<html>
<body>
<font size=3>At 07:45 AM 10/10/2005, Hal Rosenstock wrote:<br>
<blockquote type=cite class=cite cite="">On Sun, 2005-10-09 at 10:19,
Sean Hefty wrote: <br>
> >I think iWARP can be on top of TCP or SCTP. But why wouldn't it
care ?<br>
> <br>
> I'm referring to the case that iWarp is running over TCP. I
know that it can<br>
> run over SCTP, but I'm not familiar with the details of that
protocol. With<br>
> TCP, this is an end-to-end connection, so layering iWarp over it,
only the<br>
> endpoints need to deal with it. I believe the same is true for
SCTP.<br><br>
Yes, SCTP is similar in those regards.</font></blockquote><br>
SCTP creates a connection and then multiplexes a set of sessions over
it. You can conceptually think of it as akin to IB RD but where all
QP are bound to the same EEC.<br><br>
<br>
<blockquote type=cite class=cite cite=""><font size=3>> >Doesn't a
routing decision still need to be made at the IP layer ?<br>
> <br>
> Routing of the IP packets is done at the IP layer, but I don't see
how this<br>
> affects iWarp.<br><br>
It does under the "covers", those covers being IP
routing.</font></blockquote><br>
iWARP uses IP routing so there is zero difference between iWARP and any
other IP-based protocol suite that operates above the IP layer.<br><br>
<br>
<blockquote type=cite class=cite cite=""><font size=3>> >Doesn't
the IP next hop need to be determined (e.g. gateway when the<br>
> >destination is off the local IP subnet) ? Is there something
that<br>
> >precludes iWARP from working across IP subnets ?<br>
> <br>
> I can't think of anything that would preclude iWarp from working
<br>
> across subnets.<br><br>
Doesn't the IP next hop need determining in that case ? Why is that
not<br>
relevant ? I don't think the iWARP connection is end to end in all<br>
cases.</blockquote><br>
TCP / SCTP are end-to-end thus iWARP is end-to-end. The fact that
there is an intermediate router / gateway between does not matter.
That is just a bit of IP routing to forward the packets. The ARP /
ND protocols determine the next hop for the IP layer thus iWARP just like
TCP/SCTP is not affected or cognizant of the underlying fabric
topology.<br><br>
Mike</font></body>
</html>