Custom Queuing
Printed From: CertCities.com Forums
Forum Name: CCIE
Forum Discription: Discuss the CCIE written and lab here.
URL: http://certcities.com/forums/forum_posts.asp?tid=5058
Printed Date: 23 October 2007 at 8:15pm
Topic: Custom Queuing
Posted by: hudsonmbg
Subject: Custom Queuing
Date Posted: 18 June 2007 at 8:38am
Hi,
I have been reading across CCIE Lab work book and came across a task to configure QoS on a router to make sure traffic from the web server is given a guaranteed bandwidth of 50% of the bandwidth, without using the policy map command. The solution to this was the following config below:
access-list 182 permit tcp host 167.1.4.119 eq www any
queue-list 1 protocol ip 1 list 182
queue-list 1 default 2
I don't know how the above config provides the guaranteed bandwidth to the http traffic. I tried to reason it this way, that since just two queues have been configured, each has a portion of 50% bandwidth on the link. Is this correct or does someone out there have the right answer to my fears?
Thanks,
What I don't understand is how this config will enable
-------------
Bishop(TCP/IP), CCNP |
Replies:
Posted by: Headhunter
Date Posted: 18 June 2007 at 8:43am
it is put in queue 1 all other traffic is put in queue 2
-------------
Koen
CCSI#30501 CCNP CCIP CCVP CCSP CCDP CQS-Cisco Wireless LAN Design & Support Cisco Unity Design Specialist Cisco IP Telephony Design Specialist JNCIA-ER MCSE MCSA:Messaging |
Posted by: BosonMichael
Date Posted: 18 June 2007 at 9:19am
I'm guessing they're using the defaults, which would be to equally share each list. Thus, list 1 would get half the bandwidth, and list 2 would get the other half.
If you manually want to specify a particular percentage of bandwidth, you should throw in some byte-count statements in your queue lists, such as:
queue-list 1 queue 1 byte-count 4000
queue-list 1 queue 2 byte-count 1000
This would give your first queue 4000 bytes for every 5000 (4000+1000) bytes sent, thereby guaranteeing queue 1 80% of your available bandwidth.
From http://www.cisco.com/en/US/tech/tk331/tk336/technologies_des ign_guide09186a0080237a48.shtml#wp16395 - Cisco :
Custom queuing, or bandwidth allocation, reserves a portion of the bandwidth of a link for each selected traffic type. To configure custom queuing, the network manager must determine how much bandwidth to reserve for each traffic type. If a particular type of traffic is not using the bandwidth reserved for it, then other traffic types may use the unused bandwidth.
Custom queuing works by cycling through the series of queues in round-robin order and sending the portion of allocated bandwidth for each queue before moving to the next queue. If one queue is empty, the router sends packets from the next queue that has packets ready to send. Queuing of packets is still first in, first out in nature in each classification (unless APPN is running in the router, in which case the queue is ordered by SNA transmission priority), but bandwidth sharing can be achieved between the different classes of traffic.
-------------
BosonMichael (formerly TMichael)
MCSE+I, MCSE: Security, MCDST, MCDBA, OCP, CCNP, CCDP, CNE, SCSA, Security+, Linux+, Server+, Network+, A+
Served proudly, US Army, 98C Intelligence Analyst, '89-'92 |
|