nanog mailing list archives

RE: QoS/CoS in the real world?


From: "Jeff Hancock" <jeff () masergy com>
Date: Wed, 24 Jul 2002 13:40:25 -0400


Steve,

Hope this info helps answer your questions about QoS, implementations
and customers.  Forwarded from a product person person in our org...

------------------------------------------------------------------------
Sorry I didn't see this note earlier, but wanted to make you aware that
Masergy Communications is actually offering such a service on a native
MPLS based IP network.  We provide differentiated IP services via
customer DSCP marking at the network edge. QoS is supported end to end
through the Masergy core via promotion to the MPLS EXP marking.  

Masergy closely manages its network by service class.  This allows each
marking to have its own end-to-end SLA, customized to the type of
customer traffic sent with each marking.

Customers see the need for QoS in two broad categories: 
1) Prioritizing business applications for performance reasons 
2) Providing guaranteed performance to real-time IP applications such as
IP voice and IP videoconferencing

Some real examples: A Masergy customer does file backups overnight.
When the backups continued into the next morning performance of daily
business activities suffered.  By lowering priority of the backup
traffic, acceptable performance for both the backups and day users can
be provided at a lower cost to the customer.  Most of our customers have
similar stories (the p2p example mentioned previously is another good
one).  

An interesting application is that customers can mark all outbound
traffic as priority--this is a simple config and requires little smarts
on the part of the edge router.  Any traffic that originates and
terminates on the Masergy network is prioritized. All traffic from
outside, non-business sites (i.e. surfing, p2p, radio etc.) gets
best-effort treatment.  

Note that many of the applications that need priority are not high
bandwidth--MS Exchange for example is a low BW app, but notoriously
sensitive to network quality issues.  QoS in the manner described above
can enhance performance even for lower BW applications.

Another customer application is video conferencing - specifically
replacing current ISDN video architectures with IP equivalents.  IP QoS
and MPLS allow Masergy to engineer a class of service for voice and
video that provides low jitter and 100% guaranteed throughput across our
core.  MPLS fast fail-over improves application performance in the case
of a core network link or hardware failure. Without differentiated QoS,
we would not be able to guarantee this level of performance.  

One of the major issues with properly utilizing QoS is giving the
customer the ability to view and manage performance.  Masergy customers
use the Service Control Center - a secure, web-based interface for
managing their service.  It provides per QoS level and application
statistics on network utilization and performance.  Customers can change
their access bandwidth and enable additional QoS capabilities in real
time.  

http://www.masergy.com
------------------------------------------------------------------------
--

-----------------------------------------------------------------------
Jeff Hancock                            P:      703-846-0161    
Senior Engineer                         F:      703-846-0149
Masergy Communications, Inc.            C:      
2901 Telstar, Ct.                               E:
mailto:jeff () masergy com
Falls Church, VA, 22042                 W:      http://www.masergy.com
-----------------------------------------------------------------------

-----Original Message-----
From: Stephen J. Wilcox [mailto:steve () opaltelecom co uk] 
Sent: Thursday, July 18, 2002 5:26 PM
To: John Evans
Cc: nanog () merit edu
Subject: RE: QoS/CoS in the real world?




On Thu, 18 Jul 2002, John Evans wrote:


I realise this is a US-centric list, however, a significant number of
providers in Europe have deployed Diffserv as a means of supporting 
(and
selling) differential SLAs.  Of these, some have deployed Diffsev at
the
edge and some both the edge and core.  See Clarence Filsfils
presentation at
NANOG 25 for a description of typical core deployments.

2. Hype aside, to what extent do customers actually want this

Surely end customers want a service with SLAs that will support their
applications, and at low cost?  It then becomes a provider cost 
consideration as to whether these SLA assurances can most 
competitively satisfied with mechanisms such as Diffserv or without.

I have to say that the majority of users barely understand how their
outlook client works let alone the difference between applications. I'm
starting to think theres no demand for these services other than that
which the hype says is there.

THis is in line with what people said about using qos behind the scenes
but customers dont know.. kind of what I thought to begin with

STeve


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.

or perhaps they are just not on this list.

cheers

John

-----Original Message-----
From: owner-nanog () merit edu [mailto:owner-nanog () merit edu]On Behalf
Of Stephen J. Wilcox
Sent: 14 July 2002 00:47
To: nanog () merit edu
Subject: Re: QoS/CoS in the real world?



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











Current thread: