Krishna, I added the "mls qos srr-queue output dscp-map" commands so that the cos-map and dscp-map match with equivalent values. This is not a requirement as your question is stated.
In addition for the link to the router you need: mls qos trust dscp On the server ports: mls qos trust dscp On the phone ports: mls qos trust cos mls qos trust device cisco-phone This is assuming there are no other stated requirements for marking traffic requiring class-maps and policy-maps and service policies. Michael Sears From: Krishna [mailto:vinayak_...@yahoo.com] Sent: Sunday, October 14, 2012 6:59 PM To: Sears, Michael (msears) Cc: Online Study Subject: Re: LAN QOS QUESTION michael, thanks for your input on this query.. i am using 3750 switch provided by proctor labs.. I am well aware lan qos queuing and thresholds , but not sure where should i have to keep those values unless if they are explicitly stated. adding to that question, i assume i need to put "mls qos trust dscp" for the traffic coming from router to switch isn't it?? I see some guys putting as mls qos trust cos which i feel incorrect since layer 2 to laye3 mappings were done using cos-dscp mapping. please correct me if i am wrong. thank you krishna. ________________________________ From: "michael.se...@compucom.com<mailto:michael.se...@compucom.com>" <michael.se...@compucom.com<mailto:michael.se...@compucom.com>> To: ccie_voice@onlinestudylist.com<mailto:ccie_voice@onlinestudylist.com> Cc: vinayak_...@yahoo.com<mailto:vinayak_...@yahoo.com> Sent: Sunday, October 14, 2012 4:50 PM Subject: RE: LAN QOS QUESTION On a Cisco 3750 --> I used the Enterprise_QoS_SRND [1] pages 105 through 112 to put together the following QoS configuration to meet your stated requirements. I would recommend you follow the SRND when writing your QoS configuration it's pretty much cut and paste. Requirements: assign cos 5 to priority queue assign cos 3 4 to queue 2 cos 4 exceed 60% should be dropped Solution: mls qos mls qos map cos-dscp 0 8 16 24 32 46 48 56 mls qos srr-queue output cos-map queue 1 threshold 3 5 mls qos srr-queue output cos-map queue 2 threshold 3 3 mls qos srr-queue output cos-map queue 2 threshold 1 4 mls qos srr-queue output dscp-map queue 1 threshold 3 46 mls qos srr-queue output dscp-map queue 2 threshold 3 24 mls qos srr-queue output dscp-map queue 2 threshold 1 32 mls qos queue-set output 1 threshold 2 60 100 100 100 Note how cos 3 and 4 are both in queue 2 but in different thresholds. Then since cos 4 is in threshold 1 it is marked down to 60% to discard cos 4 above 60%. Hope this helps. Keep in mind QoS will vary depending on switch type. INE has some great Videos on understanding LAN QoS and the relationships between Queues and Thresholds and related configurations. http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Book.html What switch type are you using? Michael Sears Message: 1 Date: Sat, 13 Oct 2012 18:40:10 -0700 (PDT) From: Krishna <vinayak_...@yahoo.com<mailto:vinayak_...@yahoo.com>> To: Online Study <ccie_voice@onlinestudylist.com<mailto:ccie_voice@onlinestudylist.com>> Subject: Re: [OSL | CCIE_Voice] lan qos- cos 5 threshold 1 in queue 1 doesn't show in running config Message-ID: <1350178810.93468.yahoomail...@web164602.mail.gq1.yahoo.com<mailto:1350178810.93468.yahoomail...@web164602.mail.gq1.yahoo.com>> Content-Type: text/plain; charset="iso-8859-1" hi guys, i was wondering whether i am doing right way of doing lan qos or not ?? the requirements are assign cos 5 to priority queue , cos 3 4 ?to queue 2 with 60% exceed of cos 4 should be dropped. so here is my configuration for that mls qos? mls qos srr-queue output cos-map queue 1 threshold 1 5 mls qos srr-queue output cos-map queue 2 threshold 2 3 mls qos srr-queue output cos-map queue 2 threshold 1 4 mls qos queue-set output 2 threshold 3 60 100 100 272 when i issued show run | i ?mls commands, i see every ?mls qos command except the cos 5 which is assigned to q1 t1. ?Is my approach is correct in dealing this question correctly?? does it matter whether we assign cos values to t1 or t2 or t3 in the queues??? your input is much appreciated. thank you krishna.
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