Bandwidth seeting in 3845

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Sep 5th, 2007
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In my office the 30Mb internet line is directly connected to 3845 cisco router's Gigabyte interface.But internet is getting very slow.Any settings needed for receiving 30Mb bandwidth in router?Pls help me...

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lgijssel Wed, 09/05/2007 - 01:12
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When the ISP has fixed the interface to full duplex, autonegotiation will put you in half-duplex mode.

Check for excessive collisions on the interface to see if this might be the case here. Anyway, you should verify your duplex setting with the provider.



spremkumar Wed, 09/05/2007 - 01:15
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Hi Sanu

You really dont need to do any config to recieve 30Mbps on your router but make sure that you are not peaking upto the whole 30Mb subscribed which may result in slowness in acesss.

You can verify the same using show interface gig x/x.


sanuchakkalayil Wed, 09/05/2007 - 20:31
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hai prem..

We r using mrtg for bandwidth monitoring..But the maximum usage shown in graph is 22 Mb.even thogh people are feeling slowness in internet.How can I know 30Mb is getting or not?

Joseph W. Doherty Thu, 09/06/2007 - 18:32
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22 Mbps peaks over logical 30 Mbps link riding across a gig physical link?

I suspect you have insufficient bandwidth for load that's being offered. I also suspect there is no fancy queuing or congestion management.

There are way to prove or disprove my suspicions, but the simply method is to increase your bandwidth, say 2x, especially if your ISP would allow a "trial" increase for a couple of days. (I'm assuming the 30 Mbps is just a logical restriction.)

If your ISP supports tier pricing, you could also try leaving you first tier at 30 Mbps but with a second tier up to 60 Mbps. If this is possible, don't be surprised to see you still only graph 22 Mbps, but performance dramatically improves.


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