Peter, Good feedback. I will update the draft after the Orlando to include your comments.
Thx Shahram -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Meyer, Peter Sent: Monday, March 11, 2013 5:49 PM To: [email protected] Subject: Re: [TICTOC] comments on draft-ietf-tictoc-1588overmpls-04.txt Hi Shahram et al, Some comments on draft -04. 1) Section 3. "A generic method is defined in this document that does not require deep packet inspection at line rate, and can deterministically identify Timing messages. The generic method is applicable to MPLS and MPLS-TP networks." May want to add that this would apply only to one-step TC (I imagine that is the point of the correction at line rate). A two-step TC would need to do deep packet inspection as it uses sourcePortIdentity & sequenceId fields for Follow_up or Delay_Resp. 2) Section 4. "An MPLS domain can serve multiple customers. This means that the MPLS domain (maintained by a service provider) may provide timing services to multiple customers, each having their own Timing domain. Therefore LER BCs need to interact with multiple grandmasters, and consequently multiple time references." This should be re-phrased. It switches from an optional situation ("may provide timing services") to mandatory situation ("LER BCs need to interact"). Some words such as "in such a deployment scenario, ...." and replace "can" with "may". We have seen at ITU at least (with participation from operators BT, FT, DT, CMCC, AT&T, Sprint, etc.) that this multiple operator domain case was not useful enough to be included in standardization process for Telecom networks. 3) Section 19. "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." This new statement to handle peer-delay (which in earlier drafts did not have a communication path listed), also allows a BC to be embedded in an LSR with a communication path between BC's as a single-hop LSP (mentioned March 22, 2012 in my feedback to draft -03, subject "[TICTOC] Updated 1588 over MPLS draf-03"). Architecture diagrams Figure 1 and Figure should be updated to reflect the possibility of either BC or TC implementation. Section 18.2 and section 18.3 and section 21 should also be updated to reflect the possibility of either BC or TC. I understand the RFC is intended to be generic and not targeted only at TC. 4) Section 20. "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." This seems much more applicable to the TC LSR and should be stated. >From section 4 we see the TC uses the primary synchronization domain (that of the service provide) to correct PTP messages. 5) Section 20. "Timing messages (as opposed to regular customer data) SHOULD not be encrypted or authenticated on an end-to-end basis." I think there is a security draft in parallel being developed that may be relevant to that statement. Regards, Peter -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: February 23, 2013 2:23 AM To: [email protected] Cc: [email protected] Subject: [TICTOC] I-D Action: draft-ietf-tictoc-1588overmpls-04.txt A New Internet-Draft is available from the on-line Internet-Drafts directories. This draft is a work item of the Timing over IP Connection and Transfer of Clock Working Group of the IETF. Title : Transporting Timing messages over MPLS Networks Author(s) : Shahram Davari Amit Oren Manav Bhatia Peter Roberts Laurent Montini Filename : draft-ietf-tictoc-1588overmpls-04.txt Pages : 36 Date : 2013-02-22 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 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. Two methods for transporting Timing messages over MPLS are defined. 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, which is suitable for both MPLS and MPLS-TP networks. The IETF datatracker status page for this draft is: https://datatracker.ietf.org/doc/draft-ietf-tictoc-1588overmpls There's also a htmlized version available at: http://tools.ietf.org/html/draft-ietf-tictoc-1588overmpls-04 A diff from the previous version is available at: http://www.ietf.org/rfcdiff?url2=draft-ietf-tictoc-1588overmpls-04 Internet-Drafts are also available by anonymous FTP at: ftp://ftp.ietf.org/internet-drafts/ _______________________________________________ TICTOC mailing list [email protected] https://www.ietf.org/mailman/listinfo/tictoc _______________________________________________ TICTOC mailing list [email protected] https://www.ietf.org/mailman/listinfo/tictoc _______________________________________________ TICTOC mailing list [email protected] https://www.ietf.org/mailman/listinfo/tictoc
