RE: Towards Consensus on TCP connections

["Douglas Otis" <dotis@sanlight.net>]

> -----Original Message-----
> From: owner-ips@ece.cmu.edu [mailto:owner-ips@ece.cmu.edu]On Behalf Of
> Jeff Fellin
> Sent: Wednesday, August 16, 2000 11:41 AM
> To: ips@ece.cmu.edu
> Subject: Re: Towards Consensus on TCP connections
>
>
>
> Folks,
> After reading all the discussion and debate on this issue, I decided to
> research if the SCSI standards (T10/X3) have done with developing other
> transport protocols, and how those protocols dealt with connectivity
> issues between the endpoints. For the most part the other transport
> protocols SCSI over Scheduled Transport (SST), which is a working draft
> and the SCSI-3 Generic Packetized Prococol (SCSI-GPP), which is a proposed
> technical report have a concept of a Logical or Virtual connection. This
> Logical or Virtual connection has at least one connection through the
> network, but may have more up to endpoint configuration parameters. So,
> it appears the other groups have not come to a consensus as to
> the approach.
>
> Most of the drafts are available on the T10's web site:
> 	www.t10.org
>
> Except for the definition of the Scheduled transfer protocol, which is on
> T11's web site:
> 	www.t11.org
>
> The most interesting thing I came up with is the SCSI-GPP definition is
> written to allow connections over IP networks. Annexes E and F describe
> the mapping and processing capabilities. If this is a work in progress
> should we take advantage of there previous start and work with T10 to
> have a better definition of a protocol for storage over IP?
>
> What I understand from a quick read of the SST and SCSI-GPP protocol
> definitions is they have dealt with the issues of security, error
> recovery,
> connection management, transfer of SCSI bus control signals (bus reset,
> abort tasks.
>
> If we don't use the SCSI-GPP than I propose changing the one LUN per
> TCP connection group to be a SCSI target id that multiplexes all LUN's
> of the target id onto the connection group. I believe this will decrease
> the amount of connections and provide data channels for large transfers.

see: ftp://ftp.t10.org/t10/drafts/gpp/gpp-r09.pdf

Jeff,

There is a considerable difference between the SCSI-GPP and iSCSI.  With GPP
there are only 256 possible LUNs per target (among other notable features).
Under iSCSI, there are 18,447,000,000,000,000,000 possible LUNs per target
and this 64-bit LUN value is implied in some cases.

Doug