Re: USBIP protocol

[Matthew Wilcox <matthew@wil.cx>]

On Sat, Aug 30, 2008 at 12:31:43AM +0200, Marcel Holtmann wrote:
> Hi Matthew,
> 
> > > I'm in the middle of implementing a userspace client for usbip and I
> > > strongly feel that the protocol needs to be changed before it is merged.
> > >
> > >  - I'm unconvinced that TCP is the correct protocol to be running this over.
> > >    I understand the reluctance to use UDP, but the protocol is fundamentally
> > >    packet-based.  If TCP is used, the delimitation of packets within the
> > >    stream needs to be much more robust. 
> > 
> > If you want reliable transport with record boundaries an alternative
> > would be also SCTP. Main drawback is that firewalls often don't support it
> > though (but presumably that wouldn't be a big issue for this)
> 
> I would also have proposed SCTP. The telco carries seems be very happy
> with it.

I'm actually looking into the sunrpc protocol.  That has the advantages:
 - Already has an in-kernel implementation
 - Widely understood and properly documented
 - Can be run over TCP or UDP or even RDMA

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."