Re: [TICTOC] draft minutes of tictoc meeting at IETF 81

Folks,

I've heard that my .txt file attachment was stripped off on some 
systems. Here are the minutes in line for your review...

Karen

DRAFT (15 Aug 2011)
Minutes for TICTOC meeting @ IETF-80
28 July 2011, 15:20 EDT (19:20 UTC)

The meeting started at 15:20 EDT.  Karen O'Donoghue and Yaakov Stein 
chaired the meeting
Dave Marlow took minutes.  Karen was jabber scribe.

Karen bashed the agenda and the blue sheets were distributed.  Karen 
provided the status
for the Working group since the last meeting: 3 working group drafts, 3 
individual
submissions, and no interim meetings.

Stefano Ruffino provided slides for an ITU-T SG15/Q13 update which 
Yaakov presented.
SG15/Q13 had an interim meeting in May 2011.  There were two primary 
topics of
interest to TICTOC: (1) Packet timing performance aspects for frequency 
(G.826x series);
and (2)Time Sync in packet networks (G.827x series).  The frequency work 
is maturing
while the time/phase work has its requirements document (G.8271) updated 
and other
documents are identified and being started.  SG15/Q13 is also working on 
a definition
and terminology document for both frequency and time of day (G.8260).

Yang Cui provided a Security Requirements discussion based on IPsec 
security for packet
based synchronization, 
draft-xu-tictoc-ipsec-security-for-synchronization-01.  As described
by its Abstract, this document analyses the need for security methods 
for synchronization
messages distributed over the Internet and gives a solution on how to 
mark the
synchronization message when IPSec is implemented in end to end 
frequency synchronization.
It was pointed out that the Introduction has requirements language (i.e. 
SHALLs) and
these will need to be taken out of this section.   There was 
considerable discussion on
the IEEE 1588 PTP use case across the Internet where Yaakov and Greg 
Dowd pointed out you
cannot have transparent clocks you must tunnel.  On a discussion of 
whether to encrypt
packets across 3GPP, someone from the jabber room pointed out that with 
3GPP you must
encrypt.  Yaakov asked whether the authors have talked with anyone in 
the closing IPsec
WG about this draft and Yang indicated that he has and they do not have 
any questions.
Karen asked whether the Working Group thought this work should be 
pursued, but got little
feedback.  Peter Lothberg said that in some use cases this could be 
useful but this
provides no value for the Internet use case.  Yang said that the 
femtocell is getting
greater use and there is no protection in the femtocell.  Greg Dowd said 
that femtocells
are meant to provide telephone calls and that they can be stopped by 
dropping all data.
He said we needed to clarify the threat models we are building the 
security for.

Karen discussed time synchronization protocol security requirements.  
The expired
TICTOC Requirements draft had recently been resubmitted
(draft-ietf-tictoc-requirements-01).  This draft identifies three 
security mechanisms to
consider.  Karen went over a survey that was done at the beginning of 
the TICTOC work
where four questions were identified that cover the different aspects 
for possible
security services.  Karen said that a volunteer editor has been 
identified to work on
general time synchronization security requirements.  The goal is to have 
a draft by the
next meeting.

Greg Dowd provided a PTPv2 MIB discussion based on 
draft-ietf-tictoc-ptp-mib-00.  This
MIB goes beyond the earlier drafts that only covered the PTPv2 telecom 
profile.  This
MIB covers all the PTPv2 devices.  The current draft is in its third 
version and
Greg felt it was now semantically correct.  Asked whether this MIB has 
been deployed,
Greg said that it has.  Measuring the performance of a PTPv2 node is 
outside the
present scope, but this could be added later.  Yaakov asked whether 
there was
commonality between this MIB and the NTPv4 MIB (RFC 5907), Greg said 
that this
MIB was PTPv2 specific with little commonality to the NTP MIB.  Dave 
Marlow said
that he had read the draft and found little commonality with the NTP MIB 
but was
very supportive of this draft which appears very thorough.  The Chairs 
said that
there needs to be MIB Doctor review (which they would pursue) and review by
TICTOC participants for this draft to progress.

Yaakov lead a discussion on Transporting PTP messages (IEEE 1588) over 
MPLS Networks,
draft-ietf-tictoc-1588overmpls-01.  He said that the draft very mature 
with three
individual drafts and now one TICTOC version.  There has been 
considerable discussion
on the list.  Yaakov asked what was needed before this goes to WGLC?  
Luca Martini
said that there are some text formatting issues and that some sections 
have given a
a wrong impression.  Of particular concern were the two modes (IP over 
MPLS and
Pseudowire), Pseudowire is not needed if timing is a service of the 
network and there
is only one clock over the network.  Pseudowire is needed if PTP is used 
directly over
Ethernet, and Yaakov pointed out that in many parts of the world there 
are many clocks
that a carrier transports separately.  There were some concerns from the 
MPLS
community, George Swallow pointed out an issue with fast reroute to 
address a fault.
There were concerns whether the draft was ready for last call or not, 
and what
procedure should be taken to get comments from the MPLS community.  
George suggested
to at least announce to the MPLS list about a WGLC in TICTOC.

Tal Mizrahi briefed UDP Checksum Trailer in Timing Protocols,
draft-mizrahi-tictoc-checksum-trailer-00.  This draft proposes a 
Checksum Trailer
extension to NTP, OWAMP and TWAMP that allows intermediate nodes to 
reflect the
checksum modification in the last 2 octets of the packet rather than in 
the UDP
checksum field.  This is to bring a capability already in IEEE 1588 into 
these other
protocols.  Yaakov asked why this is being brought into OWAMP and 
TWAMP.  Tal said
these are performance protocols that transfer time and could be 
benefited as well.
An issue related to the NTP extension field had been raised and 
discussed on the
mailing list.  This proposed technique requires an extension field without
authentication (i.e. without a MAC) to be practical; however, the NTPv4 
spec
(i.e. RFC 5905) REQUIRES all extension fields to include authentication.
Discussion on the list included opinions that the RFC was wrong and this 
is not
a requirement for NTPv4.  Additional effort is needed to determine if 
NTPv4 spec
should be changed or not.  Yaakov pointed out that both OWAMP and TWAMP 
have
authenticated modes.  This draft is intended for non authenticated 
packets only.
Yaakov said that in the case of OWAMP this is very limiting because its 
default is
to be authenticated.  In addition Yaakov said that OWAMP and TWAMP would 
require
an extension to their control protocols.  OWAMP and TWAMP are IPPM 
protocols, the
Chairs took an action to send this draft to the IPPM chairs.  Tal was asked
whether the mechanisms discussed in the draft had been implemented and he
said the mechanisms had not yet been implemented.

Dave Marlow discussed Network Time Mechanisms for Improving Computer 
Clock Accuracy,
draft-marlow-tictoc-computer-clock-accuracy-00.  This draft had not been 
updated
since the last meeting but Dave briefed the discussion that had been on 
the list.
Vladimir Smotlacha provided to the list, references to his papers 
describing NTP
servers which use OCXO oscillators to achieve much higher 
synchronization accuracy
than the experimental results described in this draft.  The use case in 
the draft
covers client accuracy and thus is outside the Vladimir's use case which 
addresses
server accuracy.  In June, Karen had forwarded a note from Dave Mills to 
the list
which mentioned that additional experimental results with NTP Interleave 
are in his
book.  Dave Mill's book provides experimental results for both an 
unloaded scenario
(which is a very similar to the experiment described in the draft) and a 
loaded
scenario.  Dave Mills, in his email, pointed out that Interleave showed 
greater
improvement in the loaded scenarios and with digest computations (e.g. 
Autokey).
Dave Marlow and Tim Plunkett are looking at the experimental results in 
the book and
comparing this to their results.  Tim Frost provided a paper on Minimum 
Time-Dispersion
Metrics  to the list. Dave indicated that this provides direction 
towards identifying
a common set of metrics for network time synchronization experiments.  A 
common set of
metrics or perhaps a benchmarking draft could be a candidate for future 
TICTOC work.
Greg Dowd said that there are products on the market that can provide a 
hardware time
stamp based on a programmable sequence off of a packet data network, 
this provides a
direction for the second mechanism outlined in the draft.  Yaakov 
mentioned that
his company tried NTP interleave on their highly optimized products and 
did not
see a significant difference in performance.   Dave said he and Tim 
Plunkett would
like to update their draft with the new information.  He solicited 
comments and
contributions on mechanisms to achieve greater client accuracy.

Karen led an additional NTP discussion.  The NTP control protocol which 
is an
appendix of RFC 1305 (NTPv3) is not in a current standard since RFC 1305 
was deprecated.
Volunteers are needed to get this important work documented and 
standardized.  Brian
Haberman (along with Karen, co-chair of the NTP working group) suggested 
in line with
Dave Hart to get rid of mode 7 and just document mode 6.  Harlan Stenn, 
via jabber
requested that mode 7 be documented as well.  Dave Hart, via jabber, 
said that mode 7
is fragile and vendor specific, so that there is no use in standardizing 
it.  Harlan
volunteered to document the NTP control protocol.  It was pointed out 
that RFC 5905 needs
to be redone since mode 6 is identified for future use; however, if this 
is an IANA
controlled field then just a change by IANA is needed.  Karen asked for 
volunteers to
document the NTP interleave extensions.  There has been email on list 
discussing Autokey
bugs/vulnerabilities being found by PTB (Germany's Standards 
Organization).  There were
no details discussed at this meeting but this is a concern that must be 
followed.  There
was a short discussion on what work would be carried out in the NTP WG 
and what should
be done in the TICTOC WG.  Brian said that all NTP control protocol work 
should be done
in the NTP WG but he had no opinion at this time as to where Interleave 
work should be
done.  All co-chairs agreed that email on any NTP topic should be sent 
to both lists.

The meeting adjourned at 17:20 EDT (21:20 UTC).

On 8/15/11 10:25 AM, Karen O'Donoghue wrote:
> Folks,
>
> Below are the draft minutes for the recent tictoc meeting. Thanks to 
> Dave Marlow for the timely production of the minutes. Please review 
> and submit any comments or changes as soon as possible.
>
> Regards,
> Karen
>
>
>
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