Bandwidth shaping 2 links with 2921 router

[Steve Chapman]

I have 2 links to 2 different departments switch with an up link of 10mb. I want to guarantee that both departments get at least 5mb, but can use part of the other 5mb that not in use. Is this possible? 

Thanks

Steve

[Joseph W. Doherty]

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Posting

Should be easy for interface egress traffic.

Very, very difficult for interface ingress.  If possible, ingress is often best dealt with on other side of link's egress.

PS:

Likely next question might be how.

For egress if, physical inteface is 10 Mbps

something like:

class-map match-any deptA

match . . .

class-map match-any deptB

match . . .

policy-map 5050

class deptA

bandwidth percent 49

class deptB

bandwidth percent 49

interface (10mbps)

service-policy output 5050

[Steve Chapman]

Joseph,

I assume this just limits them to 5mb each.  I was wondering if there was a way to guarantee 5mb each, but allow them to use the other 5mb if it not being used by the other department. 

example

dept a is using 2mb so dept b could use up to 8mb, but if dept a needs more it would take to back from dept b.

[Joseph W. Doherty]

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

No, CBWFQ bandwidth statements provide a minimum guarantee.  If there's unused bandwidth, it may be used.  I.e. each dept is guaranteed half the bandwidth, but if the other dept. was only using 25%, the other dept. could use 75%.

PS:

Oh, if you wondering why 49% rather than 50%, I think the IOS version you're likely will have might need 1% for class-default.