QoS/CoS in the real world?

Nathan Stratton nathan at robotics.net
Tue Jul 9 01:10:21 UTC 2002


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

I was providing this as a service so my customers at Exario. We 2 G.726 
VoIP channels and data over one PVC on a 192kbps DSL link. I developed 
patent pending process to make that happen. Priority based queuing was 
required for VoIP traffic, but because of starvation selected WFQ for the 
3 data queues. The scheduler had to be smart enough to fill the space 
between voice samples with fragmented data based on the MTU of the link so 
as to keep jitter down. 
 
> 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?

Well every customer that used voice had to have QoS if they also wanted 
data, but we also were able to sell data QoS to customers. We could 
prioritize credit card transactions, or bulk ftp transfers or any 
application that wanted based on IP or port.

> Also, how are people implementing bandwidth on demand (dynamic allocation
> controlled by the customer) solutions to customers

Because my last mile aggregation was DSL or T1 everything was frame or ATM 
based so I decided to stick with a ATM core. We setup PVCs on our ATM 
switches based on what customers wanted and built back office systems to 
change bandwidth based on customer requirements. 


><>
Nathan Stratton
nathan at robotics.net 
http://www.robotics.net

> Cheers
> 
> Steve




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