06-19-2012 09:48 PM - edited 03-04-2019 04:43 PM
class FTP
shape average percent 28
shape avergae 25
bandwidth percent 26
if shape command define Max BW limit and bandwidth percent command define Min BW, how these command will work?
06-19-2012 10:30 PM
Hi Santosh,
The thing is that bandwidth command reserve bandwidth for the time of congestion. If there is no congestion on the interface then particular class can go higher than the bandwidth value configured and kinda ignore it. If congestion happens then bandwidth command guarantee to provide at least this amount of traffic to go through.
Shape as you said is maximum - if there is no congestion, shape will still limit traffic to what is configured using shaping mechanisms.
You can find more specifics of shaping here:
http://www.cisco.com/en/US/tech/tk543/tk545/technologies_tech_note09186a00800a3a25.shtml
http://www.cisco.com/en/US/docs/ios/12_2/qos/configuration/guide/qcfcbshp.pdf
http://www.cisco.com/en/US/docs/ios/12_1t/12_1t2/feature/guide/clsbsshp.html
Nik
06-19-2012 11:03 PM
Nik,
Thanks for links, so as per above example, class FTP will get only 25% BW during congestion & and non congestion. It will never cross 25% and bandwidth pecent 26 will not play any role.
06-20-2012 12:34 AM
Hi
As far as I know there is no command like " shape average percent 28", at least on the platforms I worked with. Will be glad to check if you have some docs for that.
So I think what will work is only this:
shape avergae 25
bandwidth percent 26
The thing is that shape average X shape not on percentage but on exact CIR value in bps, so this class will be shaped for 25 bps and never come up to 26% of the interface bandwidth.
Nik
06-20-2012 02:11 AM
Nik,
Found that command on 1721 router
Router(config-pmap-c)#shape average percent ?
<1-100> Percentage
http://www.cisco.com/en/US/docs/ios/12_2t/qos/command/reference/qftcmd9.html
EX. So if CIR is 1000000 (1Mb)
shape average 200000
bandwidth 100000
will mean during with no utilization - traffic will able to reach upto 200 Kb and in congestion it will get minimum BW of 100 kb, so is that correct.
06-21-2012 12:32 AM
Thanks Santosh,
good also to learn some commands.
Yes - your understanding is correct. Bandwidth command will provide garantee amount during congestion and shape will provide maximum for all the time.
Nik
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide