Re: FC/IP vs. iSCSI

[Matthew Jacob <mjacob@feral.com>]

I'm certainly inclined to agree. The sole realistic purpose of requirements
I've seen to date FC/IP is to utilize an existing FC environment so that
management and data go over the same wire. If you're carrying SCSI over TCP/IP
now, it's somewhat absured to try and carry FC/IP over the same transport.
It's as if you want to tunnel TCP/IP over TCP/IP, which is a cute trick, but a
trick for all that.

If you have an existing FC optical environment, it could probably run
GigEthernet just as well- and it then becomes a question as to whether iSCSI
serves the systems and applications as well or better than FC-SCSI or FC/IP
over the same physical media.

-matt


On 16 Aug 2000 csapuntz@cisco.com wrote:

> 
> FC/IP is NOT an alternative to iSCSI for most applications.
> 
> Unfortunately, making a protocol that works well in complex networks
> is not as simple as just putting stuff into IP packets. IP packet
> headers are not magical pixie dust that suddenly make higher-layer
> protocol issues go away.
> 
> The FibreChannel stack today has the following deficiencies which do
> not disappear when tunneling over IP:
> 	- FCP has no congestion control
> 	- FCP deals poorly with packet loss
> 	- Target naming is done with either 24-bit port IDs or 64-bit WWNs,
> 	   neither of which scale to Internet size
> 	- No secure login
> 
> Of course, you could address all the deficiencies by fixing FCP. But
> by the time you do that, I maintain you will most likely end up with
> something in the same order of complexity as iSCSI/TCP/IP.
> 
> -Costa
> 
>