5Mbps out of 45Mpbs

Unanswered Question
Apr 1st, 2009

Hey Guys, I have a ds3 link that seems to not be giving me the bandwidth I want. The two routers are connected via serial and appear to be configured correctly.

There are no policy maps or anything like that which would stop traffic or shape it in anyway.

Any ideas on some quick ways to tell if it's a config issue or perhaps the ISP?



I have this problem too.
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Rick Morris Wed, 04/01/2009 - 12:59

what are you using to verify bandwidth?

Have you run a speed test with a free test on the internet?

I would start there.

I would also do a sho interface and see what your interfaces show for errors, if any.

Brent Rockburn Wed, 04/01/2009 - 13:03

We have solar winds monitoring the bandwidth and it's a site to site DS3 so i can't go to the internet to do speed tests, Also I don't see any errors on the controllers nor the interfaces themselves.

I'm kind of at a lost. Do you know of any traffic generating software that I could use to see what the saturation point is on the ds3?

Rick Morris Wed, 04/01/2009 - 13:10

One of the things I have done in the past is an SQL querie. Those typically fill up the entire pipe if it is available, or maybe an FTP of a file that is very large.

pciaccio Wed, 04/01/2009 - 13:26

Try using IPerf. It is free on sourceforge.net.

Your issue may be that your servers or workstations are not TCP tuned for optimal transmission over a WAN network. How far away geographically are your sites? the further away the distance the larger the TCP window size you need. You can use the (Bandwidth)(Delay) product to calculate your TCP window size. Use IPerf to test out the link to see if it is not your ISP or carrier provider...Good Luck...


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