RE: TCP Mapping

["Hollenbeck, Scott" <shollenbeck@verisign.com>]

Hong and I have already exchanged private messages on this topic.  I'll
repeat what I said here.

First, I do expect to have to edit the TCP draft slightly to address some
comments I received from members of the IESG.  That won't happen until after
IETF-54.

Second, I'm very much against putting application-layer semantics into the
layer above TCP -- it smells like a layering violation to me.  I explicitly
added an <extension> element as a child of the <epp> element to support
adding features like data pushing from the "server" -- that's where I think
such extensions belong.  Plus, it's not wise to believe that EPP messages
aren't likely to exceed a certain length based on experiences with domain
name provisioning.  There may well be other operating environments where all
32 bits (and maybe even more -- I gave some serious thought to a 64-bit
length field in the header) are needed.  Being short-sighted now means we're
going to have issues in the future.

Third, this whole pushing thing may be a better candidate for implementation
using BEEP.  If that's true, it doesn't belong in the TCP draft at all.

I've already started work on a draft document describing how to properly
extend the protocol, and I expect -00 to be ready some time after the
Yokohama meeting.  I think it will be far easier to deal with extension
drafts _after_ we have the mechanics documented a bit better.

-Scott-

> -----Original Message-----
> From: Liu, Hong [mailto:Hong.Liu@neustar.biz]
> Sent: Friday, June 28, 2002 5:55 PM
> To: 'ietf-provreg@cafax.se'
> Subject: TCP Mapping
> 
> 
> Scott,
> 
> I would like to know whether it is still possible to make 
> changes to the TCP
> mapping document at this point. We have been working on a 
> draft for EPP TCP
> PUSH extension, as we promised before. Sorry, we missed the 
> -00 deadline
> this time...
> 
> There are a number of ways to do it, but we find it the 
> simplest to use the
> Total Length header of the EPP datagram in the TCP mapping to 
> differentiate
> the server-pushed message from other messages. We are 
> considering using only
> the highest bit in the header, but maybe a better way is to 
> reserve the
> highest octet for other extensions. EPP messages do not need 
> 2^32-1 octects,
> 2^24-1 should be sufficiently large. What do you think?
> 
> We would also like to hear from you and others on the list about other
> alternatives. Thanks!
> 
> --Hong
>