Re: FC over IP: Requirements

[Murali Rajagopal <muralir@lightsand.com>]

David:

The authors of FC Over IP draft see at least 3 distinct options.
Briefly, this is what we think:

1. Make effective use of the Congestion Indicator (CE) bit from a modern
ECN capable Router but 
without the use of any transport. This indicator will then be used as a
feedback signal to the 
FC-IP device and will have a bearing on the FC BB credit control between
this device and the upstream 
FC Switch.

2. Investigate the possible use of a subset of full TCP functionality
that would suit the requirements 
of this application. 

3. Similarly, investigate the posible use of a subset of SCTP.

As you can tell, these are mutually exclusive and would be difficult to
combine them.

Regards,

Murali Rajagopal

muralir@lightSand.com

David Robinson wrote:
> 
> Elizabeth,
> It is good to see you making progress on the FC over IP requirements.
> As there is now another draft that is FC over IP (with SCTP as
> the transport) published, is it possible that we can merge the
> two efforts?  I would not like to see as a result one protocol
> to tunnel between two FC clouds and another to direct attach
> FC to IP.
> 
> Possible considerations are if there are mechanisms to adapt
> one or the other draft to allow a merging? Are the transport level
> retry mechanisms you discuss also going to be fundemental problems
> with the SCTP proposal as well? If you do use TCP as a transport
> will your solutions to congestion control etc be sufficient to
> remove the need for SCTP? I would not like to see two groups
> trying to solve the same problem independantly.
> 
>         -David
>