TCP and WAN issue

Roland Dobbins rdobbins at cisco.com
Tue Mar 27 21:58:13 UTC 2007



On Mar 27, 2007, at 2:41 PM, Philip Lavine wrote:

> This is the exact issue. I can only get between 5-7 Mbps. So the  
> question is really what incremental performance gain do WAN  
> accelerators/optimizers offer?

I don't know if you'd get much of a performance benefit from this  
approach.  Bandwidth savings, possibly, depending upon your  
application.  We have a box called a WAAS which is a WAN optimizer,  
so do several other vendors (search online for 'wan optimizer' or  
'wan optimization', you should get a lot of hits), but I have no  
experience with these types of boxes.

> Can registry/OS tweaks really make a significant difference because  
> so far with all the "speed enhancements" I have deployed to the  
> registry based on the some of the aforementioned sites I have seen  
> no improvement.

I'm not a Windows person, so I don't know the answer to this; I know  
you can do a fair amount of optimization with other OSes, depending  
upon the OS and your NICs.  The MTU, MSS, window-size stuff mentioned  
previously all applies, as do jumbo frames, if your end-stations and  
network infrastructure support them.

What you want to see is large packets, as large as your end-to-end  
infrastructure can support.

> I  guess I am looking for a product that as a wrapper can multiplex  
> a single socket connection.

Your application should be able to do that, potentially, and as other  
folks mentioned, your app can potentially be tweaked to open up  
multiple connections.  I think there are also NICs which do something  
of this sort, but it's not something I've personally used (maybe  
others have experiences they can relate?).

My general advice would be to look at all the things mentioned  
previously you can potentially do with your existing OSes, network  
infrastructure, and apps, and do them prior to looking at specialized  
boxes.

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Roland Dobbins <rdobbins at cisco.com> // 408.527.6376 voice

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