Re: [nvo3] [Tofoo] FW: I-D Action: draft-zhou-li-vxlan-soe-01.txt

[Joe Touch <[e-mail]>]

Hi, all,

I had a comment and a question:

Comment - (from the doc) overlays do have a hard MTU limit; it is the 
limit of the encapsulation mechanism. E.g., without additional layers, 
for UDP in IPv4 this would be a at most 65507 bytes (i.e., IPv4 max - 
(min IP header + UDP header)). Using additional adaptation layers, this 
could be larger (e.g., see SEAL).

Question - the code appears to have the VXLAN layer do the 
fragmentation, with the OS layer implementing the rest of TCP. There are 
a lot of interactions, notably:

	- any mechanism outside of the TCP source and TCP destination
	that interprets the TCP header will result in a decrease in
	functionality
		i.e., the TCP connection will support only the
		intersection of options and features supported
		by the source, dest, *and* VXLAN layers

		(rather than being limited only by the
		source-dest pair)

	- if passed a full TCP segment, this mechanism will be
	incompatible with TCP security (e.g., TCP MD5, TCP-AO, and
	the results of the TCPCRYPT WG.

I'm not quite sure from your doc whether you're re-segmenting TCP 
segments, or merely collecting them for aggregate transit (e.g., as is 
done in burst-mode Ethernet).

Can you please clarify?

Joe


On 5/19/2014 8:01 PM, Zhou, Han wrote:
> Hi,
>
> We have updated the VXLAN-SOE draft according to earlier comments. Now it is fully compatible with VXLAN-GPE. And some examples are added for better understanding.
>
> A prototype is also implemented here (patch based on Open vSwitch):
> https://github.com/hzhou8/openvswitch/commit/9a7deb8b432ce83a9c09d7d4ff85fa050f7dd2be
>
> netperf TCP_STREAM test result between a pairs of VMs on hosts with 10G interfaces:
>
> Before the change: 2.62 Gbits/sec
> After the change: 6.68 Gbits/sec
> Speedup is ~250%.
>
> The patch attracted some interests in OVS community, but since this RFC draft is in very early stage so it is regarded as inappropriate by Jesse to apply the change to OVS tree.
> The discuss mail-thread:
> http://openvswitch.org/pipermail/discuss/2014-May/013981.html
> http://openvswitch.org/pipermail/discuss/2014-May/013898.html
>
> So we would like to request a review here by NVO3/TOFOO groups and VXLAN authors: is this VXLAN extension is worth formally put into VXLAN as a standard, so that more people can benefit from it?
>
> Best regards,
> Han
>
> -----Original Message-----
> From: I-D-Announce [mailto:[e-mail]] On Behalf Of [e-mail]
> Sent: Friday, May 02, 2014 8:09 PM
> To: [e-mail]
> Subject: I-D Action: draft-zhou-li-vxlan-soe-01.txt
>
>
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
>
>
>          Title           : Segmentation Offloading Extension for VXLAN
>          Authors         : Han Zhou
>                            Chengyuan Li
> 	Filename        : draft-zhou-li-vxlan-soe-01.txt
> 	Pages           : 13
> 	Date            : 2014-05-02
>
> Abstract:
>     Segmentation offloading is nowadays common in network stack
>     implementation and well supported by para-virtualized network device
>     drivers for virtual machine (VM)s. This draft describes an extension
>     to Virtual eXtensible Local Area Network (VXLAN) so that segmentation
>     can be decoupled from physical/underlay networks and offloaded
>     further to the remote end-point thus improving data-plane performance
>     for VMs running on top of overlay networks.
>
>
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-zhou-li-vxlan-soe/
>
> There's also a htmlized version available at:
> http://tools.ietf.org/html/draft-zhou-li-vxlan-soe-01
>
> A diff from the previous version is available at:
> http://www.ietf.org/rfcdiff?url2=draft-zhou-li-vxlan-soe-01
>
>
> Please note that it may take a couple of minutes from the time of submission
> until the htmlized version and diff are available at tools.ietf.org.
>
> Internet-Drafts are also available by anonymous FTP at:
> ftp://ftp.ietf.org/internet-drafts/
>
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