Appropriate use of SLA

dougw1215

Is using an SLA on an Internet-facing device appropriate/accurate?  I'm getting response time complaints (surprising, right?) but, from what I can see, it is not purely a bandwidth issue as I have adequate bandwidth available. 

I'm trying to get a better handle on the quality of our Internet connection by using an HTTP Get SLA on the router that services that connection.  The SLA is to a public web site and, during business hours, spends a huge majority of time in "Warning" and "Critical" states.

I'm new to SLA monitoring and I'm trying to determine if I can use this to support saying "yes - we have some sort of problem", or if not having a Responder on the other end makes it a moot point.

Thanks!

wbrown

I would also be running a couple icmpEcho operations on that router as well.  One of which would be icmpEcho to your provider edge and the other would be icmpEcho to the external site you're using as a test (I use the Dilbert page).

This will give you a true measurement of the response time from your provider and across your provider rather than just the combination of DNS lookup+HTTP request+whatever latency.

Having an SLA responder is not necessary for the simple ICMP tests but it is required for the port or application specific tests (such as VoIP) to a network device that would otherwise not be listening on those ports.

FYI - I've had mixed results when using pathEcho operations.  Some devices support it and some do not, while I've also had Orion sometimes see the operation while other times it does not.  If your device supports it and Orion is able to see and monitor the operation then I would use this as well to try pinpointing where your latency is happening.