Determining Latency

chrismeng · ‎08-21-2006

VPN Scenario:

Site A -> VPN Cloud <- Site B

Network Scenario bypassing VPN:

Site A -> ISP Router A -> Internet Cloud <- ISP Router B <- Site B

I work for a service provider and new to VPN's. We have a customer who has a site to site VPN about 1000KM apart (VPN Scenario above). Site A runs applications which accesses data from the Server at Site B. The applications on Site A continually time out several times in a day and causing the customer some frustration. Both sites have a 2M link to the Internet. The customer believe it's because there are latency issues between Site A and Site B ranging from 40ms to 150ms which is causing their apps to time out - is this possible?

How do I determine where the problem really lies? Is latency really killing the customer's apps? What latency is acceptable for VPN applications?

To measure the actual latency within the Service Provider's network from Site A to Site B (Network Scenario above) , would a good way be to ping from ISP Router A to ISP Router B?

Any help would be appreciated.

Thanks.

spremkumar · ‎08-21-2006

Hi

The latency especially in the Internet cloud wont be the same at all the times.

It is determined by various factors like the traffic pattern in the cloud,the load being handled by the SP at both the ends also the load in the respective customer links.

And you don't provide any kinda SLA in the internet cloud for any latency since it depends on lots of factors which may not be in the control of service providers in respective locations.

what i would like to insist here is to have a premium kinda bandwidth availed from the SP on both the sides so that they can atleast give some least difference in the latency range rather compared to the current one which you are getting at present.

AFAIK SPs usually have different offings which actually decides the price factor.The whole thing revolves around pay more for better service.

or as an alternative plan you can think off switching over to a SP who can provide VPN in these locations.

If you can mention the locations it would be easy to check out for possible VPN providers in these location in that case you dont need to worry about the latency factor at all.

regds