriptions using SDP for different scenarios. The examples are given for SIP-based transactions and are abbreviated and do not show the complete signaling for convenience. - 11.1 Offer for specific media loopback type + 10.1 Offer for specific media loopback type A client sends an INVITE request with offer SDP which looks like: v=0 o=alice 2890844526 2890842807 IN IP4 host.atlanta.example.com s=Example i=An example session e=alice@example.com c=IN IP4 host.atlanta.example.com t=0 0 @@ -840,22 +764,21 @@ c=IN IP4 host.biloxi.example.com t=0 0 m=audio 49270 RTP/AVP 0 a=loopback:rtp-media-loopback a=loopback-mirror:0 a=rtpmap:0 pcmu/8000 The server is accepting to mirror the media from the client at the media level. - 11.2 Offer for choice of media loopback type - + 10.2 Offer for choice of media loopback type A client sends an INVITE request with offer SDP which looks like: v=0 o=alice 2890844526 2890842807 IN IP4 host.atlanta.example.com s=Example i=An example session e=alice@example.com c=IN IP4 host.atlanta.example.com t=0 0 m=audio 49170 RTP/AVP 0 112 113 @@ -879,67 +802,21 @@ t=0 0 m=audio 49270 RTP/AVP 0 112 a=loopback:rtp-pkt-loopback a=loopback-mirror:0 a=rtpmap:0 pcmu/8000 a=rtpmap:112 encaprtp/8000 The server is accepting to mirror the media from the client at the packet level using the encapsulated RTP payload format. - 11.3 Offer for choice of media loopback type with loopback primer - - A client sends an INVITE request with offer SDP which looks like: - - v=0 - o=alice 2890844526 2890842807 IN IP4 host.atlanta.example.com - s=Example - i=An example session - e=alice@example.com - c=IN IP4 host.atlanta.example.com - t=0 0 - m=audio 49170 RTP/AVP 0 112 113 114 - a=loopback:rtp-media-loopback rtp-pkt-loopback - a=loopback-source:0 - a=rtpmap:0 pcmu/8000 - a=rtpmap:112 encaprtp/8000 - a=rtpmap:113 rtploopback/8000 - a=rtpmap:114 loopbkprimer/8000 - - The client is offering to source the media and expects the server - to mirror the RTP stream at either the media or rtp level. The - client also expects the server to source media until it receives - packets from the server per media described with the loopbkprimer - payload type. - - A server sends a response with SDP which looks like: - - v=0 - o=bob 2890844526 2890842807 IN IP4 host.biloxi.example.com - s=Example - i=An example session - e=user@example.com - c=IN IP4 host.biloxi.example.com - t=0 0 - m=audio 49270 RTP/AVP 0 113 114 - a=loopback:rtp-pkt-loopback - a=loopback-mirror:0 114 - a=rtpmap:0 pcmu/8000 - a=rtpmap:113 rtploopback/8000 - a=rtmap:114 loopbkprimer/8000 - - The server is accepting to mirror the media from the client at the - packet level using the direct loopback RTP payload format. The - server is also accepting to source media until it receives media - packets from the client. - - 11.4 Response to INVITE request rejecting loopback media + 10.3 Response to INVITE request rejecting loopback media A client sends an INVITE request with offer SDP which looks like: v=0 o=alice 2890844526 2890842807 IN IP4 host.atlanta.example.com s=Example i=An example session e=user@example.com c=IN IP4 host.atlanta.example.com t=0 0 @@ -962,91 +839,50 @@ t=0 0 m=audio 0 RTP/AVP 0 a=loopback:rtp-media-loopback a=loopback-mirror:0 a=rtpmap:0 pcmu/8000 NOTE: Loopback request may be rejected by either not including the loopback mode attribute (for backward compatibility) or setting the media port number to zero, or both, in the response. - 11.5 Response to INVITE request rejecting loopback media with - loopback primer payload type - - A client sends an INVITE request with offer SDP which looks like: - - v=0 - o=alice 2890844526 2890842807 IN IP4 host.atlanta.example.com - s=Example - i=An example session - e=alice@example.com - c=IN IP4 host.atlanta.example.com - t=0 0 - m=audio 49170 RTP/AVP 0 100 - a=loopback:rtp-media-loopback - a=loopback-source:0 - a=rtpmap:0 pcmu/8000 - a=rtpmap:100 loopbkprimer/8000 - - The client is offering to source the media and expects the server - to mirror the RTP stream at the media level. The client (offerer) - also expects the server (answerer) to source media until it - receives packets from the server using the loopbkprimer payload - type. - - A server sends a response with answer SDP which looks like: - - v=0 - o=bob 2890844526 2890842807 IN IP4 host.biloxi.example.com - s=Example - i=An example session - e=bob@example.com - c=IN IP4 host.biloxi.example.com - t=0 0 - m=audio 0 RTP/AVP 0 - a=loopback:rtp-media-loopback - a=loopback-mirror:0 - - NOTE: Loopback request may be rejected by either not including the - loopback mode attribute (for backward compatibility) or setting the - media port number to zero, or both, in the response. - - 12. Security Considerations + 11. Security Considerations The security considerations of [RFC3261] and [RFC3264] apply. Furthermore, given that media loopback may be automated without the end user's knowledge, the server of the media loopback should be aware of denial of service attacks. It is recommended that sessions with media loopback are authenticated and the frequency of such sessions is limited by the server. - 13. Implementation Considerations + 12. Implementation Considerations The media loopback approach described in this document is a complete solution that would work under all scenarios. However, it is believed that the solution may not be light-weight enough for the common case. In light of this concern, this section clarifies which features of the loopback proposal MUST be implemented for all implementations and which features MAY be deferred if the complete solution is not desired. All implementations MUST support the rtp-pkt-loopback option for loopback-type attribute. In addition, for the loopback-mode attribute, all implementations of an offerer MUST at a minimum be able to act as a loopback-source. All implementation MUST also at a minimum support the direct media loopback payload type. The rtp- media-loopback attribute MAY be implemented in complete implementations of this draft. - 14. IANA Considerations + 13. IANA Considerations - 14.1 SDP Attributes + 13.1 SDP Attributes This document defines three new media-level SDP attributes. IANA has registered the following attributes: Contact name: Kaynam Hedayat . Attribute name: "loopback". Type of attribute: Media level. Subject to charset: No. Purpose of attribute: The 'loopback' attribute is used to @@ -1068,33 +903,34 @@ as a loopback-mirror. Allowed attribute values: The parameter to 'loopback-source' is a media format ("") description as defined in RFC 4566 Section 5.14. Contact name: Kaynam Hedayat . Attribute name: "loopback-mirror". Type of attribute: Media level. Subject to charset: No. + Purpose of attribute: The 'loopback-mirror' attribute specifies that the receiver will mirror (echo) all received media back to the sender of the RTP stream. Allowed attribute values: The parameter to 'loopback-mirror' is a media format ("") description as defined in RFC 4566 Section 5.14. - 14.2 MIME Types + 13.2 MIME Types The IANA has registered the following MIME types: - 14.2.1 audio/encaprtp + 13.2.1 audio/encaprtp To: ietf-types@iana.org Subject: Registration of media type audio/encaprtp Type name: audio Subtype name: encaprtp Required parameters: @@ -1133,21 +968,21 @@ framing, and hence is only defined for transfer via RTP. Transfer within other framing protocols is not defined at this time. Author: Kaynam Hedayat. Change controller: IETF Audio/Video Transport working group delegated from the IESG. - 14.2.2 video/encaprtp + 13.2.2 video/encaprtp To: ietf-types@iana.org Subject: Registration of media type video/encaprtp Type name: video Subtype name: encaprtp Required parameters: @@ -1186,27 +1021,28 @@ framing, and hence is only defined for transfer via RTP. Transfer within other framing protocols is not defined at this time. Author: Kaynam Hedayat. Change controller: IETF Audio/Video Transport working group delegated from the IESG. - 14.2.3 text/encaprtp + 13.2.3 text/encaprtp To: ietf-types@iana.org Subject: Registration of media type text/encaprtp Type name: text + Subtype name: encaprtp Required parameters: rate:RTP timestamp clock rate, which is equal to the sampling rate. The typical rate is 8000; other rates may be specified. Optional parameters: none @@ -1238,21 +1074,22 @@ framing, and hence is only defined for transfer via RTP. Transfer within other framing protocols is not defined at this time. Author: Kaynam Hedayat. Change controller: IETF Audio/Video Transport working group delegated from the IESG. - 14.2.4 application/encaprtp + 13.2.4 application/encaprtp + To: ietf-types@iana.org Subject: Registration of media type application/encaprtp Type name: application Subtype name: encaprtp Required parameters: @@ -1291,21 +1127,21 @@ framing, and hence is only defined for transfer via RTP. Transfer within other framing protocols is not defined at this time. Author: Kaynam Hedayat. Change controller: IETF Audio/Video Transport working group delegated from the IESG. - 14.2.5 audio/rtploopback + 13.2.5 audio/rtploopback To: ietf-types@iana.org Subject: Registration of media type audio/rtploopback Type name: audio Subtype name: rtploopback Required parameters: @@ -1344,28 +1180,27 @@ framing, and hence is only defined for transfer via RTP. Transfer within other framing protocols is not defined at this time. Author: Kaynam Hedayat. Change controller: IETF Audio/Video Transport working group delegated from the IESG. - 14.2.6 video/rtploopback + 13.2.6 video/rtploopback To: ietf-types@iana.org Subject: Registration of media type video/rtploopback Type name: video - Subtype name: rtploopback Required parameters: rate:RTP timestamp clock rate, which is equal to the sampling rate. The typical rate is 8000; other rates may be specified. Optional parameters: none @@ -1396,24 +1232,23 @@ framing, and hence is only defined for transfer via RTP. Transfer within other framing protocols is not defined at this time. Author: Kaynam Hedayat. Change controller: IETF Audio/Video Transport working group delegated from the IESG. - 14.2.7 text/rtploopback + 13.2.7 text/rtploopback To: ietf-types@iana.org - Subject: Registration of media type text/rtploopback Type name: text Subtype name: rtploopback Required parameters: rate:RTP timestamp clock rate, which is equal to the sampling rate. The typical rate is 8000; other rates @@ -1449,21 +1284,21 @@ framing, and hence is only defined for transfer via RTP. Transfer within other framing protocols is not defined at this time. Author: Kaynam Hedayat. Change controller: IETF Audio/Video Transport working group delegated from the IESG. - 14.2.8 application/rtploopback + 13.2.8 application/rtploopback To: ietf-types@iana.org Subject: Registration of media type application/rtploopback Type name: application Subtype name: rtploopback @@ -1503,242 +1338,21 @@ framing, and hence is only defined for transfer via RTP. Transfer within other framing protocols is not defined at this time. Author: Kaynam Hedayat. Change controller: IETF Audio/Video Transport working group delegated from the IESG. - 14.2.9 audio/loopbkprimer - - To: ietf-types@iana.org - - Subject: Registration of media type audio/loopbkprimer - - Type name: audio - - Subtype name: loopbkprimer - - Required parameters: - - rate:RTP timestamp clock rate, which is equal to the - sampling rate. The typical rate is 8000; other rates - may be specified. - - Optional parameters: none - - Encoding considerations: This media type is framed - binary data. - - Security considerations: See Section 12 of this document. - - Interoperability considerations: none - Published specification: This MIME type is described fully - within this document. - - Applications which use this media type: Applications wishing - to monitor and ensure the quality of transport to the - edge of a given VoIP, Real-Time Text or Video Over IP - Service. - - Additional information: none - - Person & email address to contact for further information: - - Kaynam Hedayat - EMail: kaynam.hedayat@exfo.com - - Intended usage: COMMON - - Restrictions on usage: This media type depends on RTP - framing, and hence is only defined for transfer via - RTP. Transfer within other framing protocols is not - defined at this time. - - Author: - Kaynam Hedayat. - - Change controller: IETF Audio/Video Transport working - group delegated from the IESG. - - 14.2.10 video/loopbkprimer - - To: ietf-types@iana.org - - Subject: Registration of media type video/loopbkprimer - - Type name: video - - Subtype name: loopbkprimer - - Required parameters: - - rate:RTP timestamp clock rate, which is equal to the - sampling rate. The typical rate is 8000; other rates - may be specified. - - Optional parameters: none - - Encoding considerations: This media type is framed - binary data. - - Security considerations: See Section 12 of this document. - - Interoperability considerations: none - - Published specification: This MIME type is described fully - within this document. - - Applications which use this media type: Applications wishing - to monitor and ensure the quality of transport to the - edge of a given VoIP, Real-Time Text or Video Over IP - Service. - - Additional information: none - - Person & email address to contact for further information: - - Kaynam Hedayat - EMail: kaynam.hedayat@exfo.com - - Intended usage: COMMON - - Restrictions on usage: This media type depends on RTP - framing, and hence is only defined for transfer via - RTP. Transfer within other framing protocols is not - defined at this time. - - Author: - Kaynam Hedayat. - - Change controller: IETF Audio/Video Transport working - group delegated from the IESG. - - 14.2.11 text/loopbkprimer - - To: ietf-types@iana.org - - Subject: Registration of media type text/loopbkprimer - - Type name: text - - Subtype name: encaprtp - - Required parameters: - - rate:RTP timestamp clock rate, which is equal to the - sampling rate. The typical rate is 8000; other rates - may be specified. - - Optional parameters: none - - Encoding considerations: This media type is framed - binary data. - - Security considerations: See Section 12 of this document. - - Interoperability considerations: none - - Published specification: This MIME type is described fully - within this document. - - Applications which use this media type: Applications wishing - to monitor and ensure the quality of transport to the - edge of a given VoIP, Real-Time Text or Video Over IP - Service. - - Additional information: none - - Person & email address to contact for further information: - - Kaynam Hedayat - EMail: kaynam.hedayat@exfo.com - - Intended usage: COMMON - - Restrictions on usage: This media type depends on RTP - framing, and hence is only defined for transfer via - RTP. Transfer within other framing protocols is not - defined at this time. - - Author: - Kaynam Hedayat. - - Change controller: IETF Audio/Video Transport working - group delegated from the IESG. - - 14.2.12 application/loopbkprimer - - To: ietf-types@iana.org - - Subject: Registration of media type - application/loopbkprimer - - Type name: application - - Subtype name: loopbkprimer - - Required parameters: - - rate:RTP timestamp clock rate, which is equal to the - sampling rate. The typical rate is 8000; other rates - may be specified. - - Optional parameters: none - - Encoding considerations: This media type is framed - binary data. - - Security considerations: See Section 12 of this document. - - Interoperability considerations: none - - Published specification: This MIME type is described fully - within this document. - - Applications which use this media type: Applications wishing - to monitor and ensure the quality of transport to the - edge of a given VoIP, Real-Time Text or Video Over IP - Service. - - Additional information: none - - Person & email address to contact for further information: - - Kaynam Hedayat - EMail: kaynam.hedayat@exfo.com - - Intended usage: COMMON - - Restrictions on usage: This media type depends on RTP - framing, and hence is only defined for transfer via - RTP. Transfer within other framing protocols is not - defined at this time. - - Author: - Kaynam Hedayat. - - Change controller: IETF Audio/Video Transport working - group delegated from the IESG. - - 15. Additional Authors and Acknowledgements - - The following people have contributed to the task of authoring this - document: Chelliah Sivachelvan (Cisco). - - The authors acknowledge the contributions and comments of , Muthu - ArulMozhi Perumal, Flemming Andreasen, Jeff Bernstein, Paul - Kyzivat, and Dave Oran. - - 16. Normative References + 14. Normative References [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, June 2002. [RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model with the Session Description Protocol (SDP)", RFC 3264, June 2002.