| draft-ietf-mmusic-duplication-grouping-02.txt | draft-ietf-mmusic-duplication-grouping-03.txt | |||
|---|---|---|---|---|
| MMUSIC A. Begen | MMUSIC A. Begen | |||
| Internet-Draft Cisco | Internet-Draft Cisco | |||
| Intended status: Standards Track Y. Cai | Intended status: Standards Track Y. Cai | |||
| Expires: November 28, 2013 Microsoft | Expires: January 12, 2014 Microsoft | |||
| H. Ou | H. Ou | |||
| Cisco | Cisco | |||
| May 27, 2013 | July 11, 2013 | |||
| Duplication Grouping Semantics in the Session Description Protocol | Duplication Grouping Semantics in the Session Description Protocol | |||
| draft-ietf-mmusic-duplication-grouping-02 | draft-ietf-mmusic-duplication-grouping-03 | |||
| Abstract | Abstract | |||
| Packet loss is undesirable for real-time multimedia sessions, but can | Packet loss is undesirable for real-time multimedia sessions, but can | |||
| occur due to congestion, or other unplanned network outages. This is | occur due to congestion, or other unplanned network outages. This is | |||
| especially true for IP multicast networks, where packet loss patterns | especially true for IP multicast networks, where packet loss patterns | |||
| can vary greatly between receivers. One technique that can be used | can vary greatly between receivers. One technique that can be used | |||
| to recover from packet loss without incurring unbounded delay for all | to recover from packet loss without incurring unbounded delay for all | |||
| the receivers is to duplicate the packets and send them in separate | the receivers is to duplicate the packets and send them in separate | |||
| redundant streams. This document defines the semantics for grouping | redundant streams. This document defines the semantics for grouping | |||
| redundant streams in the Session Description Protocol (SDP). The | redundant streams in the Session Description Protocol (SDP). The | |||
| semantics defined in this document are to be used with the SDP | semantics defined in this document are to be used with the SDP | |||
| Grouping Framework [RFC5888]. SSRC-level (Synchronization Source) | Grouping Framework. SSRC-level (Synchronization Source) grouping | |||
| grouping semantics are also defined in this document for RTP streams | semantics are also defined in this document for RTP streams using | |||
| using SSRC multiplexing. | SSRC multiplexing. | |||
| Status of This Memo | Status of This Memo | |||
| This Internet-Draft is submitted in full conformance with the | This Internet-Draft is submitted in full conformance with the | |||
| provisions of BCP 78 and BCP 79. | provisions of BCP 78 and BCP 79. | |||
| Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
| working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
| Drafts is at http://datatracker.ietf.org/drafts/current/. | Drafts is at http://datatracker.ietf.org/drafts/current/. | |||
| Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
| material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
| This Internet-Draft will expire on November 28, 2013. | This Internet-Draft will expire on January 12, 2014. | |||
| Copyright Notice | Copyright Notice | |||
| Copyright (c) 2013 IETF Trust and the persons identified as the | Copyright (c) 2013 IETF Trust and the persons identified as the | |||
| document authors. All rights reserved. | document authors. All rights reserved. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
| (http://trustee.ietf.org/license-info) in effect on the date of | (http://trustee.ietf.org/license-info) in effect on the date of | |||
| publication of this document. Please review these documents | publication of this document. Please review these documents | |||
| skipping to change at page 3, line 30 | skipping to change at page 3, line 30 | |||
| [RFC2119]. | [RFC2119]. | |||
| 3. Duplication Grouping | 3. Duplication Grouping | |||
| 3.1. "DUP" Grouping Semantics | 3.1. "DUP" Grouping Semantics | |||
| Each "a=group" line is used to indicate an association relationship | Each "a=group" line is used to indicate an association relationship | |||
| between the redundant streams. The streams included in one "a=group" | between the redundant streams. The streams included in one "a=group" | |||
| line are called a Duplication Group. | line are called a Duplication Group. | |||
| Using the framework in [RFC5888], this document defines "DUP" as the | Using the SDP Grouping Framework in [RFC5888], this document defines | |||
| grouping semantics for redundant streams. | "DUP" as the grouping semantics for redundant streams. | |||
| The "a=group:DUP" semantics MUST be used to group the redundant | The "a=group:DUP" semantics MUST be used to group the redundant | |||
| streams except when the streams are specified in the same media | streams except when the streams are specified in the same media | |||
| description, i.e., in the same "m" line (See Section 3.2). In an | description, i.e., in the same "m" line (See Section 3.2). In an | |||
| "a=group:DUP" line, the order of the listed redundant streams does | "a=group:DUP" line, the order of the listed redundant streams does | |||
| not strictly indicate the order of transmission, although it is | not strictly indicate the order of transmission, although it is | |||
| RECOMMENDED that the stream listed first is sent first, with the | RECOMMENDED that the stream listed first is sent first, with the | |||
| other stream(s) being the (time-delayed) duplicate(s). | other stream(s) being the (time-delayed) duplicate(s). | |||
| 3.2. Duplication Grouping for SSRC-Multiplexed RTP Streams | 3.2. Duplication Grouping for SSRC-Multiplexed RTP Streams | |||
| skipping to change at page 5, line 4 | skipping to change at page 5, line 4 | |||
| In this example, the redundant streams use the same IP destination | In this example, the redundant streams use the same IP destination | |||
| address (232.252.0.1) but they are sourced from different addresses | address (232.252.0.1) but they are sourced from different addresses | |||
| (198.51.100.1 and 198.51.100.2). Thus, the receiving host needs to | (198.51.100.1 and 198.51.100.2). Thus, the receiving host needs to | |||
| join both source-specific multicast (SSM) sessions separately. | join both source-specific multicast (SSM) sessions separately. | |||
| v=0 | v=0 | |||
| o=ali 1122334455 1122334466 IN IP4 dup.example.com | o=ali 1122334455 1122334466 IN IP4 dup.example.com | |||
| s=DUP Grouping Semantics | s=DUP Grouping Semantics | |||
| t=0 0 | t=0 0 | |||
| m=video 30000 RTP/AVP 100 | m=video 30000 RTP/AVP 100 | |||
| c=IN IP4 232.252.0.1/127 | c=IN IP4 233.252.0.1/127 | |||
| a=source-filter:incl IN IP4 232.252.0.1 198.51.100.1 198.51.100.2 | a=source-filter:incl IN IP4 233.252.0.1 198.51.100.1 198.51.100.2 | |||
| a=rtpmap:100 MP2T/90000 | a=rtpmap:100 MP2T/90000 | |||
| a=ssrc:1000 cname:ch1@example.com | a=ssrc:1000 cname:ch1@example.com | |||
| a=ssrc:1010 cname:ch1@example.com | a=ssrc:1010 cname:ch1@example.com | |||
| a=ssrc-group:DUP 1000 1010 | a=ssrc-group:DUP 1000 1010 | |||
| a=mid:Ch1 | a=mid:Ch1 | |||
| Note that in actual use, SSRC values, which are random 32-bit | Note that in actual use, SSRC values, which are random 32-bit | |||
| numbers, can be much larger than the ones shown in this example. | numbers, can be much larger than the ones shown in this example. | |||
| Also note that this SDP description does not use the 'duplication- | Also note that this SDP description does not use the 'duplication- | |||
| delay' attribute (defined in [I-D.ietf-mmusic-delayed-duplication]) | delay' attribute (defined in [I-D.ietf-mmusic-delayed-duplication]) | |||
| skipping to change at page 8, line 9 | skipping to change at page 8, line 9 | |||
| Media Attributes in the Session Description Protocol | Media Attributes in the Session Description Protocol | |||
| (SDP)", RFC 5576, June 2009. | (SDP)", RFC 5576, June 2009. | |||
| [RFC5888] Camarillo, G. and H. Schulzrinne, "The Session Description | [RFC5888] Camarillo, G. and H. Schulzrinne, "The Session Description | |||
| Protocol (SDP) Grouping Framework", RFC 5888, June 2010. | Protocol (SDP) Grouping Framework", RFC 5888, June 2010. | |||
| 8.2. Informative References | 8.2. Informative References | |||
| [I-D.ietf-avtext-rtp-duplication] | [I-D.ietf-avtext-rtp-duplication] | |||
| Begen, A. and C. Perkins, "Duplicating RTP Streams", | Begen, A. and C. Perkins, "Duplicating RTP Streams", | |||
| draft-ietf-avtext-rtp-duplication-01 (work in progress), | draft-ietf-avtext-rtp-duplication-02 (work in progress), | |||
| December 2012. | March 2013. | |||
| [I-D.ietf-mmusic-delayed-duplication] | [I-D.ietf-mmusic-delayed-duplication] | |||
| Begen, A., Cai, Y., and H. Ou, "Delayed Duplication | Begen, A., Cai, Y., and H. Ou, "Delayed Duplication | |||
| Attribute in the Session Description Protocol", draft- | Attribute in the Session Description Protocol", draft- | |||
| ietf-mmusic-delayed-duplication-01 (work in progress), | ietf-mmusic-delayed-duplication-02 (work in progress), May | |||
| March 2013. | 2013. | |||
| [IC2011] Evans, J., Begen, A., Greengrass, J., and C. Filsfils, | [IC2011] Evans, J., Begen, A., Greengrass, J., and C. Filsfils, | |||
| "Toward Lossless Video Transport (to appear in IEEE | "Toward Lossless Video Transport (to appear in IEEE | |||
| Internet Computing)", November 2011. | Internet Computing)", November 2011. | |||
| [RFC2354] Perkins, C. and O. Hodson, "Options for Repair of | [RFC2354] Perkins, C. and O. Hodson, "Options for Repair of | |||
| Streaming Media", RFC 2354, June 1998. | Streaming Media", RFC 2354, June 1998. | |||
| [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. | [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. | |||
| End of changes. 9 change blocks. | ||||
| 15 lines changed or deleted | 15 lines changed or added | |||
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