QoS to limit bandwith to a particular app?

Question

We run Lotus Notes that replicates to another server at another location over a T1. I'm tyring to set up a policy that will say any traffic destined for this server will be given "Lower" priority. I don't care if this maxes out the link all day, as long as other data will be able to flow freely over the link and the replication data will take the back seat.

We are already using CBWFQ on our network, so I belive I have to stick with that

I made an access list:

access-list 102 permit tcp any 10.90.3.91 0.0.0.0 range 1350 1352

Then I defined a class-map:

class-map NotesRepData match access-group 102

Now I was going to put the class-map statement into our existing policy which looks similar to this:

Poilcy-Map Voice Class VoicePayload Priority 880 Class VoiceSignaling Priority 128 Class class-default fair-queue

Here's where my problem comes in.. I don't know what I should put in for my class here..

Poilcy-Map Voice Class VoicePayload Priority 880 Class VoiceSignaling Priority 128

> Class NotesRepData
>> Bandwidth x or Priority X?

Class class-default fair-queue

From what I can see this will allocate/guarantee bandwidth for the

specific application, but what I really want to do is is just make this data take a back seat. Do I need to define a traffic class that encompases all traffic BUT this traffic?

Something like this: (i.e. access-list 102 deny tcp any host 10.90.3.91 range 1350 1352 access-list 102 permit ip any any)

Then define a policy map:

Poilcy-Map Voice Class VoicePayload Priority 880 Class VoiceSignaling Priority 128 Class NotesRepData Bandwidth percent 100 Class class-default fair-queue

This looks to me like Voice Traffic would still get priority, then other data would get 100 percent of the remaining bandwidth, then replication data would get whatever is left over.

I tried setting up priority-lists and priority-groups, but it told me that CBWFQ is in use.

Any input is appreciated!

Thanks,

-DZ

ghsu2001 · Accepted Answer

You could use Instead priority-list i found it easier

for example: priority-list 1 protocol ip low tcp 1350 priority-list 1 protocol ip low tcp 1352

interface serial0/0 (or whatever is your T1) priority-group 1

I hope that's help.

collinsr · Answer

How about doing this:Create a class map such as:class map not_Lotusmatch not access-group 102With CBWFQ you should not reserve more than  75% of the bandwidth.Therefore 880 Kbps + 128 Kbps = 65% of the T1Poilcy-Map Voice  Class VoicePayload    Priority 880  Class VoiceSignaling    Priority 128  Class Not_Lotus    Bandwidth percent 10  Class class-default     fair-queue

Charlie Root · Answer

while you can configure several classes for priority queue, they will actually all end-up in the same queue:CE8#sh policy-map in se1/0 ou Serial1/0  Service-policy output: LAB-WAN-OUT-01    Class-map: VOICE (match-any)[...]      Queueing        Strict Priority        Output Queue: Conversation 264[...]    Class-map: VOICE_CLASSIFY (match-all)[...]      Queueing        Strict Priority        Output Queue: Conversation 264Notice conversation ID. So it's just the same as you'd have assigned both voicepayload and signalling to the same class. Besides, having 65% of the line speed for priority queue will most likely leave other traffic no chance to pass through because router will unconditionally serve priority queue as long as there is traffic. Normally you shouldn't allocate above 20-30% for priority queue.Back to your original question, with CBWFQ 'priority queue' (LLQ, strict priority) always get absolute service priority, that is this queue is served as long as there are packets. When...

QoS to limit bandwith to a particular app?

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