Re: [TICTOC] [mpls] Comments on draft-ietf-tictoc-1588overmpls

Greg Mirsky <gregimirsky@gmail.com> Fri, 02 August 2013 16:05 UTC

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Date: Fri, 02 Aug 2013 18:04:58 +0200
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From: Greg Mirsky <gregimirsky@gmail.com>
To: Shahram Davari <davari@broadcom.com>
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Subject: Re: [TICTOC] [mpls] Comments on draft-ietf-tictoc-1588overmpls
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Hi Shahram,
I think that John suggested creation of LSPs interconnecting all
1588-capable nodes. It is absolutely not what current document defines but
that reminds me of what I've suggested around November of 2011.
Regards,
Greg
On Aug 2, 2013 6:43 AM, "Shahram Davari" <davari@broadcom.com> wrote:

> Hi John
>
> In that case I fail to understand the difference between your proposal and
> the current draft.
>
> In both cases you need a special LSP to tell the HW to Timestamp the
> packet and I assume you need to use RSVPTE to sign it. That is what the
> draft does.
>
> Regards,
> Shahram
>
>
> On Aug 2, 2013, at 12:52 PM, "John E Drake" <jdrake@juniper.net> wrote:
>
> > Shahram,
> >
> > The LSPs would be between LSRs that are 1588 capable, so they could be
> one or more hops.
> >
> > Yours Irrespectively,
> >
> > John
> >
> >
> >> -----Original Message-----
> >> From: Shahram Davari [mailto:davari@broadcom.com]
> >> Sent: Friday, August 02, 2013 3:24 AM
> >> To: <stbryant@cisco.com>
> >> Cc: mpls-chairs@tools.ietf.org; tictoc-chairs@tools.ietf.org; int-
> >> ads@tools.ietf.org; rtg-ads@tools.ietf.org; draft-ietf-tictoc-
> >> 1588overmpls@tools.ietf.org; John E Drake; mpls@ietf.org;
> >> tictoc@ietf.org
> >> Subject: Re: [mpls] Comments on draft-ietf-tictoc-1588overmpls
> >>
> >> Hi Stewart
> >>
> >> We have already looked at similar approach. The issue with one hop LSP
> >> is that not all LSRs are 1588 capable. One of the requirements is for
> >> non-1588 capable routers to just switch the packet normally.
> >>
> >> Regards,
> >> Shahram
> >>
> >>
> >> On Aug 2, 2013, at 12:02 PM, "Stewart Bryant" <stbryant@cisco.com>
> >> wrote:
> >>
> >>> Talking to John Drake about this, an alternative general
> >>> model is for the LSP is that it is an LSP that timestamps
> >>> the packet and then passes it to an application associated
> >>> with the LSP at that hop.
> >>>
> >>> This has a lot of merit.
> >>>
> >>> If however we think about it some more we have a
> >>> type of network service chaining going on here and
> >>> so we don't need an LSP per say, because the path
> >>> and instruction can be in the packet.
> >>>
> >>> In other words a general solution  to the problem
> >>> is to define an LSP with the properties that the
> >>> packet is passed one hop, timestamped and delivered
> >>> to the associated application.
> >>>
> >>> How this is MPLS construct is used to support time
> >>> tranfer is entirely within the scope of TICTOC, but
> >>> at the MPLS layer we have a clean reusable network
> >>> service.
> >>>
> >>> - Stewart
> >>>
> >>>
> >>> ============
> >>> SB> This draft does not seem to provide a precise definition
> >>> SB> the properties of the new LSP type that it wishes to
> >>> SB> define, in particular it does it define the PHB of those
> >>> SB> LSPs, nor the full interaction with the MPLS
> >>> SB> architecture.
> >>> SB>
> >>> SB> I have not tracked TICTOC for a while but I thought that
> >>> SB> the original plan was to define the concept of an offset
> >>> SB> into a packet to do the correction.
> >>> SB>
> >>> SB> It is disappointing that the opportunity was not taken
> >>> SB> to define a timing shim inside the timing LSP so that
> >>> SB> a time correction could be added to any packet such that
> >>> SB> the MPLS system was isolated from the details of the
> >>> SB> complexity of the particular time transfer type.
> >>>
> >>> SB> I think that much more clarify is needed in terms of
> >>> SB> definition of the new LSP type, since it is unclear
> >>> SB> from this text how to implement one.
> >>> SB>
> >>> SB> There are a lot of other MPLS services such as
> >>> SB> LSP ping that need to be considered.
> >>> SB>
> >>> SB> Please see inline for more comments. However these
> >>> SB> comments are made in the context of the text as written
> >>> SB> whilst I have a fundamental concern that this approach
> >>> SB> lacks an MPLS architectural soundness that need
> >>> SB> greater thought with significant impact on the
> >>> SB> draft.
> >>>
> >>> - Stewart
> >>>
> >>>
> >>> TICTOC Working Group                                           S.
> >> Davari
> >>> Internet-Draft                                                   A.
> >> Oren
> >>> Intended status: Standards Track                          Broadcom
> >> Corp.
> >>> Expires: December 17, 2013                                     M.
> >> Bhatia
> >>>                                                             P.
> >> Roberts
> >>>                                                         Alcatel-
> >> Lucent
> >>>                                                             L.
> >> Montini
> >>>                                                             L.
> >> Martini
> >>>                                                          Cisco
> >> Systems
> >>>                                                          June 15,
> >> 2013
> >>>
> >>>
> >>>           Transporting Timing messages over MPLS Networks
> >>>                  draft-ietf-tictoc-1588overmpls-05
> >>>
> >>> Abstract
> >>>
> >>>  This document defines the method for transporting Timing messages
> >>>  such as PTP and NTP over an MPLS network.  The method allows for
> >> the
> >>>  easy identification of these PDUs at the port level to allow for
> >> port
> >>>
> >>> SB> What is a port
> >>>
> >>>  level processing of these PDUs in both LERs and LSRs.
> >>>
> >>>  The basic idea is to transport Timing messages inside dedicated
> >> MPLS
> >>>  LSPs.  These LSPs only carry Timing messages and possibly Control
> >> and
> >>>  Management packets, but they do not carry customer traffic.
> >>>
> >>> SB> More specifically they only carry traffic associated with the
> >>> SB> timing service and its support.
> >>> SB> The question arose WRT BFD - surely BFD is allowed, BUT surely
> >>> SB> also it gets carried in a structure that causes it to get
> >>> SB> timestamped.
> >>>
> >>>  Two methods for transporting Timing messages over MPLS are defined.
> >>>
> >>> SB> Perhaps the right approach is to define the new LSP type and then
> >>> SB> seperately to define  the mapping of the various timing services
> >>> SB> over that LSP type.
> >>>
> >>>  The first method is to transport Timing messages directly over the
> >>>  dedicated MPLS LSP via UDP/IP encapsulation, which is suitable for
> >>>  MPLS networks.  The second method is to transport Timing messages
> >>>  inside a PW via Ethernet encapsulation.
> >>>
> >>> SB> I think that we should note that there are some
> >>> SB> h/w reasons for this preference. A clean sheet approach
> >>> SB> would have been to use PTP over MPLS with no intermediate
> >>> SB> layers.
> >>>
> >>> Status of this Memo
> >>>
> >>>  This Internet-Draft is submitted in full conformance with the
> >>>  provisions of BCP 78 and BCP 79.
> >>>
> >>>  Internet-Drafts are working documents of the Internet Engineering
> >>>  Task Force (IETF).  Note that other groups may also distribute
> >>>  working documents as Internet-Drafts.  The list of current
> >> Internet-
> >>>  Drafts is at http://datatracker.ietf.org/drafts/current/.
> >>>
> >>>  Internet-Drafts are draft documents valid for a maximum of six
> >> months
> >>>  and may be updated, replaced, or obsoleted by other documents at
> >> any
> >>>  time.  It is inappropriate to use Internet-Drafts as reference
> >>>  material or to cite them other than as "work in progress."
> >>>
> >>>  This Internet-Draft will expire on December 17, 2013.
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013               [Page
> >> 1]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> Copyright Notice
> >>>
> >>>  Copyright (c) 2013 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.  Code Components extracted from this document
> >> must
> >>>  include Simplified BSD License text as described in Section 4.e of
> >>>  the Trust Legal Provisions and are provided without warranty as
> >>>  described in the Simplified BSD License.
> >>>
> >>>
> >>> Table of Contents
> >>>
> >>>  1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .
> >> 5
> >>>
> >>>  2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .
> >> 7
> >>>
> >>>  3.  Problem Statement  . . . . . . . . . . . . . . . . . . . . . .
> >> 8
> >>>
> >>>  4.  Timing over MPLS Architecture  . . . . . . . . . . . . . . . .
> >> 9
> >>>
> >>>  5.  Dedicated LSPs for Timing messages . . . . . . . . . . . . . .
> >> 12
> >>>
> >>>  6.  Timing over LSP Encapsulation  . . . . . . . . . . . . . . . .
> >> 13
> >>>    6.1.  Timing over UDP/IP over MPLS Encapsulation . . . . . . . .
> >> 13
> >>>    6.2.  Timing over PW Encapsulation . . . . . . . . . . . . . . .
> >> 13
> >>>    6.3.  Other Timing Encapsulation methods . . . . . . . . . . . .
> >> 14
> >>>
> >>>  7.  Timing message Processing  . . . . . . . . . . . . . . . . . .
> >> 15
> >>>
> >>>  8.  Protection and Redundancy  . . . . . . . . . . . . . . . . . .
> >> 16
> >>>
> >>>  9.  ECMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
> >> 17
> >>>
> >>>  10. PHP  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
> >> 18
> >>>
> >>>  11. Entropy  . . . . . . . . . . . . . . . . . . . . . . . . . . .
> >> 19
> >>>
> >>>  12. OAM, Control and Management  . . . . . . . . . . . . . . . . .
> >> 20
> >>>
> >>>  13. QoS Considerations . . . . . . . . . . . . . . . . . . . . . .
> >> 21
> >>>
> >>>  14. FCS and Checksum Recalculation . . . . . . . . . . . . . . . .
> >> 22
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013               [Page
> >> 2]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>>  15. Behavior of LER/LSR  . . . . . . . . . . . . . . . . . . . . .
> >> 23
> >>>    15.1. Behavior of Timing-capable/aware LER . . . . . . . . . . .
> >> 23
> >>>    15.2. Behavior of Timing-capable/aware LSR . . . . . . . . . . .
> >> 23
> >>>    15.3. Behavior of non-Timing-capable/aware LSR . . . . . . . . .
> >> 24
> >>>
> >>>  16. Other considerations . . . . . . . . . . . . . . . . . . . . .
> >> 25
> >>>
> >>>  17. Security Considerations  . . . . . . . . . . . . . . . . . . .
> >> 26
> >>>
> >>>  18. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .
> >> 27
> >>>
> >>>  19. IANA Considerations  . . . . . . . . . . . . . . . . . . . . .
> >> 28
> >>>
> >>>  20. References . . . . . . . . . . . . . . . . . . . . . . . . . .
> >> 29
> >>>    20.1. Normative References . . . . . . . . . . . . . . . . . . .
> >> 29
> >>>    20.2. Informative References . . . . . . . . . . . . . . . . . .
> >> 29
> >>>
> >>>  Appendix 1.  Routing extensions for Timing-aware Routers . . . . .
> >> 32
> >>>
> >>>  Appendix 2.  Signaling Extensions for Creating Timing LSPs . . . .
> >> 33
> >>>
> >>>  Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .
> >> 34
> >>>
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> >>> Davari, et al.          Expires December 17, 2013               [Page
> >> 3]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>>  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 RFC2119 [RFC2119].
> >>>
> >>>  When used in lower case, these words convey their typical use in
> >>>  common language, and are not to be interpreted as described in
> >>>  RFC2119 [RFC2119].
> >>>
> >>>
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> >>> Davari, et al.          Expires December 17, 2013               [Page
> >> 4]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 1.  Introduction
> >>>
> >>>  The objective of Precision Time Protocol (PTP) and Network Timing
> >>>  Protocol (NTP) are to synchronize independent clocks running on
> >>>  separate nodes of a distributed system.
> >>>
> >>>  [IEEE-1588] defines PTP messages for frequency, phase and time
> >>>  synchronization.  The PTP messages include PTP PDUs over UDP/IP
> >>>  (Annex D and E of [IEEE-1588]) and PTP PDUs over Ethernet (Annex F
> >> of
> >>>  [IEEE-1588]).
> >>>
> >>> SB> Sure BUT it is acknowledged that IEEE is open to the definition
> >>> SB> of other PTP mappings if they provide better optimisation.
> >>>
> >>>  This document defines mapping and transport of the PTP
> >>>  messages defined in [IEEE-1588] over MPLS/MPLS-TP networks.  PTP
> >>>  defines several clock types: ordinary clocks, boundary clocks, end-
> >>>  to-end transparent clocks, and peer-to-peer transparent clocks.
> >>>  Transparent clocks require intermediate nodes to update correction
> >>>  field inside PTP message that reflects the transit time in the
> >> node.
> >>>
> >>>  [RFC5905] defines NTP messages for clock and time synchronization.
> >>>  The PTP messages (PDUs) are transported over UDP/IP.  This document
> >>> SB> Should that be NTP messages?
> >>> SB> It needs to be made clear as soon as you introduce NTP that
> >>> SB> they use different time representations.
> >>>
> >>>  defines mapping and transport of the NTP messages defined in
> >>>  [RFC5905] over MPLS networks.
> >>>
> >>>  One key attribute of all of these Timing messages is that the Time
> >>>  stamp processing should occur as close as possible to the actual
> >>>  transmission and reception at the physical port interface.  This
> >>>  targets optimal time and/or frequency recovery by avoiding variable
> >>>  delay introduced by queues internal to the clocks.
> >>>
> >>> SB> As I recall NTP has no epoch point defined, and I am not sure
> >>> SB> where that point is in the case of PTP in this mapping
> >>> SB> Hopefully this will get defined in due course.
> >>>
> >>>  To facilitate the fast and efficient recognition of Timing messages
> >>>  at the port level when the Timing messages are carried over MPLS
> >>>  LSPs,
> >>>
> >>> SB> Over a new LSP type with time optimied characteristics
> >>>
> >>>  this document defines the specific encapsulations that should
> >>>  be used.
> >>> SB> Hopefully it will also define the PHP
> >>>
> >>>  In addition, it can be expected that there will exist LSR/
> >>>  LERs where only a subset of the physical ports will have the port-
> >>>  based Timing message processing capabilities.
> >>> SB> Do you need to clarify that this only works at base and not in
> >>> SB> a label heirarchy.
> >>>
> >>>
> >>>  In order to ensure
> >>>  that the LSPs carrying Timing packets always enter and exit ports
> >>>  with this capability, routing extensions are defined to advertise
> >>>  this capability on a port basis and to allow for the establishment
> >> of
> >>>  LSPs that only transit such ports.  While this path establishment
> >>>  restriction may be applied only at the LER Ingress and/or egress
> >>>  ports, it becomes more important when using transparent clock
> >> capable
> >>>  LSRs in the path.
> >>> SB> I do not understand the implications of the last
> >>> SB> sentences - starting ", it becomes"
> >>>
> >>>
> >>>  Port based Timing message processing involves Timing message
> >>>  recognition.  Once the Timing messages are recognized they can be
> >>>  modified based on the reception or transmission Time-stamp.
> >>>
> >>>  This document provides two methods for transporting Timing messages
> >>>  over MPLS.  One is applicable to MPLS environment and the other one
> >>>  is applicable to MPLS/MPLS-TP environment
> >>>
> >>> SB> I think the sentence is incomplete.
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013               [Page
> >> 5]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>>  The solution involves transporting Timing messages over dedicated
> >>>  LSPs called Timing LSPs.  These LSPs carry Timing messages and MAY
> >>>  carry Management and control messages, but not data plane client
> >>>  traffic.
> >>>
> >>> SB> It is not clear why this restriction applies.
> >>>
> >>>  Timing LSPs can be established statically or via signaling.
> >>> SB> s/statically/by provisioning/network management/
> >>>
> >>>  Extensions to control plane (OSPF, ISIS, etc.) is required to
> >> enable
> >>>  routers to distribute their Timing processing capabilities over
> >> MPLS
> >>>  to other routers.  However such extensions are outside the scope of
> >>>  this document.
> >>>
> >>>  When signaling is used to setup the PTP LSP, Extensions to
> >> signaling
> >>> SB> is it a PTP LSP or a Timing LSP?
> >>>
> >>>  protocols (e.g., RSVP-TE) are required for establishing PTP LSPs.
> >>>  However such extensions are outside the scope of this document.
> >>>
> >>> SB> for mpls-tp GMPLS is the signalling protocol
> >>>
> >>>  While the techniques included herein allow for the establishment of
> >>>  paths optimized to include Time-stamping capable links, the
> >>>  performance of the Slave clocks is outside the scope of this
> >>>  document.
> >>>
> >>>  At the time of publishing this specification, Transparent Clocking
> >>>  (TC) is only defined for PTP.  Therefore at this time any part of
> >>>  this specification that talks about Transparent Clocking applies
> >> only
> >>>  to PTP.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013               [Page
> >> 6]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 2.  Terminology
> >>>
> >>>  1588: The timing and synchronization as defined by IEEE 1588.
> >>>
> >>> SB> I think that there is a more formal name for the 1588 group
> >>> SB> that needs to be used here.
> >>> SB> Also do we need to talk about 1588-200? as there is
> >>> SB> an update in progress
> >>>
> >>>  NTP: The timing and synchronization protocol defined by IETF RFC-
> >> 1305
> >>>  and RFC-5905.
> >>>
> >>>  PTP: The timing and synchronization protocol used by 1588.
> >>> SB> need the proper name for 1588
> >>>
> >>>  Master Clock: The source of 1588 timing to a set of slave clocks.
> >>>
> >>>  Master Port: A port on a ordinary or boundary clock that is in
> >> Master
> >>>  state.  This is the source of timing toward slave ports.
> >>>
> >>> SB> I am not sure the reader knows what a port is
> >>>
> >>>  Slave Clock: A receiver of 1588 timing from a master clock.
> >>>
> >>>  Slave Port: A port on a boundary clock or ordinary clock that is
> >>>  receiving timing from a master clock.
> >>>
> >>>  Ordinary Clock: A device with a single PTP port.
> >>>
> >>>  Transparent Clock.  A device that measures the time taken for a PTP
> >>>  event message to transit the device and then updates the
> >>>  correctionField of the message with this transit time.
> >>>
> >>>  Boundary Clock: A device with more than one PTP port.  Generally
> >>>  boundary clocks will have one port in slave state to receive timing
> >>>  and then other ports in master state to re-distribute the timing.
> >>>
> >>>  PTP LSP: An LSP dedicated to carry PTP messages
> >>>
> >>> SB> PTP or timing?
> >>>
> >>>
> >>>  PTP PW: A PW within a PTP LSP that is dedicated to carry PTP
> >>>  messages.
> >>>
> >>> SB> Ah I don't think that PWE3 know what one of these is
> >>>
> >>>  CW: Pseudowire Control Word
> >>>
> >>>  LAG: Link Aggregation
> >>>
> >>>  ECMP: Equal Cost Multipath
> >>>
> >>>  CF: Correction Field, a field inside certain PTP messages (message
> >>>  type 0-3)that holds the accumulative transit time inside
> >> intermediate
> >>>  switches
> >>>
> >>>  Timing messages: Timing Protocol messages that are exchanged
> >> between
> >>>  routers in order to establish a synchronized clock.
> >>>
> >>> SB> A number of these definitions look like copies of IEEE1588
> >>> SB> definitions. We need to provide references and note the
> >>> SB> priority of the IEEE base reference.
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013               [Page
> >> 7]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 3.  Problem Statement
> >>>
> >>>  [IEEE-1588] has defined methods for transporting PTP messages over
> >>>  Ethernet and IP networks.  [RFC5905] has defined the method of
> >>>  transporting NTP messages over IP networks.  There is a need to
> >>>  transport Timing messages over MPLS networks while supporting the
> >>>  Transparent Clock (TC), Boundary Clock (BC) and Ordinary Clock (OC)
> >>>  functionality in the LER and LSRs in the MPLS network.
> >>>
> >>>  There are multiple ways of transporting Timing over MPLS.  However,
> >>>  there is a requirement to limit the possible encapsulation options
> >> to
> >>>  simplify the Timing message identification and processing required
> >> at
> >>>  the port level.
> >>>
> >>>  When Timing-awareness is needed, Timing messages should not be
> >>>  transported over LSPs or PWs that are carrying customer traffic
> >>>  because LSRs perform Label switching based on the top label in the
> >>>  stack.
> >>>
> >>> SB> Have you explained why?
> >>>
> >>>  To detect Timing messages inside such LSPs require special
> >>>  hardware to do deep packet inspection at line rate.  Even if such
> >>>  hardware exists, the payload can't be deterministically identified
> >> by
> >>>  LSRs because the payload type is a context of the PW label, and the
> >>>  PW label and its context are only known to the Edge routers (PEs/
> >>>  LERs); LSRs dont know what is a PWs payload (Ethernet, ATM, FR,
> >> CES,
> >>>  etc).  Even if one restricts an LSP to only carry Ethernet PWs, the
> >>>  LSRs dont have the knowledge of whether PW Control Word (CW) is
> >>>  present or not and therefore can not deterministically identify the
> >>>  payload.
> >>>
> >>>  A generic method is defined in this document that does not require
> >>>  deep packet inspection at line rate, and can deterministically
> >>>  identify Timing messages.  This method can be used to detect Timing
> >>>  Messages in both one-step and two-step clock implementations of
> >>>  ordinary, boundary and transparent clocks.
> >>>
> >>> SB> Needs a ref and I am sure many MPLS specialists will not
> >> understand
> >>> SB> the msg types.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013               [Page
> >> 8]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 4.  Timing over MPLS Architecture
> >>>
> >>>  Timing messages are exchange between Timing ports on ordinary and
> >>>
> >>> SB> Have you defined a timing port?
> >>>
> >>>  boundary clocks.  Boundary clocks terminate the Timing messages and
> >>>  act as master for other boundary clocks or for slave clocks.  End-
> >> to-
> >>>  End Transparent clocks do not terminate the Timing messages but
> >> they
> >>>  do modify the contents of the Timing messages as they transit
> >> across
> >>>  the transparent clock.
> >>>
> >>>  Master/Slave clocks (OCs), Boundary Clocks (BC) and Transparent
> >> Clock
> >>>
> >>>  (TC) could be implemented in either LERs or LSRs.
> >>>
> >>> SB> LER and LSR need to be expanded
> >>>
> >>>  An example is shown in Figure 1, where the LERs act as Ordinary
> >> Clock
> >>>  (OC) and are the initiating/terminating point for Timing messages.
> >>>  The ingress LER encapsulates the Timing messages in Timing LSP and
> >>>  the Egress LER terminates the Timing LSP.  The LSRs act as
> >>>  Transparent Clock (TC) and just update the Timing field in the
> >> Timing
> >>>  messages.
> >>>
> >>>
> >>>     +--------+     +-------+     +-------+     +-------+     +------
> >> --+
> >>>     |Switch, |     |       |     |       |     |       |
> >> |Switch, |
> >>>     | Router |-----|  LER  |-----|  LSR  |-----|  LER  |-----|
> >> Router |
> >>>     |        |     |  OC   |     |  TC   |     |  OC   |     |
> >> |
> >>>     +--------+     +-------+     +-------+     +-------+     +------
> >> --+
> >>>                    /                                 \
> >>>     +-------+     /                                   \     +-------
> >> +
> >>>     |  LER  |    /                                     \    |  LER
> >> |
> >>>     | Master|---/                                       \---| Slave
> >> |
> >>>     | Clock |                                               | Clock
> >> |
> >>>     +-------+                                               +-------
> >> +
> >>>
> >>>    Figure (1) - Deployment example 1 of timing over MPLS network
> >>>
> >>>  Another example is shown in Figure2, where LERs terminate the
> >> Timing
> >>>  messages received from switch/routers that are outside of the MPLS
> >>>  network acting as OC or BC.  In this example LERs regenerate the
> >>>  clock and initiate timing messages encapsulated in Timing LSP
> >> toward
> >>>  the MPLS network, while the LSRs act as Transparent Clock (TC) and
> >>>  just update the Timing field in the Timing messages, which are
> >>>  already encapsulated in Timing LSPs.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013               [Page
> >> 9]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>>    +--------+     +-------+     +-------+     +-------+     +-------
> >> -+
> >>>    |Switch, |     |       |     |       |     |       |     |Switch,
> >> |
> >>>    | Router |-----|  LER  |-----|  LSR  |-----|  LER  |-----| Router
> >> |
> >>>    | OC/BC  |     |  BC   |     |  TC   |     |  BC   |     | OC/BC
> >> |
> >>>    +--------+     +-------+     +-------+     +-------+     +-------
> >> -+
> >>>
> >>>    Figure (2) - Deployment example 2 of timing over MPLS network
> >>>
> >>>
> >>>  Another example is shown in Figure 3, where LERs do not terminate
> >> the
> >>>  Timing messages received from switch/routers that are outside of
> >> the
> >>>  MPLS network acting as OC, TC or BC.  The LERs act as TC and update
> >>>  the Timing field in the Timing messages as they transit the LER,
> >>>  while encapsulating them in timing LSP.  The LSRs also act as
> >>>  Transparent Clock (TC) and just update the Timing field in the
> >> Timing
> >>>  messages which are already encapsulated in Timing LSPs.
> >>>
> >>>     +--------+     +-------+     +-------+     +-------+     +------
> >> --+
> >>>     |Switch, |     |       |     |       |     |       |
> >> |Switch, |
> >>>     | Router |-----|  LER  |-----|  LSR  |-----|  LER  |-----|
> >> Router |
> >>>     |OC/TC/BC|     |  TC   |     |  TC   |     |  TC   |
> >> |OC/TC/BC|
> >>>     +--------+     +-------+     +-------+     +-------+     +------
> >> --+
> >>>
> >>>   Figure (3) - Deployment example 3 of timing over MPLS network
> >>>
> >>>  Another example is shown in Figure 4, where LERs and LSRs support
> >>>  Boundary Clocks.  A single-hop LSP is created between two adjacent
> >>>  LSRs engaged in BC operation.  Other methods such as PTP transport
> >>>  over Ethernet MAY be used for transporting timing messages if the
> >>>  link between the two routers is Ethernet.
> >>>
> >>>    +--------+     +-------+     +-------+     +-------+     +-------
> >> -+
> >>>    |Switch, |     |       |     |       |     |       |     |Switch,
> >> |
> >>>    | Router |-----|  LER  |-----|  LSR  |-----|  LER  |-----| Router
> >> |
> >>>    | OC/BC  |     |  BC   |     |  BC   |     |  BC   |     | OC/BC
> >> |
> >>>    +--------+     +-------+     +-------+     +-------+     +-------
> >> -+
> >>>
> >>>  Figure (4) - Deployment example 3 of timing over MPLS network
> >>>
> >>>  An MPLS domain MAY serve multiple customers.  In these cases the
> >> MPLS
> >>>  domain (maintained by a service provider) may provide timing
> >> services
> >>>  to multiple customers, each having their own Timing domain.
> >>>
> >>>  The Timing over MPLS architecture assumes full mesh of Timing LSPs
> >>>  between all LERs supporting this specification.
> >>>
> >>> SB> Note sure this is right - the salves surely do not need to
> >>> SB> exchange timing amongst themselves
> >>>
> >>>  It supports
> >>>  Point-to- point (VPWS) and Multipoint (VPLS) services.
> >>>
> >>> SB> What does that mean? You do not carry user data traffic?
> >>> SB> Maybe it's the ordering of the statemnets that is causing
> >>> SB> confusion.
> >>>
> >>>  This means
> >>>  that a customer may purchase a Point-to-point Timing service
> >> between
> >>>  two customer sites or a Multipoint Timing service between more than
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 10]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>>  two customer sites.
> >>>
> >>>  The Timing over MPLS architecture supports P2P or P2MP Timing LSPs.
> >>>  This means that the Timing Multicast messages such as PTP Multicast
> >>>  event messages can be transported over P2MP Timing LSP or be
> >>>  replicated and transported over many P2P Timing LSPs.
> >>>
> >>> SB> Note we do not yet have a definition of a P2MP mpls-tp LSP
> >>> SB> nor a P2MP PW, although we are close.
> >>>
> >>>  Timing messages, that do not require Time stamping or Correction
> >>>  Field update MAY be transported over Timing LSPs to simplify
> >> hardware
> >>>  and software.
> >>>
> >>>  PTP Announce messages that determine the Timing LSP terminating
> >> point
> >>>  behavior such as BC/OC/TC SHOULD be transported over the Timing LSP
> >>>  to simplify hardware and software.
> >>>
> >>> SB> have you defined and referenced PTP announce msgs?
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 11]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 5.  Dedicated LSPs for Timing messages
> >>>
> >>>  Many methods have been considered for identifying the Timing
> >> messages
> >>>  when they are encapsulated in MPLS such as using GAL/G-ACH or a new
> >>>  reserved label.  These methods were not attractive since they
> >> either
> >>>  required deep packet inspection at line rate in the intermediate
> >> LSRs
> >>>  or they required use of a scarce new reserved label.  Also one of
> >> the
> >>>  goals was to reuse existing OAM mechanisms.
> >>>
> >>> SB> RLs = SPLs are not so rare now. In any case needs a ref.
> >>>
> >>>  The method defined in this document can be used by LER and LSRs to
> >>>  identify Timing messages in MPLS tunnels by just looking at the top
> >>>  label in the MPLS label stack, which only carry Timing messages as
> >>>  well as OAM, but not data plane client traffic.
> >>>
> >>>  Compliant implementations MUST use dedicated LSPs to carry Timing
> >>>  messages over MPLS.
> >>>
> >>> SB> I think that we need a definition of the properies of these LSPs
> >>>
> >>>  These LSPs are herein referred to as "Timing
> >>>  LSPs" and the labels associated with these LSPs as "Timing LSP
> >>>  labels".  The Timing LSPs that runs between Ingress and Egress LERs
> >>>  MUST be co-routed.  Alternatively, a single bidirectional co-routed
> >>>  LSP can be used.
> >>>
> >>> SB> I though that you said you could use M2MP LSPs - these are not
> >>> SB> bidirectional.
> >>>
> >>>  Co-routing of the two directions is required to limit the
> >> difference
> >>>  in the delays in the Master clock to Slave clock direction compared
> >>>  to the Slave clock to Master clock direction.  The Timing LSP MAY
> >> be
> >>>  MPLS/MPLS-TP LSP.
> >>>
> >>>  The Timing LSPs could be configured or signaled via RSVP-TE/GMPLS.
> >>>  New Extensions to RSVP-TE/GMPLS TLVs are required; however they are
> >>>  outside the scope of this document.
> >>>
> >>>  The Timing LSPs MAY carry essential MPLS/MPLS-TP OAM traffic such
> >> as
> >>>  BFD and LSP Ping but the LSP data plane client plane traffic MUST
> >> be
> >>>  Timing packets only.
> >>>
> >>> SB> Why?
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 12]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 6.  Timing over LSP Encapsulation
> >>>
> >>> The encapsulations is not LSP is it?
> >>>
> >>>  This document defines two methods for carrying Timing messages over
> >>>  MPLS.  The first method is carrying UDP/IP encapsulated Timing
> >>>  messages over Timing LSPs, and the second method, is carrying
> >>>  Ethernet encapsulated Timing messages over Ethernet PWs inside
> >> Timing
> >>>  LSPs.
> >>>
> >>> 6.1.  Timing over UDP/IP over MPLS Encapsulation
> >>>
> >>>  The simplest method of transporting Timing messages over MPLS is to
> >>>  encapsulate Timing PDUs in UDP/IP and then encapsulate them in
> >> Timing
> >>>  LSP.  This format is shown in Figure 4.
> >>>
> >>>
> >>>                   +----------------------+
> >>>                   |   Timing LSP Label   |
> >>>                   +----------------------+
> >>>                   |        IPv4/6        |
> >>>                   +----------------------+
> >>>                   |         UDP          |
> >>>                   +----------------------+
> >>>                   |     Timing PDU       |
> >>>                   +----------------------+
> >>>
> >>>     Figure (4) - Timing over UDP/IP over MPLS Encapsulation
> >>>
> >>>
> >>>  This encapsulation is very simple and is useful when the network
> >>>  between Timing Master Clock and Slave Clock is MPLS network.
> >>>
> >>> SB> Simple is a judgement call
> >>>
> >>>  In order for an LER/LSR to process Timing messages, the Timing LSP
> >>>  Label must be at the top label of the label stack.  The LER/LSR
> >> MUST
> >>>  know that the Timing LSP Label is used for carrying Timing
> >> messages.
> >>>  This can be accomplished via static configuration or via RSVP-TE
> >>>  signaling.
> >>>
> >>>  The UDP/IP encapsulation of PTP MUST follow Annex D and E of
> >>>  [IEEE-1588].  While the UDP/IP encapsulation of NTP MUST follow
> >>>  [RFC5905].
> >>>
> >>> 6.2.  Timing over PW Encapsulation
> >>>
> >>>  Another method of transporting Timing over MPLS networks is by
> >>>  encapsulating Timing PDUs in PW which in turn is transported over
> >>>  Timing LSPs.  In case of PTP, Ethernet PW encapsulation [RFC4448],
> >>>  shown in Fig 5(A) MUST be used and the Ethernet encapsulation of
> >> PTP
> >>>  MUST follow Annex F of [IEEE-1588].
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 13]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>>  The RAW mode or Tagged mode defined in [RFC4448] MAY be used and
> >> the
> >>>  Payload MUST have 0, 1, or 2 VLAN tags (S-VLAN and C-VLAN).  The
> >>>  Timing over PW encapsulation MUST use the Control Word (CW) as
> >>>  specified in [RFC4448] to ensure proper detection of PTP messages
> >>>  inside the MPLS packets for Timing over LSP and Timing over PW
> >>>  encapsulation.
> >>>
> >>> SB> That needs explanation
> >>>
> >>>  The use of Sequence Number in the CW is optional.
> >>>
> >>> SB> Given that s/n are never in practice deployed, you could probably
> >>> SB> simplify things by sayig that they are not used.
> >>>
> >>>  Timing over PW encapsulation for NTP MUST use NTP over UDP/IP over
> >> PW
> >>>  (the IP PW discussed in [RFC4447]) shown in Fig 5(B).
> >>>
> >>>                   +----------------+  +----------------+
> >>>                    |Timing LSP Label|  |Timing LSP Label|
> >>>                    +----------------+  +----------------+
> >>>                    |    PW Label    |  |    PW Label    |
> >>>                    +----------------+  +----------------+
> >>>                    |  Control Word  |  |      IP        |
> >>>                    +----------------+  +----------------+
> >>>                    |    Ethernet    |  |      UDP       |
> >>>                    |     Header     |  +----------------+
> >>>                    +----------------+  |   Timing PDU   |
> >>>                    |S-VLAN(Optional)|  |                |
> >>>                    +----------------+  +----------------+
> >>>                    |C-VLAN(Optional)|        (B)
> >>>                    +----------------+
> >>>                    |   Timing PDU   |
> >>>                    |                |
> >>>                    +----------------+
> >>>                           (A)
> >>>
> >>>             Figure (5) - Timing over PW Encapsulations
> >>>
> >>>  In order for an LSR to process PTP messages, the top label of the
> >>>  label stack (the Tunnel Label) MUST be a Timing label.
> >>>
> >>> S> You said that before.
> >>>
> >>> 6.3.  Other Timing Encapsulation methods
> >>>
> >>>  In future other timing encapsulation methods may be introduced,
> >> such
> >>>  as a new shim header after the Bottom of Stack to carry the Timing
> >>>  information.  Such new encapsulations are outside the scope of this
> >>>  document.
> >>>
> >>>
> >>> SB> Taking a pure MPLS pov, you can simplify a lot of the text
> >>> SB> out of the definition of the LSP
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 14]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> SB> I think we need a section on LSP processing
> >>>
> >>> 7.  Timing message Processing
> >>>
> >>>  Each Timing protocol such as PTP and NTP, define their set of
> >> Timing
> >>>  messages.  For example PTP defines SYNC, DELAY_REQ, DELAY_RESP,
> >>>  FOLLOW_UP, etc messages.
> >>>
> >>>  Some of the Timing messages require time stamping or correction
> >> field
> >>>  update at port level and some dont.  It is the job of the LER/LSR
> >> to
> >>>  parse the timing message and find out the type of the Timing
> >> message
> >>>  and decide whether and how to Time- stamp it (e.g., BC) or update
> >>>  correction field(e.g., TC).
> >>>
> >>>
> >>> SB> AAAAAAAAAAAH. Surely this is the function of the PTP prcessing
> >>> SB> function rather than the LER?
> >>>
> >>>  For example the following PTP messages (called Event messages)
> >>>  require time-stamping or correction field update:
> >>>
> >>>  o  SYNC
> >>>
> >>>  o  DELAY_REQ (Delay Request)
> >>>
> >>>  o  PDELAY_REQ (Peer Delay Request)
> >>>
> >>>  o  PDELAY_RESP (Peer Delay Response)
> >>>
> >>>  SYNC and DELAY_REQ are exchanged between Master Clock and Slave
> >> Clock
> >>>  and MUST be transported over PTP LSPs.  PDELAY_REQ and PDELAY_RESP
> >>>  are exchanged between adjacent PTP clocks (i.e.  Master, Slave,
> >>>  Boundary, or Transparent) and SHOULD be transported over single hop
> >>>  PTP LSPs.  If Two Step PTP clocks are present, then the FOLLOW_UP,
> >>>  and PDELAY_RESP_FOLLOW_UP messages MUST also be transported over
> >> the
> >>>  PTP LSPs.
> >>>
> >>>  For a given instance of 1588 protocol, SYNC and DELAY_REQ MUST be
> >>>  transported over two PTP LSPs that are in opposite directions.
> >> These
> >>>  PTP LSPs, which are in opposite directions MUST be congruent and
> >> co-
> >>>  routed.  Alternatively, a single bidirectional co-routed LSP can be
> >>>  used.
> >>>
> >>>  Except as indicated above for the two-step PTP clocks, Non-Event
> >> PTP
> >>>  message types do not need to be processed by intermediate routers.
> >>>  These message types MAY be carried in PTP Tunnel LSPs.
> >>>
> >>> SB> Are you saying that a timing P router has to be msg type
> >> sensitive?
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 15]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 8.  Protection and Redundancy
> >>>
> >>>
> >>> SB> This is a bit of a jump - I don't know how the LSP itself works
> >> yet!
> >>>
> >>>  In order to ensure continuous uninterrupted operation of slave
> >>>  clocks, usually as a general practice, slave clocks (or ports)
> >> track
> >>>  redundant master clocks.
> >>>
> >>>  It is the responsibility of the network operator to ensure that
> >>>  physically disjoint Timing LSPs are established between a slave
> >> clock
> >>>  (or port) and redundant master clocks (or ports).
> >>>
> >>>  When a slave clock (or port) listens to redundant master clocks or
> >>>  ports, any prolonged Timing LSP outage will trigger the slave clock
> >>>  or port to switch to a redundant master clock or port.
> >>>
> >>>  LSP/PW protection such as Linear protection Switching (1:1, 1+1),
> >>>  Ring protection switching or MPLS Fast Reroute (FRR) generally
> >> switch
> >>>  alternative path that usually cause a change in delay, which if
> >>>  undetected by slave clock can reduce accuracy of the slave clock.
> >>>
> >>>  Therefore protection switching MAY be used, as long as phase jumps
> >>>  upon switchover due to differences in path latency are detected and
> >>>  compensated for (such compensation not being required if BCs or
> >> peer-
> >>>  peer TCs are used throughout).
> >>>
> >>>  Note that any protection or reroute mechanism that adds additional
> >>>  MPLS label to the label stack, such as Facility Backup Fast
> >> Reroute,
> >>>  MUST ensure that the pushed label is also a Timing Label to ensure
> >>>  recognition of the MPLS frame as containing Timing messages, as it
> >>>  transits the backup path.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 16]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 9.  ECMP
> >>>
> >>>  To ensure the optimal operation of slave clocks and avoid error
> >>>  introduced by forward and reverse path delay asymmetry, the
> >> physical
> >>>  path for Timing messages from master clock to slave Clock and vice
> >>>  versa must be the same for all Event Timing messages listed in
> >>>  section 7.
> >>>
> >>>  Therefore the Timing LSPs MUST not be subject to ECMP (Equal Cost
> >>>  Multipath).
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 17]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 10.  PHP
> >>>
> >>>  To ensure that the label on the top of the label stack is the
> >> Timing
> >>>  LSP Label, PHP MUST not be used.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
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> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 18]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 11.  Entropy
> >>>
> >>>  To ensure all Timing messages in a Timing LSP take the same path,
> >>>  Entropy Label MUST NOT be used for the Timing LSP[RFC6790] and
> >>>  Entropy Label MUST NOT be used for the PWs that are carried inside
> >>>  Timing LSP [RFC6391].
> >>>
> >>> SB> This is incorrect - you mean that all msgs of the same timing
> >>> SB> flow need to have the same EL value.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
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> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 19]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 12.  OAM, Control and Management
> >>>
> >>>  In order to monitor Timing LSPs and their encapsulated PWs, they
> >> MUST
> >>>  be able to carry OAM and management messages.  These management
> >>>  messages MUST be differentiated from Timing messages via already
> >>>  defined IETF methods.
> >>>
> >>>  For example BFD [RFC5880], [RFC5884] and LSP-Ping [RFC4389] MAY run
> >>>  over PTP LSPs via UDP/IP encapsulation or via GAL/G-ACH.  These
> >>>  Management protocols can easily be identified by the UDP
> >> Destination
> >>>  Port number or by GAL/G-ACH respectively.
> >>>
> >>>  Also BFD, LSP-Ping and other management messages MAY run over the
> >> PWs
> >>>  encapsulated in Timing LSP via one of the defined VCCVs (Type 1, 3
> >> or
> >>>  4) [RFC5085] (note that VCCV Type 2 using Router Alert Label is
> >> going
> >>>  to be deprecated by IETF).  In this case G-ACH, PW label (TTL=1) or
> >>>  GAL-ACH are used to identify such management messages.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 20]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 13.  QoS Considerations
> >>>
> >>>  In network deployments where not every LSR/LER is Timing-aware, it
> >> is
> >>>  important to reduce the impact of the non-Timing-aware LSR/LERs on
> >>>  the timing recovery in the slave clock.  The Timing messages are
> >> time
> >>>  critical and must be treated with the highest priority.  Therefore
> >>>  Timing over MPLS messages must be treated with the highest priority
> >>>  in the routers.  This can be achieved by proper setup of Timing
> >> LSPs.
> >>>
> >>>  It is recommended that the Timing LSPs are setup or configured
> >>>  properly to indicate EF-PHB [RFC3246]for the CoS and Green
> >> [RFC2697]
> >>>  for drop eligibility.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 21]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 14.  FCS and Checksum Recalculation
> >>>
> >>>  When time-stamp generation and timing packet adjustment is
> >> performed
> >>>  near the physical port hardware, the process MUST include
> >>>  recalculation of the Ethernet FCS.
> >>>
> >>> SB> The above is confusing - an LSR always recomputes the link layer
> >>> SB> CRC which may or may not be Ethernet.
> >>>
> >>>  Also FCS retention for the
> >>>  payload Ethernet described in [RFC4720] MUST NOT be used.
> >>>
> >>>  For UDP/IP encapsulation mode of Timing over MPLS, the UDP checksum
> >>>  may be required as per UDP transport standards.
> >>>
> >>> SB> You really need to be working on getting the IPv6 C?S computation
> >>> SB> removed from PTP msgs.
> >>>
> >>>  When UDP checksum is used, each Timing-aware LER/LSR must either
> >>>  incrementally update the UDP checksum after Time stamping or
> >>>  Correction Field update or verify the UDP checksum on reception
> >> from
> >>>  upstream and recalculate the checksum completely on transmission to
> >>>  downstream node after Time stamping or Correction Field update.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 22]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 15.  Behavior of LER/LSR
> >>>
> >>>  Timing-capable/aware LERs and LSRs are routers that have one or
> >> more
> >>>
> >>> SB> You mean physical interfaces?
> >>>
> >>>  interfaces that can perform Timing operations (OC/BC/TC) on Timing
> >>>  packets and are configured to do so.  Timing-capable/aware LERs and
> >>>  LSRs can advertise their Timing-capability per-interface via
> >> control
> >>>  plane such as OSPF or IS-IS.
> >>> SB> ISIS and OSPF are routing protocols.
> >>>
> >>> The Timing-capable/aware LERs can then
> >>>  signals Timing LSPs via RSVP-TE signaling.  Alternatively the
> >> Timing
> >>>  capability of LER and LSRs may be configured in a centralized
> >>>  controller and the Timing LSP may be setup using manual
> >> configuration
> >>>  or other methods such as SDN.
> >>>
> >>> SB> it can also be configured individually rather then through
> >>> SB> a cebtral controllwe
> >>>
> >>> 15.1.  Behavior of Timing-capable/aware LER
> >>>
> >>>  When a Timing-capable/aware LER behaves as a Transparent clock and
> >>>  receives a Timing message from a Timing-capable/aware non-MPLS
> >>>  interface, the LER updates the Correction Field (CF) and
> >> encapsulates
> >>>  and forwards the timing message over previously established Timing
> >>>  LSP.
> >>>
> >>> SB> You need to call out the details so that people properly
> >>> SB> understand the definition of the new LSP.
> >>>
> >>>  Also when a Timing message is received from a Timing-capable/
> >>>  aware MPLS interface, LER updates the Correction Filed (CF) and
> >>>  decapsulates the MPLS encapsulation and forwards the timing message
> >>>  to a non-MPLS interface.
> >>>
> >>>  When a Timing-capable/aware LER behaves as a Boundary clock and
> >>>  receives a Timing message from a Timing-capable/aware non MPLS
> >>>  interface, the LER Timestamps the Timing packet and sends it to the
> >>>  LERs Boundary clock processing module.  Also when a Timing message
> >> is
> >>>  received from a Timing- capable/aware MPLS interface, the LER
> >>>  Timestamps the Timing packet and sends it to the LERs Boundary
> >> clock
> >>>  processing module.
> >>>
> >>>  When a Timing-capable/aware LER behaves as an Ordinary Clock toward
> >>>  the MPLS network, and receives a Timing message from a Timing-
> >>>  capable/aware MPLS interface, the LER Timestamps the Timing packet
> >>>  and sends it to the LERs Ordinary clock processing module.
> >>>
> >>> 15.2.  Behavior of Timing-capable/aware LSR
> >>>
> >>>  When a Timing-capable/aware LSR behaves as a Transparent clock and
> >>>  receives a Timing message from a Timing-capable/aware MPLS
> >> interface,
> >>>  The LSR updates the Correction Filed (CF) and forwards the timing
> >>>  message over another MPLS interface.
> >>>
> >>>  When a Timing-capable/aware LSR behaves as a Boundary clock and
> >>>  receives a Timing message from a Timing-capable/aware MPLS
> >> interface.
> >>>  The LSR performs the functions of a Boundary Clock in terminating
> >> the
> >>>  received Timing message and re-generating a new timing message over
> >>>  another (or the same) MPLS interface.
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 23]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 15.3.  Behavior of non-Timing-capable/aware LSR
> >>>
> >>>  It is most beneficial when all LSRs in the path of a Timing LSP be
> >>>  timing-Capable/aware LSRs.  This would ensure the highest quality
> >>>  time and clock synchronization by Timing Slave Clocks.  However,
> >> this
> >>>  specification does not mandate that all LSRs in path of a Timing
> >> LSP
> >>>  be Timing- capable/aware.
> >>>
> >>>  Non-Timing-capable/aware LSRs just switch the packets encapsulated
> >> in
> >>>  Timing LSPs and dont perform any Timing operation (TC or BC).
> >>>  However as explained in QoS section the Timing over MPLS packets
> >> MUST
> >>>  be still be treated with the highest priority based on their
> >> Traffic
> >>>  Class (TC) marking.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 24]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 16.  Other considerations
> >>>
> >>>  [IEEE-1588] defines an optional peer-to-peer Transparent clocking
> >>>  that requires peer delay measurement between two adjacent Timing-
> >>>  capable/ aware routers/switches.  Peer delay measurement messages
> >>>  need to be time stamped and terminated by the Timing-capable/aware
> >>>  routers/ switches.  This means that two adjacent LSRs may be
> >> engaged
> >>>  in a peer delay measurement.
> >>>
> >>>  For transporting such peer delay measurement messages a single-hop
> >>>  LSP SHOULD to be created between the two adjacent LSRs engaged in
> >>>  peer delay measurement to carry peer delay measurement messages.
> >>>  Other methods such as PTP transport over Ethernet MAY be used for
> >>>  transporting peer delay measurement messages if the link between
> >> the
> >>>  two routers is Ethernet.
> >>>
> >>>  In Peer-to-peer transparent clocking (P2P TC), a Timing-capable/
> >> ware
> >>>  routers/switches MUST maintain a list of all the neighbors it needs
> >>>  to send a PDelay_Req to, where each neighbor corresponds to a
> >> timing
> >>>  LSP.
> >>>
> >>>  The use of Explicit Null Label (Label= 0 or 2) is acceptable as
> >> long
> >>>  as either the Explicit Null label is the bottom of stack label
> >>>  (applicable only to UDP/IP encapsulation) or the label below the
> >>>  Explicit Null label is a PTP label.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 25]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 17.  Security Considerations
> >>>
> >>>  MPLS PW security considerations in general are discussed in
> >> [RFC3985]
> >>>  and [RFC4447],and those considerations also apply to this document.
> >>>
> >>>  An experimental security protocol is defined in [IEEE-1588].The PTP
> >>>  security extension and protocol provides group source
> >> authentication,
> >>>  message integrity, and replay attack protection for PTP messages.
> >>>
> >>>  When the MPLS network (provider network) serves multiple customers,
> >>>  it is important to maintain and process each customers clock and
> >>>  Timing messages separately from other customers to ensure there is
> >> no
> >>>  cross- customer effect.  For example if an LER BC is synchronized
> >> to
> >>>  a specific grandmaster, belonging to customer A, then the LER MUST
> >>>  use that BC clock only for customer A to ensure that customer A
> >>>  cannot attack other customers by manipulating its time.
> >>>
> >>>  Timing messages MAY be encrypted or authenticated, provided that
> >> the
> >>>  LERs/LSRs that are Timing capable/aware can authenticate/ decrypt
> >> the
> >>>  timing messages.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 26]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 18.  Acknowledgements
> >>>
> >>>  The authors would like to thank Ron Cohen, Yaakov Stein, Tal
> >> Mizrahi,
> >>>  Stefano Ruffini, Peter Meyer, and other members of IETF for
> >> reviewing
> >>>  and providing feedback on this draft.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 27]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 19.  IANA Considerations
> >>>
> >>>  There are no IANA requirements in this specification.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 28]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 20.  References
> >>>
> >>> 20.1.  Normative References
> >>>
> >>>  [IEEE-1588]
> >>>             IEEE 1588-2008, "IEEE Standard for a Precision Clock
> >>>             Synchronization Protocol for Networked Measurement and
> >>>             Control Systems".
> >>>
> >>>  [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
> >>>             Requirement Levels", BCP 14, RFC 2119, March 1997.
> >>>
> >>>  [RFC3985]  Bryant, S. and P. Pate, "Pseudo Wire Emulation Edge-to-
> >>>             Edge (PWE3) Architecture", RFC 3985, March 2005.
> >>>
> >>>  [RFC4389]  Thaler, D., Talwar, M., and C. Patel, "Neighbor
> >> Discovery
> >>>             Proxies (ND Proxy)", RFC 4389, April 2006.
> >>>
> >>>  [RFC4447]  Martini, L., Rosen, E., El-Aawar, N., Smith, T., and G.
> >>>             Heron, "Pseudowire Setup and Maintenance Using the Label
> >>>             Distribution Protocol (LDP)", RFC 4447, April 2006.
> >>>
> >>>  [RFC4448]  Martini, L., Rosen, E., El-Aawar, N., and G. Heron,
> >>>             "Encapsulation Methods for Transport of Ethernet over
> >> MPLS
> >>>             Networks", RFC 4448, April 2006.
> >>>
> >>>  [RFC4720]  Malis, A., Allan, D., and N. Del Regno, "Pseudowire
> >>>             Emulation Edge-to-Edge (PWE3) Frame Check Sequence
> >>>             Retention", RFC 4720, November 2006.
> >>>
> >>>  [RFC5085]  Nadeau, T. and C. Pignataro, "Pseudowire Virtual Circuit
> >>>             Connectivity Verification (VCCV): A Control Channel for
> >>>             Pseudowires", RFC 5085, December 2007.
> >>>
> >>>  [RFC5880]  Katz, D. and D. Ward, "Bidirectional Forwarding
> >> Detection
> >>>             (BFD)", RFC 5880, June 2010.
> >>>
> >>>  [RFC5884]  Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow,
> >>>             "Bidirectional Forwarding Detection (BFD) for MPLS Label
> >>>             Switched Paths (LSPs)", RFC 5884, June 2010.
> >>>
> >>> 20.2.  Informative References
> >>>
> >>>  [I-D.ietf-pwe3-fat-pw]
> >>>             Bryant, S., Filsfils, C., Drafz, U., Kompella, V.,
> >> Regan,
> >>>             J., and S. Amante, "Flow Aware Transport of Pseudowires
> >>>             over an MPLS Packet Switched Network",
> >>>             draft-ietf-pwe3-fat-pw-07 (work in progress), July 2011.
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 29]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>>  [ISO]      ISO/IEC 10589:1992, "Intermediate system to Intermediate
> >>>             system routeing information exchange protocol for use in
> >>>             conjunction with the Protocol for providing the
> >>>             Connectionless-mode Network Service (ISO 8473)".
> >>>
> >>>  [RFC1195]  Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
> >>>             dual environments", RFC 1195, December 1990.
> >>>
> >>>  [RFC2328]  Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.
> >>>
> >>>  [RFC2697]  Heinanen, J. and R. Guerin, "A Single Rate Three Color
> >>>             Marker", RFC 2697, September 1999.
> >>>
> >>>  [RFC3246]  Davie, B., Charny, A., Bennet, J., Benson, K., Le
> >> Boudec,
> >>>             J., Courtney, W., Davari, S., Firoiu, V., and D.
> >>>             Stiliadis, "An Expedited Forwarding PHB (Per-Hop
> >>>             Behavior)", RFC 3246, March 2002.
> >>>
> >>>  [RFC3630]  Katz, D., Kompella, K., and D. Yeung, "Traffic
> >> Engineering
> >>>             (TE) Extensions to OSPF Version 2", RFC 3630,
> >>>             September 2003.
> >>>
> >>>  [RFC3784]  Smit, H. and T. Li, "Intermediate System to Intermediate
> >>>             System (IS-IS) Extensions for Traffic Engineering (TE)",
> >>>             RFC 3784, June 2004.
> >>>
> >>>  [RFC4970]  Lindem, A., Shen, N., Vasseur, JP., Aggarwal, R., and S.
> >>>             Shaffer, "Extensions to OSPF for Advertising Optional
> >>>             Router Capabilities", RFC 4970, July 2007.
> >>>
> >>>  [RFC4971]  Vasseur, JP., Shen, N., and R. Aggarwal, "Intermediate
> >>>             System to Intermediate System (IS-IS) Extensions for
> >>>             Advertising Router Information", RFC 4971, July 2007.
> >>>
> >>>  [RFC5120]  Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
> >>>             Topology (MT) Routing in Intermediate System to
> >>>             Intermediate Systems (IS-ISs)", RFC 5120, February 2008.
> >>>
> >>>  [RFC5305]  Li, T. and H. Smit, "IS-IS Extensions for Traffic
> >>>             Engineering", RFC 5305, October 2008.
> >>>
> >>>  [RFC5329]  Ishiguro, K., Manral, V., Davey, A., and A. Lindem,
> >>>             "Traffic Engineering Extensions to OSPF Version 3",
> >>>             RFC 5329, September 2008.
> >>>
> >>>  [RFC5340]  Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
> >>>             for IPv6", RFC 5340, July 2008.
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 30]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>>  [RFC5905]  Mills, D., Martin, J., Burbank, J., and W. Kasch,
> >> "Network
> >>>             Time Protocol Version 4: Protocol and Algorithms
> >>>             Specification", RFC 5905, June 2010.
> >>>
> >>>  [RFC6391]  Bryant, S., Filsfils, C., Drafz, U., Kompella, V.,
> >> Regan,
> >>>             J., and S. Amante, "Flow-Aware Transport of Pseudowires
> >>>             over an MPLS Packet Switched Network", RFC 6391,
> >>>             November 2011.
> >>>
> >>>  [RFC6790]  Kompella, K., Drake, J., Amante, S., Henderickx, W., and
> >>>             L. Yong, "The Use of Entropy Labels in MPLS Forwarding",
> >>>             RFC 6790, November 2012.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 31]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 1.  Routing extensions for Timing-aware Routers
> >>>
> >>>  MPLS-TE routing relies on extensions to OSPF [RFC2328] [RFC5340]
> >> and
> >>>  IS-IS [ISO] [RFC1195] in order to advertise Traffic Engineering
> >> (TE)
> >>>  link information used for constraint-based routing.
> >>>
> >>>  Indeed, it is useful to advertise data plane TE router link
> >>>  capabilities, such as the capability for a router to be Timing-
> >> aware.
> >>>  This capability MUST then be taken into account during path
> >>>  computation to prefer or even require links that advertise
> >> themselves
> >>>  as Timing-aware.  In this way the path can ensure the entry and
> >> exit
> >>>  points into the LERs and, if desired, the links into the LSRs are
> >>>  able to perform port based time-stamping thus minimizing their
> >> impact
> >>>  on the performance of the slave clock.
> >>>
> >>>  extensions are required to OSPF and IS-IS in order to advertise
> >>>  Timing-aware capabilities of a link.  Such extensions are outside
> >> the
> >>>  scope of this document; however such extension SHOULD be able to
> >>>  signal the following information per Router Link:
> >>>
> >>>  o  Capable of processing PTP, NTP or other Timing flows
> >>>
> >>>  o  Capable of performing Transparent Clock operation
> >>>
> >>>  o  Capable of performing Boundary Clock operation
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 32]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> 2.  Signaling Extensions for Creating Timing LSPs
> >>>
> >>>  RSVP-TE signaling MAY be used to setup the timing LSPs.  When RSVP-
> >> TE
> >>>  is used to setup Timing LSPs, some information that indicates that
> >>>  the LSP is carrying Timing flows MUST be included in the new
> >>>  Extensions to RSVP-TE:
> >>>
> >>>  The following information MAY also be included in the new
> >> Extensions
> >>>  to RSVP-TE:
> >>>
> >>>  o  Offset from Bottom of Stack (BoS) to the start of the Time-stamp
> >>>     field
> >>>
> >>>  o  Number of VLANs in case of PW encapsulation
> >>>
> >>>  o  Timestamp field Type
> >>>
> >>>     *  Correction Field, Timestamp
> >>>
> >>>  o  Timestamp Field format
> >>>
> >>>     *  64-bit PTPv1, 80-bit PTPv2, 32-bit NTP, 64-bit NTP, 128-bit
> >>>        NTP, etc.
> >>>
> >>>  Note that in case the above optional information is signaled with
> >>>  RSVP-TE for a Timing LSP, all the Timing packets carried in that
> >> LSP
> >>>  must have the same signaled characteristics.  For example if
> >>>  Timestamp format is signaled as 64-bit PTPv1, then all Timing
> >> packets
> >>>  must use 64-bit PTPv1 time-stamp.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 33]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>> Authors' Addresses
> >>>
> >>>  Shahram Davari
> >>>  Broadcom Corp.
> >>>  San Jose, CA  95134
> >>>  USA
> >>>
> >>>  Email: davari@broadcom.com
> >>>
> >>>
> >>>  Amit Oren
> >>>  Broadcom Corp.
> >>>  San Jose, CA  95134
> >>>  USA
> >>>
> >>>  Email: amito@broadcom.com
> >>>
> >>>
> >>>  Manav Bhatia
> >>>  Alcatel-Lucent
> >>>  Bangalore,
> >>>  India
> >>>
> >>>  Email: manav.bhatia@alcatel-lucent.com
> >>>
> >>>
> >>>  Peter Roberts
> >>>  Alcatel-Lucent
> >>>  Kanata,
> >>>  Canada
> >>>
> >>>  Email: peter.roberts@alcatel-lucent.com
> >>>
> >>>
> >>>  Laurent Montini
> >>>  Cisco Systems
> >>>  San Jose CA
> >>>  USA
> >>>
> >>>  Email: lmontini@cisco.com
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 34]
> >
> >>> Internet-Draft        Transporting Timing over MPLS            June
> >> 2013
> >>>
> >>>
> >>>  Luca
> >>>  Cisco Systems
> >>>  San Jose CA
> >>>  USA
> >>>
> >>>  Email: lmartini@cisco.com
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Davari, et al.          Expires December 17, 2013              [Page
> >> 35]
> >
> >>>
> >>> --
> >>> For corporate legal information go to:
> >>>
> >>> http://www.cisco.com/web/about/doing_business/legal/cri/index.html
> >>>
> >>> _______________________________________________
> >>> mpls mailing list
> >>> mpls@ietf.org
> >>> https://www.ietf.org/mailman/listinfo/mpls
> >
> >
> >
> >
>
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