Minutes IETF99: tsvwg
minutes-99-tsvwg-00

AGENDA for TSVWG Meeting at IETF 99, Prague, Cz
 WG Chairs: Gorry Fairhurst, David Black and Wes Eddy
 Note Taker 1: David Dolson
 Jabber Scribe.

Session 1: 13:30-15:30  Tuesday Afternoon Session I

David Black discusses status slides
There is an open issue and significant changes are going to be required.
Spencer Dawkins: I like Chunk draft. What does ECN experimentation draft need
to say? David B: ECN makes the NS historic. The enw text will remove the IANA
registration for TCP NS field. Gorry: When will revision be ready? David: Next
week. Spencer: The ECN draft is a 3GPP dependency.

David: The SCTP n-data draft is the last of the webrtc drafts.
Bob Briscoe: There will be another dependency for an AD action wrt status
changes. David: Spencer has an action to do a status changes document fro
ECN-Nonce. Spencer: OK, thank you. Public humiation works. David: PHB mappings
are stable; I hope to resolve and send to last call. David announces WG the
adoption of the FEC framework drafts. These do not justify a new wg. Gorry:
Please talk to Gorry if interested in transport-header-encrypt or PMTUD drafts.

David: Please go to INTAREA mtgs for Tunnel MTU, MPT or SOCKS documents.
Gorry: Or speak-up to Chairs or mailing list if you think there are transport
issues.

1. Review Agenda (WG Chairs)
- no agenda changes

2. Status/updates (WG Chairs)

  2.1 Tunnel Congestion feedback
    draft-ietf-tsvwg-tunnel-congestion-feedback --- WGLC outcome
David: This needs significant work to frame an example use.

  2.2 ECN Experimentation
    draft-ietf-tsvwg-ecn-experimentation --- WGLC outcome
David: This will be updated to addresses the IANA issue.

  2.3 SCTP I-Data
    draft-ietf-tsvwg-sctp-ndata --- WGLC outcome

  2.4 DS IEEE 802.11 — WGLC Summary
    draft-ietf-tsvwg-ieee-802-11
Tim Szigeti talks to slides
- The mapping already in wide use in Cisco & Meraki APs and Apple devices.
~800M devices using recommendation. - We will avoid the overloaded word
"trust". - The LE PHB PS will obsolete RFC 3662, and thus have a cascading
effect on RFC 4594 and also this PS - Please review. David: The chairs share
sense the urgency. Depending on consensus on DSCP, we may deal with LE later.

  2.5 UDP Options - Adoption
    draft-ietf-tsvwg-udp-options
Tom Jones: I have a working implementation in FreeBSD; would like to interop
with other operating systems. David Dolson: Was the old FreeBSD code OK for
receiving datagrams with UDP options? Tom Jones: Yes

  2.6 Related work that may be of interest:
    draft-fairhurst-tsvwg-transport-encrypt
    draft-olteanu-intarea-socks-6
    draft-lencse-tsvwg-mpt
    draft-fairhurst-tsvwg-datagram-plpmtud

3. WG Drafts

 WG Drafts - Diffserv

3.1 Roland Bless - LE PHB
    draft-ietf-tsvwg-le-phb
Roland does not think 2 DSCPs are required for LE.
(No questions on draft)

  3.2 Chairs - Discussion on appropriate DSCP for LE
    - Short reports on observed remarking behaviour
      for proposed LE DSCP (please contact chairs)
Raffaello Secchi is presenting study about DSCP  LE codepoints using PATHscope
& Edgetrace. DSCP 2 might not be good because of bleaching of upper bits. Many
classes would be mapped to LE, worse than best-effort. 16% ToS bleaching or
4.7% ToS bleaching in different experiments. Fred Baker: There are 8 values
with top 3 bits set to zero. The odd values are for local use. Gorry: Half of
these are local use, the registry says the other could be allocated by IANA if
the IETF has need. Fred: The value we'd like to have in the upper 3 bits is 0,
so this might allow a DSCP of 2/4/6. I don't see the real difference. I'd
rather tell people not to bleach the DSCP.

Tom Jones: SSH is using code point 2 and 4, one for bulk transfer, one for the
rest. squatting on code points? Michael ?: Is the bleaching only to zero, or
other things as well? RS: The dominant pathology is ToS bleaching, and a small
number of other changes unrelated to original values. Michael ?: This is
probably not intentional remarking. Brian Trammel: It looks like DSCPs are used
inside of network, but could leaks out. Brian: 10s of ASes might be ToS
(precedence) bleaching. How many ASes were in sample? RS: We could tell where
DSCP was changed along the path. Brian: How many ASes were traversed by
measurements? RS: 30 in our tests so far. Brian: So, we're talking about 10^-4.
 Can we just make phone calls to the ASes with broken routers? David Black:
IANA registry: code points in pool 3 ending in 01 may be utilized for future
standards allocation. Gorry: is this going to be better than CS1. Rolan Bless:
The term "IP precedence bleach" is more accurate. We should stop working around
broken implementations. Why is SSH broken? David: Michael's comment: operators
might not be clear on what config their equipment is doing.

David (as chair): Can I see a show of hands straw poll: how many think they
understand the issue? (About a dozen). David (as chair): How many think we have
enough info today? could we stick with DSCP 2 or pick an odd-numbered one? How
many people who understand the issue think we have enough info to make decison
now? No hands raised.

Bob Briscoe: It could be a mix of No and Not sure.
David: No raised hands is important.
Roland: The odd code points would be worse than 2, given bleaching.
David: The reason to not choose 2 also applies to not choosing others.
Tim Chown: We don't know if people will fix.  Why did we pick 2?
David: The even numbered code points are for standards action; others for local
use. Tim Chown: I'm inclined to go with codepoint 2. Brian Trammel: I didn't
raise my hand. Did you do pathscope measurements for 1 and 5? Tom: I had
results for DSCP 1 that show it's as as expected. Gorry: PATHspider shows 1
gets thru network. Not bad from traversal point of view. Brian: for SSH
problem, can ew just do a pull request in SSH code? Tom: pull request is ~12
years old. They will probably never take it. Tom: The bleaching behavior is
same as 2 but without the peril of 2. David B: We cannot make a decision now.

WG Milestones Review
David
Tim: The 802.11 should be noted as "Proposed Standard", not Informational.
David B: This is atypo - will fix.
Gorry: I would like more info on the LE DSCP from peoplw. Raffaello, can you do
more measurements? Raffaelo: Yes. Gorry: Let's get to the bottom of it. Speak
to Raffaello if you also wish to make measurements of DSCPs. David: Can get NAT
support publihsed by the End of Year? (yes) David: For L4S? Bob: Maybe a
milestone before Sept. 2018. Essentially the drafts are finished, except
TCP-Prague; drafts are in holding pattern. Gorry: We can do an early WG last
call to get consensus, even if we freeze and do not immediately publish. David
: UDP Options -- We are waiting to hear about implementation work. David: Is
June a possible milestone date for the FEC drafts? (yes)

  WG Drafts - ECN

  3.3 Bob Briscoe - Guidelines for Adding Congestion Notification
                    Propagating ECN Across IP Tunnel Headers
    draft-ietf-tsvwg-ecn-encap-guidelines
We want New Radio to support ECN? And therefore L4S.
David: This also came up at 3GPP liason meeting. (see Liasion slot in TSVWG on
Thursday.) David: we hope to have published...

    draft-ietf-tsvwg-rfc6040update-shim
This exists so te IETF community can update other proposed standards.
Bob: In Problem#1 slide the figures are wrong.
Bob: "NSH" is vague, not applicable.
Bob: We did not find any evidence of automatic configuration of GRE.
Gorry: Does anyone in room know cases where GRE is automatically configured?
e.g. in VPN usage? Brian Trammel: If BANANA is chartered, a new automated GRE
tunnel setup might show up, at least we have this list to start from. Jake
Holland: AMT RFC7450 is missing from list. Bob: I will look. We only need to
know about shim-types. Christian H: Is it conceptually hard to handle ECN in
Teredo? (No.) If we specified it, would it be updated? Dave Dolson: Do I
understand this is about finding inner header after the Ethernet E.g., in
CAPWAP? Bob: We need to propagate both ECN and CE across layers. Christian: In
Teredo, an operator is not exactly the end-user.

  WG Drafts - L4S

Gorry: We need people to activity participate in these L4S drafts - please
comment on list.

  3.5 Bob Briscoe -  L4S Internet Service: Architecture
    draft-ietf-tsvwg-l4s-arch
3GPP discussion for August

  3.6 Bob Briscoe -  Identifying Modified ECN Semantics
    draft-ietf-tsvwg-ecn-l4s-id
Clarifies: ECN is used as a default classifier, but there may be other
classifier. E.g., ECN combined with other fields of traffic (e.g., IP address).
Adding hooks in Linux to let people add other classifiers. But advantage of the
default is it being end-to-end eventually. David Black (from floor): DSCP
classifiers help an enormous amount for incremental deployment. Bob: The more
identifiers you add to the classifier, the less incremental the deployment can
be. Bob: There are business motivations... David: Some wording changes should
be added to draft to indicate it is optional. Andrew: We cannot see how to test
without other classifiers. So if we don't add it, someone else will. Bob:
(slides) Some people are still using ToS byte for load-balancing. Gorry: This
is something people have to fix. David Dolson: suggests putting ECN-bleaching
(or otherwise bad behavior) in tools like traceroute. Andrew: There can be
reordering when entire ToS field is still used for load-balancing entropy (e.g.
ECMP). Multiple router vendors have support for both currently specified
methods and legacy byte-based methods. Many devices still have wrong defaults.

  3.7 Koen De Schepper - DualQ Coupled AQM for L4S
    draft-ietf-tsvwg-aqm-dualq-coupled
Gorry: BBR isn't in any working group. But we should of course  pay attention
to what is happening in the real Internet. Koen: Please test and try.

--------------------------------------------------------------------------------------------------
 Session 2: 18:10-19:10  Thursday Afternoon Session III

 4. Agenda recap (WG Chairs) (10 mins)

  Liaison Notices (WG Chairs)

 5. WG drafts - Transport Protocols

   5.1 Michael Tuexen - SCTP NAT Support (5 mins)
     draft-ietf-tsvwg-natsupp

   5.2 Michael Tuexen- RFC 4960 Errata and Issues (10 mins)
     draft-ietf-tsvwg-rfc4960-errata

 6. WG Drafts - FECFRAME

  6.1 Vincent Roca - FECFRAME (10 mins)
    draft-ietf-tsvwg-fecframe-ext
  6.2 Vincent Roca - RLC FEC Scheme for FECFRAME (5 mins)
    draft-ietf-tsvwg-rlc-fec-scheme

  6.3 Michael Tuexen - UDP Encapsulation of SCTP (5 mins)
    draft-tuexen-tsvwg-sctp-udp-encaps-cons