akamaitechnologies.com and CS0

Question

Hi,

I am brand new to using solarwinds products. So far, I am very impressed. We are using NTA to get to the bottom of performance issues, slow network, internet bandwidth issues. Our ISP said we wave a lot of broadcast traffic which I am attempting to narrow down.

It appears that the service causing the most trafic is CS0, in conjunction with domain akamaitechnologies.com. On endpoint (PC) in particular is causing most of this traffic. Can anyone offer some insight as to what is happening?

Thanks much,

Rick

liamdwyer · Answer

Good morning, just saw this as I was looking for something myself.  Took me forever to figure out what was coming from Akamai but we finally tracked down the traffic to Skype banging back and forth.

We then put a QoS policy in the firewall.

Hope that helps.

cnorborg · Answer

CS0 or "Class Selector 0" is one QoS marking of many that can aid you in determining what traffic is more important in getting from one end to the other.   You can see ratings of CS0 through CS7, and generally speaking the lower the # the less important the traffic is.  So, CS0 traffic is also known as "Best Effort", "Bulk", or most likely to be dropped or delayed!!  ie: the least important traffic...   
   Things like routing protocols and applications that need low latency, like VoIP, are usually among the highest rated.

Here is an aritcle explaining a bit.

http://www.cisco.com/en/US/products/ps6902/products_implementation_design_guide_chapter09186a0080666638.html#wp1098099

But, to answer your question, yes, in general its normal for most internet traffic to be tagged CS0.   That means that it was either specifically tagged as being "Best Effort", or didn't get a marking so it was just left at the default of "CS0"...

rhlee222 · Answer

Thanks again, you have been very helpful. Is in normal for all internet traffic to be tagged CS0 in NetFlow?