Just to clarify: by simpler I meant Boundary clock is not required. From: [email protected] [mailto:[email protected]] On Behalf Of Shahram Davari Sent: Thursday, July 08, 2010 11:06 AM To: [email protected]; [email protected] Subject: Re: [TICTOC] FW: 1588 over MPLS draft
Hi Sebastian, Thanks for reading the draft. I will try to give you're my own understanding of the issue. We know that if we want better accuracy and control and less complex algorithms in the Slave, it is best that most hops between 1588 Master and Slave perform Transparent Clocking (TC). As you mentioned one method is to use direct IP routing. However there are cases that this doesn't work. For example MPLS-TP networks don't support IP routing. Also when 1588 Master and Slave are in two different Ethernet networks separated by an MPLS network, it is simpler to just tunnel 1588 packets via Ethernet PW. I hope this helps. Thanks Shahram From: [email protected] [mailto:[email protected]] Sent: Thursday, July 08, 2010 8:37 AM To: Shahram Davari; [email protected] Subject: RE: [TICTOC] FW: 1588 over MPLS draft Hi, After reading this interesting draft, I would have some questions for clarification (sorry, I will not attend to the Maastricht meeting). My first general question is related to the objective of TICTOC regarding this topic: is it planned that TICTOC would develop a specific mechanism for transporting PTP over MPLS as the one proposed in this document? If so, is it oriented to telecoms applications, or to other types of applications? My second question would be to better understand why there is a need for transporting PTP over MPLS. It is still unclear to me. FYI, similar discussions happened in June in ITU-T Q13/15 during the last Geneva meeting. My understanding of the context of this draft is that the network between a PTP master and a PTP slave experiences full timing support for PTP, such as TC in every node (or possibly BC, that is also slightly evoked in the document?). In this context, it can be questioned if the PTP timing delivery is really done "end-to-end", since every node has to process the PTP messages. Therefore, is it really appropriate in this case to put the PTP messages into a tunneling transport, such as MPLS? It looks more logical to me in this situation to transport the PTP timing flows outside MPLS (e.g. simply over UDP/IP) on a hop-by-hop basis (e.g. each node delivers its timing to the next one). But maybe I misunderstood or missed something... Any thoughts? Thanks. BR, Sébastien ________________________________ De : [email protected] [mailto:[email protected]] De la part de Shahram Davari Envoyé : mercredi 7 juillet 2010 21:36 À : [email protected] Objet : [TICTOC] FW: 1588 over MPLS draft From: Shahram Davari Sent: Wednesday, July 07, 2010 12:12 PM To: '[email protected]'; '[email protected]'; '[email protected]'; '[email protected]' Subject: 1588 over MPLS draft Hi All, Please find attached our first draft of 1588 over MPLS. Since we have some technical issues converting the Word format to Txt we couldn't upload the draft before the cut-off date. However we will present the draft in the next IETF meeting and will upload the draft after the meeting. Note that the main WG is TicToc but may require consultation with MPLS and PWE3 WGs. Thanks, Shahram Davari
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