QoS/CoS in the real world?

Mon Jul 15 01:26:58 UTC 2002

On Sun, 14 Jul 2002, Marshall Eubanks wrote:

> 
> 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 ?

If we are not using our WAN connections to capacity, then p2p traffic can
expand and fill the pipe, but if business packets are filling the pipes,
then the p2p stuff is throttled back. This makes 100% use of an expensive
resource.

> 
> 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
> > 
> 

Art Houle     				e-mail:  houle at acns.fsu.edu.
Academic Computing & Network Services 	 Voice:  850-644-2591
Florida State University		   FAX:  850-644-8722