draft-ietf-mmusic-sctp-sdp-14.txt   draft-ietf-mmusic-sctp-sdp-15.txt 
MMUSIC C. Holmberg MMUSIC C. Holmberg
Internet-Draft S. Loreto Internet-Draft S. Loreto
Intended status: Standards Track G. Camarillo Intended status: Standards Track G. Camarillo
Expires: September 6, 2015 Ericsson Expires: March 10, 2016 Ericsson
March 5, 2015 September 7, 2015
Stream Control Transmission Protocol (SCTP)-Based Media Transport in the Stream Control Transmission Protocol (SCTP)-Based Media Transport in the
Session Description Protocol (SDP) Session Description Protocol (SDP)
draft-ietf-mmusic-sctp-sdp-14 draft-ietf-mmusic-sctp-sdp-15
Abstract Abstract
SCTP (Stream Control Transmission Protocol) is a transport protocol The Stream Control Transmission Protocol (SCTP) is a transport
used to establish associations between two endpoints. protocol used to establish associations between two endpoints.
This specification describes how to describe SCTP associations using This specification describes how to describe SCTP associations using
the Session Description Protocol (SDP), and defines the following new the Session Description Protocol (SDP), and defines the following new
SDP Media Description protocol identifiers (proto values):'SCTP', SDP Media Description protocol identifiers (proto values):'SCTP',
'SCTP/DTLS', 'UDP/DTLS/SCTP' and 'TCP/DTLS/SCTP'. 'SCTP/DTLS', 'UDP/DTLS/SCTP' and 'TCP/DTLS/SCTP'.
The specification also describes how to use the new proto values The specification also describes how to use the new proto values
together with the SDP Offer/Answer mechanism in order to negotiate together with the SDP Offer/Answer mechanism in order to negotiate
and establish SCTP associations, and how to indicate the SCTP and establish SCTP associations, and how to indicate the SCTP
application usage. application usage.
skipping to change at page 1, line 43 skipping to change at page 1, line 43
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 September 6, 2015. This Internet-Draft will expire on March 10, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2015 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 2, line 28 skipping to change at page 2, line 28
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. SCTP Terminology . . . . . . . . . . . . . . . . . . . . . . 4 3. SCTP Terminology . . . . . . . . . . . . . . . . . . . . . . 4
4. SDP Media Descriptions . . . . . . . . . . . . . . . . . . . 4 4. SDP Media Descriptions . . . . . . . . . . . . . . . . . . . 4
4.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2. Protocol Identifiers . . . . . . . . . . . . . . . . . . 5 4.2. Protocol Identifiers . . . . . . . . . . . . . . . . . . 5
4.3. Media Format Management . . . . . . . . . . . . . . . . . 5 4.3. Media Format Management . . . . . . . . . . . . . . . . . 5
4.4. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.4. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.4.1. General . . . . . . . . . . . . . . . . . . . . . . . 6 4.4.1. General . . . . . . . . . . . . . . . . . . . . . . . 6
4.4.2. ABNF . . . . . . . . . . . . . . . . . . . . . . . . 6 4.4.2. ABNF . . . . . . . . . . . . . . . . . . . . . . . . 6
4.5. Example . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.5. Example . . . . . . . . . . . . . . . . . . . . . . . . . 6
5. SDP 'sctp-port' Attribute . . . . . . . . . . . . . . . . . . 6 5. SDP 'sctp-port' Attribute . . . . . . . . . . . . . . . . . . 7
5.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 6 5.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 7 5.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.3. Mux Category . . . . . . . . . . . . . . . . . . . . . . 7 5.3. Mux Category . . . . . . . . . . . . . . . . . . . . . . 7
6. SDP 'max-message-size' Attribute . . . . . . . . . . . . . . 7 6. SDP 'max-message-size' Attribute . . . . . . . . . . . . . . 8
6.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 7 6.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 8 6.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.3. Mux Category . . . . . . . . . . . . . . . . . . . . . . 8 6.3. Mux Category . . . . . . . . . . . . . . . . . . . . . . 8
7. UDP/DTLS/SCTP Transport Realization . . . . . . . . . . . . . 8 7. UDP/DTLS/SCTP Transport Realization . . . . . . . . . . . . . 9
8. TCP/DTLS/SCTP Transport Realization . . . . . . . . . . . . . 9 8. TCP/DTLS/SCTP Transport Realization . . . . . . . . . . . . . 9
9. SCTP Association Management . . . . . . . . . . . . . . . . . 9 9. SCTP Association Management . . . . . . . . . . . . . . . . . 9
9.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 9 9.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 9
9.2. SDP sendrecv/sendonly/recvonly/inactive Attribute . . . . 9 9.2. SDP sendrecv/sendonly/recvonly/inactive Attribute . . . . 10
9.3. SDP setup Attribute . . . . . . . . . . . . . . . . . . . 9 9.3. SDP setup Attribute . . . . . . . . . . . . . . . . . . . 10
9.3.1. General . . . . . . . . . . . . . . . . . . . . . . . 9 9.3.1. General . . . . . . . . . . . . . . . . . . . . . . . 10
9.3.2. SCTP Association Initiation . . . . . . . . . . . . . 10 9.3.2. SCTP Association Initiation . . . . . . . . . . . . . 10
9.3.3. TLS Role Determination . . . . . . . . . . . . . . . 10 9.3.3. TLS Role Determination . . . . . . . . . . . . . . . 10
9.4. SDP connection Attribute . . . . . . . . . . . . . . . . 11 9.4. SDP connection Attribute . . . . . . . . . . . . . . . . 11
10. SDP Offer/Answer Procedures . . . . . . . . . . . . . . . . . 11 10. SDP Offer/Answer Procedures . . . . . . . . . . . . . . . . . 11
10.1. General . . . . . . . . . . . . . . . . . . . . . . . . 11 10.1. General . . . . . . . . . . . . . . . . . . . . . . . . 11
10.2. Generating the Initial SDP Offer . . . . . . . . . . . . 12 10.2. Generating the Initial SDP Offer . . . . . . . . . . . . 12
10.3. Generating the SDP Answer . . . . . . . . . . . . . . . 12 10.3. Generating the SDP Answer . . . . . . . . . . . . . . . 12
10.4. Offerer Processing of the SDP Answer . . . . . . . . . . 13 10.4. Offerer Processing of the SDP Answer . . . . . . . . . . 13
10.5. Modifying the Session . . . . . . . . . . . . . . . . . 13 10.5. Modifying the Session . . . . . . . . . . . . . . . . . 14
11. Multihoming Considerations . . . . . . . . . . . . . . . . . 14 11. Multihoming Considerations . . . . . . . . . . . . . . . . . 14
12. NAT Considerations . . . . . . . . . . . . . . . . . . . . . 14 12. NAT Considerations . . . . . . . . . . . . . . . . . . . . . 15
12.1. General . . . . . . . . . . . . . . . . . . . . . . . . 14 12.1. General . . . . . . . . . . . . . . . . . . . . . . . . 15
12.2. ICE Considerations . . . . . . . . . . . . . . . . . . . 15 12.2. ICE Considerations . . . . . . . . . . . . . . . . . . . 15
13. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 15 13. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 15
13.1. Establishment of UDP/DTLS/SCTP association . . . . . . . 15 13.1. Establishment of UDP/DTLS/SCTP association . . . . . . . 16
14. Security Considerations . . . . . . . . . . . . . . . . . . . 16 14. Security Considerations . . . . . . . . . . . . . . . . . . . 16
15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
15.1. New SDP proto values . . . . . . . . . . . . . . . . . . 17 15.1. New SDP proto values . . . . . . . . . . . . . . . . . . 17
15.2. New SDP Attributes . . . . . . . . . . . . . . . . . . . 17 15.2. New SDP Attributes . . . . . . . . . . . . . . . . . . . 17
15.2.1. sctp-port . . . . . . . . . . . . . . . . . . . . . 17 15.2.1. sctp-port . . . . . . . . . . . . . . . . . . . . . 17
15.2.2. max-message-size . . . . . . . . . . . . . . . . . . 18 15.2.2. max-message-size . . . . . . . . . . . . . . . . . . 18
15.3. association-usage Name Registry . . . . . . . . . . . . 18 15.3. association-usage Name Registry . . . . . . . . . . . . 18
16. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 19 16. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 19
17. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 19 17. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 19
18. References . . . . . . . . . . . . . . . . . . . . . . . . . 21 18. References . . . . . . . . . . . . . . . . . . . . . . . . . 21
18.1. Normative References . . . . . . . . . . . . . . . . . . 21 18.1. Normative References . . . . . . . . . . . . . . . . . . 21
18.2. Informative References . . . . . . . . . . . . . . . . . 22 18.2. Informative References . . . . . . . . . . . . . . . . . 23
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24
1. Introduction 1. Introduction
SDP (Session Description Protocol) [RFC4566] provides a general- SDP (Session Description Protocol) [RFC4566] provides a general-
purpose format for describing multimedia sessions in announcements or purpose format for describing multimedia sessions in announcements or
invitations. TCP-Based Media Transport in the Session Description invitations. TCP-Based Media Transport in the Session Description
Protocol (SDP) [RFC4145] specifies a general mechanism for describing Protocol (SDP) [RFC4145] specifies a general mechanism for describing
and establishing TCP [RFC0793] streams. Connection-Oriented Media and establishing TCP [RFC0793] streams. Connection-Oriented Media
Transport over the Transport Layer Security (TLS) Protocol in SDP Transport over the Transport Layer Security (TLS) Protocol in SDP
[RFC4572] extends RFC4145 [RFC4145] for describing TCP-based media [RFC4572] extends RFC4145 [RFC4145] for describing TCP-based media
streams that are protected using TLS. streams that are protected using TLS.
SCTP (Stream Control Transmission Protocol) [RFC4960] is a transport The Stream Control Transmission Protocol (SCTP) [RFC4960] is a
protocol used to establish associations between two endpoints. transport protocol used to establish associations between two
endpoints.
This specification defines how to describe SCTP associations using This specification defines how to describe SCTP associations using
the Session Description Protocol (SDP) [RFC4566], and defines the the Session Description Protocol (SDP) [RFC4566], and defines the
following new SDP Media Description [RFC4566] protocol identifiers following new SDP Media Description [RFC4566] protocol identifiers
(proto values):'SCTP', 'SCTP/DTLS', 'UDP/DTLS/SCTP' and 'TCP/DTLS/ (proto values):'SCTP', 'SCTP/DTLS', 'UDP/DTLS/SCTP' and 'TCP/DTLS/
SCTP'. SCTP'.
The specification also describes how to use the new proto values The specification also describes how to use the new proto values
together with the SDP Offer/Answer mechanism [RFC3264] in order to together with the SDP Offer/Answer mechanism [RFC3264] in order to
negotiate and establish SCTP associations, and how to indicate the negotiate and establish SCTP associations, and how to indicate the
SCTP application usage. SCTP application usage.
NOTE: TLS is designed to run on top of a byte-stream oriented NOTE: TLS is designed to run on top of a byte-stream oriented
transport protocol providing a reliable, in-sequence delivery like transport protocol providing a reliable, in-sequence delivery like
TCP. [RFC6083] presents serious limitations with transporting SCTP TCP. [RFC6083] presents serious limitations with transporting TLS on
on top of TLS. Therefore, defining a mechanism to negotiate media top of SCTP. Therefore, defining a mechanism to negotiate media
streams transported using SCTP on top of TLS is outside the scope of streams transported using TLS on top of SCTP, i.e. 'SCTP/TLS', is
this specification. outside the scope of this specification.
2. Terminology 2. Terminology
In this document, the key words "MUST", "MUST NOT", "REQUIRED", In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT
RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as
described in BCP 14, RFC 2119 [RFC2119] and indicate requirement described in BCP 14, RFC 2119 [RFC2119] and indicate requirement
levels for compliant implementations. levels for compliant implementations.
3. SCTP Terminology 3. SCTP Terminology
skipping to change at page 6, line 26 skipping to change at page 6, line 28
This specification creates an IANA registry for 'association-usage' This specification creates an IANA registry for 'association-usage'
values. values.
4.4.2. ABNF 4.4.2. ABNF
sctp-m-line = %x6d "=" sctp-m-line = %x6d "="
("application" SP sctp-port SP "SCTP" SP fmt CRLF) / ("application" SP sctp-port SP "SCTP" SP fmt CRLF) /
("application" SP sctp-port SP "SCTP/DTLS" SP fmt CRLF) / ("application" SP sctp-port SP "SCTP/DTLS" SP fmt CRLF) /
("application" SP udp-port SP "UDP/DTLS/SCTP" SP fmt CRLF) / ("application" SP udp-port SP "UDP/DTLS/SCTP" SP fmt CRLF) /
("application" SP tcp-port SP "TCP/DTLS/SCTP" SP fmt CRLF) ("application" SP tcp-port SP "TCP/DTLS/SCTP" SP fmt CRLF)
sctp-port = port sctp-port = port
udp-port = port udp-port = port
tcp-port = port tcp-port = port
fmt = association-usage fmt = association-usage
association-usage = token association-usage = token
token and port as defined in RFC4566
4.5. Example 4.5. Example
m=application 12345 UDP/DTLS/SCTP webrtc-datachannel m=application 12345 UDP/DTLS/SCTP webrtc-datachannel
a=max-message-size: 100000 a=max-message-size: 100000
5. SDP 'sctp-port' Attribute 5. SDP 'sctp-port' Attribute
5.1. General 5.1. General
This section defines a new SDP media-level attribute, 'sctp-port'. This section defines a new SDP media-level attribute, 'sctp-port'.
The attribute can be associated with an SDP media description (m- The attribute can be associated with an SDP media description (m-
line) with a 'UDP/DTLS/SCTP' or a 'TCP/DTLS/SCTP' proto value, in line) with a 'UDP/DTLS/SCTP' or a 'TCP/DTLS/SCTP' proto value. In
which case the m- line port value indicates the port of the that case the m- line port value indicates the port of the underlying
underlying transport-layer protocol (UDP or TCP), on which SCTP is transport layer protocol (UDP or TCP), and the 'sctp-port' value
carried, and the 'sctp-port' value indicates the SCTP port. indicates the SCTP port.
No default value is defined for the SDP sctp-port attribute. No default value is defined for the SDP sctp-port attribute.
Therefore, if the attribute is not present, the associated m- line Therefore, if the attribute is not present, the associated m- line
MUST be considered invalid. MUST be considered invalid.
Usage of the SDP sctp-port attribute with other proto values is not Usage of the SDP sctp-port attribute with other proto values is not
specified, and MUST be discarded if received. specified, and MUST be discarded if received.
5.2. Syntax 5.2. Syntax
skipping to change at page 8, line 25 skipping to change at page 8, line 38
message-size' attribute when associated with an m- line containing message-size' attribute when associated with an m- line containing
one of the following proto values: 'SCTP', 'SCTP/DTLS', 'UDP/DTLS/ one of the following proto values: 'SCTP', 'SCTP/DTLS', 'UDP/DTLS/
SCTP' or 'TCP/DTLS/SCTP'. Usage of the attribute with other proto SCTP' or 'TCP/DTLS/SCTP'. Usage of the attribute with other proto
values needs to be defined in a separate specification. values needs to be defined in a separate specification.
6.2. Syntax 6.2. Syntax
The ABNF for the SDP 'max-message-size' attribute is: The ABNF for the SDP 'max-message-size' attribute is:
max-message-size-attr = "a=max-message-size:" max-message-size max-message-size-attr = "a=max-message-size:" max-message-size
max-message-size = 1*DIGIT max-message-size = 1*40DIGIT
Leading zeroes MUST NOT be used. Leading zeroes MUST NOT be used.
6.3. Mux Category 6.3. Mux Category
The mux category for the SDP 'max-message-size' attribute is SPECIAL. The mux category for the SDP 'max-message-size' attribute is SPECIAL.
The mux rules depends on the proto value of the associated m- line. The mux rules depends on the proto value of the associated m- line.
If the proto value is 'SCTP' or 'SCTP/DTLS' the rules are identical If the proto value is 'SCTP' or 'SCTP/DTLS' the rules are identical
to the rules associated with the TRANSPORT mux category. to the rules associated with the TRANSPORT mux category.
skipping to change at page 11, line 5 skipping to change at page 11, line 15
If the underlying transport protocol is modified, the endpoints MUST If the underlying transport protocol is modified, the endpoints MUST
establish a new DTLS connection. In such case the 'active/passive' establish a new DTLS connection. In such case the 'active/passive'
status of the endpoints will again be determined following the status of the endpoints will again be determined following the
procedures in [RFC4145], and the new status will be used to determine procedures in [RFC4145], and the new status will be used to determine
the (D)TLS roles of the endpoints associated with the new DTLS the (D)TLS roles of the endpoints associated with the new DTLS
connection. connection.
NOTE: The procedure above is identical to the one defined for SRTP- NOTE: The procedure above is identical to the one defined for SRTP-
DTLS in [RFC5763]. DTLS in [RFC5763].
NOTE: As described in [add-reference], if the Interactive
Connectivity Establishment (ICE) mechanism [RFC5245] is used, all ICE
candidates associated with an SCTP association on top of a DTLS
connection as part of the same DTLS connection. Thus, a switch from
one candidate pair to another candidate pair will not trigger the
establishment of a new DTLS connection.
9.4. SDP connection Attribute 9.4. SDP connection Attribute
The SDP connection attribute is used following the procedures in The SDP connection attribute is used following the procedures in
[RFC4145], with the additional SCTP specific considerations described [RFC4145], with the additional SCTP specific considerations described
in this section. in this section.
If the m- line proto value is 'TCP/DTLS/SCTP', an SDP connection If the m- line proto value is 'TCP/DTLS/SCTP', an SDP connection
attribute associated with that m- line applies to both the SCTP attribute associated with that m- line applies to both the SCTP
association and the TCP connection. Therefore, an attribute 'new' association and the TCP connection. Therefore, an attribute 'new'
value indicates that both a new SCTP association and new TCP value indicates that both a new SCTP association and new TCP
skipping to change at page 15, line 12 skipping to change at page 15, line 27
which provides similar features of Network Address and Port which provides similar features of Network Address and Port
Translation (NAPT). Translation (NAPT).
Current NATs typically do not support SCTP. [RFC6951] defines a Current NATs typically do not support SCTP. [RFC6951] defines a
mechanism for sending SCTP on top of UDP, which makes it possible to mechanism for sending SCTP on top of UDP, which makes it possible to
use SCTP with NATs and firewalls that do not support SCTP. use SCTP with NATs and firewalls that do not support SCTP.
12.2. ICE Considerations 12.2. ICE Considerations
At the time of writing this specification, no procedures have been At the time of writing this specification, no procedures have been
defined for using ICE (Interactive Connectivity Establishment) defined for using ICE [RFC5245] together with SCTP as transport layer
[RFC5245] together with SCTP as transport layer protocol. Such protocol. Such procedures, including the associated SDP Offer/Answer
procedures, including the associated SDP Offer/Answer procedures, are procedures, are outside the scope of this specification, and might be
outside the scope of this specification, and might be defined in a defined in a future specification.
future specification.
When the transport layer protocol is UDP (in case of an SCTP When the transport layer protocol is UDP (in case of an SCTP
association on top of a DTLS connection on top of UDP), if ICE is association on top of a DTLS connection on top of UDP), if ICE is
used, the ICE procedures defined in [RFC5245] are used. used, the ICE procedures defined in [RFC5245] are used.
When the transport layer protocol is TCP (in case of an SCTP When the transport layer protocol is TCP (in case of an SCTP
association on top of a DTLS connection on top of TCP), if ICE is association on top of a DTLS connection on top of TCP), if ICE is
used, the ICE procedures defined in [RFC6544] are used. used, the ICE procedures defined in [RFC6544] are used.
13. Examples Implementations MUST treat all ICE candidate pairs associated with a
an SCTP association on top of a DTLS connection as part of the same
DTLS connection. Thus, there will only be one DTLS handshake even if
there are multiple valid candidate pairs, and shifting from one
candidate pair to another will not impact the DTLS connection. If
new candidates are added, they will also be part of the same DTLS
connection.
13. Examples
13.1. Establishment of UDP/DTLS/SCTP association 13.1. Establishment of UDP/DTLS/SCTP association
SDP Offer: SDP Offer:
m=application 54111 UDP/DTLS/SCTP webrtc-datachannel m=application 54111 UDP/DTLS/SCTP webrtc-datachannel
c=IN IP4 192.0.2.1 c=IN IP4 192.0.2.1
a=setup:actpass a=setup:actpass
a=connection:new a=connection:new
a=sctp-port:5000 a=sctp-port:5000
a=max-message-size:100000 a=max-message-size:100000
- The offerer indicates that the usage of the - The offerer indicates that the usage of the
UDP/DTLS/SCTP association will be as defined UDP/DTLS/SCTP association will be as defined
for the 'webrtc-datachannel' format value. for the 'webrtc-datachannel' format value.
- The offerer UDP port value is 54111. - The offerer UDP port value is 54111.
- The offerer SCTP port value is 5000. - The offerer SCTP port value is 5000.
- The offerer indicates that it can take either the - The offerer indicates that it can take either the
active or the passive role. active or the passive role.
SDP Answer: SDP Answer:
m=application 64300 UDP/DTLS/SCTP webrtc-datachannel m=application 64300 UDP/DTLS/SCTP webrtc-datachannel
c=IN IP4 192.0.2.2 c=IN IP4 192.0.2.2
a=setup:passive a=setup:passive
a=sctp-port:6000 a=sctp-port:6000
a=max-message-size:100000 a=max-message-size:100000
- The answerer UDP port value is 64300. - The answerer UDP port value is 64300.
- The answerer SCTP port value is 6000. - The answerer SCTP port value is 6000.
- The answerer takes the passive role. - The answerer takes the passive role.
14. Security Considerations 14. Security Considerations
[RFC4566] defines general SDP security considerations, while [RFC4566] defines general SDP security considerations, while
[RFC3264], [RFC4145] and [RFC4572] define security considerations [RFC3264], [RFC4145] and [RFC4572] define security considerations
when using the SDP offer/answer mechanism to negotiate media streams. when using the SDP offer/answer mechanism to negotiate media streams.
[RFC4960] defines general SCTP security considerations, while [RFC4960] defines general SCTP security considerations, while
[RFC6083] defines security considerations when using DTLS on top of [RFC6083] defines security considerations when using DTLS on top of
SCTP. SCTP, and [I-D.ietf-tsvwg-sctp-dtls-encaps] defines security
considerations when using SCTP on top of DTLS.
This specification does not introduce new security considerations in This specification does not introduce new security considerations in
addition to those defined in the specifications listed above. addition to those defined in the specifications listed above.
15. IANA Considerations 15. IANA Considerations
15.1. New SDP proto values 15.1. New SDP proto values
[RFC EDITOR NOTE: Please replace RFCXXXX with the RFC number of this [RFC EDITOR NOTE: Please replace RFCXXXX with the RFC number of this
document.] document.]
skipping to change at page 19, line 33 skipping to change at page 19, line 33
16. Acknowledgments 16. Acknowledgments
The authors wish to thank Harald Alvestrand, Randell Jesup, Paul The authors wish to thank Harald Alvestrand, Randell Jesup, Paul
Kyzivat, Michael Tuexen, Juergen Stoetzer-Bradler, Flemming Andreasen Kyzivat, Michael Tuexen, Juergen Stoetzer-Bradler, Flemming Andreasen
and Ari Keranen for their comments and useful feedback. and Ari Keranen for their comments and useful feedback.
17. Change Log 17. Change Log
[RFC EDITOR NOTE: Please remove this section when publishing] [RFC EDITOR NOTE: Please remove this section when publishing]
Changes from draft-ietf-mmusic-sctp-sdp-13 Changes from draft-ietf-mmusic-sctp-sdp-14
o Changes based on WGLC comments from Magnus Westerlund.
o - ABNF clarification that token and port are defined in RFC4566.
o - Specify 40 as maximum digit character length for the SDP max-
message-size value.
o - Editorial clarification.
o Changes based on discussions at IETF#92.
o - Specify that all ICE candidate pairs belong to the same DTLS
connection.
Changes from draft-ietf-mmusic-sctp-sdp-13
o Changes based on comments from Paul Kyzivat. o Changes based on comments from Paul Kyzivat.
o - Text preventing usage of well-known ports removed. o - Text preventing usage of well-known ports removed.
o - Editorial clarification. o - Editorial clarification.
Changes from draft-ietf-mmusic-sctp-sdp-12 Changes from draft-ietf-mmusic-sctp-sdp-12
o Mux category rules added for new SDP attributes. o Mux category rules added for new SDP attributes.
skipping to change at page 21, line 12 skipping to change at page 21, line 28
o Text about SDP direction attributes added. o Text about SDP direction attributes added.
o Text about TLS role determination added. o Text about TLS role determination added.
18. References 18. References
18.1. Normative References 18.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model [RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model
with Session Description Protocol (SDP)", RFC 3264, June with Session Description Protocol (SDP)", RFC 3264,
2002. DOI 10.17487/RFC3264, June 2002,
<http://www.rfc-editor.org/info/rfc3264>.
[RFC4145] Yon, D. and G. Camarillo, "TCP-Based Media Transport in [RFC4145] Yon, D. and G. Camarillo, "TCP-Based Media Transport in
the Session Description Protocol (SDP)", RFC 4145, the Session Description Protocol (SDP)", RFC 4145,
September 2005. DOI 10.17487/RFC4145, September 2005,
<http://www.rfc-editor.org/info/rfc4145>.
[RFC4289] Freed, N. and J. Klensin, "Multipurpose Internet Mail [RFC4289] Freed, N. and J. Klensin, "Multipurpose Internet Mail
Extensions (MIME) Part Four: Registration Procedures", BCP Extensions (MIME) Part Four: Registration Procedures",
13, RFC 4289, December 2005. BCP 13, RFC 4289, DOI 10.17487/RFC4289, December 2005,
<http://www.rfc-editor.org/info/rfc4289>.
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
Description Protocol", RFC 4566, July 2006. Description Protocol", RFC 4566, DOI 10.17487/RFC4566,
July 2006, <http://www.rfc-editor.org/info/rfc4566>.
[RFC4571] Lazzaro, J., "Framing Real-time Transport Protocol (RTP) [RFC4571] Lazzaro, J., "Framing Real-time Transport Protocol (RTP)
and RTP Control Protocol (RTCP) Packets over Connection- and RTP Control Protocol (RTCP) Packets over Connection-
Oriented Transport", RFC 4571, July 2006. Oriented Transport", RFC 4571, DOI 10.17487/RFC4571, July
2006, <http://www.rfc-editor.org/info/rfc4571>.
[RFC4572] Lennox, J., "Connection-Oriented Media Transport over the [RFC4572] Lennox, J., "Connection-Oriented Media Transport over the
Transport Layer Security (TLS) Protocol in the Session Transport Layer Security (TLS) Protocol in the Session
Description Protocol (SDP)", RFC 4572, July 2006. Description Protocol (SDP)", RFC 4572,
DOI 10.17487/RFC4572, July 2006,
<http://www.rfc-editor.org/info/rfc4572>.
[RFC4960] Stewart, R., "Stream Control Transmission Protocol", RFC [RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol",
4960, September 2007. RFC 4960, DOI 10.17487/RFC4960, September 2007,
<http://www.rfc-editor.org/info/rfc4960>.
[RFC5061] Stewart, R., Xie, Q., Tuexen, M., Maruyama, S., and M. [RFC5061] Stewart, R., Xie, Q., Tuexen, M., Maruyama, S., and M.
Kozuka, "Stream Control Transmission Protocol (SCTP) Kozuka, "Stream Control Transmission Protocol (SCTP)
Dynamic Address Reconfiguration", RFC 5061, September Dynamic Address Reconfiguration", RFC 5061,
2007. DOI 10.17487/RFC5061, September 2007,
<http://www.rfc-editor.org/info/rfc5061>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008. DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>.
[RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
(TLS) Protocol Version 1.2", RFC 5246, August 2008. Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
<http://www.rfc-editor.org/info/rfc5234>.
[RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer [RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security Version 1.2", RFC 6347, January 2012. Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347,
January 2012, <http://www.rfc-editor.org/info/rfc6347>.
[RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type [RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type
Specifications and Registration Procedures", BCP 13, RFC Specifications and Registration Procedures", BCP 13,
6838, January 2013. RFC 6838, DOI 10.17487/RFC6838, January 2013,
<http://www.rfc-editor.org/info/rfc6838>.
[I-D.ietf-tsvwg-sctp-dtls-encaps] [I-D.ietf-tsvwg-sctp-dtls-encaps]
Tuexen, M., Stewart, R., Jesup, R., and S. Loreto, "DTLS Tuexen, M., Stewart, R., Jesup, R., and S. Loreto, "DTLS
Encapsulation of SCTP Packets", draft-ietf-tsvwg-sctp- Encapsulation of SCTP Packets", draft-ietf-tsvwg-sctp-
dtls-encaps-09 (work in progress), January 2015. dtls-encaps-09 (work in progress), January 2015.
[I-D.ietf-mmusic-sdp-mux-attributes] [I-D.ietf-mmusic-sdp-mux-attributes]
Nandakumar, S., "A Framework for SDP Attributes when Nandakumar, S., "A Framework for SDP Attributes when
Multiplexing", draft-ietf-mmusic-sdp-mux-attributes-08 Multiplexing", draft-ietf-mmusic-sdp-mux-attributes-10
(work in progress), January 2015. (work in progress), July 2015.
18.2. Informative References 18.2. Informative References
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7, RFC [RFC0793] Postel, J., "Transmission Control Protocol", STD 7,
793, September 1981. RFC 793, DOI 10.17487/RFC0793, September 1981,
<http://www.rfc-editor.org/info/rfc793>.
[RFC5245] Rosenberg, J., "Interactive Connectivity Establishment [RFC5245] Rosenberg, J., "Interactive Connectivity Establishment
(ICE): A Protocol for Network Address Translator (NAT) (ICE): A Protocol for Network Address Translator (NAT)
Traversal for Offer/Answer Protocols", RFC 5245, April Traversal for Offer/Answer Protocols", RFC 5245,
2010. DOI 10.17487/RFC5245, April 2010,
<http://www.rfc-editor.org/info/rfc5245>.
[RFC5763] Fischl, J., Tschofenig, H., and E. Rescorla, "Framework [RFC5763] Fischl, J., Tschofenig, H., and E. Rescorla, "Framework
for Establishing a Secure Real-time Transport Protocol for Establishing a Secure Real-time Transport Protocol
(SRTP) Security Context Using Datagram Transport Layer (SRTP) Security Context Using Datagram Transport Layer
Security (DTLS)", RFC 5763, May 2010. Security (DTLS)", RFC 5763, DOI 10.17487/RFC5763, May
2010, <http://www.rfc-editor.org/info/rfc5763>.
[RFC6083] Tuexen, M., Seggelmann, R., and E. Rescorla, "Datagram [RFC6083] Tuexen, M., Seggelmann, R., and E. Rescorla, "Datagram
Transport Layer Security (DTLS) for Stream Control Transport Layer Security (DTLS) for Stream Control
Transmission Protocol (SCTP)", RFC 6083, January 2011. Transmission Protocol (SCTP)", RFC 6083,
DOI 10.17487/RFC6083, January 2011,
<http://www.rfc-editor.org/info/rfc6083>.
[RFC6544] Rosenberg, J., Keranen, A., Lowekamp, B., and A. Roach, [RFC6544] Rosenberg, J., Keranen, A., Lowekamp, B., and A. Roach,
"TCP Candidates with Interactive Connectivity "TCP Candidates with Interactive Connectivity
Establishment (ICE)", RFC 6544, March 2012. Establishment (ICE)", RFC 6544, DOI 10.17487/RFC6544,
March 2012, <http://www.rfc-editor.org/info/rfc6544>.
[RFC6951] Tuexen, M. and R. Stewart, "UDP Encapsulation of Stream [RFC6951] Tuexen, M. and R. Stewart, "UDP Encapsulation of Stream
Control Transmission Protocol (SCTP) Packets for End-Host Control Transmission Protocol (SCTP) Packets for End-Host
to End-Host Communication", RFC 6951, May 2013. to End-Host Communication", RFC 6951,
DOI 10.17487/RFC6951, May 2013,
<http://www.rfc-editor.org/info/rfc6951>.
[I-D.ietf-behave-sctpnat] [I-D.ietf-behave-sctpnat]
Stewart, R., Tuexen, M., and I. Ruengeler, "Stream Control Stewart, R., Tuexen, M., and I. Ruengeler, "Stream Control
Transmission Protocol (SCTP) Network Address Translation", Transmission Protocol (SCTP) Network Address Translation",
draft-ietf-behave-sctpnat-09 (work in progress), September draft-ietf-behave-sctpnat-09 (work in progress), September
2013. 2013.
Authors' Addresses Authors' Addresses
Christer Holmberg Christer Holmberg
 End of changes. 53 change blocks. 
89 lines changed or deleted 143 lines changed or added

This html diff was produced by rfcdiff 1.42. The latest version is available from http://tools.ietf.org/tools/rfcdiff/