3550 / QoS / service-policy 1

[hunterdw]

So...

In my world, most of my connections run across routers. I have my class/policy maps setup and assigned to my interfaces using service-policy commands.

A few of my campuses are setup via "transparent lan" point-to-point fibre connections with ethernet handoff. I'm connecting them via 3550 routing switches...

How can I set priority and bandwidth on the 3550s (EMI) like I would with a router? I can't seem to find the commands I am used to...

example on a router:

class-map match-all LC-Video
match access-group name LC-VideoEndpoints
class-map match-any voice
match ip dscp ef
match ip precedence 5
class-map match-any sig
match ip precedence 3
match ip dscp af31
match ip dscp cs3
match precedence 3
!
!
policy-map voip
class voice
priority percent 33
class sig
bandwidth percent 5
class LC-Video
police 192000 conform-action transmit exceed-action drop
class class-default
fair-queue

...

then on my external interface...

service-policy output voiip

In my 3550s I don't have the same options.

Help?

--DW

 

[KiscoKid]

HI

I think you need to take a look at the following doc

http://www.cisco.com/en/US/tech/tk389/tk813/technologies_tech_note09186a00801558cb.shtml#topic3

I don't think it mentions it there but you also need to enable QoS globally with the 'mls qos' command

HTH

 

[ADB100]

Generally with switching platforms you classify your traffic on ingress ports and then schedule it on egress ports. Classification is done using class-maps like you already have, the policy-map though simply sets DSCP or CoS values and optionally applies a policer to out of profile traffic. The scheduling is generally done by mapping DSCP or CoS values to queues. With the 3550 you have by default 4 WRR queues, optionally the 4th can be configured as a strict priority queue. By default each queue has an equal weight and each buffer space for 100 packets. You can tune the weights of each queue to 'share-out' the available bandwidth and enable the priority queue for Voice.

With the config below fastethernet 0/1 allocates 5% to Q1, 25% to Q2 and 70% to Q3 with the wrr-queue bandwidth command. Q4 is the priority queue (configured with priority-queue out) so the 4th weight is ignored. CoS 1 is mapped to Q1, CoS 0 is mapped to Q2, CoS 2, 3, 4, 6 & 7 are mapped to Q3 and CoS is mapped to the strict priority queue (Q4).

interface FastEthernet0/1
wrr-queue bandwidth 5 25 70 1
wrr-queue cos-map 1 1
wrr-queue cos-map 2 0
wrr-queue cos-map 3 2 3 4 6 7
wrr-queue cos-map 4 5
priority-queue out

On trusted interfaces the DSCP value is generally trusted - these are usually switch uplinks or connections to routers etc. On user/server access ports service policies are usually applied so ingress traffic is classified according to policy.

HTH

Andy

 

[hunterdw]

ADB100--

That was what I was looking for. It was the wrr-queue statements. That's what I was going with, but I thought surely I was missing something.

How would I apply a service-policy to an interface?

For instance, let's say I want all of traffic from 192.168.1.250 to be marked as DSCP 46

normally, I would have some sort of access-list which looks for that ip address.

Then a class-map matching that access-group

Then a service-policy that contained the class and then the "set ip dscp 46" command.

I did that here too on my 3550 but I cannot apply the service-policy to an interface.

What did I miss?

 

[ADB100]

Its the same as a router. I have a 3550 with service policies applied to each access port classifying the ingress traffic from Voice/Data ports as follows:

ip access-list extended VVLAN-ANY
permit ip 10.1.100.0 0.0.0.255 any
ip access-list extended VVLAN-CALL-SIGNALLING
permit tcp 10.1.100.0 0.0.0.255 any range 2000 2002 dscp cs3
permit tcp 10.1.100.0 0.0.0.255 any range 2000 2002 dscp af31
ip access-list extended VVLAN-VOICE
permit udp 10.1.100.0 0.0.0.255 any range 16384 32767 dscp ef
ip access-list extended DVLAN-ANY
permit ip 10.1.10.0 0.0.0.255 any
!
class-map match-all DVLAN-ANY
match access-group name DVLAN-ANY
class-map match-all VVLAN-VOICE
match access-group name VVLAN-VOICE
class-map match-all VVLAN-ANY
match access-group name VVLAN-ANY
class-map match-all VVLAN-CALL-SIGNALLING
match access-group name VVLAN-CALL-SIGNALLING
!
policy-map IPPHONE+PC
class VVLAN-VOICE
set dscp ef
police 128000 8000 exceed-action drop
class VVLAN-CALL-SIGNALLING
set dscp cs3
police 32000 8000 exceed-action policed-dscp-transmit
class VVLAN-ANY
set dscp default
police 32000 8000 exceed-action policed-dscp-transmit
class DVLAN-ANY
set dscp default
police 5000000 8000 exceed-action policed-dscp-transmit
!
interface FastEthernet0/1
switchport access vlan 10
switchport mode access
switchport voice vlan 100
service-policy input IPPHONE+PC
wrr-queue bandwidth 5 25 70 1
wrr-queue cos-map 1 1
wrr-queue cos-map 2 0
wrr-queue cos-map 3 2 3 4 6 7
wrr-queue cos-map 4 5
priority-queue out
spanning-tree portfast
!

HTH

Andy

 

[ADB100]

A couple of things in global config as well:

mls qos map policed-dscp 0 24 to 8
!
mls qos map cos-dscp 0 8 16 24 32 46 48 56
mls qos map ip-prec-dscp 0 8 16 24 32 46 48 56
!
The first line dictates what the service-policy command 'policed-dscp-transmit' does, the second 2 lines set the CoS & IP Precedence to DSCP maps.

HTH

Andy

 

[hunterdw]

I can't get my interfaces to accept the service-policy input command. I type it in, it appears to accept it, but it doesn't show up in the "show run"

I'll try a few things then open a TAC case if I can't get it.

Thanks.

 

[ADB100]

I would check your IOS, is 'mls qos' enabled in global config and you haven't got any 'mls qos trust' statements on the interfaces as well.

IOS for the 3550 is free as long as you aren't upgrading to EMI.

Service policies won't attach if there is a problem with them but I seem to remember you get a message on the console saying why (if you are telnet'd in try 'term mon' to see the messages).

HTH

Andy

 

[hunterdw]

I got it. The service-policy input worked this time.

I'm thinkin I had a brain fart

Thanks,

--DW