Re: LU access through an iSCSI session

["Matt Wakeley" <matt_wakeley@agilent.com>]

The talk of making "lots of TCP connections look like a big pipe" is NOT meant for
congestion control.  It is meant to obtain higher bandwidth on a local network, such
as in a data room.

For example, one could have multiple 1Gbit TCP connections from a host to say a
switch.  The switch might be connected via a very high speed backbone to another
area where the storage devices are, where there is another such switch.  Similarly,
a disc array may be connected via multiple 1Gbit TCP connections to that switch.

There is lots of early discussions on why multiple TCP connections are required to
obtain parallel paths through the fabric.  You might check out the email archives,
especially messages posted by Randy Haagens.

-Matt

Randall Stewart wrote:

> Matt Wakeley wrote:
>
> > .....snip....snip....
> > Again, the *only* answer is "Yes".  The multiple TCP connections make up a
> > *single* session.  The session just happens to have lots of "TCP connections"
> > to make it look like it has a "big pipe" (for example, 4 1Gbit connections can
> > be used to emulate a 4Gbit link).
> >
> > If you want different "LU views" per TCP connection, then each TCP connection
> > would be a separate, independent iscsi session.
>
> ....snip....snip.....
>
> The above talk of making "lots of TCP connections look like a big pipe" sounds
> once
> again like attempting to get around congestion control in the network... I know
> we
> had this conversation before.. but what is stated above strongly implies this
> .... and
> I don't think this is the behavior one would want on the Big I-internet. I can
> see
> a private network doing this ... but I don't see how it could be supported in a
> standard manner that can be used on the Iternet...
>
> R