10-23-2013 12:23 PM - edited 03-04-2019 09:24 PM
Hi,
I'm facing issue with QoS which is causing TP Video Quality degradation.
TelePresence is connected to L3 Switch (C3560G) where I've trusted dscp in the interface and for the uplink connecting to 6500 L2 switch I've configured trust COS. There is only cos-dscp mapping in my L3 switch and no dscp-cos mapping. Will this cause any issue while sending the packet to L2 switch,as I'm trusting COS in the L2 switch interface.
Moreover in TP, I'm seeing voice/video traffic marked as Best Effort and I've no option to change this in TP. Is this due to QoS configuration issue in the switch.
10-23-2013 06:24 PM
Hi,
Are you seeing TP packets been remarked? Can you trust DSCP on all switches? Trust COS could protential break the DSCP value, because COS 5 maps to dscp 40 by default. You can change the default setting, but you could also just trust DSCP.
HTH,
Lei Tian
10-24-2013 02:55 AM
Can I do trust DSCP in 6k Catalyst L2 switch
10-24-2013 03:51 AM
Yes, you can trust DSCP on Cat6k L2 switch. It will use the incoming DSCP value for internal DSCP value, if the line card uses cos to queue map, it will use the DSCP to COS map to determine the egress queue.
The following document is very good for QoS on 6500.
http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/white_paper_c11_538840.html
HTH,
Lei Tian
10-24-2013 06:59 AM
Hi,
But when I check the QoS statistics in the interface connected to TP, input is showing DSCP marked traffic, but output is showing DSCP 0. Is this causing the TP to take BE marking??
And for the uplink, I'm seeing classified traffic in input and output.
C3560G-24PS-01#sh mls qos interface g0/1 statistics
GigabitEthernet0/1
dscp: incoming
-------------------------------
0 - 4 : 50551521 0 0 0 2763
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 11238456
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 1952380679
35 - 39 : 0 0 0 0 0
40 - 44 : 0 0 0 0 0
45 - 49 : 0 888132 0 11750 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 : 2154167344 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 : 0 0 0 0 0
45 - 49 : 0 0 0 0 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 6 0 0 0
60 - 64 : 0 0 0 0
cos: incoming
-------------------------------
0 - 4 : 63546934 0 0 2024775 1952380679
5 - 7 : 833252 0 0
cos: outgoing
-------------------------------
0 - 4 : 3006653445 0 0 0 0
5 - 7 : 2547879 0 0
Policer: Inprofile: 0 OutofProfile: 0
-------------------------------------------Uplink--------------------------------------
C3560G-24PS-01#sh mls qos interface g0/25 statistics
GigabitEthernet0/25
dscp: incoming
-------------------------------
0 - 4 : 1750957418 0 0 0 2
5 - 9 : 0 0 0 15 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 0 0
20 - 24 : 0 0 0 0 21608274
25 - 29 : 0 1569363 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 7515571 0 580817471 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 10 0 0 0
60 - 64 : 0 0 0 0
dscp: outgoing
-------------------------------
0 - 4 : 3977529209 0 0 0 2763
5 - 9 : 0 0 0 0 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 2 0 0 0
20 - 24 : 0 0 0 0 11236432
25 - 29 : 0 34575004 0 0 0
30 - 34 : 0 0 0 0 1952380679
35 - 39 : 0 0 0 0 0
40 - 44 : 0 0 0 0 0
45 - 49 : 0 45515260 0 21055 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 : 3397982841 15 0 23116921 0
5 - 7 : 7515489 438424644 0
cos: outgoing
-------------------------------
0 - 4 : 3996821898 0 75291 45811453 1952380679
5 - 7 : 46425936 21055 51948
Policer: Inprofile: 0 OutofProfile: 0
10-24-2013 08:30 AM
What DSCP value that TP uses? Can you confirmed it is marked before entering the switch? Can you share the configure for interface g0/1 and g0/25?
HTH,
Lei Tian
10-24-2013 09:51 AM
TP uses EF for voice and AF4 for video by default and there is no option to edit it. I suspect that since the ouput to TP from g0/1 is DSCP 0, TP is taking it as BE.
Below are the config.
----------------------------------
C3560G-24PS-01#sh run int g0/1
interface GigabitEthernet0/1
description : Telepresence Room
switchport voice vlan 180
srr-queue bandwidth share 1 30 35 5
priority-queue out
mls qos trust dscp
spanning-tree portfast
end
C3560G-24PS-01#sh run int g0/25
interface GigabitEthernet0/25
description Link to Cat6500_L2switch port 5/8.
switchport trunk encapsulation dot1q
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
queue-set 2
priority-queue out
mls qos trust cos
auto qos voip trust
spanning-tree guard loop
spanning-tree cost 500
end
10-24-2013 03:37 PM
This may not be remarked by 3560. Clear the statics and run a test TP call, see if you see packet increase in the correct DSCP value on g0/1 incoming, and g0/25 outgoing direction.
HTH,
Lei Tian
10-24-2013 10:29 PM
Will this cause any impact for other traffic? I've many IP Phones connecting through same uplink..
10-24-2013 11:20 PM
Just now I had a check on the switch interface connecting Router where there is no trust configured. Should I configure trust COS or DSCP here.
Cat6500_L2switch> sh port qos 7/8
QoS is enabled for the switch.
QoS policy source for the switch set to local.
Port Interface Type Interface Type Policy Source Policy Source
config runtime config runtime
----- -------------- -------------- ------------- -------------
7/8 port-based port-based COPS local
Port TxPort Type RxPort Type Trust Type Trust Type Def CoS Def CoS
config runtime config runtime
----- ------------ ------------ ------------ ------------- ------- -------
7/8 1p3q1t 1p1q0t untrusted untrusted 0 0
Port Ext-Trust Ext-Cos
----- --------- -------
7/8 untrusted 0
(*)Runtime trust type set to untrusted.
10-25-2013 04:34 AM
No, the test will not impact your applicaiton. Yes, QoS needs to configured end to end. You need to have trust dscp on the interface connecting Router.
HTH,
Lei Tian
10-25-2013 05:08 AM
So, will trusting QoS cause any outage..??
10-25-2013 07:47 AM
No, I dont expect any outage of chaning interface qos trust level.
HTH,
Lei Tian
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