QOS Classification and Marking

QOS Classification and Marking


Task is to match the HTTP packets originating from R1 to mark dscp cs4 and see that the traffic is matching at R4.
R1 Config
ip access-list extended HTTP
 permit tcp any any eq www
!
class-map match-all CMAP-HTTP
 match access-group name HTTP
!
!
policy-map POLICY-HTTP
 class CMAP-HTTP
  set dscp cs4
!
interface FastEthernet0/0
 ip address 12.1.1.1 255.255.255.0
 duplex auto
 speed auto
 service-policy output POLICY-HTTP

Make R4 as http serve to accept the traffic and configure access-list to check the http traffic with dscp cs4

R4 Config
ip http server
!
interface FastEthernet0/0
 ip address 34.1.1.4 255.255.255.0
 ip access-group MATCH-HTTP in
 duplex auto
 speed auto
!
ip access-list extended MATCH-HTTP
 permit tcp any any dscp cs4
 permit ip any any

Lets generate some http traffic towards R4



Check traffic in R4

QOS Hold-Queue and Tx-Ring

QOS Hold-Queue and Tx-Ring

Config is to the change the in and out hold queue, also change the Tx-ring-limit



We will change the bandwidth of the serial link on router R2 to 64Kbps
TX-ring Limit to 10 packets, hold queue in 12 and out 10, as we will be only able to generate the desired result in gns3 with this conifg otherwise we have get some live traffic.

R2 Config
interface Serial1/0
 bandwidth 64
 ip address 23.1.1.2 255.255.255.0
 tx-ring-limit 10
 tx-queue-limit 10
 serial restart-delay 0
 clock rate 64000
 hold-queue 12 in
 hold-queue 10 out
end

Now with the config done we will try to ping R4 loopback from R1, there are no drops

Now we try to ping again with high packet size and timeout of 1 we are not seeing any packets drops



Now let us change the hold-queue to 5 out and ping again
R2(config-if)#hold-queue 5 out
 

 
we are able to ping R4 loopback without any problem, now lets change the tx-ring-limit on R2 to 5 and ping again with same packet size
R2(config-if)#tx-ring-limit 5
In the output we can see getting some of the ping drops and see that output queue is filled up sometime, now we are able to fill up the output queue and get see the desired result