Utilizing WAN Link

Unanswered Question
Apr 17th, 2009


Determining if the WAN needs to be upgraded or if I need QOS enabled. I have a site which uses a 10mb WAN link. The users are complaining about slow network. Looking at MRTG, I can see the bandwidth does peak a couple of times a day. (explaining the users complains). But on average, it runs around 4mb. To my surprise, when I ran Iperf for about 2 minutes non-stop, I can fill up the 10mb link. I'm deducing that if a user starts a huge file transfer, he will eventually fill up the link as well. That explains the peaks. My question is by enabling QOS, will I be able to lower the priorty of file transfer and increase the priority for applications (office suite).


I have this problem too.
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Jon Marshall Fri, 04/17/2009 - 10:01


If the link was constantly running at it's full capacity then it would be time to look at an upgrade. But as it is it sounds like most of the time 10Mb is perfectly adequate.

If you are sure that the traffic spikes are caused by traffic that is not for office suite then yes QOS could be utilised but you would need to apply it on both ends of the WAN link.



tonyp8581 Fri, 04/17/2009 - 10:07


Thanks for your quick reply. Is there any other way besides QOS that will allow me to control a user utilizing the

WAN link by initiating a file transfer.

Thanks again.

Joseph W. Doherty Fri, 04/17/2009 - 16:43

None come immediately to my mind. There are different QoS methods, though. What you can do varies by platfrom and IOS. If you're using a software based router, FQ or WFQ (or GTS) would probably be an easy and effective method. If you're using a LAN switch, it can become much more complicated. (If you describe your platform, and WAN hand-off [and actual available WAN bandwidth], might be able to provide some suggestions.)


BTW, transient congestion and FIFO queuing often leads to user complaints.


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