Last Modified: 2005-07-25
|Done||Server Features Negotiation submitted to IESG|
|Done||Complete IESG requested fixes to provrel and servfeat|
|Done||Revised proposed standard version of SIP (2543bis) submitted to IESG|
|Done||SIP Events specification to IESG|
|Done||The UPDATE Method submitted for Proposed Standard|
|Done||SIP extensions for media authorization (call-auth) submitted as Informational|
|Done||Preconditions extensions (manyfolks) spec to IESG|
|Done||SIP Privacy specification to IESG|
|Done||SIP Privacy and Security Requirements to IESG|
|Done||The MESSAGE Method submitted for Proposed Standard|
|Done||The Replaces Header submitted for Proposed Standard|
|Done||Refer spec to IESG|
|Done||SIP NAT extension submitted to IESG|
|Done||SIP over SCTP specification and applicability statement|
|Done||Mechanism for Content Indirection in SIP submitted to IESG for Proposed Standard|
|Done||The SIP Referred-By Header submitted to IESG for Proposed Standard|
|Done||Session Timer spec, revised to IESG|
|Done||Caller preferences specification submitted to IESG|
|Done||Submit SIP Identity documents to IESG for Proposed Standard|
|Done||The SIP Join Header submitted to IESG for Proposed Standard|
|Done||Replaces header to IESG (PS)|
|Done||Upgrade S/MIME requirement for AES in 3261 to IESG (PS)|
|Done||Application Interaction to IESG (BCP)|
|Done||Presence Publication to IESG (PS)|
|Done||Resource Priority signaling mechanism to IESG (PS)|
|Apr 04||Connection reuse mechanism to IESG (PS)|
|Done||Guidelines for Authors of SIP extensions submitted as Informational|
|Done||Enhancements for Authenticated Identity Management to IESG (BCP)|
|May 04||Mechanism for obtaining globally routable unique URIs to IESG (PS)|
|Done||MIB spec to IESG|
|Sep 04||Review WG status (consider closing) and/or submit a future milestones plan to IESG|
|Done||Request History mechanism to IESG (PS)|
|RFC2976||PS||The SIP INFO Method|
|RFC3204||PS||MIME media types for ISUP and QSIG Objects|
|RFC3261||PS||SIP: Session Initiation Protocol|
|RFC3262||PS||Reliability of Provisional Responses in SIP|
|RFC3263||PS||SIP: Locating SIP Servers|
|RFC3265||PS||SIP-Specific Event Notification|
|RFC3310||I||Hypertext Transfer Protocol (HTTP) Digest Authentication Using Authentication and Key Agreement (AKA)|
|RFC3311||PS||The Session Initiation Protocol UPDATE Method|
|RFC3312||PS||Integration of Resource Management and SIP|
|RFC3313||I||Private Session Initiation Protocol (SIP)Extensions for Media Authorization|
|RFC3319||PS||Dynamic Host Configuration Protocol (DHCPv6)Options for Session Initiation Protocol (SIP) Servers|
|RFC3323||PS||A Privacy Mechanism for the Session Initiation Protocol (SIP)|
|RFC3325||I||Private Extensions to the Session Initiation Protocol (SIP) for Asserted Identity within Trusted Networks|
|RFC3326||PS||The Reason Header Field for the Session Initiation Protocol (SIP)|
|RFC3327||PS||Session Initiation Protocol Extension for Registering Non-Adjacent Contacts|
|RFC3329||PS||Security Mechanism Agreement for the Session Initiation Protocol (SIP) Sessions|
|RFC3361||PS||DHCP Option for SIP Servers|
|RFC3420||PS||Internet Media Type message/sipfrag|
|RFC3428||PS||Session Initiation Protocol Extension for Instant Messaging|
|RFC3486||Standard||Compressing the Session Initiation Protocol|
|RFC3515||PS||The Session Initiation Protocol (SIP) Refer Method|
|RFC3581||PS||An Extension to the Session Initiation Protocol (SIP) for Symmetric Response Routing|
|RFC3608||Standard||Session Initiation Protocol Extension Header Field for Service Route Discovery During Registration|
|RFC3840||Standard||Indicating User Agent Capabilities in the Session Initiation Protocol (SIP)|
|RFC3841||Standard||Caller Preferences for the Session Initiation Protocol (SIP)|
|RFC3853||Standard||S/MIME AES Requirement for SIP|
|RFC3891||Standard||The Session Inititation Protocol (SIP) 'Replaces' Header|
|RFC3892||Standard||The SIP Referred-By Mechanism|
|RFC3893||Standard||SIP Authenticated Identity Body (AIB) Format|
|RFC3903||Standard||An Event State Publication Extension to the Session Initiation Protocol (SIP)|
|RFC3911||Standard||The Session Inititation Protocol (SIP) 'Join' Header|
|RFC3968||BCP||The Internet Assigned Number Authority (IANA) Header Field Parameter Registry for the Session Initiation Protocol (SIP)|
|RFC3969||BCP||The Internet Assigned Number Authority (IANA) Universal Resource Identifier (URI) Parameter Registry for the Session Initiation Protocol (SIP)|
|RFC4028||Standard||Session Timers in the Session Initiation Protocol (SIP)|
|RFC4032||Standard||Update to the Session Initiation Protocol (SIP) Preconditions Framework|
|RFC4092||Standard||Usage of the Session Description Protocol (SDP) Alternative Network Address Types (ANAT) Semantics in the Session Initiation Protocol (SIP)|
Minutes, SIP WG, IETF 63Reported by Dean Willis and Adam Roach
Edited by Dean Willis
Status, presented by Rohan MahySlides presented.
Note that content-indirection has finally cleared security review and requires a small RFC editor note that will be drafted by Allison.
Discussion of milestones:
Suggested that it would be a good idea to have a regular report on status for WGLC, etc.
The WG will consider getting a WG secretary as an assigned role.
Noted that if we can't track the work we have, we shouldn't accept new work.
Proposed that we delete the response identity work from our work plan. We plan to reopen this during the discussion of the related draft in the Tuesday session.
Discussion on priority of resource conveyance. Proposed schedule is for Spring 06. James Polk thinks we can get it done sooner, and should due to dependencies. We agreed to reopen the schedule discussion after the WG discussion of this draft in the Tuesday session.
Discussion of SIP Security Flows
There seems to be some support for this work, and a consensus that this stuff if important. Possibility raised that we might also need to update 3261 and related documents, either to add clarity or to fix bugs, and that this is more important than getting example flows. We also have references to outdated security documents, and common implementations may also not be acceptable for current security review. It was noted that S/MIME implementation issues have been common at SIPIts. Poll: Who has an implementation of S/MIME? At least 5 in the room, and two others at last SIPit who are not represented in this room. consensus: We do not have all required expertise in this room. A significant problem is that there is a knowledge gap between the implementation community and the IETF security area. We'll work on a plan for reducing that gap. An important goal is to move the knowledge from this document (once it's there) into the broader community.
Topic: GRUUDiscussion led by Jonathan Rosenberg
Changes since last version reviewed.
Comment: Opaque parameter: Cullen offered a lengthy comment supporting the idea that nodes other than proxies be able to extract the AOR from the GRUU. The current text seems to allow this if the opaque parameter is used. Rohan will send to Jonathan commentary on an apparent error in the current text.
Comment: We may need to discuss the situation where a client has two connections to different proxies.
Comment: Would like to see more discussion on the opaque parameter. Jonathan will plan to clarify the general usage and synchronize the work with the SIP outbound dual-registration use case.
Comment: When is the GRUU assigned? Is it a function of registering a contact, or is it a function of someone needing the GRUU? Jonathan considers this to be a function of domain policy. It would appear that it cannot be constructed after the registration, but could be constructed before. Further discussion of this can be added to the GRUU document.
Comment: There needs to be something about the ability of a user agent to determine whether an AOR is or is not a GRUU when it receives a GRUU. This relates somehow to use of the GRUU in transfer cases. One possibility might be a ";user=gruu" parameter. Discussion seem to indicate that the receiver just has to try the URI and see if it works -- it can't really care whether or not the contact is a GRUU. Proposed to keep as-is, except for clarification.
Comment: We have a September milestone. Will we make it? This seems to depend on the acceptance of today's proposals.
Issue: The Double Role of GRUU
Proposed three solutions 1) GRUU for new requests only, 2) Amend use of Contact in mid-dialog request, 3) , keep as is
Comment: The SBCs are going to ruin GRUU in all the usages proposed. This may more strongly affect #2, and favors #1.
Comment: The contact information is usually wrong anyhow. This favors #2.
Comment: Currently, route sets in a dialog are immutable. The ability to use applications at the end point is dependent on this,
Comment: #2 is favorable, because it also encourages endpoints to deal properly with. Draft should note that when used with Replaces, INVITES to a GRUU should only get automatic and not interactive service treatments. This will require some changes in the document relating to edge proxy behavior and moving treatment.
Comment: After the preceding discussion, Cullen no longer favors #2.
Comment: Multiple implementations have proposed to use multiple contacts in dialog as a failover mechanism, This does not favor idea 2.
Poll: Does anyone strongly object to "keeping the text as is"? for this issue with clarification as discussed above)? Consensus on this position is reported.
Topic: Dialog retargeting
Discussion led by Jonathan Rosenberg
Slides included in GRUU deck
No open issues, currently in WGLC
Topic: End to Middle SecurityDiscussion led by Kumiko Ono
Issue #1 UA reaction to (undecipherable) error? If there is only 1 error code and the UAC doesn't support e2m, they don't really know what to do.
Comment: What we want here is the client to encrypt the body and add the proxy to the keying. This differs from the current usage, in which we want the UAC to change the target of the body rather than adding a key.
Comment: The confusion on this relates to confusions on the 493 response, and that leads to the question of response identity. It might be possible to use SIPS to target the alleged proxy.
Comment: We must be careful to not accidentally introduce errors that lead to "base 400" style behavior. This favors a separate error code.
Proposed that we move forward with a separate response code.
Issue #2: How does a proxy indicate disclosure of a specific content type or whole body?
Proposed that an error code without body type have semantics of "disclose whole body". No objections were noted to this proposal.
Issue #3: Do we need a labeling mechanism to instruct a server to validate a signature
Proposed: No. No objection noted.
Issue #4: How does a UA know if the target proxy server complied to the UA's request?
Proposed that if we don 't have a use case for this and one is not forthcoming, that we discard this requirement. Further discussion deferred to list.
Noted that we expect to go to WGLC with the next rev of the dratf.
Topic: Outbound ConnectionsDiscussion led by Cullen Jennings
Changes in terminology since last draft reviewed. Critical terms are "flow" and "flow ID".
Comment: The terminology is still confusing. Some definition changes were discussed, including use of the term "epoch" to refer to a set of TCP and UDP connections.
Issue: default max retry time is 30 minutes. Does this need to change? No changes were suggested.
Issue: Keepalive. Proposed that we use STUN keepalives for both TCP and UDP. This would require changes to the STUN document.
Comment: ICE also uses STUN over TCP.
Comment: The client needs to know that this is supported. Currently, this is done as a URI parameter.
Discussion of this followed, without conclusion.
Issue; Keepalive Times? Proposed that this be 30s for UDP and 10 minutes for TCP. Noted that 1% of one operator's boxes have UDP timeouts of 15s on their NAT bindings.
Comment: We are not doing this because TCP's keepalive does not work, but because the feedback is not delivered fast enough to the SIP system
Comment: Need to make sure that the document shows that the timer resets on each instance of normal traffic.
Comment: Do we know enough about the performance and congestion impact of this?
Proposed: 30s for UDP and 2min for TCP.
Comment: If UAs do this at startup, we have a potential for a restart avalanche. Discussion on this is deferred.
Issue: Flow questions:
Noted that we cannot assume that all UAs using this will have multiple flows.
Issue: Transport integrity for flow matching.
Do we want the security section say that this only works with integrity protection? general consensus on "no".
Further issues taken to list, including route construction logic.
Topic: Refer: Feature TagsDiscussion led by Orit Levin
- Topic of discussion: Which feature tags do we want to include
in the REFER? Does the referer include all features it knows
about? Only the ones that it thinks are relevant for the call?
- Paul Kyzivat: Allowing the referer to pick which features
to include is a slippery slope. Doesn't think disclosing
feature tags is a security risk. Proposes that the referer
should (or must) include all feature tags it knows about
- JDR: Disagree with Paul on the security issue. Also, has
a concern that people will start using these to bypass normal
SIP negotiation (e.g. not offering video if the referer does
not indicate support for video). Further, thinks it is realistic
to pick which feature tags make sense to include: presumably,
the purpose of the mechanism is to allow changes in the user
interface, and it should be possible to identify which features
might have an impact on the interface.
- Paul Kyzivat: Don't feel strongly about the topics -- seems to
hinge on security. If there are no security reasons to not
include *all* feature tags, then including all feature tags
can only be a good thing.
- Cullen Jennings: We need to make sure this isn't going to rely
on implementors deciding what things to include. Also, the list
of features can grow to be quite long, if you include everything.
Propose that we set up a concrete registry of feature parameters
that should be included in REFER requests.
- Rohan Mahy: Would it be reasonable to include only those features
that cannot be discovered via SIP negotiation?
- Proposal: Use MAY and SHOULD recommendations around which official
tags are to be included in REFER requests. The text will be vetted
on the list.
- Cullen: This is tricky; as an implementor, I can't tell which tags
I should include in a REFER -- and I can't count on what other people
- Rohan: There are really only two options. You can either have an
explicit list of what must be included. This will always be out
of date (and consequently always wrong). Alternately, you can leave
it up to the discretion of the implementors, in which case it will
only sometimes be wrong, which is better than always being wrong.
- Cullen: That doesn't make sense. An IANA registry makes a lot more
- Paul Kyzivat: I don't know why we need this at all. How does knowing
ahead of time that the thing to be invited is a focus make a
- Orit: Consider isfocus. Most of the time, you're not going to be
talking to a focus. But somtimes you are, and you can either
find out ahead of time, or have to query for it.
- Paul: No, you don't. You get that fact in the 180 or 200 response
to the INVITE.
- Dean Willis: I'm confused and my head hurts. Are we reaching a
- Consensus: no.
- Chair proposal: We will have a group of interested parties get
together after the meeting to come up with a plan to conclude the
Topic Refer: NorefersubDiscussion led by Orit Levin
- Should we use a "Refer-Sub: false" mechanism, or a Supported/Require
- Adam Roach: We already decided this. Let's not re-open this.
- RjS: This is not the timme to do this.
- JDR: The new proposal doesn't seem to be general in any way.
- Consensus: Leave it as we defined previously.
- Should remove the use-case discussing single-hop? There was an
explicit request to do this.
- RjS: This seems to work.
- JDR: It's impractical.
- RjS: I've seen deployments that do this.
- JDR: Okay. It's not worth debating.
- Cullen: Is this a recommendation, or simply an observation?
- Consensus: Just an observation. The draft should reflect this fact.
Topic: Location ConveyanceDiscussion led by James Polk
- Topic: Location Header Option-tags
- HGS: This seems to be a table of contents for the body. If
we're going to do that, it should be more generic. We would
basically want this for any non-SDP body type. (Some discussion
around this point, but basically results in agreement with
- Dave Oran: I'm not sure how these specific option tags allow
a user agent that doesn't know its location but having the
wherewithal to select, e.g., between civic or geoloc
information. (Longer discussion, taken offline).
- Cullen: SHould look at whether this can be based on the
SIP identity work. (James expresses some concerns that the
ECRIT work shouldn't block on SIP identity).
- Unknown Speaker 1: Is it possible to include information both
from the terminal and by the proxy?
- James: What do you do in the case of conflicts?
- Unknown 1: Use what the UA provides.
- James: Service providers don't want to trust that.
- Topic: Dean doesn't like using OPTIONS to fetch UAC's location.
- Several: Dean isn't the only one.
- Consensus: This should be a SUB/NOT mechanism. (e.g. UA
subscribes to own presence).
- Open Issue: Which event package should be used? (Presence,
new one defined in SIPPING, or new one defined somewhere else)
- Several Speakers: Presence is done, filtering has had a lot
of work done on it. It makes no sense to do this work all over
again with the same end result.
- Others: It may be too heavy to expect people to deploy presence
just for emergency services. It's a bit complicated.
- Rohan: I will put together an email discussing why presence
isn't the right way to do this.
- Proposal: Take this text out of the draft, put it elsewhere,
and progress it separately.
- Will be taken to the list. If we can't close quickly, we will
split the draft.
Topic: Response IdentityDiscussion led by Feng Cao
- HGS: This appears to be reinventing TLS using HTTP-digest-like
- JDR: We need a way to figure out a way to verify that the
connected party is who they say they are.
- Jon Peterson: Don't conflate the party or parties who respond
with the party to whom you are connected.
- General discussion: It's not clear what this document solves
that TLS does not. The response authentication stuff simply
doesn't make sense, given that SIP mandates TLS.
Topic: SIP SAMLDiscussion led by Jon Peterson
- Several people spoke up in support of role-based authorization.
This was followed by a dogpile of varying use cases.
- HGS: The barrier to entry seems to be high -- doing the work
to put in the first installation is wasted, since there's no
one to talk to.
- High level issue: should we split framework from mechanism?
- Cullen: We don't want to freeze the framework before we start
on the mechanism.
- Poll for consensus: Should we take this on as a working group
- Cullen: Where does this go in our schedule?
- Result: Rough consensus to add as a working group item.
Topic: Answer and Alert Mode ExtensionsDiscussion led by Dean Willis
- Paul Kyzivat: The emphasis thing doesn't seem to make much sense.
Semantics are unclear.
- Dave Oran: I'm not confused. I'm sure it's bogus. You can use
an "Alert-Info" header that specifies a different mode of
ringing operation. You can use "Priority" if you want to emphasize
- Andrew Allen: We're not sure how priority is getting used.
- JDR: This presumes a discrete set of policies, which need to be
well-defined at the UAS -- otherwise, this is pretty useless.
- Francois Audet: We definitely need to have better defined
semantics for this, including examples.
- JDR: Yes, this does need to have applicablity outside the OMA.
Also, note that this benefits from role-based authorization.
- Paul Kyzivat: In the general case, this has significant ability
to be abused. Loopback and push-to-talk don't allow covert listening.
Once it is applied to two-way calls, you need to have much stronger
- Several others spoke in favor of having stronger requirements
around security and policy.
- JDR: There are two seperable issues here. First, the policy needs
to be clearer, so that we understand how the override and emphasis
stuff works precisely. As a separate issue, we need to be able to
determine how users are authorized to request these kinds of
- Comment: OMA has an authorization model around this mechanism that it may be possible to
RjS = Robert Sparks
JDR = Jonathan Rosenberg
HGS = Henning Schulzrinne