RE: Connected mode draft and retransmit implosion

Isnt tcp timers in the order of msec and ib timers in the order of usecs?
I think its just a problem of tuning the stack for the application in
question.

~Ajoy

On Fri, 13 Aug 2004, bill wrote:

> Yes, that is exactly the problem... Both layers retransmitting at the
> same time
> 
> And possibly not recovering for quite a while
> Bill
> 
> > -----Original Message-----
> > From: [email protected] 
> > [mailto:[email protected]] On Behalf Of Fab Tillier
> > Sent: Friday, August 13, 2004 5:42 PM
> > To: 'bill'; [email protected]
> > Subject: RE: [Ipoverib] Connected mode draft and retransmit implosion
> > 
> > 
> > > From: bill [mailto:[email protected]]
> > > Sent: Friday, August 13, 2004 4:57 PM
> > > 
> > > Vivek,
> > > 
> > > So I have been concerned about the Connected mode draft and 
> > I run into 
> > > a simple problem here...
> > > 
> > > Imagine I have a TCP socket running over a 64K RC MTU link.
> > > 
> > > I transmit the IP packet (all 64K of it)
> > > 
> > > Infiniband breaks the packet up into a bunch of 2K Infiniband MTU 
> > > packets (all 32 of them) - lets say I loose the second packet.
> > > 
> > > No problem IB will retransmit the packet over the link and 
> > it gets to 
> > > the other side...
> > > 
> > > The problem that I want to see - is what happens if the TCP 
> > retransmit 
> > > timer goes off - causing the whole TCP segment to be retransmitted.
> > 
> > Wouldn't you end up with the same packet getting sent twice?  
> > If so, why is this problematic (aside from the inefficiency)?
> > 
> > - Fab
> > 
> > 
> > 
> > _______________________________________________
> > IPoverIB mailing list
> > [email protected] https://www1.ietf.org/mailman/listinfo/ipoverib
> > 
> 
> 
> 
> _______________________________________________
> IPoverIB mailing list
> [email protected]
> https://www1.ietf.org/mailman/listinfo/ipoverib
>