10-27-2011 08:55 AM - edited 03-07-2019 03:05 AM
Hi I'm working on a catalyst c3750 and for my work i need to prioritize certain streams independent of their bandwith usage.
The streams are the following:
- voice
- video
- data
I created policy maps based on vlans like below:
policy-map VOICE
class class-default
set precedence 5
policy-map VIDEO
class class-default
set precedence 4
policy-map DATA
class class-default
set precedence 0
Based on these policy maps i configured the correct vlans so that they are marked with the correct settings.
interface vlan 100
description data
ip address 172.16.0.1 255.255.255.0
service-policy input DATA
end
interface vlan 101
description data
ip address 172.16.1.1 255.255.255.0
service-policy input VOICE
end
interface vlan 102
description data
ip address 172.16.2.1 255.255.255.0
service-policy input VIDEO
end
I set the interfaces to use vlan-based cos and this is working, i see all packets being marked with the cos bit set and the tos byte as well.
But know I need to find out how my data gets prioritized... I assume i need to configure the queues so that the one with higher priority are always in the highes queu and then going downards with different queues. But i've been reading on this and i don't get it working by configuring the qeues.
I verify this by using a laptop with a 1Gb interface sending 3 streams with iperf (video,voice and data) to a 100mb laptop. I send 100Mb of data, 5 mbit of voice and 20mbit of video. Data should have a lot of lost packets and video and voice none! But i can't get this working.
Anybody an idea of how to do this?
thanks
steven
10-29-2011 04:29 PM
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
http://www.cisco.com/en/US/products/hw/switches/ps5023/products_tech_note09186a0080883f9e.shtml
10-30-2011 01:46 AM
Hi Steven,
How do you verify it it not working? Can you post some sh mls interface int statistics, sh mls qos queue-set and
sh mls qos input?
You have to set egress queue per port basis.
Best regards,
Alex
EDIT: Joseph 's link is very helpful.
10-31-2011 12:52 AM
Hi
the problem with the link is that it's the about QoS in general. Off course you need to finetune this according to the settings that I need specifically. But there's just the problem...I can't seem to get it working for my use case and it's hard to find out where it goes wrong.
How I verify this? I have 3 streams running from 1 client to another client with udp traffic being sent from A -> B. A sends 3 streams of 5 Mb (simulating voice), 20 Mb (simulating video) and 85Mb (simulating data). Because i'm oversending i should see lost packets but according to my settings voice and video should not be dropped. Although this happens of course.
I will check with your commands to see if I have some more information for you!
thanks anyway for the help!
sg
10-31-2011 01:41 AM
Hi,
You perhaps should not see the drops in your ingress flow as there you have 1Gb.
Check with the commands and lets view the output.
Best regards,
Alex
11-02-2011 02:28 AM
Guys
thank you for your help already. Today i had some time to check it and actually, it seems more or less working... More or less because sometimes i see on my vlan 102 some drops.
Gigabit interface is sending 100Mb of data (vlan 100), 10mb of voice (vlan 101) and 20mb of video (vlan 102). Sometimes i notice drops on my outgoing interface 3/0/1 which is the fastethernet one. I think i have now to play with the queue settings, but what is the best approach for this?
The problem is as well that when I increase the bandwith of the voice and video throughputs, that i will see some drops there as well. I off course know how much bandwith we're sending from our video , but for voice it can be 10 or either 100 calls together, but the bandwith is much less in this case...but I want to know what in case this traffic increases and we see drops on the outgoing interfaces????
thanks again!
the results:
sh mls qos interface gigabitEthernet 3/0/1
GigabitEthernet3/0/1
trust state: not trusted
trust mode: not trusted
trust enabled flag: ena
COS override: dis
default COS: 0
DSCP Mutation Map: Default DSCP Mutation Map
Trust device: none
qos mode: vlan-based
FastEthernet3/0/1
trust state: not trusted
trust mode: not trusted
trust enabled flag: ena
COS override: dis
default COS: 0
DSCP Mutation Map: Default DSCP Mutation Map
Trust device: none
qos mode: vlan-based
switchsteven#show mls qos interface fastEthernet 3/0/1 statistics
FastEthernet3/0/1 (All statistics are in packets)
dscp: incoming
-------------------------------
0 - 4 : 285 0 0 0 15
5 - 9 : 0 0 0 0 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 0 0
20 - 24 : 0 0 0 0 0
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 0
35 - 39 : 0 0 0 0 0
40 - 44 : 0 0 0 0 0
45 - 49 : 0 0 0 0 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 0 0 0 0
60 - 64 : 0 0 0 0
dscp: outgoing
-------------------------------
0 - 4 : 1035298 0 0 0 0
5 - 9 : 0 0 0 0 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 0 0
20 - 24 : 0 0 0 0 0
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 0
35 - 39 : 0 0 0 0 0
40 - 44 : 2118728 0 0 0 0
45 - 49 : 0 0 0 408587 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 0 0 0 0
60 - 64 : 0 0 0 0
cos: incoming
-------------------------------
0 - 4 : 468 0 0 0 0
5 - 7 : 0 0 0
cos: outgoing
-------------------------------
0 - 4 : 10380858 0 0 0 0
5 - 7 : 2118774 408606 2
output queues enqueued:
queue: threshold1 threshold2 threshold3
-----------------------------------------------
queue 0: 2135886 0 0
queue 1: 10436595 30 426
queue 2: 0 0 0
queue 3: 417123 0 145
output queues dropped:
queue: threshold1 threshold2 threshold3
-----------------------------------------------
queue 0: 277 0 0
queue 1: 1982167 0 0
queue 2: 0 0 0
queue 3: 34331 0 0
Policer: Inprofile: 0 OutofProfile: 0
show mls qos interface gigabitEthernet 3/0/1 statistics
GigabitEthernet3/0/1 (All statistics are in packets)
dscp: incoming
-------------------------------
0 - 4 : 10328367 0 0 0 0
5 - 9 : 0 0 0 0 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 0 0
20 - 24 : 0 0 0 0
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 0
35 - 39 : 0 0 0 0 0
40 - 44 : 0 0 0 0 0
45 - 49 : 0 0 0 0 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 0 0 0 0
60 - 64 : 0 0 0 0
dscp: outgoing
-------------------------------
0 - 4 : 4 0 0 0 0
5 - 9 : 0 0 0 0 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 0 0
20 - 24 : 0 0 0 0 0
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 0
35 - 39 : 0 0 0 0 0
40 - 44 : 3 0 0 0 0
45 - 49 : 0 0 0 4 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 0 0 0 0
60 - 64 : 0 0 0 0
cos: incoming
-------------------------------
0 - 4 : 10328557 0 0 0 0
5 - 7 : 0 0 0
cos: outgoing
-------------------------------
0 - 4 : 56 0 0 0 0
5 - 7 : 33 24 0
output queues enqueued:
queue: threshold1 threshold2 threshold3
-----------------------------------------------
queue 0: 34 0 0
queue 1: 112 0 62
queue 2: 0 0 0
queue 3: 25 0 6
output queues dropped:
queue: threshold1 threshold2 threshold3
-----------------------------------------------
queue 0: 0 0 0
queue 1: 0 0 0
queue 2: 0 0 0
queue 3: 0 0 0
Policer: Inprofile: 0 OutofProfile: 0
switchsteven#show mls qos queue-set
Queueset: 1
Queue : 1 2 3 4
----------------------------------------------
buffers : 25 25 25 25
threshold1: 100 200 100 100
threshold2: 100 200 100 100
reserved : 50 50 50 50
maximum : 400 400 400 400
Queueset: 2
Queue : 1 2 3 4
----------------------------------------------
buffers : 25 25 25 25
threshold1: 100 200 100 100
threshold2: 100 200 100 100
reserved : 50 50 50 50
maximum : 400 400 400 400
Queue : 1 2
----------------------------------------------
buffers : 20 80
bandwidth : 20 80
priority : 0 20
threshold1: 100 100
threshold2: 100 100
11-02-2011 03:36 AM
Hi Steve,
You can use vlan based qos and then queue in the hardware. So basically you do all the marking/policing etc under the vlan and then push those dscp values into respective queues . The HW queue I believe WRR and you can assigh 1Priority queue and 3 normal queues.( I need to double check the number of queues). So, once you classify and mark the packets then they get pushed into the respecive queues and then the scheduler kicks in.
However the only condition to use mls qos vlan-based is that it can be used only on trunk ports
HTH
Regards,
Kishore
11-02-2011 04:23 PM
Steven, what is the output of "sh mls qos maps dscp-output-q"? I do not see voice signaling in the default egress queue location - queue 3 threshold 1. What do you need to configure exactly? The egress QoS on 3750 require SRR config as Kishore suggested.
For more information please take a look at this document:
Best regards,
Alex
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide