Hi Sam, Please count me in for OAM. It will help to have the Overlay OAM work aligned.
Thanks, Nagendra From: nvo3 <nvo3-boun...@ietf.org<mailto:nvo3-boun...@ietf.org>> on behalf of Greg Mirsky <gregimir...@gmail.com<mailto:gregimir...@gmail.com>> Date: Tuesday, October 4, 2016 at 7:04 PM To: "Bocci, Matthew (Nokia - GB)" <matthew.bo...@nokia.com<mailto:matthew.bo...@nokia.com>> Cc: NVO3 <nvo3@ietf.org<mailto:nvo3@ietf.org>> Subject: Re: [nvo3] Discussion on encapsulation formats and next steps Dear Matthew, Sam, et. al, I think that concentrating on the proposal to "focus on control plane and OAM" we can achieve practical results despite differences among data plane encapsulations. Please count me in. Regards, Greg On Tue, Oct 4, 2016 at 2:24 AM, Bocci, Matthew (Nokia - GB) <matthew.bo...@nokia.com<mailto:matthew.bo...@nokia.com>> wrote: Folks, Following the lengthy discussion on this list about the pros and cons of the three encapsulation formats, we would like to summarise where the main points of the discussion and to provide some thoughts on next steps. As a reminder, the question that we asked was: For a given encap, do you have significant technical objections? Thank you for the lively discussion. We have summarised the key points for each draft as follows: Geneve ---------- - Can't be implemented cost-effectively in all use cases because variable length header and order of the TLVs makes is costly (in terms of number of gates) to implement in hardware - Fork-lift upgrade from widely deployed VXLAN (no backwards compatibility mechanisms) - Header doesn't fit into largest commonly available parse buffer (256 bytes in NIC). Cannot justify doubling buffer size unless it is mandatory for hardware to process additional option fields. GUE ---------- - There were a significant number of objections related to the complexity of implementation in hardware, similar to those noted for Geneve above. - In addition, there were concerns raised that GUE does not support a sufficient number of extensions due to its reliance on a limited flags field, which is already almost 45% allocated. VXLAN-GPE ---------- - GPE is not day-1 backwards compatible with VXLAN. Although the frame format is similar, it uses a different UDP port, so would require changes to existing implementations even if the rest of the GPE frame is the same. - GPE is insufficiently extensible. Numerous extensions and options have been designed for GUE and Geneve. Note that these have not yet been validated by the WG. - Security e.g. of the VNI has not been addressed by GPE. Although a shim header could be used for security and other extensions, this has not been defined yet and its implications on offloading in NICs are not understood. Unfortunately, no rough consensus emerged from the list discussion. The chairs and our AD have also been trying to form a design team to take forward the encapsulation discussion and see if there is potential to design a common encapsulation. However, there has been insufficient interest in this initiative. We would like to hear opinions and confirmation or disagreement on interest in creating a DP encapsulation that addresses the various technical concerns. For the upcoming Seoul IETF, we propose that we will put aside the discussion of specific encapsulations and focus on control plane and OAM. In particular, the chairs feel there was insufficient discussion of the impact of a software solution that implements some or all of the potential options/extensions allowed by e.g. Geneve on all elements of the NVO3 architecture. We would like the working group to consider more carefully the implications of different encapsulations in real environments consisting of both software and hardware implementations and spanning multiple data centers. For example, OAM functions such as path MTU discovery become challenging with multiple encapsulations along the data path. We would like to encourage solid reviews of the three proposals on the list, particularly how they would work in the general architecture. With this in mind, we are also considering holding a virtual interim meeting the week of 24th October. More details will follow. We would like to start a conversation within the WG about what functionality the WG should focus on and standardize. What do you think should be easy to do? What would be incredibly useful? What, if not done, risks causing harm to the industry? The start of this discussion of WG direction will occur on the mailing list and in the virtual interim." Best regards Matthew and Sam _______________________________________________ nvo3 mailing list nvo3@ietf.org<mailto:nvo3@ietf.org> https://www.ietf.org/mailman/listinfo/nvo3
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