| rfc8859v4.txt | rfc8859.txt | |||
|---|---|---|---|---|
| Internet Engineering Task Force (IETF) S. Nandakumar | Internet Engineering Task Force (IETF) S. Nandakumar | |||
| Request for Comments: 8859 Cisco | Request for Comments: 8859 Cisco | |||
| Category: Standards Track May 2020 | Category: Standards Track August 2020 | |||
| ISSN: 2070-1721 | ISSN: 2070-1721 | |||
| A Framework for Session Description Protocol (SDP) Attributes When | A Framework for Session Description Protocol (SDP) Attributes When | |||
| Multiplexing | Multiplexing | |||
| Abstract | Abstract | |||
| The purpose of this specification is to provide a framework for | The purpose of this specification is to provide a framework for | |||
| analyzing the multiplexing characteristics of Session Description | analyzing the multiplexing characteristics of Session Description | |||
| Protocol (SDP) attributes when SDP is used to negotiate the usage of | Protocol (SDP) attributes when SDP is used to negotiate the usage of | |||
| skipping to change at line 118 ¶ | skipping to change at line 118 ¶ | |||
| 5.42. RFC 7195: SDP Extension for Circuit-Switched Bearers in | 5.42. RFC 7195: SDP Extension for Circuit-Switched Bearers in | |||
| PSTN | PSTN | |||
| 5.43. RFC 7272: IDMS Using the RTP Control Protocol (RTCP) | 5.43. RFC 7272: IDMS Using the RTP Control Protocol (RTCP) | |||
| 5.44. RFC 5159: Open Mobile Alliance (OMA) Broadcast (BCAST) SDP | 5.44. RFC 5159: Open Mobile Alliance (OMA) Broadcast (BCAST) SDP | |||
| Attributes | Attributes | |||
| 5.45. RFC 6193: Media Description for IKE in SDP | 5.45. RFC 6193: Media Description for IKE in SDP | |||
| 5.46. RFC 2326: Real Time Streaming Protocol | 5.46. RFC 2326: Real Time Streaming Protocol | |||
| 5.47. RFC 6064: SDP and RTSP Extensions for 3GPP | 5.47. RFC 6064: SDP and RTSP Extensions for 3GPP | |||
| 5.48. RFC 3108: ATM SDP | 5.48. RFC 3108: ATM SDP | |||
| 5.49. 3GPP TS 183.063 | 5.49. 3GPP TS 183.063 | |||
| 5.50. 3GPP TS 24.182 | 5.50. 3GPP TS 24.229 | |||
| 5.51. 3GPP TS 24.183 | 5.51. ITU T.38 | |||
| 5.52. 3GPP TS 24.229 | 5.52. ITU-T Q.1970 | |||
| 5.53. ITU T.38 | 5.53. ITU-T H.248.15 | |||
| 5.54. ITU-T Q.1970 | 5.54. RFC 4975: The Message Session Relay Protocol | |||
| 5.55. ITU-T H.248.15 | 5.55. Historical Attributes | |||
| 5.56. RFC 4975: The Message Session Relay Protocol | ||||
| 5.57. Historical Attributes | ||||
| 6. bwtype Attribute Analysis | 6. bwtype Attribute Analysis | |||
| 6.1. RFC 4566: SDP | 6.1. RFC 4566: SDP | |||
| 6.2. RFC 3556: SDP Bandwidth Modifiers for RTCP Bandwidth | 6.2. RFC 3556: SDP Bandwidth Modifiers for RTCP Bandwidth | |||
| 6.3. RFC 3890: Bandwidth Modifier for SDP | 6.3. RFC 3890: Bandwidth Modifier for SDP | |||
| 7. rtcp-fb Attribute Analysis | 7. rtcp-fb Attribute Analysis | |||
| 7.1. RFC 4585: RTP/AVPF | 7.1. RFC 4585: RTP/AVPF | |||
| 7.2. RFC 5104: Codec Control Messages in AVPF | 7.2. RFC 5104: Codec Control Messages in AVPF | |||
| 7.3. RFC 6285: Unicast-Based Rapid Acquisition of Multicast RTP | 7.3. RFC 6285: Unicast-Based Rapid Acquisition of Multicast RTP | |||
| Sessions (RAMS) | Sessions (RAMS) | |||
| 7.4. RFC 6679: ECN for RTP over UDP/IP | 7.4. RFC 6679: ECN for RTP over UDP/IP | |||
| skipping to change at line 155 ¶ | skipping to change at line 153 ¶ | |||
| 8.6. RFC 7104: Duplication Grouping Semantics in the SDP | 8.6. RFC 7104: Duplication Grouping Semantics in the SDP | |||
| 9. ssrc-group Attribute Analysis | 9. ssrc-group Attribute Analysis | |||
| 9.1. RFC 5576: Source-Specific SDP Attributes | 9.1. RFC 5576: Source-Specific SDP Attributes | |||
| 9.2. RFC 7104: Duplication Grouping Semantics in the SDP | 9.2. RFC 7104: Duplication Grouping Semantics in the SDP | |||
| 10. QoS Mechanism Token Analysis | 10. QoS Mechanism Token Analysis | |||
| 10.1. RFC 5432: QoS Mechanism Selection in SDP | 10.1. RFC 5432: QoS Mechanism Selection in SDP | |||
| 11. k= Attribute Analysis | 11. k= Attribute Analysis | |||
| 11.1. RFC 4566: SDP | 11.1. RFC 4566: SDP | |||
| 12. content Attribute Analysis | 12. content Attribute Analysis | |||
| 12.1. RFC 4796 | 12.1. RFC 4796 | |||
| 12.2. 3GPP TS 24.182 | ||||
| 12.3. 3GPP TS 24.183 | ||||
| 13. Payload Formats | 13. Payload Formats | |||
| 13.1. RFC 5109: RTP Payload Format for Generic FEC | 13.1. RFC 5109: RTP Payload Format for Generic FEC | |||
| 14. Multiplexing Considerations for Encapsulating Attributes | 14. Multiplexing Considerations for Encapsulating Attributes | |||
| 14.1. RFC 3407: cpar Attribute Analysis | 14.1. RFC 3407: cpar Attribute Analysis | |||
| 14.2. RFC 5939 Analysis | 14.2. RFC 5939 Analysis | |||
| 14.2.1. Recommendation: Procedures for Potential Configuration | 14.2.1. Recommendation: Procedures for Potential Configuration | |||
| Pairing | Pairing | |||
| 14.3. RFC 6871 Analysis | 14.3. RFC 6871 Analysis | |||
| 14.3.1. Recommendation: Dealing with Payload Type Numbers | 14.3.1. Recommendation: Dealing with Payload Type Numbers | |||
| 14.3.2. Recommendation: Dealing with Latent Configurations | 14.3.2. Recommendation: Dealing with Latent Configurations | |||
| 15. IANA Considerations | 15. IANA Considerations | |||
| 15.1. New "Multiplexing Categories" Subregistry | 15.1. New "Multiplexing Categories" Subregistry | |||
| 15.2. "Mux Category" Column for Subregistries | 15.2. "Mux Category" Column for Subregistries | |||
| 15.2.1. Table: SDP bwtype | 15.2.1. Table: SDP bwtype | |||
| 15.2.2. Table: att-field | 15.2.2. Table: attribute-name | |||
| 15.2.3. Table: content SDP Parameters | 15.2.3. Table: content SDP Parameters | |||
| 15.2.4. Table: Semantics for the "group" SDP Attribute | 15.2.4. Table: Semantics for the "group" SDP Attribute | |||
| 15.2.5. Table: "rtcp-fb" Attribute Values | 15.2.5. Table: "rtcp-fb" Attribute Values | |||
| 15.2.6. Table: "ack" and "nack" Attribute Values | 15.2.6. Table: "ack" and "nack" Attribute Values | |||
| 15.2.7. Table: "depend" SDP Attribute Values | 15.2.7. Table: "depend" SDP Attribute Values | |||
| 15.2.8. Table: "cs-correlation" Attribute Values | 15.2.8. Table: "cs-correlation" Attribute Values | |||
| 15.2.9. Table: Semantics for the "ssrc-group" SDP Attribute | 15.2.9. Table: Semantics for the "ssrc-group" SDP Attribute | |||
| 15.2.10. Table: SDP/RTSP Key Management Protocol Identifiers | 15.2.10. Table: SDP/RTSP Key Management Protocol Identifiers | |||
| 15.2.11. Table: Codec Control Messages | 15.2.11. Table: Codec Control Messages | |||
| 15.2.12. Table: QoS Mechanism Tokens | 15.2.12. Table: QoS Mechanism Tokens | |||
| skipping to change at line 1983 ¶ | skipping to change at line 1983 ¶ | |||
| +--------------------+--------------+-------+--------------+ | +--------------------+--------------+-------+--------------+ | |||
| | bc_service | Not impacted | S | NORMAL | | | bc_service | Not impacted | S | NORMAL | | |||
| +--------------------+--------------+-------+--------------+ | +--------------------+--------------+-------+--------------+ | |||
| | bc_program | Not impacted | S | NORMAL | | | bc_program | Not impacted | S | NORMAL | | |||
| +--------------------+--------------+-------+--------------+ | +--------------------+--------------+-------+--------------+ | |||
| | bc_service_package | Not impacted | S | NORMAL | | | bc_service_package | Not impacted | S | NORMAL | | |||
| +--------------------+--------------+-------+--------------+ | +--------------------+--------------+-------+--------------+ | |||
| Table 49: 3GPP TS 183.063 Attribute Analysis | Table 49: 3GPP TS 183.063 Attribute Analysis | |||
| 5.50. 3GPP TS 24.182 | 5.50. 3GPP TS 24.229 | |||
| [IMS-CAT] specifies an IP multimedia subsystem for customized | ||||
| alerting tones. | ||||
| +============+=========================+=======+==============+ | ||||
| | Name | Notes | Level | Mux Category | | ||||
| +============+=========================+=======+==============+ | ||||
| | g.3gpp.cat | Usage defined for the | M | NORMAL | | ||||
| | | IP multimedia subsystem | | | | ||||
| +------------+-------------------------+-------+--------------+ | ||||
| Table 50: 3GPP TS 24.182 Attribute Analysis | ||||
| 5.51. 3GPP TS 24.183 | ||||
| [IMS-CRS] specifies an IP multimedia subsystem for customized ringing | ||||
| signal. | ||||
| +============+=========================+=======+==============+ | ||||
| | Name | Notes | Level | Mux Category | | ||||
| +============+=========================+=======+==============+ | ||||
| | g.3gpp.crs | Usage defined for the | M | NORMAL | | ||||
| | | IP multimedia subsystem | | | | ||||
| +------------+-------------------------+-------+--------------+ | ||||
| Table 51: 3GPP TS 24.183 Attribute Analysis | ||||
| 5.52. 3GPP TS 24.229 | ||||
| [IP-CALL] specifies an IP multimedia call control protocol based on | [IP-CALL] specifies an IP multimedia call control protocol based on | |||
| Session Initial protocol and Session Description Protocol. | Session Initial protocol and Session Description Protocol. | |||
| +=================+============================+=======+===========+ | +=================+============================+=======+===========+ | |||
| | Name | Notes | Level | Mux | | | Name | Notes | Level | Mux | | |||
| | | | | Category | | | | | | Category | | |||
| +=================+============================+=======+===========+ | +=================+============================+=======+===========+ | |||
| | secondary-realm | secondary-realm MUST be | M | TRANSPORT | | | secondary-realm | secondary-realm MUST be | M | TRANSPORT | | |||
| | | the one that corresponds | | | | | | the one that corresponds | | | | |||
| skipping to change at line 2047 ¶ | skipping to change at line 2019 ¶ | |||
| +-----------------+----------------------------+-------+-----------+ | +-----------------+----------------------------+-------+-----------+ | |||
| | omr-s-att | Not impacted | M | NORMAL | | | omr-s-att | Not impacted | M | NORMAL | | |||
| +-----------------+----------------------------+-------+-----------+ | +-----------------+----------------------------+-------+-----------+ | |||
| | omr-m-bw | Not impacted | M | NORMAL | | | omr-m-bw | Not impacted | M | NORMAL | | |||
| +-----------------+----------------------------+-------+-----------+ | +-----------------+----------------------------+-------+-----------+ | |||
| | omr-s-bw | Not impacted | M | NORMAL | | | omr-s-bw | Not impacted | M | NORMAL | | |||
| +-----------------+----------------------------+-------+-----------+ | +-----------------+----------------------------+-------+-----------+ | |||
| | omr-codecs | Not impacted | M | NORMAL | | | omr-codecs | Not impacted | M | NORMAL | | |||
| +-----------------+----------------------------+-------+-----------+ | +-----------------+----------------------------+-------+-----------+ | |||
| Table 52: 3GPP TS 24.229 Attribute Analysis | Table 50: 3GPP TS 24.229 Attribute Analysis | |||
| 5.53. ITU T.38 | 5.51. ITU T.38 | |||
| [T.38] defines procedures for real-time Group 3 facsimile | [T.38] defines procedures for real-time Group 3 facsimile | |||
| communications over IP networks. | communications over IP networks. | |||
| +=======================+=============+=======+==============+ | +=======================+=============+=======+==============+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +=======================+=============+=======+==============+ | +=======================+=============+=======+==============+ | |||
| | T38FaxVersion | Refer to | M | TBD | | | T38FaxVersion | Refer to | M | TBD | | |||
| | | notes below | | | | | | notes below | | | | |||
| +-----------------------+-------------+-------+--------------+ | +-----------------------+-------------+-------+--------------+ | |||
| skipping to change at line 2100 ¶ | skipping to change at line 2072 ¶ | |||
| | T38FaxUdpFECMaxSpan | Refer to | M | TBD | | | T38FaxUdpFECMaxSpan | Refer to | M | TBD | | |||
| | | notes below | | | | | | notes below | | | | |||
| +-----------------------+-------------+-------+--------------+ | +-----------------------+-------------+-------+--------------+ | |||
| | T38ModemType | Refer to | M | TBD | | | T38ModemType | Refer to | M | TBD | | |||
| | | notes below | | | | | | notes below | | | | |||
| +-----------------------+-------------+-------+--------------+ | +-----------------------+-------------+-------+--------------+ | |||
| | T38VendorInfo | Refer to | M | TBD | | | T38VendorInfo | Refer to | M | TBD | | |||
| | | notes below | | | | | | notes below | | | | |||
| +-----------------------+-------------+-------+--------------+ | +-----------------------+-------------+-------+--------------+ | |||
| Table 53: ITU T.38 Attribute Analysis | Table 51: ITU T.38 Attribute Analysis | |||
| NOTE: As per Section 9 of [RFC8843], there exists no publicly | NOTE: As per Section 9 of [RFC8843], there exists no publicly | |||
| available specification that defines procedures for multiplexing/ | available specification that defines procedures for multiplexing/ | |||
| demultiplexing fax protocol flows over a single 5-tuple. Once such a | demultiplexing fax protocol flows over a single 5-tuple. Once such a | |||
| specification is available, the multiplexing category assignments for | specification is available, the multiplexing category assignments for | |||
| the attributes in this section could be revisited. | the attributes in this section could be revisited. | |||
| 5.54. ITU-T Q.1970 | 5.52. ITU-T Q.1970 | |||
| [Q.1970] defines Bearer Independent Call Control (BICC) IP bearer | [Q.1970] defines Bearer Independent Call Control (BICC) IP bearer | |||
| control protocol. | control protocol. | |||
| +=======+=====================================+=======+==========+ | +=======+=====================================+=======+==========+ | |||
| | Name | Notes | Level | Mux | | | Name | Notes | Level | Mux | | |||
| | | | | Category | | | | | | Category | | |||
| +=======+=====================================+=======+==========+ | +=======+=====================================+=======+==========+ | |||
| | ipbcp | ipbcp version identifies the types | S | SPECIAL | | | ipbcp | ipbcp version identifies the types | S | SPECIAL | | |||
| | | of IP bearer control protocol | | | | | | of IP bearer control protocol | | | | |||
| | | (IPBCP) message used in BICC (ITU-T | | | | | | (IPBCP) message used in BICC (ITU-T | | | | |||
| | | Q.1901) environment that are | | | | | | Q.1901) environment that are | | | | |||
| | | limited to single-media payload. | | | | | | limited to single-media payload. | | | | |||
| | | Refer to the pertinent ITU-T | | | | | | Refer to the pertinent ITU-T | | | | |||
| | | specifications while multiplexing. | | | | | | specifications while multiplexing. | | | | |||
| +-------+-------------------------------------+-------+----------+ | +-------+-------------------------------------+-------+----------+ | |||
| Table 54: ITU-T Q.1970 Attribute Analysis | Table 52: ITU-T Q.1970 Attribute Analysis | |||
| 5.55. ITU-T H.248.15 | 5.53. ITU-T H.248.15 | |||
| ITU-T H.248.15 [H.248.15] defines the Gateway Control Protocol SDP | ITU-T H.248.15 [H.248.15] defines the Gateway Control Protocol SDP | |||
| H.248 package attribute. | H.248 package attribute. | |||
| +==========+=====================================+=======+==========+ | +==========+=====================================+=======+==========+ | |||
| | Name | Notes | Level | Mux | | | Name | Notes | Level | Mux | | |||
| | | | | Category | | | | | | Category | | |||
| +==========+=====================================+=======+==========+ | +==========+=====================================+=======+==========+ | |||
| | h248item | It is only applicable for | B | SPECIAL | | | h248item | It is only applicable for | B | SPECIAL | | |||
| | | signaling the inclusion of H.248 | | | | | | signaling the inclusion of H.248 | | | | |||
| skipping to change at line 2158 ¶ | skipping to change at line 2130 ¶ | |||
| | | is an issue. This is only a | | | | | | is an issue. This is only a | | | | |||
| | | concern in environments using a | | | | | | concern in environments using a | | | | |||
| | | decomposed server/gateway with | | | | | | decomposed server/gateway with | | | | |||
| | | H.248 signaled between them. The | | | | | | H.248 signaled between them. The | | | | |||
| | | ITU-T will need to do further | | | | | | ITU-T will need to do further | | | | |||
| | | analysis of various packages when | | | | | | analysis of various packages when | | | | |||
| | | they specify how to signal the | | | | | | they specify how to signal the | | | | |||
| | | use of multiplexing to a gateway. | | | | | | use of multiplexing to a gateway. | | | | |||
| +----------+-------------------------------------+-------+----------+ | +----------+-------------------------------------+-------+----------+ | |||
| Table 55: ITU-T H.248.15 Attribute Analysis | Table 53: ITU-T H.248.15 Attribute Analysis | |||
| 5.56. RFC 4975: The Message Session Relay Protocol | 5.54. RFC 4975: The Message Session Relay Protocol | |||
| [RFC4975] describes the Message Session Relay Protocol, a protocol | [RFC4975] describes the Message Session Relay Protocol, a protocol | |||
| for transmitting a series of related instant messages in the context | for transmitting a series of related instant messages in the context | |||
| of a session. Message sessions are treated like any other media | of a session. Message sessions are treated like any other media | |||
| stream when set up via a rendezvous or session-creation protocol such | stream when set up via a rendezvous or session-creation protocol such | |||
| as the Session Initiation Protocol. | as the Session Initiation Protocol. | |||
| +======================+=============+=======+==============+ | +======================+=============+=======+==============+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +======================+=============+=======+==============+ | +======================+=============+=======+==============+ | |||
| skipping to change at line 2184 ¶ | skipping to change at line 2156 ¶ | |||
| | accept-wrapped-types | Refer to | M | TBD | | | accept-wrapped-types | Refer to | M | TBD | | |||
| | | notes below | | | | | | notes below | | | | |||
| +----------------------+-------------+-------+--------------+ | +----------------------+-------------+-------+--------------+ | |||
| | max-size | Refer to | M | TBD | | | max-size | Refer to | M | TBD | | |||
| | | notes below | | | | | | notes below | | | | |||
| +----------------------+-------------+-------+--------------+ | +----------------------+-------------+-------+--------------+ | |||
| | path | Refer to | M | TBD | | | path | Refer to | M | TBD | | |||
| | | notes below | | | | | | notes below | | | | |||
| +----------------------+-------------+-------+--------------+ | +----------------------+-------------+-------+--------------+ | |||
| Table 56: RFC 4975 Attribute Analysis | Table 54: RFC 4975 Attribute Analysis | |||
| NOTE: As per Section 9 of [RFC8843], there exists no publicly | NOTE: As per Section 9 of [RFC8843], there exists no publicly | |||
| available specification that defines procedures for multiplexing/ | available specification that defines procedures for multiplexing/ | |||
| demultiplexing MSRP flows over a single 5-tuple. Once such a | demultiplexing MSRP flows over a single 5-tuple. Once such a | |||
| specification is available, the multiplexing categories assignments | specification is available, the multiplexing categories assignments | |||
| for the attributes in this section could be revisited. | for the attributes in this section could be revisited. | |||
| 5.57. Historical Attributes | 5.55. Historical Attributes | |||
| This section specifies analysis for the attributes that are included | This section specifies analysis for the attributes that are included | |||
| for historic usage alone by the [IANA]. | for historic usage alone by the [IANA]. | |||
| +=========+=====================+=======+==============+ | +=========+=====================+=======+==============+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +=========+=====================+=======+==============+ | +=========+=====================+=======+==============+ | |||
| | rtpred1 | Historic attributes | M | CAUTION | | | rtpred1 | Historic attributes | M | CAUTION | | |||
| +---------+---------------------+-------+--------------+ | +---------+---------------------+-------+--------------+ | |||
| | rtpred2 | Historic attributes | M | CAUTION | | | rtpred2 | Historic attributes | M | CAUTION | | |||
| +---------+---------------------+-------+--------------+ | +---------+---------------------+-------+--------------+ | |||
| Table 57: Historical Attribute Analysis | Table 55: Historical Attribute Analysis | |||
| 6. bwtype Attribute Analysis | 6. bwtype Attribute Analysis | |||
| This section specifies handling of specific bandwidth attributes when | This section specifies handling of specific bandwidth attributes when | |||
| used in multiplexing scenarios. | used in multiplexing scenarios. | |||
| 6.1. RFC 4566: SDP | 6.1. RFC 4566: SDP | |||
| [RFC4566] defines SDP that is intended for describing multimedia | [RFC4566] defines SDP that is intended for describing multimedia | |||
| sessions for the purposes of session announcement, session | sessions for the purposes of session announcement, session | |||
| skipping to change at line 2229 ¶ | skipping to change at line 2201 ¶ | |||
| | Name | Notes | Level | Mux | | | Name | Notes | Level | Mux | | |||
| | | | | Category | | | | | | Category | | |||
| +===========+=================================+=======+==========+ | +===========+=================================+=======+==========+ | |||
| | bwtype:CT | Not impacted | S | NORMAL | | | bwtype:CT | Not impacted | S | NORMAL | | |||
| +-----------+---------------------------------+-------+----------+ | +-----------+---------------------------------+-------+----------+ | |||
| | bwtype:AS | For media-level usage, the | B | SUM | | | bwtype:AS | For media-level usage, the | B | SUM | | |||
| | | aggregate of individual | | | | | | aggregate of individual | | | | |||
| | | bandwidth values is considered. | | | | | | bandwidth values is considered. | | | | |||
| +-----------+---------------------------------+-------+----------+ | +-----------+---------------------------------+-------+----------+ | |||
| Table 58: RFC 4566 bwtype Analysis | Table 56: RFC 4566 bwtype Analysis | |||
| 6.2. RFC 3556: SDP Bandwidth Modifiers for RTCP Bandwidth | 6.2. RFC 3556: SDP Bandwidth Modifiers for RTCP Bandwidth | |||
| [RFC3556] defines an extension to SDP to specify two additional | [RFC3556] defines an extension to SDP to specify two additional | |||
| modifiers for the bandwidth attribute. These modifiers may be used | modifiers for the bandwidth attribute. These modifiers may be used | |||
| to specify the bandwidth allowed for RTCP packets in an RTP session. | to specify the bandwidth allowed for RTCP packets in an RTP session. | |||
| +===========+================================+=======+==========+ | +===========+================================+=======+==========+ | |||
| | Name | Notes | Level | Mux | | | Name | Notes | Level | Mux | | |||
| | | | | Category | | | | | | Category | | |||
| skipping to change at line 2254 ¶ | skipping to change at line 2226 ¶ | |||
| | | the individual values while | | | | | | the individual values while | | | | |||
| | | multiplexing. | | | | | | multiplexing. | | | | |||
| +-----------+--------------------------------+-------+----------+ | +-----------+--------------------------------+-------+----------+ | |||
| | bwtype:RR | Session-level usage represents | B | SUM | | | bwtype:RR | Session-level usage represents | B | SUM | | |||
| | | session aggregate, and media- | | | | | | session aggregate, and media- | | | | |||
| | | level usage indicates SUM of | | | | | | level usage indicates SUM of | | | | |||
| | | the individual values while | | | | | | the individual values while | | | | |||
| | | multiplexing. | | | | | | multiplexing. | | | | |||
| +-----------+--------------------------------+-------+----------+ | +-----------+--------------------------------+-------+----------+ | |||
| Table 59: RFC 3556 bwtype Analysis | Table 57: RFC 3556 bwtype Analysis | |||
| 6.3. RFC 3890: Bandwidth Modifier for SDP | 6.3. RFC 3890: Bandwidth Modifier for SDP | |||
| [RFC3890] defines SDP Transport Independent Application Specific | [RFC3890] defines SDP Transport Independent Application Specific | |||
| Maximum (TIAS) bandwidth modifier that does not include transport | Maximum (TIAS) bandwidth modifier that does not include transport | |||
| overhead; instead, an additional packet-rate attribute is defined. | overhead; instead, an additional packet-rate attribute is defined. | |||
| The transport-independent bitrate value together with the maximum | The transport-independent bitrate value together with the maximum | |||
| packet rate can then be used to calculate the real bitrate over the | packet rate can then be used to calculate the real bitrate over the | |||
| transport actually used. | transport actually used. | |||
| skipping to change at line 2278 ¶ | skipping to change at line 2250 ¶ | |||
| +=============+==================================+=======+==========+ | +=============+==================================+=======+==========+ | |||
| | bwtype:TIAS | The usage of TIAS is not | B | SPECIAL | | | bwtype:TIAS | The usage of TIAS is not | B | SPECIAL | | |||
| | | defined under offer/answer | | | | | | defined under offer/answer | | | | |||
| | | usage. | | | | | | usage. | | | | |||
| +-------------+----------------------------------+-------+----------+ | +-------------+----------------------------------+-------+----------+ | |||
| | maxprate | The usage of TIAS and | B | SPECIAL | | | maxprate | The usage of TIAS and | B | SPECIAL | | |||
| | | maxprate is not well | | | | | | maxprate is not well | | | | |||
| | | defined under multiplexing. | | | | | | defined under multiplexing. | | | | |||
| +-------------+----------------------------------+-------+----------+ | +-------------+----------------------------------+-------+----------+ | |||
| Table 60: RFC 3890 bwtype Analysis | Table 58: RFC 3890 bwtype Analysis | |||
| NOTE: The intention of TIAS is that the media-level bitrate is | NOTE: The intention of TIAS is that the media-level bitrate is | |||
| multiplied with the known per-packet overhead for the selected | multiplied with the known per-packet overhead for the selected | |||
| transport and the maxprate value to determine the worst-case bitrate | transport and the maxprate value to determine the worst-case bitrate | |||
| from the transport to more accurately capture the required usage. | from the transport to more accurately capture the required usage. | |||
| Summing TIAS values independently across "m=" lines and multiplying | Summing TIAS values independently across "m=" lines and multiplying | |||
| the computed sum with maxprate and the per-packet overhead would | the computed sum with maxprate and the per-packet overhead would | |||
| inflate the value significantly. Instead, performing multiplication | inflate the value significantly. Instead, performing multiplication | |||
| and adding the individual values is a more appropriate usage. | and adding the individual values is a more appropriate usage. | |||
| skipping to change at line 2336 ¶ | skipping to change at line 2308 ¶ | |||
| +---------+-----------------------------+-------+------------------+ | +---------+-----------------------------+-------+------------------+ | |||
| | nack | Feedback parameters MUST be | M | SPECIAL | | | nack | Feedback parameters MUST be | M | SPECIAL | | |||
| | app | handled in the app specific | | | | | app | handled in the app specific | | | | |||
| | | way when multiplexed. | | | | | | way when multiplexed. | | | | |||
| +---------+-----------------------------+-------+------------------+ | +---------+-----------------------------+-------+------------------+ | |||
| | trr-int | The attribute value MUST be | M | IDENTICAL-PER-PT | | | trr-int | The attribute value MUST be | M | IDENTICAL-PER-PT | | |||
| | | the same for a given codec | | | | | | the same for a given codec | | | | |||
| | | configuration. | | | | | | configuration. | | | | |||
| +---------+-----------------------------+-------+------------------+ | +---------+-----------------------------+-------+------------------+ | |||
| Table 61: RFC 4585 Attribute Analysis | Table 59: RFC 4585 Attribute Analysis | |||
| 7.2. RFC 5104: Codec Control Messages in AVPF | 7.2. RFC 5104: Codec Control Messages in AVPF | |||
| [RFC5104] specifies a few extensions to the messages defined in the | [RFC5104] specifies a few extensions to the messages defined in the | |||
| Audio-Visual Profile with Feedback (AVPF). They are helpful | Audio-Visual Profile with Feedback (AVPF). They are helpful | |||
| primarily in conversational multimedia scenarios where centralized | primarily in conversational multimedia scenarios where centralized | |||
| multipoint functionalities are in use. However, some are also usable | multipoint functionalities are in use. However, some are also usable | |||
| in smaller multicast environments and point-to-point calls. | in smaller multicast environments and point-to-point calls. | |||
| +======+==========================+=======+==================+ | +======+==========================+=======+==================+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +======+==========================+=======+==================+ | +======+==========================+=======+==================+ | |||
| | ccm | The attribute value MUST | M | IDENTICAL-PER-PT | | | ccm | The attribute value MUST | M | IDENTICAL-PER-PT | | |||
| | | be the same for a given | | | | | | be the same for a given | | | | |||
| | | codec configuration. | | | | | | codec configuration. | | | | |||
| +------+--------------------------+-------+------------------+ | +------+--------------------------+-------+------------------+ | |||
| Table 62: RFC 5104 Attribute Analysis | Table 60: RFC 5104 Attribute Analysis | |||
| 7.3. RFC 6285: Unicast-Based Rapid Acquisition of Multicast RTP | 7.3. RFC 6285: Unicast-Based Rapid Acquisition of Multicast RTP | |||
| Sessions (RAMS) | Sessions (RAMS) | |||
| [RFC6285] describes a method of using the existing RTP and RTCP | [RFC6285] describes a method of using the existing RTP and RTCP | |||
| machinery that reduces the acquisition delay. In this method, an | machinery that reduces the acquisition delay. In this method, an | |||
| auxiliary unicast RTP session carrying the Reference Information to | auxiliary unicast RTP session carrying the Reference Information to | |||
| the receiver precedes or accompanies the multicast stream. This | the receiver precedes or accompanies the multicast stream. This | |||
| unicast RTP flow can be transmitted at a faster-than-natural bitrate | unicast RTP flow can be transmitted at a faster-than-natural bitrate | |||
| to further accelerate the acquisition. The motivating use case for | to further accelerate the acquisition. The motivating use case for | |||
| skipping to change at line 2376 ¶ | skipping to change at line 2348 ¶ | |||
| compressed audio and video. | compressed audio and video. | |||
| +======+==========================+=======+==================+ | +======+==========================+=======+==================+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +======+==========================+=======+==================+ | +======+==========================+=======+==================+ | |||
| | nack | The attribute value MUST | M | IDENTICAL-PER-PT | | | nack | The attribute value MUST | M | IDENTICAL-PER-PT | | |||
| | rai | be the same for a given | | | | | rai | be the same for a given | | | | |||
| | | codec configuration. | | | | | | codec configuration. | | | | |||
| +------+--------------------------+-------+------------------+ | +------+--------------------------+-------+------------------+ | |||
| Table 63: RFC 6285 Attribute Analysis | Table 61: RFC 6285 Attribute Analysis | |||
| 7.4. RFC 6679: ECN for RTP over UDP/IP | 7.4. RFC 6679: ECN for RTP over UDP/IP | |||
| [RFC6679] specifies how Explicit Congestion Notification (ECN) can be | [RFC6679] specifies how Explicit Congestion Notification (ECN) can be | |||
| used with the RTP running over UDP, using the RTCP as a feedback | used with the RTP running over UDP, using the RTCP as a feedback | |||
| mechanism. It defines a new RTCP Extended Report (XR) block for | mechanism. It defines a new RTCP Extended Report (XR) block for | |||
| periodic ECN feedback, a new RTCP transport feedback message for | periodic ECN feedback, a new RTCP transport feedback message for | |||
| timely reporting of congestion events, and a STUN extension used in | timely reporting of congestion events, and a STUN extension used in | |||
| the optional initialization method using ICE. | the optional initialization method using ICE. | |||
| skipping to change at line 2398 ¶ | skipping to change at line 2370 ¶ | |||
| | Name | Notes | Level | Mux | | | Name | Notes | Level | Mux | | |||
| | | | | Category | | | | | | Category | | |||
| +=================+============================+=======+===========+ | +=================+============================+=======+===========+ | |||
| | ecn-capable-rtp | ECN markup is enabled at | M | IDENTICAL | | | ecn-capable-rtp | ECN markup is enabled at | M | IDENTICAL | | |||
| | | the RTP session level. | | | | | | the RTP session level. | | | | |||
| +-----------------+----------------------------+-------+-----------+ | +-----------------+----------------------------+-------+-----------+ | |||
| | nack ecn | This attribute enables ECN | M | IDENTICAL | | | nack ecn | This attribute enables ECN | M | IDENTICAL | | |||
| | | at the RTP session level. | | | | | | at the RTP session level. | | | | |||
| +-----------------+----------------------------+-------+-----------+ | +-----------------+----------------------------+-------+-----------+ | |||
| Table 64: RFC 6679 Attribute Analysis | Table 62: RFC 6679 Attribute Analysis | |||
| 7.5. RFC 6642: Third-Party Loss Report | 7.5. RFC 6642: Third-Party Loss Report | |||
| In a large RTP session using the RTCP feedback mechanism defined in | In a large RTP session using the RTCP feedback mechanism defined in | |||
| [RFC4585], a feedback target may experience transient overload if | [RFC4585], a feedback target may experience transient overload if | |||
| some event causes a large number of receivers to send feedback at | some event causes a large number of receivers to send feedback at | |||
| once. This overload is usually avoided by ensuring that feedback | once. This overload is usually avoided by ensuring that feedback | |||
| reports are forwarded to all receivers, allowing them to avoid | reports are forwarded to all receivers, allowing them to avoid | |||
| sending duplicate feedback reports. However, there are cases where | sending duplicate feedback reports. However, there are cases where | |||
| it is not recommended to forward feedback reports, and this may allow | it is not recommended to forward feedback reports, and this may allow | |||
| skipping to change at line 2426 ¶ | skipping to change at line 2398 ¶ | |||
| +=======+==========================+=======+==================+ | +=======+==========================+=======+==================+ | |||
| | nack | The attribute value MUST | M | IDENTICAL-PER-PT | | | nack | The attribute value MUST | M | IDENTICAL-PER-PT | | |||
| | tllei | be the same for a given | | | | | tllei | be the same for a given | | | | |||
| | | codec configuration. | | | | | | codec configuration. | | | | |||
| +-------+--------------------------+-------+------------------+ | +-------+--------------------------+-------+------------------+ | |||
| | nack | The attribute value MUST | M | IDENTICAL-PER-PT | | | nack | The attribute value MUST | M | IDENTICAL-PER-PT | | |||
| | pslei | be the same for a given | | | | | pslei | be the same for a given | | | | |||
| | | codec configuration. | | | | | | codec configuration. | | | | |||
| +-------+--------------------------+-------+------------------+ | +-------+--------------------------+-------+------------------+ | |||
| Table 65: RFC 6642 Attribute Analysis | Table 63: RFC 6642 Attribute Analysis | |||
| 7.6. RFC 5104: Codec Control Messages in AVPF | 7.6. RFC 5104: Codec Control Messages in AVPF | |||
| [RFC5104] specifies a few extensions to the messages defined in the | [RFC5104] specifies a few extensions to the messages defined in the | |||
| Audio-Visual Profile with Feedback (AVPF). They are helpful | Audio-Visual Profile with Feedback (AVPF). They are helpful | |||
| primarily in conversational multimedia scenarios where centralized | primarily in conversational multimedia scenarios where centralized | |||
| multipoint functionalities are in use. However, some are also usable | multipoint functionalities are in use. However, some are also usable | |||
| in smaller multicast environments and point-to-point calls. | in smaller multicast environments and point-to-point calls. | |||
| +=======+==========================+=======+==================+ | +=======+==========================+=======+==================+ | |||
| skipping to change at line 2456 ¶ | skipping to change at line 2428 ¶ | |||
| +-------+--------------------------+-------+------------------+ | +-------+--------------------------+-------+------------------+ | |||
| | ccm | The attribute value MUST | M | IDENTICAL-PER-PT | | | ccm | The attribute value MUST | M | IDENTICAL-PER-PT | | |||
| | tstr | be the same for a given | | | | | tstr | be the same for a given | | | | |||
| | | codec configuration. | | | | | | codec configuration. | | | | |||
| +-------+--------------------------+-------+------------------+ | +-------+--------------------------+-------+------------------+ | |||
| | ccm | The attribute value MUST | M | IDENTICAL-PER-PT | | | ccm | The attribute value MUST | M | IDENTICAL-PER-PT | | |||
| | vbcm | be the same for a given | | | | | vbcm | be the same for a given | | | | |||
| | | codec configuration. | | | | | | codec configuration. | | | | |||
| +-------+--------------------------+-------+------------------+ | +-------+--------------------------+-------+------------------+ | |||
| Table 66: RFC 5104 Attribute Analysis | Table 64: RFC 5104 Attribute Analysis | |||
| 8. group Attribute Analysis | 8. group Attribute Analysis | |||
| This section analyzes SDP "group" attribute semantics [RFC5888]. | This section analyzes SDP "group" attribute semantics [RFC5888]. | |||
| 8.1. RFC 5888: SDP Grouping Framework | 8.1. RFC 5888: SDP Grouping Framework | |||
| [RFC5888] defines a framework to group "m=" lines in SDP for | [RFC5888] defines a framework to group "m=" lines in SDP for | |||
| different purposes. | different purposes. | |||
| +===========+==============+=======+==============+ | +===========+==============+=======+==============+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +===========+==============+=======+==============+ | +===========+==============+=======+==============+ | |||
| | group:LS | Not impacted | S | NORMAL | | | group:LS | Not impacted | S | NORMAL | | |||
| +-----------+--------------+-------+--------------+ | +-----------+--------------+-------+--------------+ | |||
| | group:FID | Not impacted | S | NORMAL | | | group:FID | Not impacted | S | NORMAL | | |||
| +-----------+--------------+-------+--------------+ | +-----------+--------------+-------+--------------+ | |||
| Table 67: RFC 5888 Attribute Analysis | Table 65: RFC 5888 Attribute Analysis | |||
| 8.2. RFC 3524: Mapping Media Streams to Resource Reservation Flows | 8.2. RFC 3524: Mapping Media Streams to Resource Reservation Flows | |||
| [RFC3524] defines an extension to the SDP grouping framework. It | [RFC3524] defines an extension to the SDP grouping framework. It | |||
| allows requesting a group of media streams to be mapped into a single | allows requesting a group of media streams to be mapped into a single | |||
| resource reservation flow. The SDP syntax needed is defined, as well | resource reservation flow. The SDP syntax needed is defined, as well | |||
| as a new "semantics" attribute called Single Reservation Flow (SRF). | as a new "semantics" attribute called Single Reservation Flow (SRF). | |||
| +===========+==============+=======+==============+ | +===========+==============+=======+==============+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +===========+==============+=======+==============+ | +===========+==============+=======+==============+ | |||
| | group:SRF | Not impacted | S | NORMAL | | | group:SRF | Not impacted | S | NORMAL | | |||
| +-----------+--------------+-------+--------------+ | +-----------+--------------+-------+--------------+ | |||
| Table 68: RFC 3524 Attribute Analysis | Table 66: RFC 3524 Attribute Analysis | |||
| 8.3. RFC 4091: ANAT Semantics | 8.3. RFC 4091: ANAT Semantics | |||
| [RFC4091] defines ANAT semantics for the SDP grouping framework. | [RFC4091] defines ANAT semantics for the SDP grouping framework. | |||
| (Note: [RFC4091] has been obsoleted by [RFC8445].) The ANAT | (Note: [RFC4091] has been obsoleted by [RFC8445].) The ANAT | |||
| semantics allow alternative types of network addresses to establish a | semantics allow alternative types of network addresses to establish a | |||
| particular media stream. | particular media stream. | |||
| +============+==============================+=======+==============+ | +============+==============================+=======+==============+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +============+==============================+=======+==============+ | +============+==============================+=======+==============+ | |||
| | group:ANAT | ANAT semantics is obsoleted. | S | CAUTION | | | group:ANAT | ANAT semantics is obsoleted. | S | CAUTION | | |||
| +------------+------------------------------+-------+--------------+ | +------------+------------------------------+-------+--------------+ | |||
| Table 69: RFC 4091 Attribute Analysis | Table 67: RFC 4091 Attribute Analysis | |||
| 8.4. RFC 5956: FEC Grouping Semantics in SDP | 8.4. RFC 5956: FEC Grouping Semantics in SDP | |||
| [RFC5956] defines the semantics for grouping the associated source | [RFC5956] defines the semantics for grouping the associated source | |||
| and FEC-based repair flows in SDP. The semantics defined in the | and FEC-based repair flows in SDP. The semantics defined in the | |||
| document are to be used with the SDP Grouping Framework [RFC5888]. | document are to be used with the SDP Grouping Framework [RFC5888]. | |||
| These semantics allow the description of grouping relationships | These semantics allow the description of grouping relationships | |||
| between the source and repair flows when one or more source and/or | between the source and repair flows when one or more source and/or | |||
| repair flows are associated in the same group; they also provide | repair flows are associated in the same group; they also provide | |||
| support for additive repair flows. SSRC-level grouping semantics are | support for additive repair flows. SSRC-level grouping semantics are | |||
| also defined in this document for RTP streams using SSRC | also defined in this document for RTP streams using SSRC | |||
| multiplexing. | multiplexing. | |||
| +==============+==============+=======+==============+ | +==============+==============+=======+==============+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +==============+==============+=======+==============+ | +==============+==============+=======+==============+ | |||
| | group:FEC-FR | Not impacted | S | NORMAL | | | group:FEC-FR | Not impacted | S | NORMAL | | |||
| +--------------+--------------+-------+--------------+ | +--------------+--------------+-------+--------------+ | |||
| Table 70: RFC 5956 Attribute Analysis | Table 68: RFC 5956 Attribute Analysis | |||
| 8.5. RFC 5583: Signaling Media Decoding Dependency in SDP | 8.5. RFC 5583: Signaling Media Decoding Dependency in SDP | |||
| [RFC5583] defines semantics that allow for signaling the decoding | [RFC5583] defines semantics that allow for signaling the decoding | |||
| dependency of different media descriptions with the same media type | dependency of different media descriptions with the same media type | |||
| in SDP. This is required, for example, if media data is separated | in SDP. This is required, for example, if media data is separated | |||
| and transported in different network streams as a result of using a | and transported in different network streams as a result of using a | |||
| layered or multiple descriptive media coding process. | layered or multiple descriptive media coding process. | |||
| +===========+==========================+=======+==================+ | +===========+==========================+=======+==================+ | |||
| skipping to change at line 2549 ¶ | skipping to change at line 2521 ¶ | |||
| +-----------+--------------------------+-------+------------------+ | +-----------+--------------------------+-------+------------------+ | |||
| | depend | The attribute value MUST | M | IDENTICAL-PER-PT | | | depend | The attribute value MUST | M | IDENTICAL-PER-PT | | |||
| | lay | be the same for a given | | | | | lay | be the same for a given | | | | |||
| | | codec configuration. | | | | | | codec configuration. | | | | |||
| +-----------+--------------------------+-------+------------------+ | +-----------+--------------------------+-------+------------------+ | |||
| | depend | The attribute value MUST | M | IDENTICAL-PER-PT | | | depend | The attribute value MUST | M | IDENTICAL-PER-PT | | |||
| | mdc | be the same for a given | | | | | mdc | be the same for a given | | | | |||
| | | codec configuration. | | | | | | codec configuration. | | | | |||
| +-----------+--------------------------+-------+------------------+ | +-----------+--------------------------+-------+------------------+ | |||
| Table 71: RFC 5583 Attribute Analysis | Table 69: RFC 5583 Attribute Analysis | |||
| 8.6. RFC 7104: Duplication Grouping Semantics in the SDP | 8.6. RFC 7104: Duplication Grouping Semantics in the SDP | |||
| [RFC7104] defines the semantics for grouping redundant streams in | [RFC7104] defines the semantics for grouping redundant streams in | |||
| SDP. The semantics defined in this document are to be used with the | SDP. The semantics defined in this document are to be used with the | |||
| SDP Grouping Framework. Grouping semantics at the synchronization | SDP Grouping Framework. Grouping semantics at the synchronization | |||
| source (SSRC) level are also defined in this document for RTP streams | source (SSRC) level are also defined in this document for RTP streams | |||
| using SSRC multiplexing. | using SSRC multiplexing. | |||
| +===========+==============+=======+==============+ | +===========+==============+=======+==============+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +===========+==============+=======+==============+ | +===========+==============+=======+==============+ | |||
| | group:DUP | Not impacted | S | NORMAL | | | group:DUP | Not impacted | S | NORMAL | | |||
| +-----------+--------------+-------+--------------+ | +-----------+--------------+-------+--------------+ | |||
| Table 72: RFC 7104 Attribute Analysis | Table 70: RFC 7104 Attribute Analysis | |||
| 9. ssrc-group Attribute Analysis | 9. ssrc-group Attribute Analysis | |||
| This section analyzes "ssrc-group" semantics. | This section analyzes "ssrc-group" semantics. | |||
| 9.1. RFC 5576: Source-Specific SDP Attributes | 9.1. RFC 5576: Source-Specific SDP Attributes | |||
| [RFC5576] defines a mechanism for describing RTP media sources -- | [RFC5576] defines a mechanism for describing RTP media sources -- | |||
| which are identified by their synchronization source (SSRC) | which are identified by their synchronization source (SSRC) | |||
| identifiers -- in SDP, to associate attributes with these sources and | identifiers -- in SDP, to associate attributes with these sources and | |||
| skipping to change at line 2590 ¶ | skipping to change at line 2562 ¶ | |||
| +===================+==============+=======+==============+ | +===================+==============+=======+==============+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +===================+==============+=======+==============+ | +===================+==============+=======+==============+ | |||
| | ssrc-group:FID | Not impacted | SR | NORMAL | | | ssrc-group:FID | Not impacted | SR | NORMAL | | |||
| +-------------------+--------------+-------+--------------+ | +-------------------+--------------+-------+--------------+ | |||
| | ssrc-group:FEC | Not impacted | SR | NORMAL | | | ssrc-group:FEC | Not impacted | SR | NORMAL | | |||
| +-------------------+--------------+-------+--------------+ | +-------------------+--------------+-------+--------------+ | |||
| | ssrc-group:FEC-FR | Not impacted | SR | NORMAL | | | ssrc-group:FEC-FR | Not impacted | SR | NORMAL | | |||
| +-------------------+--------------+-------+--------------+ | +-------------------+--------------+-------+--------------+ | |||
| Table 73: RFC 5576 Attribute Analysis | Table 71: RFC 5576 Attribute Analysis | |||
| 9.2. RFC 7104: Duplication Grouping Semantics in the SDP | 9.2. RFC 7104: Duplication Grouping Semantics in the SDP | |||
| [RFC7104] defines the semantics for grouping redundant streams in | [RFC7104] defines the semantics for grouping redundant streams in | |||
| SDP. The semantics defined in this document are to be used with the | SDP. The semantics defined in this document are to be used with the | |||
| SDP Grouping Framework. Grouping semantics at the synchronization | SDP Grouping Framework. Grouping semantics at the synchronization | |||
| source (SSRC) level are also defined in this document for RTP streams | source (SSRC) level are also defined in this document for RTP streams | |||
| using SSRC multiplexing. | using SSRC multiplexing. | |||
| +================+==============+=======+==============+ | +================+==============+=======+==============+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +================+==============+=======+==============+ | +================+==============+=======+==============+ | |||
| | ssrc-group:DUP | Not impacted | SR | NORMAL | | | ssrc-group:DUP | Not impacted | SR | NORMAL | | |||
| +----------------+--------------+-------+--------------+ | +----------------+--------------+-------+--------------+ | |||
| Table 74: RFC 7104 Attribute Analysis | Table 72: RFC 7104 Attribute Analysis | |||
| 10. QoS Mechanism Token Analysis | 10. QoS Mechanism Token Analysis | |||
| This section analyzes QoS tokes specified with SDP. | This section analyzes QoS tokes specified with SDP. | |||
| 10.1. RFC 5432: QoS Mechanism Selection in SDP | 10.1. RFC 5432: QoS Mechanism Selection in SDP | |||
| [RFC5432] defines procedures to negotiate QoS mechanisms using the | [RFC5432] defines procedures to negotiate QoS mechanisms using the | |||
| SDP offer/answer model. | SDP offer/answer model. | |||
| skipping to change at line 2632 ¶ | skipping to change at line 2604 ¶ | |||
| | | that corresponds to the "m=" | | | | | | that corresponds to the "m=" | | | | |||
| | | line chosen for setting up the | | | | | | line chosen for setting up the | | | | |||
| | | underlying transport flow. | | | | | | underlying transport flow. | | | | |||
| +------+--------------------------------+-------+-----------+ | +------+--------------------------------+-------+-----------+ | |||
| | nsis | rsvp attribute MUST be the one | B | TRANSPORT | | | nsis | rsvp attribute MUST be the one | B | TRANSPORT | | |||
| | | that corresponds to the "m=" | | | | | | that corresponds to the "m=" | | | | |||
| | | line chosen for setting up the | | | | | | line chosen for setting up the | | | | |||
| | | underlying transport. | | | | | | underlying transport. | | | | |||
| +------+--------------------------------+-------+-----------+ | +------+--------------------------------+-------+-----------+ | |||
| Table 75: RFC 5432 Attribute Analysis | Table 73: RFC 5432 Attribute Analysis | |||
| NOTE: A single Differentiated Services Code Point (DSCP) for each | NOTE: A single Differentiated Services Code Point (DSCP) for each | |||
| flow being multiplexed doesn't impact multiplexing, since QoS | flow being multiplexed doesn't impact multiplexing, since QoS | |||
| mechanisms are signaled/scoped per flow. For scenarios that involve | mechanisms are signaled/scoped per flow. For scenarios that involve | |||
| having different DSCP code points for packets being transmitted over | having different DSCP code points for packets being transmitted over | |||
| the same 5-tuple, issues as discussed in [RFC7657] need to be taken | the same 5-tuple, issues as discussed in [RFC7657] need to be taken | |||
| into consideration. | into consideration. | |||
| 11. k= Attribute Analysis | 11. k= Attribute Analysis | |||
| skipping to change at line 2656 ¶ | skipping to change at line 2628 ¶ | |||
| sessions for the purposes of session announcement, session | sessions for the purposes of session announcement, session | |||
| invitation, and other forms of multimedia session initiation. | invitation, and other forms of multimedia session initiation. | |||
| +======+===================================+=======+==============+ | +======+===================================+=======+==============+ | |||
| | Name | Notes | Level | Mux Category | | | Name | Notes | Level | Mux Category | | |||
| +======+===================================+=======+==============+ | +======+===================================+=======+==============+ | |||
| | k= | It is not recommended to use this | S | CAUTION | | | k= | It is not recommended to use this | S | CAUTION | | |||
| | | attribute under multiplexing. | | | | | | attribute under multiplexing. | | | | |||
| +------+-----------------------------------+-------+--------------+ | +------+-----------------------------------+-------+--------------+ | |||
| Table 76: RFC 4566 Attribute Analysis | Table 74: RFC 4566 Attribute Analysis | |||
| 12. content Attribute Analysis | 12. content Attribute Analysis | |||
| 12.1. RFC 4796 | 12.1. RFC 4796 | |||
| [RFC4796] defines a new SDP media-level attribute, "content". The | [RFC4796] defines a new SDP media-level attribute, "content". The | |||
| "content" attribute defines the content of the media stream to a more | "content" attribute defines the content of the media stream to a more | |||
| detailed level than the media description line. The sender of an SDP | detailed level than the media description line. The sender of an SDP | |||
| session description can attach the "content" attribute to one or more | session description can attach the "content" attribute to one or more | |||
| media streams. The receiving application can then treat each media | media streams. The receiving application can then treat each media | |||
| skipping to change at line 2684 ¶ | skipping to change at line 2656 ¶ | |||
| +-----------------+--------------+-------+--------------+ | +-----------------+--------------+-------+--------------+ | |||
| | content:speaker | Not impacted | M | NORMAL | | | content:speaker | Not impacted | M | NORMAL | | |||
| +-----------------+--------------+-------+--------------+ | +-----------------+--------------+-------+--------------+ | |||
| | content:main | Not impacted | M | NORMAL | | | content:main | Not impacted | M | NORMAL | | |||
| +-----------------+--------------+-------+--------------+ | +-----------------+--------------+-------+--------------+ | |||
| | content:sl | Not impacted | M | NORMAL | | | content:sl | Not impacted | M | NORMAL | | |||
| +-----------------+--------------+-------+--------------+ | +-----------------+--------------+-------+--------------+ | |||
| | content:alt | Not impacted | M | NORMAL | | | content:alt | Not impacted | M | NORMAL | | |||
| +-----------------+--------------+-------+--------------+ | +-----------------+--------------+-------+--------------+ | |||
| Table 77: RFC 4796 Attribute Analysis | Table 75: RFC 4796 Attribute Analysis | |||
| 12.2. 3GPP TS 24.182 | ||||
| [IMS-CAT] specifies an IP multimedia subsystem for customized | ||||
| alerting tones. | ||||
| +============+=========================+=======+==============+ | ||||
| | Name | Notes | Level | Mux Category | | ||||
| +============+=========================+=======+==============+ | ||||
| | g.3gpp.cat | Usage defined for the | M | NORMAL | | ||||
| | | IP multimedia subsystem | | | | ||||
| +------------+-------------------------+-------+--------------+ | ||||
| Table 76: 3GPP TS 24.182 Attribute Analysis | ||||
| 12.3. 3GPP TS 24.183 | ||||
| [IMS-CRS] specifies an IP multimedia subsystem for customized ringing | ||||
| signal. | ||||
| +============+=========================+=======+==============+ | ||||
| | Name | Notes | Level | Mux Category | | ||||
| +============+=========================+=======+==============+ | ||||
| | g.3gpp.crs | Usage defined for the | M | NORMAL | | ||||
| | | IP multimedia subsystem | | | | ||||
| +------------+-------------------------+-------+--------------+ | ||||
| Table 77: 3GPP TS 24.183 Attribute Analysis | ||||
| 13. Payload Formats | 13. Payload Formats | |||
| 13.1. RFC 5109: RTP Payload Format for Generic FEC | 13.1. RFC 5109: RTP Payload Format for Generic FEC | |||
| [RFC5109] describes a payload format for generic Forward Error | [RFC5109] describes a payload format for generic Forward Error | |||
| Correction (FEC) for media data encapsulated in RTP. It is based on | Correction (FEC) for media data encapsulated in RTP. It is based on | |||
| the exclusive-or (parity) operation. The payload format allows end | the exclusive-or (parity) operation. The payload format allows end | |||
| systems to apply protection using various protection lengths and | systems to apply protection using various protection lengths and | |||
| levels, in addition to using various protection group sizes to adapt | levels, in addition to using various protection group sizes to adapt | |||
| skipping to change at line 3088 ¶ | skipping to change at line 3088 ¶ | |||
| +----------+--------------+ | +----------+--------------+ | |||
| | RS | SUM | | | RS | SUM | | |||
| +----------+--------------+ | +----------+--------------+ | |||
| | RR | SUM | | | RR | SUM | | |||
| +----------+--------------+ | +----------+--------------+ | |||
| | TIAS | SPECIAL | | | TIAS | SPECIAL | | |||
| +----------+--------------+ | +----------+--------------+ | |||
| Table 80 | Table 80 | |||
| 15.2.2. Table: att-field | 15.2.2. Table: attribute-name | |||
| The following values have been added to the "att-field" subregistry | The following values have been added to the "attribute-name" | |||
| of the "Session Description Protocol (SDP) Parameters" registry. The | subregistry of the "Session Description Protocol (SDP) Parameters" | |||
| references have been updated to point to this RFC as well as the | registry. The references have been updated to point to this RFC as | |||
| previous references. | well as the previous references. | |||
| NOTE: The attributes from [FLUTE] ("flute-tsi", "flute-ch", "FEC- | NOTE: The attributes from [FLUTE] ("flute-tsi", "flute-ch", "FEC- | |||
| declaration", "FEC-OTI-extension", "content-desc") were not analyzed | declaration", "FEC-OTI-extension", "content-desc") were not analyzed | |||
| for their multiplexing behavior, due to the expired status of the | for their multiplexing behavior, due to the expired status of the | |||
| draft. For the purposes of this specification, the multiplexing | draft. For the purposes of this specification, the multiplexing | |||
| category of "TBD" is assigned. | category of "TBD" is assigned. | |||
| +==========================+==================+ | +==========================+==================+ | |||
| | SDP Name | Mux Category | | | SDP Name | Mux Category | | |||
| +==========================+==================+ | +==========================+==================+ | |||
| skipping to change at line 3510 ¶ | skipping to change at line 3510 ¶ | |||
| | repair-window | SPECIAL | | | repair-window | SPECIAL | | |||
| +--------------------------+------------------+ | +--------------------------+------------------+ | |||
| | rams-updates | CAUTION | | | rams-updates | CAUTION | | |||
| +--------------------------+------------------+ | +--------------------------+------------------+ | |||
| | imageattr | IDENTICAL-PER-PT | | | imageattr | IDENTICAL-PER-PT | | |||
| +--------------------------+------------------+ | +--------------------------+------------------+ | |||
| | cfw-id | NORMAL | | | cfw-id | NORMAL | | |||
| +--------------------------+------------------+ | +--------------------------+------------------+ | |||
| | portmapping-req | CAUTION | | | portmapping-req | CAUTION | | |||
| +--------------------------+------------------+ | +--------------------------+------------------+ | |||
| | g.3gpp.crs | NORMAL | | ||||
| +--------------------------+------------------+ | ||||
| | ecn-capable-rtp | IDENTICAL | | | ecn-capable-rtp | IDENTICAL | | |||
| +--------------------------+------------------+ | +--------------------------+------------------+ | |||
| | visited-realm | TRANSPORT | | | visited-realm | TRANSPORT | | |||
| +--------------------------+------------------+ | +--------------------------+------------------+ | |||
| | secondary-realm | TRANSPORT | | | secondary-realm | TRANSPORT | | |||
| +--------------------------+------------------+ | +--------------------------+------------------+ | |||
| | omr-s-cksum | NORMAL | | | omr-s-cksum | NORMAL | | |||
| +--------------------------+------------------+ | +--------------------------+------------------+ | |||
| | omr-m-cksum | NORMAL | | | omr-m-cksum | NORMAL | | |||
| +--------------------------+------------------+ | +--------------------------+------------------+ | |||
| skipping to change at line 3603 ¶ | skipping to change at line 3601 ¶ | |||
| | speaker | NORMAL | | | speaker | NORMAL | | |||
| +------------+--------------+ | +------------+--------------+ | |||
| | sl | NORMAL | | | sl | NORMAL | | |||
| +------------+--------------+ | +------------+--------------+ | |||
| | main | NORMAL | | | main | NORMAL | | |||
| +------------+--------------+ | +------------+--------------+ | |||
| | alt | NORMAL | | | alt | NORMAL | | |||
| +------------+--------------+ | +------------+--------------+ | |||
| | g.3gpp.cat | NORMAL | | | g.3gpp.cat | NORMAL | | |||
| +------------+--------------+ | +------------+--------------+ | |||
| | g.3gpp.crs | NORMAL | | ||||
| +------------+--------------+ | ||||
| Table 82 | Table 82 | |||
| 15.2.4. Table: Semantics for the "group" SDP Attribute | 15.2.4. Table: Semantics for the "group" SDP Attribute | |||
| The following values have been added to the "Semantics for the | The following values have been added to the "Semantics for the | |||
| 'group' SDP Attribute" subregistry of the "Session Description | 'group' SDP Attribute" subregistry of the "Session Description | |||
| Protocol (SDP) Parameters" registry. The references have been | Protocol (SDP) Parameters" registry. The references have been | |||
| updated to point to this RFC as well as the previous references. | updated to point to this RFC as well as the previous references. | |||
| skipping to change at line 4325 ¶ | skipping to change at line 4325 ¶ | |||
| suggesting the categories, contributing text, and reviewing the draft | suggesting the categories, contributing text, and reviewing the draft | |||
| of this document. I would also like to thank Magnus Westerlund, | of this document. I would also like to thank Magnus Westerlund, | |||
| Christer Holmberg, Jonathan Lennox, Bo Burman, Ari Keranen, and Dan | Christer Holmberg, Jonathan Lennox, Bo Burman, Ari Keranen, and Dan | |||
| Wing for suggesting structural changes that improved the document's | Wing for suggesting structural changes that improved the document's | |||
| readability. | readability. | |||
| I would like also to thank the following experts for their inputs and | I would like also to thank the following experts for their inputs and | |||
| reviews as listed: | reviews as listed: | |||
| Flemming Andreasen (5.24, 5.32, 5.33, 14), | Flemming Andreasen (5.24, 5.32, 5.33, 14), | |||
| Rohan Mahy (5.56), | Rohan Mahy (5.54), | |||
| Eric Burger (5.26), | Eric Burger (5.26), | |||
| Christian Huitema (5.14), | Christian Huitema (5.14), | |||
| Christer Holmberg (5.21, 5.26, 5.50, 5.51), | Christer Holmberg (5.21, 5.26, 12.2, 12.3), | |||
| Richard Ejzak (5.44, 5.52, 5.53), | Richard Ejzak (5.44, 5.50, 5.51), | |||
| Colin Perkins (5.7, 5.8, 5.9, 5.57), | Colin Perkins (5.7, 5.8, 5.9, 5.55), | |||
| Magnus Westerlund (5.2, 5.3, 5.9, 5.27, 5.47, 6.1 - 6.3, 8.3, 7), | Magnus Westerlund (5.2, 5.3, 5.9, 5.27, 5.47, 6.1 - 6.3, 8.3, 7), | |||
| Roni Even (5.12, 5.27, 8.4), | Roni Even (5.12, 5.27, 8.4), | |||
| Subha Dhesikan (5.6, 10), | Subha Dhesikan (5.6, 10), | |||
| Dan Wing (5.7, 5.12, 5.35, 5.39, 5.45), | Dan Wing (5.7, 5.12, 5.35, 5.39, 5.45), | |||
| Cullen Jennings (5.40), | Cullen Jennings (5.40), | |||
| Ali C Begen (5.1, 5.20, 5.22, 5.25, 5.38, 7.3, 8.2, 8.4, 8.6, 9.2, | Ali C Begen (5.1, 5.20, 5.22, 5.25, 5.38, 7.3, 8.2, 8.4, 8.6, 9.2, | |||
| 13.1), | 13.1), | |||
| Bo Burman (7.2, 7.6), | Bo Burman (7.2, 7.6), | |||
| Charles Eckel (5.15, 5.27, 5.28, 9.1, 8.5), | Charles Eckel (5.15, 5.27, 5.28, 9.1, 8.5), | |||
| Paul Kyzivat (5.24), | Paul Kyzivat (5.24), | |||
| Ian Johansson (5.15), | Ian Johansson (5.15), | |||
| Saravanan Shanmugham (5.11), | Saravanan Shanmugham (5.11), | |||
| Paul E Jones (5.30), | Paul E Jones (5.30), | |||
| Rajesh Kumar (5.48), | Rajesh Kumar (5.48), | |||
| Jonathan Lennox (5.36, 5, 15, 9.1, 11.1), | Jonathan Lennox (5.36, 5, 15, 9.1, 11.1), | |||
| Mo Zanaty (5.4, 5.5, 5.23, 8.1, 8.3, 8.5, 12.1), | Mo Zanaty (5.4, 5.5, 5.23, 8.1, 8.3, 8.5, 12.1), | |||
| Christian Huitema (5.14), | Christian Huitema (5.14), | |||
| Qin Wu (5.47, PM-Dir review), | Qin Wu (5.47, PM-Dir review), | |||
| Hans Stokking (5.43, 5.16), | Hans Stokking (5.43, 5.16), | |||
| Christian Groves (5.48, 5.54), and | Christian Groves (5.48, 5.52), and | |||
| Thomas Stach. | Thomas Stach. | |||
| I would like to thank Chris Lonvick for the SECDIR review, Dan | I would like to thank Chris Lonvick for the SECDIR review, Dan | |||
| Romascanu for the Gen-ART review, and Sabrina Tanamal for the IANA | Romascanu for the Gen-ART review, and Sabrina Tanamal for the IANA | |||
| review. | review. | |||
| Thanks to Ben Campbell for Area Director review suggestions. Thanks | Thanks to Ben Campbell for Area Director review suggestions. Thanks | |||
| to Spencer Dawkins, Stephen Farrel, Alissa Cooper, Mirja Kühlewind, | to Spencer Dawkins, Stephen Farrel, Alissa Cooper, Mirja Kühlewind, | |||
| and the entire IESG for their reviews. | and the entire IESG for their reviews. | |||
| End of changes. 43 change blocks. | ||||
| 82 lines changed or deleted | 82 lines changed or added | |||
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