End-to-End Session Identification in IP-Based Multimedia Communication Networks
draft-jones-insipid-session-id-01
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
|
|
|---|---|---|---|
| Authors | Paul Jones , Chris Pearce , James Polk , Gonzalo Salgueiro | ||
| Last updated | 2012-10-22 | ||
| Replaces | draft-jones-ipmc-session-id | ||
| Replaced by | draft-ietf-insipid-session-id, draft-ietf-insipid-session-id, RFC 7989 | ||
| RFC stream | (None) | ||
| Formats | |||
| Additional resources | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-jones-insipid-session-id-01
Network Working Group P. Jones
Internet Draft C. Pearce
Intended status: Standards Track J. Polk
Expires: April 22, 2013 G. Salgueiro
Cisco Systems
October 22, 2012
End-to-End Session Identification in IP-Based Multimedia
Communication Networks
draft-jones-insipid-session-id-01.txt
Abstract
This document describes an end-to-end Session Identifier for use in
IP-based Multimedia Communication systems that enables endpoints,
intermediate devices, and management systems to identify a session
end-to-end, associate multiple endpoints with a given multipoint
conference, track communication sessions when they are redirected,
and associate one or more media flows with a given communication
session.
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on April 22, 2013.
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Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document.
Table of Contents
1. Introduction...................................................2
2. Conventions used in this document..............................3
3. Session Identifier Requirements and Use Cases..................3
4. Constructing the Session Identifier............................3
5. Transmitting the Session Identifier in SIP.....................4
6. Endpoint Behavior..............................................5
7. Processing by Intermediaries...................................6
8. Associating Endpoints in a Multipoint Conference...............6
9. Correlating Media Flows with Sessions..........................7
10. Various Call Flow Operations Utilizing the Session ID.........7
10.1. Basic Session-ID Construction with 2 UUIDs...............7
10.2. Basic Call Transfer using REFER..........................8
10.3. Basic Call Transfer using reINVITE......................10
10.4. Single Focus Conferencing...............................11
10.5. Single Focus Conferencing using WebEx...................12
10.6. Basic 3PCC for two UAs..................................13
11. Compatibility with a Previous Implementation.................14
12. Security Considerations......................................15
13. IANA Considerations..........................................15
14. Acknowledgments..............................................16
15. References...................................................16
15.1. Normative References....................................16
15.2. Informative References..................................16
Author's Addresses...............................................17
1. Introduction
IP-based multimedia communication systems like SIP [1] and H.323 [2]
have the concept of a "call identifier" that is globally unique. The
identifier is intended to represent an end-to-end communication
session from the originating device to the terminating device. Such
an identifier is useful for troubleshooting, billing, session
tracking, and so forth.
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Unfortunately, there are a number of factors that contribute to the
fact that the current call identifiers defined in SIP and H.323 are
not suitable for end-to-end session identification. A fundamental
issue in protocol interworking is the fact that the syntax for the
call identifier in SIP and H.323 is different between the two
protocols. This important fact makes it impossible for call
identifiers to be exchanged end-to-end when a network utilizes one or
more session protocols.
Another reason why the current call identifiers are not suitable to
identify the session end-to-end is that in real-world deployments
devices like session border controllers often change the session
signaling as it passes through the device, including the value of the
call identifier. While this is deliberate and useful, it makes it
very difficult to track sessions end-to-end.
This draft presents a new identifier, referred to as the Session
Identifier, or "Session ID", and associated syntax intended to
overcome the issues that exist with the currently defined call
identifiers. The proposal in this document attempts to comply with
the requirements specified in [5]. This proposal also has
capabilities not mentioned in [5], shown in call flows in section 10.
Additionally, this proposal attempts to account for a previous,
proprietary version of a SIP Session ID header, proposing a backwards
compatibility of sorts, described in section 11.
2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [3] when they
appear in ALL CAPS. These words may also appear in this document in
lower case as plain English words, absent their normative meanings.
3. Session Identifier Requirements and Use Cases
Requirements and Use Cases for the end-to-end Session Identifier can
be found in a separate memo titled "Requirements for an End-to-End
Session Identification in IP-Based Multimedia Communication Networks"
[5].
4. Constructing the Session Identifier
The Session Identifier is comprised of two RFC 4122 defined UUIDs
[4], with each UUID created by the endpoints participating in the
session. The SIP user agent (UA) initially transmitting the SIP
request will create a UUID and transmit that to the ultimate
destination UA. Likewise, the responding UA will create a UUID and
transmit that to the first UA. These two distinct UUIDs form what is
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referred to as the Session Identifier and is represented in this
document in set notation of the form {A,B}, where A is UUID value
from the UA transmitting a message and B is the UUID value from the
intended recipient of the message, i.e., not an intermediary server
along the signaling path. The set {A,B} is equal to the set {B,A},
and thus both represent the same Session Identifier.
In the case where only one UUID is known, such as when a UA first
initiates a SIP request, the Session ID would be {A}, where "A"
represents the single UUID value transmitted.
Devices that act upon the Session Identifier may wish to represent
these UUID values in some manner other than a pair of distinct values
for, as examples, logging or internal value comparison. A device MAY
take the two UUID values and produce a single 32-octet binary value
that can be efficiently compared with other values. When
constructing a single binary value out of the component UUIDs, it is
RECOMMENDED that devices perform a binary comparison of the two
UUIDs, starting with the most significant byte of each UUID. The
UUID with the higher binary value is placed after the UUID with the
lower binary value. As an example, if the Session Identifier {A,B}
is stored and treated as a single binary value and "A" is numerically
greater than "B", then the two values would be concatenated as B||A.
When only one UUID value is known, entities MAY assume the absent
UUID has a value of zero (i.e., 16 octets with a zero value).
Consider the following example.
Endpoint 1 produces this UUID: 0xaeffa652b22911dfa81f12313a006823
Endpoint 2 produces this UUID: 0xbe11afc8b22911df86c412313a006823
The resulting concatenated Session Identifier would be:
0xaeffa652b22911dfa81f12313a006823be11afc8b22911df86c412313a006823
In the above example, the UUIDs are presented as a string of
hexadecimal characters that correspond to the binary values
comprising the UUID as shown in the table at the end of Section 4.1.2
of RFC 4122 [4].
How a device acting on Session Identifiers stores, processes, or
utilizes the Session Identifier is outside the scope of this
document.
5. Transmitting the Session Identifier in SIP
Each session initiated or accepted MUST have a local UA-generated
UUID associated with the session. This value MUST remain unchanged
throughout the duration of that session.
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A SIP UA MUST convey its Session Identifier UUID in all transmitted
messages within the same session. To do this, each transmitted
message MUST include the "Session-ID" header. The Session-ID header
has the following syntax:
Session-ID = "Session-ID" HCOLON sess-id
( SEMI rcvr-uuid )
*( SEMI generic-param )
sess-id = 32(DIGIT / %x61-66) ;32 chars of [0-9a-f]
rcvr-uuid = "rcvr" EQUAL 32(DIGIT / %x61-66)
The "sess-id" value represents the UUID value of the UA transmitting
the message. If the UA transmitting the message previously received
a UUID value from its peer endpoint, it MUST include that UUID as the
"rcvr" parameter. For example, using the UUID values from the
previous section, a Session-ID header might appear like this:
Session-ID: aeffa652b22911dfa81f12313a006823;
rcvr=be11afc8b22911df86c412313a006823
The UUID values are presented as strings of hexadecimal characters,
with the most significant byte of the UUID appearing first.
6. Endpoint Behavior
To comply with this specification, SIP UAs MUST include a Session-ID
header-value in all messages transmitted as a part of a communication
session. Session-ID header-values MUST NOT be present in any other
SIP header than the Session-ID header.
A non-intermediary UAS that receives a Session-ID header MUST take
note of the first UUID value that it receives in the Session-ID
header and assume that that is the UUID of the peer endpoint within
that communications session. UAs MUST include this received UUID
value as the "rcvr" parameter when transmitting subsequent messages.
UAs MUST ignore the value in the "rcvr" parameter in any message it
receives, as this value may be incorrect due to service interactions
as shown in examples later in this document.
For any purpose the UA has for the Session-ID, it MUST assume that
the Session-ID is {A,B} where "A" is the UUID value of this endpoint
and "B" is the UUID value of the peer endpoint, taken from the most
recently received message within this session.
An endpoint MUST assume that the UUID value of the peer UA MAY change
at any time due to service interactions. However, once an UA
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allocates a UUID value for a communication session, the UA MUST NOT
change that UUID value for the duration of the session, including
when communication attempts are retried due to receipt of 4xx
messages, when the session is redirected in response to a 3xx
message, or when a session is transferred via a REFER message [6].
It is also important to note that if a session is forked by an
intermediary in the network, the initiating UA may receive multiple
responses back from different endpoints, each of which will contain a
different UUID value. UAs MUST take care to ensure that the correct
UUID value is returned in the "rcvr" parameter when responding to
those endpoints.
7. Processing by Intermediaries
Intermediaries that wish to utilize the Session-ID MAY extract the
UUID header-values from any SIP message. Alternatively,
intermediaries MAY observe the first UUID value in the Session-ID
header for messages sent in each direction and use those values to
locally construct the Session Identifier.
Intermediaries MUST NOT alter the UUID values found in the Session-ID
header, except as described in this section.
If performing interworking between SIP and another session protocol,
an intermediary MUST convert the Session-ID header as necessary so
that it properly places the correct UUID value of the message
transmitter and assumed recipient. This is a protocol gateway or
interworking function.
Intermediary devices that transfer a call, such as by joining
together two different "call legs", MUST properly construct a
Session-ID header that contains the correct UUID values and correct
placement of those values. As described above, the recipient of any
message initiated by the intermediary will assume that the first UUID
value belongs to the peer endpoint.
Devices that initiate communication sessions following the procedures
for third party call control MUST fabricate a UUID value that will be
utilized only temporarily. Once the responding endpoint provides a
UUID value in a response message, the temporary value MUST be
discarded and replaced with the endpoint-provided UUID value. Refer
to the third-party call control example for an illustration.
8. Associating Endpoints in a Multipoint Conference
Multipoint Control Units (MCUs) group two or more sessions into a
single multipoint conference. The MCU should utilize the same UUID
value for each session that is grouped into the same conference. In
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so doing, each individual session in the conference will have a
unique Session Identifier (since each endpoint will create a unique
UUID of its own), but will also have one UUID in common with all
other participants in the conference.
Intermediary devices, such as proxies or session border controllers,
or network diagnostics equipment might assume that when they see two
or more sessions with different Session Identifiers, but with one
UUID in common, that the sessions are part of the same conference.
Note, however, that this assumption of being part of the same
conference is not always true. For example, in a SIP forking
scenario, there might also be what appears to be multiple sessions
with a shared UUID value. This is actually desirable. What is
desired is to allow for the association of related sessions. Whether
sessions are related because of forking or because endpoints are
communicating as a part of a conference does not matter. They are
nonetheless related.
9. Correlating Media Flows with Sessions
It may be desirable to insert the Session Identifier header-value
into media-related packets, such as RSVP messages or RTCP packets.
In so doing, it is possible for network elements to
1. correlate session signaling with media flows;
2. associate multiple media flows with a single session; and
3. associate multiple media flows from multiple devices that are
part of a single conference
Notwithstanding the foregoing, the use of the Session Identifier for
purposes other than end-to-end session identification is outside the
scope of this document.
10. Various Call Flow Operations Utilizing the Session ID
Seeing something frequently makes understanding easier. With that in
mind, we include several call flows with the initial UUID and the
complete Session-ID indicated per message, as well as when the
Session-ID changes according to the rules within this document during
certain operations/functions.
10.1. Basic Session-ID Construction with 2 UUIDs
Session-ID
--- Alice B2BUA Bob Carol
{A} |----INVITE----->| |
{A} | |----INVITE----->|
{B,A} | |<---200 OK------|
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{B,A} |<---200 OK------| |
{A,B} |------ACK------>| |
{A,B} | |------ACK------>|
|<==============RTP==============>|
Figure 1 - Session-ID Creation when Alice calls Bob
Operation/Rules:
o Transmitter of SIP message places its Session-ID UUID first in
order;
o UA-Alice sends its UUID in INVITE;
o B2BUA receives an INVITE with a Session-ID header-value from UA-
Alice, and transmits INVITE towards UA-Bob with an unchanged
Session-ID header-value;
o UA-Bob receives Session-ID and adds its UUID to construct the
whole/complete Session-ID header-value in the 200 OK;
o UA-Bob orders the UUIDs such that its UUID is first when UA-Bob
is transmitting the SIP message;
o B2BUA receives the 200 OK response with a complete Session-ID
header-value from UA-Bob, and transmits 200 OK towards UA-Alice
with an unchanged Session-ID header-value; while maintaining the
order of UUIDs in the Session-ID header-value;
o UA-Alice, upon reception of the 200 OK from the B2BUA, transmits
the ACK towards the B2BUA with its UUID positioned first, and
the UUID from UA-Bob positioned second in the Session-ID header-
value.
o B2BUA receives the ACK with a complete Session-ID header-value
from UA-Alice, and transmits ACK towards UA-Bob with an
unchanged Session-ID header-value; while maintaining the order
of UUIDs in the Session-ID header-value;
10.2. Basic Call Transfer using REFER
Session-ID
--- Alice B2BUA Bob Carol
| | | |
|<==============RTP==============>| |
{B,A} | |<---reINVITE----| |
{B,A} |<---reINVITE----| | |
{A,B} |-----200 OK---->| | |
{A,B} | |-----200 OK---->| |
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{B,A} | |<-----ACK-------| |
{B,A} |<-----ACK-------| | |
| | | |
{B,A} | |<----REFER------| |
{B,A} |<----REFER------| | |
{A,B} |-----200 OK---->| | |
{A,B} | |-----200 OK---->| |
{B,A} | |<-----ACK-------| |
{B,A} |<-----ACK-------| | |
{A,B} |-----NOTIFY---->| | |
{A,B} | |-----NOTIFY---->| |
{B,A} | |<----200 OK-----| |
{B,A} |<----200 OK-----| | |
| | | |
{A} |-----INVITE---->| |
{A} | |-----INVITE-------------------->|
{C,A} | |<----200 OK---------------------|
{C,A} |<----200 OK-----| |
{A,C} |------ACK------>| |
{A,C} | |------ACK---------------------->|
| | | |
|<======================RTP======================>|
| | | |
{A,B} |-----NOTIFY---->| | |
{A,B} | |-----NOTIFY---->| |
{B,A} | |<----200 OK-----| |
{B,A} |<----200 OK-----| | |
{B,A} | |<-----BYE-------| |
{B,A} |<-----BYE-------| | |
{A,B} |-----200 OK---->| | |
{A,B} | |-----200 OK---->| |
| | | |
Figure 2 - Call Transfer using REFER
Operation/Rules:
Starting from the existing Alice/Bob call described in Figure 1,
which established an existing Session-ID header-value...
o UA-Bob reINVITEs Alice to call Carol, using a REFER transaction,
as described in [RFC3515]. UA-Alice is initially put on hold,
then told in the REFER who to contact with a new INVITE, in this
case UA-Carol.
o UA-Alice retains her UUID from the Alice-to-Bob call {A} when
requesting a call with UA-Carol. This same UUID traverses the
B2BUA unchanged.
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o UA-Carol receives the INVITE with a Session-ID UUID {A}, creates
its own UUID {C}, and combines them to form a full Session-ID
{C,A} in the 200 OK to the INVITE. This Session-ID header-value
traverses the B2BUA unchanged towards UA-Alice.
o UA-Alice receives the 200 OK with the Session-ID {C,A} and both
responses to UA-Carol with an ACK, generates a NOTIFY to Bob
with a Session-ID {A,B} indicating the call transfer was
successful.
o It does not matter which UA terminates the Alice-to-Bob call;
Figure 2 shows UA-Bob doing this transaction.
10.3. Basic Call Transfer using reINVITE
Alice is talking to Bob. Bob pushes a button on his phone to transfer
Alice to Carol via the B2BUA (using reINVITE).
Session-ID
--- Alice B2BUA Bob Carol
| | | |
|<==============RTP==============>| |
| | | |
{B,A} | |<---reINVITE----| |
{A,B} | |-----200 OK---->| |
{B,A} | |<-----ACK-------| |
| | | |
{A} | |-----INVITE-------------------->|
{C,A} | |<----200 OK---------------------|
{A,C} | |------ACK---------------------->|
| | | |
|<======================RTP======================>|
| | | |
{B,A} | |<-----BYE-------| |
{B,A} |<-----BYE-------| | |
{A,B} |-----200 OK---->| | |
{A,B} | |-----200 OK---->| |
| | | |
Figure 3 - Call transfer using reINVITE
Operation/Rules:
o We assume the call between Alice and Bob from Section 10.1 is
operational with Session-ID {A,B}.
o Bob sends a reINVITE to Alice to transfer her to Carol.
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o The B2BUA intercepts this reINVITE and sends a new INVITE with
Alice's UUID {A} to Carol.
o Carol receives the INVITE and accepts the request and adds her
UUID {C} to the Session-ID for this session {C,A}.
o Bob terminates the call (which Alice could too) with a BYE using
their Session-ID {B,A}.
10.4. Single Focus Conferencing
Multiple users call into a conference server (say an MCU) to attend
one of many conferences hosted on or managed by that server. Each
user has to identify which conference they want to join, but this
information is not in the SIP messaging. Rather, it is done via an
IVR. Thus, each user goes through a two-step process of signaling to
gain entry onto their conference call.
Session-ID Conference
--- Alice Focus Bob Carol
| | | |
| | | |
{A} |----INVITE----->| | |
{M1,A} |<---200 OK------| | |
{A,M1} |-----ACK------->| | |
|<====RTP=======>| | |
{M',A} |<---reINVITE----| | |
{A||M'} |-----200 OK---->| | |
{M',A} |<-----ACK-------| | |
| | | |
| | | |
{B} | |<----INVITE-----| |
{M2,B} | |-----200 OK---->| |
{B,M2} | |<-----ACK-------| |
| |<=====RTP======>| |
{M'||B} | |----reINVITE--->| |
{B||M'} | |<----200 OK-----| |
{M'||B} | |------ACK------>| |
| | | |
| | | |
{C} | |<--------------------INVITE-----|
{M3,C} | |---------------------200 OK---->|
{C,M3} | |<---------------------ACK-------|
| |<=====================RTP======>|
{M'||C} | |--------------------reINVITE--->|
{C||M'} | |<--------------------200 OK-----|
{M'||C} | |----------------------ACK------>|
Figure 4 - Single Focus Conference Bridge
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Operation/Rules:
Alice calls into a conference server to attend a certain conference.
This is a two-step operation since Alice cannot include the
conference ID and any passcode in the INVITE.
o Alice sends an INVITE to the conference server with her UUID
{A}.
o The conference server accepts using a generic, temporary UUID
{M1}.
o Once Alice, the user, gains access to the IVR for this
conference server, she enters a specific conference ID and
whatever passcode (if needed) to enter a specific conference
call.
o Once the conference server is satisfied Alice has identified
which conference she wants to attend (including any passcode
verification), the conference server reINVITEs Alice to the
specific conference and includes the UUID {M'} for that
conference. All valid participants in the same conference will
receive this same UUID for identification purposes and to better
enable monitoring, tracking and billing functions.
o Bob goes through this two-step process of an INVITE transaction,
followed by a reINVITE transaction to get this same UUID for
that conference.
o In this example, Carol (and each additional user) goes through
the same procedures and steps as Alice to get on this same
conference.
10.5. Single Focus Conferencing using WebEx
Alice, Bob and Carol call into same Webex conference.
Session-ID Conference
--- Alice Focus Bob Carol
| | | |
|<** HTTPS *****>| | |
| Transaction | | |
| | | |
{M} |<----INVITE-----| | |
{A||M} |-----200 OK---->| | |
{M||A} |<-----ACK-------| | |
|<=====RTP======>| | |
| | | |
| |<** HTTPS *****>| |
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| | Transaction | |
| | | |
{M} | |-----INVITE---->| |
{B||M} | |<----200 OK-----| |
{M||B} | |------ACK------>| |
| |<=====RTP======>| |
| | | |
| |<****************** HTTPS *****>|
| | Transaction |
| | | |
{M} | |--------------------INVITE----->|
{C||M} | |<-------------------200 OK------|
{M||C} | |---------------------ACK------->|
| |<====================RTP=======>|
Figure 5 - Single Focus Webex Conference
Operation/Rules:
o Alice communicates with Webex server with desire to join a
certain meeting, by meeting number; also includes UA-Alice's
contact information (phone number or URI).
o Conference Focus server sends INVITE to UA-Alice to start
session with the Session-ID of that server for this A/V
conference call.
o Bob and Carol perform same function to join this same A/V
conference call as Alice.
10.6. Basic 3PCC for two UAs
External entity sets up call to both Alice and Bob for them to talk
to each other.
Session-ID
--- Alice B2BUA Bob Carol
| | |
{X} |<----INVITE-----| |
{A,X} |-----200 OK---->| |
{A} | |----INVITE----->|
{B,A} | |<---200 OK------|
{A,B} |<-----ACK-------| |
{A,B} | |------ACK------>|
|<==============RTP==============>|
Figure 6 - 3PCC initiated call between Alice and Bob
Operation/Rules:
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o Some out of band procedure directs a B2BUA (or other SIP server)
to have Alice and Bob talk to each other.
o The SIP server INVITEs Alice to a session and uses a temporary
UUID {X}.
o Alice receives and accepts this call set-up and includes her
UUID {A} in the Session-ID, now {A,X}.
o The SIP server uses Alice's UUID {A}, and discards its own {X}
to INVITE Bob to the session as if this came from Alice
originally.
o Bob receives and accepts this INVITE and adds his own UUID {B}
to the Session-ID, now {B,A} for the response.
o And the session is established.
11. Compatibility with a Previous Implementation
There is a much earlier and proprietary document that specifies the
use of a Session-ID header that we will herewith attempt to achieve
backwards compatibility. Neither Session-ID has any versioning
information, so merely adding that this document describes "version
2" is insufficient. Here are the set of rules for compatibility
between the two specifications. For the purposes of this discussion,
we will label the proprietary specification of the Session-ID as
version 0 and this specification as version 1 of the Session-ID.
The previous version only has a single value as a Session-ID, but has
a generic-parameter value that can be of use.
In order to have a Version 0 talk to a Version 0 implementation,
nothing needs to be done as far as the IETF is concerned.
In order to have a Version 1 talk to a Version 1 implementation, both
implementations need to following this document (to the letter) and
everything should be just fine.
In order to have a Version 0 talk to a Version 1 implementation,
several aspects need to be looked at. They are:
o The Version 0 UA will include a single UUID as its Session-ID.
o The Version 1 UA will respond by including a complete Session-ID
with two UUIDs, with the Version 1's UUID listed first (because
it cannot know it is talking with a Version 0 implementation at
this point).
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o The Version 0 UA will have to ignore the first UUID and react to
the second UUID, which would be the recipient's Session-ID.
o During subsequent transactions within this session, the Version
1 may receive SIP requests without its UUID, but with the
Version 0's UUID. The Version 1 UA MUST add its UUID to the
received Session-ID. The Version 0 implementation will merely
disregard it each time it receives this Version 1 UUID (if it
was not the first UUID).
In order to have a Version 1 talk to a Version 0 implementation,
several aspects need to be looked at. They are:
o The Version 1 UA will include a single UUID as its initial
Session-ID header always, not knowing which version of UA it is
communicating with.
o The Version 0 UA will respond by seeing the UUID as a valid and
complete Session-ID and not include another UUID or generic-
param. Thus, the 200 OK will not include any Session-ID part of
its own from the Version 0 implementation.
o Open question - How do we want the Version 1 implementation
interpret this?
o Another open question - how do we want all intermediaries and/or
monitoring/billing systems to interpret this single UUID
complete Session-ID?
12. Security Considerations
When creating a UUID value, endpoints SHOULD ensure that there is no
user or device-identifying information contained within the UUID. In
some environments, though, use of a MAC address, which is one option
when constructing a UUID, may be desirable, especially in some
enterprise environments. When communicating over the Internet,
though, the UUID value MUST utilize random values.
Other considerations???
13. IANA Considerations
The following is the registration for the 'Session-ID' header field
to the "Header Name" registry at http://www.iana.org/assignments/sip-
parameters:
RFC number: [this document]
Header name: 'Session-ID'
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Compact form: none
14. Acknowledgments
The authors would like to than Hadriel Kaplan and Christer Holmberg
for their useful comments during the development of this document.
This document was prepared using 2-Word-v2.0.template.dot.
15. References
15.1. Normative References
[1] Rosenberg, J., et al., "SIP: Session Initiation Protocol", RFC
3261, June 2002.
[2] Recommendation ITU-T H.323, "Packet-based multimedia
communications systems", December 2009.
[3] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[4] Leach, P., Mealling, M., Salz, R., "A Universally Unique
IDentifier (UUID) URN Namespace", RFC 4122, July 2005.
[5] Jones, et al., "Requirements for an End-to-End Session
Identification in IP-Based Multimedia Communication Networks",
draft-jones-insipid-session-id-reqts-02.txt, October 2012.
15.2. Informative References
[6] Sparks, R., "The Session Initiation Protocol (SIP) Refer
Method", RFC 3515, April 2003.
[7] Braden, R., et al., "Resource ReSerVation Protocol (RSVP) --
Version 1 Functional Specification", RFC 2205, September 1997.
[8] Schulzrinne, H., et al., "RTP: A Transport Protocol for Real-
Time Applications", RFC 3550, July 2003.
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Author's Addresses
Paul E. Jones
Cisco Systems, Inc.
7025 Kit Creek Rd.
Research Triangle Park, NC 27709
USA
Phone: +1 919 476 2048
Email: paulej@packetizer.com
IM: xmpp:paulej@packetizer.com
Chris Pearce
Cisco Systems, Inc.
2300 East President George Bush Highway
Richardson, TX 75082
USA
Phone: +1 972 813 5123
Email: chrep@cisco.com
IM: xmpp:chrep@cisco.com
James Polk
Cisco Systems, Inc.
3913 Treemont Circle
Colleyville, Texas, USAUSA
Phone: +1 817 271 3552
Email: jmpolk@cisco.com
IM: xmpp:jmpolk@cisco.com
Gonzalo Salgueiro
Cisco Systems, Inc.
7025 Kit Creek Rd.
Research Triangle Park, NC 27709
USA
Phone: +1 919 392 3266
Email: gsalguei@cisco.com
IM: xmpp:gsalguei@cisco.com
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