QoS/CoS in the real world?

Mon Jul 15 01:20:57 UTC 2002

On Sun, 14 Jul 2002 21:13:13 -0400 (EDT)
 Art Houle <houle at zeppo.acns.fsu.edu> wrote:
> 
> 
> We are using QOS to preferentially drop packets that represent
> file-sharing (kazaa, gnutella, etc).  This saves us 40Mbps of traffic
> across our multiple congested WAN links.  The trick is to mark packets
> meaningfully.  Also, the WFQ introduces some additional latency at our
> edge.

Is this different from port filtering as is commonly done with, e.g.,
gnutella ?

Or, to put it another way, how are the packets marked ? And why not just
drop them then and there, instead of later ?

Regards
Marshall Eubanks

> 
> On Sun, 14 Jul 2002, Stephen J. Wilcox wrote:
> 
> > 
> > Well, end of the week and the responses dried up pretty quickly, I think
> thats a
> > response in itself to my question!
> > 
> > Okay, heres a summary which was requested by a few people:
> > 
> > Other people too are interested in my questions, they dont implement QoS in
> any
> > saleable manner and wonder how it can be done and whats actually required. 
> > 
> > A number of people think QoS was interesting for a while but that its never
> > either found its true use or is dead.
> > 
> > There are unresolved questions from a customer point of view as to what
> they are
> > actually going to get, what difference it will make and how they can
> measure
> > their performance and the improvements from QoS.
> > 
> > There is a real demand for guaranteed bandwidth, however this tends to be
> in the
> > form of absolute guarantees rather than improvements above "normal" hence
> > ATM remaining a popular solution.
> > 
> > There is a requirement to differentiate voice traffic, however this is
> > necessarily done by the network anyway in order to offer the service, this
> being
> > the case the customer doesnt pay extra or gets to know much about how all
> the
> > fancy bits are done.
> > 
> > 
> > On the face of it this is all negative. Nobody has responded saying there
> are
> > genuine requirements for services to be offered to customers. Nor has
> anybody
> > responded with any descriptions of implementations.
> > 
> > I conclude either the people doing this are successful and keep their
> secret
> > safe or the world is yet to sell largescale QoS across IP.
> > 
> > Steve
> > 
> > 
> > On Mon, 8 Jul 2002, Stephen J. Wilcox wrote:
> > 
> > > 
> > > Hi all,
> > >  I've been looking through the various qos/cos options available, my
> particular
> > > area was in how IP (MPLS perhaps) compares and can be a substitute for
> ATM.
> > > 
> > > Well, theres lots of talk and hype out there, from simple IP queuing eg
> cisco
> > > priority queuing, rsvp, diffserv, mpls traffic engineering etc
> > > 
> > > But two things are bugging me..
> > > 
> > > 1. To what extent have providers implemented QoS for their customers
> > > 
> > > 2. Hype aside, to what extent do customers actually want this (and by
> this I
> > > dont just mean that they want the latest QoS because its the 'latest
> thing',
> > > there has to be a genuine reason for them to want it). And this takes me
> back to
> > > my ATM reference where there is a clear major market still out there of
> ATM
> > > users and what would it take to migrate them to an IP solution?
> > > 
> > > Also, how are people implementing bandwidth on demand (dynamic allocation
> > > controlled by the customer) solutions to customers
> > > 
> > > Cheers
> > > 
> > > Steve
> > > 
> > > 
> > 
> > 
> > 
> > 
> > 
> > 
> 
> Art Houle     				e-mail:  houle at acns.fsu.edu.
> Academic Computing & Network Services 	 Voice:  850-644-2591
> Florida State University		   FAX:  850-644-8722
> 