Data rate mismatch packet loss

Question

My Company uses a wide Ethernet service to our data center and have determined there is packet loss occuring from our office to servers located in the data center.

We've been able to determine that there is no packet loss inside either side of the network and the line provider suggested we use packet shaping to limit the border routers to 30MBPS (same as the line). The Duplexing is set to 100M Full on all of the interfaces between one of our computers and a remote server, with no improvement in packet loss.

Unfortunately only one side of the network has switches with this capability. Are there any alternative methods or ideas for how to address a data rate mismatch? Or are we stuck purchasing an additional switch?

score 1 · Answer 1 · answered Aug 21 '09 at 07:24

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What about packet loss from the servers to your office ? What are the traffic statistics of your line at the office and at the servers ? Is your line getting full (at any point) or not ? Do you experience packet loss after a certain level or continuously ?

We need more details on the problem before we can advise on solving it. Shaping implies that there is a machine at the end of each line manipulating the packet queue, do you have such a machine already ?

answered Aug 21 '09 at 07:24

kargig

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The packet lose is consistent during any transfer of a file (or other file action such as saving, renaming, browsing explorer, etc.). There is a media converter provided by the DC at each end of the line, as well as our own switches plugged into the media converter. According to our traffic stats, we don't really even approach our lines limits. – Ross Aug 21 '09 at 08:00

score 0 · Answer 2 · answered Aug 21 '09 at 06:35

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Without knowing what hardware you've got, it's a bit hard to tell you whether or not what you've got will do the shaping you need. I know that a Linux box stuck in the way will get the job done, though.

answered Aug 21 '09 at 06:35

womble

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Sorry forgot to mentions we have Dell Powerconnect switches. 62xx series in our office and 3448 series in our Data center – Ross Aug 21 '09 at 07:48

score 0 · Answer 3 · edited Dec 01 '09 at 14:36

From my point of view, you are not starting in the good way.
Before shaping you should ask you why you're getting packet loss and why you would like to not have loss.

With TCP you could have some loss if the link is used near 100% but you don't have to care too much with TCP because lost packets will be retransmited.
With ICMP/UDP you could also have some loss if the link is used near 100% but packets will be totaly lost. But shaping will not help, your shaping will drop packets. So you "move" your loss on the shaper.

In your case shaping can only help to ensure a minimal loss of UDP/ICMP packet by dropping TCP instead of UDP/ICMP.

This is probably not a good solution, it might only be if your 30 Mbps are not used too much most of the time but get very used by huge transfers from time to time and if you care about not losing UDP/ICMP packet, if you don't care of them just do nothing. If your link usage is high most of the time you should take more Mbps.

Data rate mismatch packet loss

3 Answers3