From: alsontra@hotmail.com
Date: Sat Mar 13 2004 - 20:15:50 GMT-3
Yes, I now understand the significance of "bandwidth remaining percent".
Your explanation was very concise and appreciated!
Alsontra -
----- Original Message -----
From: "Brian McGahan" <bmcgahan@internetworkexpert.com>
To: <alsontra@hotmail.com>; "'Tom Wojahn'" <enthusiastictom@writeme.com>;
"'William Chen'" <kwchen@netvigator.com>
Cc: <ccielab@groupstudy.com>
Sent: Saturday, March 13, 2004 12:46 PM
Subject: RE: converting custom queue to cbwfq
> "bandwidth remaining percent" doesn't directly relate to the
> max-reserved-bandwidth value. Take the following example:
>
> Policy-map XYZ
> Class A
> Bandwidth percent 30
> Class B
> Bandwidth percent 20
> Class C
> Bandwidth percent 10
>
> Classes A, B, and C have reserved 60% of the bandwidth in this
> policy, and 40% is left unreserved for the default class. In the case
that
> the line is saturated, class A gets 30% of the output queue, class B gets
> 20%, and class C gets 10%, but what happens to the rest of the 40% that is
> unreserved?
>
> Keep in mind that the "bandwidth" statement is a *minimum* bandwidth
> reservation. When there is no congestion, these classes can use as much
> bandwidth is available. Now suppose that class A is using 30%, B 20%, and
C
> 10%, and there is no default traffic being dequeued. The ratios of the
> defined classes now gets transferred over into the default class as
> "remaining" percentages. This means that classes A, B, and C share the
> default class in the ratio of 3:2:1.
>
> Now suppose that you want class C to get more of the default class
> when there is saturation of everything except the default class. This is
> the case where it is appropriate to configure the "bandwidth remaining
> percent" such as follows:
>
> Policy-map XYZ
> Class A
> Bandwidth percent 30
> bandwidth remaining percent 25
> Class B
> Bandwidth percent 20
> bandwidth remaining percent 25
> Class C
> Bandwidth percent 10
> bandwidth remaining percent 50
>
> Now in the case of complete saturation *and* the absence of any
> default traffic, the following will occur:
>
> Class A: 30% of interface bandwidth, 25% of class-default
> Class B: 20% of interface bandwidth, 25% of class-default
> Class C: 10% of interface bandwidth, 50% of class-default
>
> Make sense?
>
> HTH,
>
> Brian McGahan, CCIE #8593
> bmcgahan@internetworkexpert.com
>
> Internetwork Expert, Inc.
> http://www.InternetworkExpert.com
> Toll Free: 877-224-8987 x 705
> Outside US: 775-826-4344 x 705
>
>
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> > alsontra@hotmail.com
> > Sent: Saturday, March 13, 2004 3:39 PM
> > To: Tom Wojahn; William Chen
> > Cc: ccielab@groupstudy.com
> > Subject: Re: converting custom queue to cbwfq
> >
> > William,
> > I understand and agree with Tom's calculations. Where does
the
> > "bandwidth remaining percent" command come into place? I know that the
> > class-default takes its bandwidth from the reserved 25% of interface
> > bandwidth, so are you saying that the "bandwidth remaining percent"
> > command
> > adjust the interfaces reserved bandwidth?
> >
> > Thanks,
> > Alsontra
> >
> >
> > ----- Original Message -----
> > From: "William Chen" <kwchen@netvigator.com>
> > To: "Tom Wojahn" <enthusiastictom@writeme.com>; "ccie r&r oup"
> > <ccielab@groupstudy.com>
> > Sent: Saturday, March 13, 2004 10:00 AM
> > Subject: Re: converting custom queue to cbwfq
> >
> >
> > > You can also use the "bandwidth remaining percent" command, that you
can
> > > reserve 25% of reserved bandwidth.
> > >
> > > William Chen
> > >
> > > ----- Original Message -----
> > > From: "Tom Wojahn" <enthusiastictom@writeme.com>
> > > To: "ccie r&r oup" <ccielab@groupstudy.com>
> > > Sent: Saturday, March 13, 2004 11:16 PM
> > > Subject: converting custom queue to cbwfq
> > >
> > >
> > > > I have a scenario where you are given
> > > > the reason I am asking is my answers did not match the answers given
> > > >
> > > > 128kb serial line
> > > >
> > > > A custom queue
> > > >
> > > > queue-list 1 protocol ip 1 tcp telnet
> > > > queue-list 1 protocol ip 2 tcp 53
> > > > queue-list 1 protocol ip 3 dlsw
> > > > queue-list 1 protocol ip 4 tcp www
> > > >
> > > > queue list 1 queue 1 byte count 2000
> > > > queue-list 2 queue 1 byte count 1000
> > > > queue-list 3 queue 1 byte count 4000
> > > > queue-list 4 queue 1 byte count 1000
> > > >
> > > > build a CBWFQ using percent not kb
> > > >
> > > > My theory and work
> > > >
> > > > In this case the bandwidth of 128 not valuable information
> > > >
> > > > I have a total of 8000 bytes on the custom queue
> > > >
> > > > policy-map converttocbwfq
> > > > class-map telnet
> > > > bandwidth percent 2000/8000 or 25% to get to 75% 25/100
=
> > > > x/75 19%
> > > > class map tcpdns
> > > > bandwidth percent 1000/8000 or 12.5% to get to 75 %
> > 12.5/100
> > > > = x/75 9.375% 9%
> > > > class map dlsw
> > > > bandwidth percent 4000/8000 or 50 % to get to 75%
> > > > 50/100=x/75 38%
> > > >
> > > > class map www
> > > > bandwidth percent 1000/8000 pr 12.5 % to get to 75% 12.5
> > > > /13=x/75 9.375 9%
> > > >
> > > >
> > > > total percent 19+9+38+9 = 75%
> > > >
> > > >
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