Subject: Draft minutes for 51st IETF L2TPEXT

From: "W. Mark Townsley" <[email-masked]>
Date: Tue, 21 Aug 2001 14:35:05 +0200

Please send comments by Thursday, August 23.

Thanks,

- Mark

Meeting Description: l2tpext WG meeting at 51st IETF, London
Meeting Time: August 9th, 2001
Meeting Duration: 2 hours

Agenda:

1. Discussion of WG status
2. Current work; current status of drafts
3. Draft presentations by individuals

Proceedings:

1. Mark Townsley bashed agenda items, discussed WG status and current work.

Description of the WG status
----------------------------

Interacting with the PWE3 group
New charter and scope definition for l2tp , this includes
 - l2tpext - Group to oversee and develop extensions to l2tp protocol 
 - Mark noted the presence of many IETF and non IETF tunneling
   protocols, how to provide interaction of those with reference to l2tp was
also 
   defined within the scope of this WG.
 - ppp tunneling is within scope here as always (it is currently out of the
scope of pwe3)
 - Tunneling of other pseudo wires defined in PWE3, extensions that apply to
L2TP will be defined here.

Current work and status of drafts
---------------------------------

WG documents

Session info: Sent to IESG to PS, draft written long time ago, expired, then
came back.

ATM access: Draft that details interaction of two different access mechanisms,
draft sitting on last call forever; couple of issues with it that were posted to
the mailing list and Mark wanted the authors to address those. The issues were
not discussed further and it was agreed to keep discussions on those offline.

Header Compression: One modification for protocol ID definition from defined in
the doc to TBA

Security: IETF last call

Diff Serv: Mark noted that this draft had originally come from the pppext group,
Elwin had recently brought out many new issues with it, but accepted that these
were out of scope for this draft. David Black reported that there were no major
issues with it and he had posted some explanation to the mailing list. It was
agreed that the draft be moved to last call after a small text revision was
made.

L2TP Mib: In WG last call

Service type: Draft defined a new avp - pseudo wire type which is now a part of
the new l2tp base spec.

Multicast extension: Experimental RFC

Two new rfcs: L2TP over FR, and PPP Disconnect Cause Information

Non WG l2tp related draft

fr-svctype:  Half stays in l2tpext WG and  half goes to pwe3.  (1) How to do
fr over packet network to pwe3 and (2) how to do it over l2tp in l2tp.

L2tpext-eth : half stays in l2tp, other half moves to pwe3 as with FR.

Two fail over drafts combined into one; authors commended on getting together

2. Draft Presentations

Session Update, Elwin Stelzer
-----------------------------------

- Discussion between Elwin and Mark about the existence of session messages
after the call is up. Mark noted that WEN and SLI did this; Elwin noted that
these were not sufficient to relay user based characteristics. Other issues that
were brought up were the absence of an id in SURQ and SURP which could
potentially mean only one outstanding request; considering the possibility of
making SURQ an advertisement vs a request thereby eliminating state.

- Elwin reported that the authors planned to do away with the bitmask in the LEX
avp and make it a more specific.

IP Services,  Elwin Stelzer
---------------------------

- Elwin reported that this draft is being revised and will be resubmitted.

Session splitting, Elwin Stelzer
--------------------------------

- Elwin said that this was discussed for a while on mailing list but due to lack
of consensus/support the authors are dropping this draft.

- There was a lack of resounding consensus for both the session update and IP
services draft. It was agreed that both the drafts needed some more work before
they could become WG documents. More discussion is needed on the mailing list.
Session update draft needs some more work -- it is very general, does not list
any avps yet. It says other avps can be used but does not describe how or why ;
the draft needs to provide some justification on why it should exist.

Active Discovery Relay, Mark Townsley
-------------------------------------

- Mark reported that the draft was motivated by the need to get the PADx
messages to LNS; it is more scalable than the ethernet tunneling solution
offered by an earlier draft. It falls in the category of integration with other
tunneling methods for tunneling PPP.

- Tom suggested that a proxy mechanism as opposed to the relay mechanism can be
used to achieve what this draft proposes. Discussion ensued with people divided
over the scalability of the two approaches. More discussion on this on the
mailing list with the possibility of a new draft.

- Questions were raised about how this draft would change L2tp and by how much.
Mark noted that change will be minimal; after tunnel is up send pad relay before
bringing up the session.

- Questions were also raised about whether this mechanism should interact with
the process of pppoe service selection or should pppoe service selection be
confined to the realm of pppoe. The WG generally agreed that this was a right
direction and the draft was definitely in scope even though people were divided
on whether this draft provides the exact solution.

Failover extension, Reinaldo Penno
----------------------------------

- Much discussion about what kind of failover the draft addresses. It was
generally concluded that the draft talks about partial failover like sequence
number failover and is concerned with saving transient information. Concerns
were raised about the presence of a lot of transient information if the tunnel
has say 65000 sessions

- Nishit raised concerns about this draft not really addressing protocol
concerns but addressing application and implementation specific issues.

- The group agreed that the draft definitely needs more discussion on the
mailing list and decided to make it a WG document.

Tunnel Switching, Reinaldo Penno
--------------------------------

- WG agreed that this was a useful draft but requires more discussion.

ESP Service Type : Nishit Vasavada
----------------------------------

- Draft defines ESP Service Type for L2tp tunneling; not really a part of this
WG;but a part of pwe3 working group. It requires a new Pseudo wire type value
for ESP from IANA.

- Mark informed that the end-identifier avp in the new l2tp base draft has been
derived from this draft. This service type can become a part of the l2tp base
spec when IANA gives it a value. However, the base spec wants to keep 0 as the
pw type for PPP.

- No further discussions on this draft.

L2TP base spec, a.k.a. 'L2TPv3': Mark Townsley
----------------------------------------------

- Mark reported that the draft originated as a result of split up of RFC 2661 as
desired in previous WG meetings; describes l2tpv3; hopes to fulfill the
expectations of the next 5 years of l2tp. Bleeding versions
are the latest and greatest versions; work is still ongoing. Draft contains
changes like 32 bit session id, new terminology like cookie, LCCE. Explanation
of some terms was provided. It was clarified that the LNS is a device for
virtual interface for routing whereas the LAC has attachment VCs or native
interfaces and takes no routing decisions.

- Mark strongly urged WG to read the draft and provide comments.

- Questions were asked concerning the clarity issues with terminology of LAC,
LNS and also the 3 tunneling models. Concerns were also raised about the amount
of code changes required to support this new version. Mark replied that 80% of
the code will remain unchanged.

- Majority of the working group had not read the draft but most agreed that this
was the right direction

PPP over L2TP: Madhvi Verma
---------------------------

- Time Expired before presentation could be made