Subject: Re: [sfc] [nvo3] Comments on http://tools.ietf.org/html/draft-quinn-vxlan-gpe-03

From: Xuxiaohu <[email-masked]>
Date: Thu, 31 Jul 2014 01:55:15 +0000

> >And NSH is a service protocol and should run above the transport layer
> >so should have its own port and can address packets anywhere.
> 
> I think the intent of NSH is to be generic enough to work at different layers.
> The recent addition of the Metadata Type field in the NSH header allows for it to
> be used for purposes beyond SFC.  It could theoretically be used to essentially
> extend the header of the layer below it (e.g.
> VXLAN/LISP).  e.g. I think this could be used for Tom to carry his 64 bit VNI
> authentication.

Hi Larry,

If the Metadata Type field in the NSH header is going to be used for purposes beyond SFC, it seem much better to make the metadata-specific header and the service-path header as independent as possible from the beginning. 

Best regards,
Xiaohu