[AccessD] OT: Network speeds

"Age may effect performance."  No kidding.  I think we're all coming up
against that.

Rocky

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Michael Bahr
Sent: Tuesday, March 20, 2012 11:49 AM
To: Access Developers discussion and problem solving
Subject: Re: [AccessD] OT: Network speeds

Age may effect performace.  Age in that when you purchased the H/W did it
actually support mixed-mode, i.e. 100/1000mbps at the same time or were
there model-options?  What you would need to do is make a list of ALL H/W
devices; routers/switches/NIC's with manufacturer and model number and
investigate each one.  It could be you have a mix that support mix-mode and
not, "dumbs" down to lowest speed.  It also could be inferior cables.

Trouble shooting would be the next step.  Disconnect everything and then
connect the two devices that are the furtherest apart and test.  If you get
faster speeds and are happy then use this as your baseline.  Then one by one
start adding more devices.

I vaguely remember reading an article several years ago that tested actual
transfer speeds bewteen 100mbps and 1gbps.  The difference was Gigibit was
only ~3-4 times faster than 100mbps--not the 10x faster one would think.

Something to think about, Mike...

> Good article.  but what a PITA that brings up.
>
> I have my WIFI router / cable modem plugging into the gigabit switch 
> *in the middle*.  Does that router tell that entire middle switch to 
> dumb down to 100 mbit? if so then there's my answer as to "why".  What 
> is left unanswered is how to get around this.  I have lots of internet 
> network traffic in the living area at the front of the house, and I 
> also have internet access in my office upstairs.
>   None of it is "optional", i.e. we need internet at both ends of the 
> house for email at the very least.  Web browsing as well.
>
> I just crawled under my table up in my office and what I discovered is 
> that the switch under there has one line, going to my Virtual Machine 
> Server which shows the gigabit light and the 100 megabit light lit.  I 
> unplugged and moved the cable and both lights followed the cable.  I 
> would guess that perhaps the 100 mbit is for a virtual machine.
>
> In my server I actually have two NICs and I can assign one of those 
> NICS to support a virtual LAN just for the VMs.  However even there 
> those machines have to talk to the internet.
>
> What I discovered is that I have a 100 mbit switch down stairs behind 
> the tv.  It talks almost only to the UnRaid server in the basement.  
> One would expect that each channel would adapt (flow control) but the 
> article mentioned the transmitting NIC seems to be the object 
> modified.  What the article didn't say was whether the NIC stayed at 
> the lower speed or whether it popped back up to the higher rate as 
> soon as possible.
>
> My motherboard in the VM server only has a single NIC so if it is 
> being throttled down and then just stays there until a reboot or 
> something...
>
> So much to know, so little time.  And in this case I do not even have 
> the knowledge to troubleshoot it effectively.
>
> John W. Colby
> Colby Consulting
>
> Reality is what refuses to go away
> when you do not believe in it
>
> On 3/19/2012 12:54 PM, Michael Bahr wrote:
>> John, for Gigbit to work properly I think **everything** must be 
>> Gigibit, i.e. all network cards, wifi, routers, switches, etc.  I 
>> think Gigibit uses jumbo-frames.  Otherwise you can have a mixed-mode 
>> condition.  You do not mention what kind of router/switch you have, 
>> consumer/business/enterprize.  Oh forget enterprize--too expensive. 
>> :-) Some routers/switches may support mixed-mode.  Read the link below.
>>
>> http://www.smallnetbuilder.com/content/view/30212/54/
>>
>> Mike...
>
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