From: SAVJANI, HITESH, WWCS (hitesh@att.com)
Date: Fri Nov 17 2006 - 13:39:53 ART
John,
I see your point. However think about it this way. Shaping doesn't
necessarily drop the traffic however policing does. Shaping would drop
the traffic only if you are really flooding the traffic & buffer can't
hold it in the output queue. You configure shaping to slow down the
trasmit rate so that your provider will not drop your excessive traffic.
If you don't slow down/shape, your non tcp applications may experience
some issues. Your time sensitive applications will scream at you as
well. This is the reason I think I would configure shaping.
My 2 cents.
Regards,
Hitesh Savjani
CCIE # 17151
________________________________
From: John Moor [mailto:johmoor@gmail.com]
Sent: Friday, November 17, 2006 11:28 AM
To: SAVJANI, HITESH, WWCS; Cisco certification
Subject: Re: shaping vs policing real life
On 11/17/06, John Moor <johmoor@gmail.com> wrote:
Yes guys I know this consideration about TCP sessions drop and
slow down. The thing which does interest me the most is:
1) How much could this imact the network. How much benefit/speed
anything else we can get when using shaping instead of policing for
outside traffic on the outside interface of the customer network?? Are
there some applications which would very much depend on what is
configured shaping or policing?? Some examples...
P.S To SavJani: If we don't want dorp our own traffic we
wouldn't configured anything either policing or shaping correct??? From
this I would probably formulate following subquestion:
What could be bad.... if we do not configure shaping at all on
the outside interface?? Say Provider have configured policing and we
didn't configure anything...
On 11/17/06, SAVJANI, HITESH, WWCS <hitesh@att.com > wrote:
John,
Here is the way I understand.
1 Shaping on the enterprise edge : Being a customer we
would want to
push as much data as we can without dropping anything.
If we use
policing we will be droping our own traffic which will
not make any
sense. Will it?
2 Policing on the Provider edge : Being a service
provider, I wouldn't
want to allow my customer to send anything more than he
is paying for.
So, I will drop anything above the limit. Another reason
is sometimes
being a provider I will sell my 100 Mb pipe as 200 Mb
;-). It does
happen & is called oversubscribing. In this case I would
definitely want
my customer to stick to his allocated bandwidth.
Shaping should be used when you don't want traffic to
get dropped.
Policing will drop all the traffic which is more than
the value
configured. I would not suggest to use policing on an
interface going to
the provider. However you may want to use policing
inbound on that same
interface. It's all based on what you want to
accomplish.
HTH,
Hitesh Savjani
CCIE # 17151
-----Original Message-----
From: nobody@groupstudy.com [mailto:
nobody@groupstudy.com] On Behalf Of
John Moor
Sent: Friday, November 17, 2006 9:51 AM
To: Cisco certification
Subject: shaping vs policing real life
Hello guys,
1. We all know the difference between policing and
shaping (how they
drop
the packets). Also usually in the real life policing is
configured on
the
provider edge and shaping is configured on the customer
edge.
2. Guys could you please explain me why do we use
shaping on the
enterprise
edge and not policing. Could you please give me a couple
of real life
theoretical examples when it could be logically
explained why using
shaping
is much better than using policing??
Thanks,
This archive was generated by hypermail 2.1.4 : Fri Dec 01 2006 - 08:05:47 ART