From: Jim Brown (Jim.Brown@xxxxxxxxxxxxx)
Date: Sun Aug 11 2002 - 12:53:32 GMT-3
Shaping and policing are very different in my eyes.
With shaping I'm only allowed to use bandwidth X during time of congestion,
until then I could use all available bandwidth on the link.
With policing, I'm only allowed to use bandwidth X, even if the link isn't
congested and there is available unused bandwidth.
Policing, affects bandwidth congestion or not, shaping only affects
bandwidth when the link/interface is congested.
The access list for GTS is only identifying the traffic eligible for
shaping.
Please take this to heart, I have failed the lab in the past so I obviously
don't know enough to pass that wretched exam and I hoping someone will
correct if I'm steering anyone wrong.
I may be way off base here, but my take on a requirement that states "limit
bandwidth" is one tied to a QOS function using policing. I would interpret a
requirement stating "limit bandwidth during congestion" to shaping or
queueing.
-----Original Message-----
From: Michael Snyder [mailto:msnyder@revolutioncomputer.com]
Sent: Sunday, August 11, 2002 9:15 AM
To: 'Jim Brown'
Cc: ccielab@groupstudy.com
Subject: RE: QOS Question from Routopia LAB 3
Ok,
In other words, both effect bandwidth.
Policing affects maximum usable bandwidth.
Shaping affects minimum usable bandwidth.
Two sides of the same coin really.
Back to the question that started the thread,
; Configure the serial interface on R6 so that Ping
; traffic can only
; utilize 10% of available bandwidth. Allow BGP to
; utilize no more
; than 20% of available bandwidth. Allow all other
; traffic to utilize up
; to 70% of available link capacity.
Would GTS tied to access lists work? I know that the S in GTS stands
for shaping, but when you tie it to an access list, it's really doing a
limiting function.
-----Original Message-----
From: Jim Brown [mailto:Jim.Brown@caselogic.com]
Sent: Sunday, August 11, 2002 10:01 AM
To: 'Balaji Siva'; msnyder@revolutioncomputer.com
Cc: ccielab@groupstudy.com
Subject: RE: QOS Question from Routopia LAB 3
Custom queueing wouldn't be appropriate based on the original question
to
"limit bandwidth."
Queueing only comes into play during times of congestion. In other words
if
the traffic in question is the only traffic on the wire, it can exceed
the
desired limit if there isn't any congestion and custom queueing would
never
come into play.
This is really the difference between policing and shaping.
-----Original Message-----
From: Balaji Siva [mailto:bsivasub@cisco.com]
Sent: Sunday, August 11, 2002 8:43 AM
To: msnyder@revolutioncomputer.com
Cc: ccielab@groupstudy.com
Subject: RE: QOS Question from Routopia LAB 3
CAR is supported on many platforms..not just on 7500..
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/
qos_
c/qcprt1/qcdcar.htm#xtocid285760
now as far as custom queueing solution.. i suppose it could....i am not
a
big fan of legacy qos features
regards
Balaji
-----Original Message-----
From: Michael Snyder [mailto:msnyder@ldd.net]
Sent: Sunday, August 11, 2002 10:18 AM
To: 'Balaji Siva'
Cc: ccielab@groupstudy.com
Subject: RE: QOS Question from Routopia LAB 3
Hate to be simple, but couldn't custom queueing do this?
BTW, is CAR supported on the lab hardware? My voice qos book said it
could only run on the 7500 series and above. Then again it doesn't
cover class based queuing either, so it may out of date.
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Balaji Siva
Sent: Saturday, August 10, 2002 8:53 PM
To: William lu; Akhilesh Verma; ccielab@groupstudy.com
Subject: RE: QOS Question from Routopia LAB 3
the question is vague as it could be just LLQ for ping/bgp ..and the
rest
class-default ..if the question had just mentioned that these things are
applicable only at times of congestion.
but since it didn't..
how about this
class-map ping
match access-group 101 <--- 101 matches icmp
class-map bgp
match access-group 102 <---- 102 matches bgp
policy-map ccie
class ping
police xxxx xxxxxx <-----10 % policer
class bgp
police xxxx xxxx <----- 30 % policer
int s0
service output ccie
Regards
Balaji
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
William lu
Sent: Saturday, August 10, 2002 9:22 PM
To: Akhilesh Verma; ccielab@groupstudy.com
Subject: Re: QOS Question from Routopia LAB 3
Hi,
I would use both technique complete this scenario:
1. Use CAR to limit the bandwidth used in CBWFQ. The
default bandwidth of physical interface be used for
the bandwidth calculation if you did not use TS or
CAR. (You may no be able to use bandwidth interface
command, which use for metric only).
2. Use CBWFQ to assign the bandwidth to each type of
traffic, which specify by CAR.
This is my implementation of the question. hope have
better one.
LUW.
Akhilesh, Where can I find this lab scenario? I'd like
to play with this completed lab.
--- Akhilesh Verma <akverma@cisco.com> wrote:
> Folks,
> I am working on Routopia LAB 3
and
> I have the following
> question
>
> Configure the serial interface on R6 so that Ping
> traffic can only
> utilize 10% of available bandwidth. Allow BGP to
> utilize no more
> than 20% of available bandwidth. Allow all other
> traffic to utilize up
> to 70% of available link capacity.
>
>
> Now ordinarily One would think that this is
> classification and not
> policing . Would you do CBWFQ here or CAR ?
>
> TIA
>
> Akhilesh
> ------------------------------------------------
> ------------------------------------------------
> Akhilesh Verma,
> Cisco Systems Inc.
> Systems Engineer
> 771,Alder Drive,
> Milpitas,CA-95035
> Pager:800-365-4578
> Direct: 408-853-9033
> Mobile: 510-501-1182.
> E-mail: akverma@cisco.com
>
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