********************************************************************** IETF 81 PWE3 - TUESDAY, July 26, 2011 - 15:20 - 18:10 (170 min) Room 202 ********************************************************************** Chairs: Matthew Bocci and Andy Malis Secretary: David Sinicrope (x=No slides as of 12:00 EDT Tuesday, July 26, 2011) **** 20 min - Agenda bash, WG Agenda and Status - Andy Malis and Matthew Bocci See slides, Matthew presented the WG status. There was a last minute change to the agenda to account for late presentaiton slides draft-martini-pwe3-status-aggregation-protocol was moved to last on the agenda. Goals and Milestones - are a bit out of date. The Chairs will revise in the coming weeks. Document Status 1 - The OAM Msg Map draft should be past Auth 48 as last editor just responded. Status 2 - Status 3 - draft-ietf-pwe3-dyanmic-ms-pw Luca: The text was removed from the WG document and put into a separate document. Should it be published as a WG document straight away or should it start as an ID? Andy: anyone have an objection to starting this as a WG document. (none) And no objection on the list so start as a WG document Status 4 - draft-ietf-pwe3-mpls-tp-gal-in-pw - Luca: You should be able to make use of the GAL for PW. The comments are more addressed to VCCV design which this document doesn't cover. We can cover the comments in the VCCV documents and should progress this document. Dave A: If we allow the GAL in an IP/MPLS network and not a -TP network then could be an issue for MS PW. Could be excluded from ECMP. Stewart: They are exluded from ECMP. Dave: if steps are in place to address problem then objections withdrawn. Status 5 - draft-ietf-pwe3-packet-pw - Andy (as author) - authors think draft is ready for WG last call. Comment asking for an optional mode that is more efficient on wire. Please write separate draft for optional mode and go throug WG process to get WG consensus rather than holding up this draft. Want to get this draft out because other drafts waiting on it. draft-ietf-pwe3-static-pw-status - No discusson on the list, but offline comments indicate SP bypass mode has a limited applicability and doesn't work if you switch between static and dynamic domains in MS-PW. Really applicable to all dynamic. Is this satisfactory to the WG? No objection. Status 6 - **** 10 min - A Unified Control Channel for Pseudowires - Tom Nadeau http://tools.ietf.org/html/draft-nadeau-pwe3-vccv-2 See slides, Tom presented. Solution: VCCV 2.0 Too many options in original VCCV. This draft narrows scope making both CW and ACH methods mandatory. VCCV Capability Advertisement Outstanding Issues Order of PW label and GAL are worked out. Authors feel draft ready to adopt as WG doc with some work to applicability statements. Matthew: about a dozen folks (out of 100 in the room) have read draft. Adoption call will be taken to the list. **** 10 min - Targeted LDP Hello Reduction - Tom Nadeau (Giles?) http://tools.ietf.org/html/draft-pdutta-mpls-tldp-hello-reduce Tom presented, see slides. This docuemnt has been around for quite a while. All feedback from MPLS WG was addressed in v02 and moved from informational to Standards Track. It was noted that the reduced procedure is compatible with RFC 5036 implementations. Presented in PWE and MPLS on the mailing list. If moving forward it Rosh?: support for draft. Did quite a bit of analysis and reduced processing significantly Nurit: Do you rely on BFD to check connectivity? Luca: No. There is a keep alive on the TCP session. Luca: discussion long ago whether we would need hello packets in targeted sessions. Perhaps they could be removed entirely. These packets don't serve a purpose than to create a method of attack. Tom: Those points were raised at the last meeting. Luca: We could do an addendum to RFC 5036 to remove them. Tom: Yes either way would work. Loa: Was going to ask how much of a problem this is, but since analysis was done can it be published? Another thing is a convention thing on multicast as "m-LDP" and would like to see targetted LDP as "t-LDP". This is a bit more general than PWE3 and it should be taken into MPLS WG. Document will be considered further in the MPLS WG. Himanshu: If this is a security issue if you were to receive hellos from the attacking station what do you do? Tom: whatever you do in the MPLS case. It is a potential security hold. Pranjal: Not trying to avoid security issues, but rather minimize them. Himanshu: This doesn't fill the gap for security. Tom: yes but it helps. Ilya (via Jabber): does it only applly when BFD used? Tom: no it applies in all cases Luca: It doesn't fix the security problem and the problem is not really a DoS attack, but this should be addressed in the MPLS WG. Rosh?: We don't run BFD in our deployment. **** 10 min - CP extension for the MSP application - Hongjie Hao http://tools.ietf.org/html/draft-hao-pwe3-iccp-extension-for-msp Yuxia Ma presented for Hongjie, see slides. Looking forward to more comments no further request from the WG. Luca: Question on what protection mechansims MSP is defined as. Kam Lam: G.841 defines the generic protection mechanisms for MSP. Luca: What PWs would this be applied to? Probably no issue to do what you are asking for, but want to understand the issue. Could possibly add them to current document. Yuxia: The scenario is similar, but the information in the message is different. Daniel: We have ICCP draft which describes sync with LACP. Now with new access technology to address. Instead of specific drafts is there a general way to address this? Luca: You cannot do a generic method, all technologies have specific information to be exchanged. Ghani: To clarify there is a number of documents in ITU-T 1. SDH G.870, a general protection scheme is G.808.1, and G.808.2, specifically for SDH is G.841. ???- you are pushing a lot of things into ICCP which do not need to be the same. Some parameters have nothing to do with making the mechanism work. Look at some of the elements which may be different and are meant to be different. There is also too heavy a load. George: Ghani, Please send the list of documents to the WG list? There is only one PW in the picture and all else is SDH? Yuxia: yes from PTN1 to PTN2 and PTN3 are all PWs. Yakov: Problem statement slide: are these Ethernet PWs or SDH PWs? Yuxia: they are SDH PWs. **** 15 min - PW Endpoint Fast Failure Protection - Yimin Shen http://tools.ietf.org/html/draft-shen-pwe3-endpoint-fast-protection Yimin presented slides. Overview - Currently we rely on global repair for PE or AC failure. Usually a back up PW to backup PE. Global repair relies on CPlane convergence. This draft introduces local repair to handle both AC and PE failure on the order of 10s of ms. Use for both LDP and BGP PWs. Proposal uses a bypass LSP to redirect PW in the event of a PW failure. Stewart: The PLR is an ordinary P router? Yimin: Yes Stewart: Then isn't there a danger that all packets going to deliver all packets on the LSP to PE2 to PE5? This could create a packet loop for IP, no? Yimin: No because PE1 will separate out the IP and only give the PW. Wim: they use specific LSPs only for PW purpose, a context specific IP address is used. Stewart: Florin: You can achieve this by just shifting the PWs to another tunnel without the complication. Taking the link between PE2 and PE4 unnecessarily consumes bandwidth. Himanshu: How does C2 find out about the traffic diversion? Yimin: The CE should understand that this will look like 1+1 protection. Nurit: Would you like to generalize this for multisegment? Yimin: yes Nurit: here it only shows two connections, but for MS you can have more than 2. is it assumed that all PWs going to this CE are on one LSP? Yimin: Yes Nurit: In the case of PE failure how does it know which PE failed? Yimin: draft describes this case. Nurit: I'll take it to the list. Matthew polled for who read the draft. 20 or so. **** 10 min - Pseudowire Communities - Pranjal Kumar Dutta http://tools.ietf.org/html/draft-pkwok-pwe3-pw-communities See slides, Pranjal presented. Luca: You're applying this to FEC 128 or 129? Pranjal: 129 Luca: how do you determine where to signal this. You are doing with BGP right? Pranjal: yes Luca: how is this different from advertising routes with communities. How would this work with LDP? Pranjal - community represents a template that has set of rules defined locally by a T-PE or S-PE Luca: we should work on how to address this in the PW control protocol, may About a dozen people read the draft. **** 10 min - Definition of P2MP PW TLV for LSP-Ping Mechanisms - Sami Boutros http://tools.ietf.org/html/draft-jain-mpls-p2mp-pw-lsp-ping Sami presented, see slides. ???: For P2PM PWs you can use the reverse label. Sami: Currently in the draft we don't recommend using this. 3-4 people have read the draft. **** 10 min - LDP extensions for Explicit Pseudowire to transport LSP mapping - Ping Pan http://tools.ietf.org/html/draft-cao-pwe3-mpls-tp-pw-over-bidir-lsp Ping presented, see slides. Need to bind both directions of the PW to the same bidirectional LSPs. In congruent mode the binding can be negotiated between the PE routers. The fast reroute issue has been debated on the list. The tunnel to be used must be clearly defined. Greg Mirsky: The terminology is not correct. Congruent is ambiguous, is it bidir corouted, or bidir associated? Also assume a single PSN tunnel exists, should assume different switching scenarios. Ping: Agree about the terminology. Not so sure about providing multiples, should talk offline. Nurit: More and more signaling requirements on PW signaling to deal with MS PW. Should we adopt RSVP-TE as a signaling mechanism for PW. Ping: should look at ideas Lou: corouted, associated unidirectional LSP - need to work on some terminology and be clear by what we mean by corouted and associated. Associated LSPs that follow same path are not corouted. Would like to see how to handled end-end protection. Ping: good comments. We would like more comments. Many have read the draft and no objections to the WG taking on this work. Andy asked that the authors take a pass through the document based on the comments from the meeting especially related to terminology. We will then take a poll to make a WG document. **** 10 min - MPLS-TP Linear Protection Applicability to MS-PW - Daniel Cohn http://tools.ietf.org/html/draft-cohn-mpls-tp-pw-prot Daniel presented, see slides. Nurit: Still some concerns about the document. Need to consider scalability per PW, especially in large network with protecting against more than one SPE failure. Would like to see a local protection mechanism. Daniel: You can say the same about single SPE failure for existing PW redundancy. Matthew: When we scoped linear potection it was felt that PW redundancy met the requirements including the scenario presented. So PW applicability was removed from linear protection. Daniel: this provides mechanisms (in Benefits (2) side) that PW redundancy doesn't. e.g., 1:1 and 1+1, external triggers. Changing PW redundancy to address these would not be as easy as applying linear protection to PWs. Matthew: many of these mechanisms listed have been addressed in implementations of PW redundancy. The adaption of linear protection is a new hurdle. About a dozen have read the draft. **** 10 min - LDP Extensions for Proactive OAM Configuration of Dynamic MPLS-TP PW - Fei Zhang http://tools.ietf.org/html/draft-zhang-mpls-tp-pw-oam-config Fei presented, see slides. Tom N: generally have a problem with configuring OAM inside of LDP and others. Comments made from VCCV survey in regard to negotiating OAM capabilities. This was cited as a disaster for compatibility. Dynamically changing the configuration of the device is better done by the provisioning system. Fei: These things can be negotiated. Tom: We've already been down this road. See the VCCV survey because it is cited as a big problem which drove the VCCV-2 draft. Matthew: this is negotiating more CV type Tom: same problem regarding dynamic changes. ~20 have read the draft. **** x10 min - MPLS LSP PW status refresh reduction for Static Pseudowires - Luca Martini http://tools.ietf.org/html/draft-martini-pwe3-status-aggregation-protocol Luca presented, see slides WG adoption call made a week ago that is still open. Express opinion on the list concerning this draft. Do not want this to be a full control protocol. There will be some strong applicability language added on what goes into protocol. Open security problem that needs to be addressed. No MD5 security. Rob: confused, from title this will be a status aggregation protocol. As reading there are no status TLVs, but checking config at each end. Luca: It is using the Static Status draft says you need to refresh the status periodically, this eliminates this by sending some configuration information. Rob: so not really aggregating, you're eliminating via configuration. Luca: yes, may need to rename document Stewart: May need a better hash mechanism and some text for hash collision. Luca: a misconnection by moving a cable, might remotely have the same hash that would falsely check correctly. Stewart: if you are worried about hash collision, you may need a better mechanism Luca: for simplicity not sure we will find a better mechanism. The authors don't believe we need anything better. Andy: It was kindly noted that if the comment is not addressed it may surface again during AD review. The draft is under call for WG adoption. Please post opinions. ************************************** Andy adjourned the meeting at 17:33 local time. ********************************************************************** WEBEX INFORMATION FOR THE PWE3 SESSION(S) ********************************************************************** All Webex Info - http://www.ietf.org/meeting/81/remote-participation.html#webex PWE3 Webex Session - https://workgreen.webex.com/workgreen/j.php?ED=180772807&UID=1245063002&RT=MiM0