[lug] Network Question

Nate Duehr nate at natetech.com
Tue Oct 7 17:09:05 MDT 2008

I agree with the others, 'cause I'm cheap... (ahem, cough... FRUGAL...)

Run some cable to a desktop or two to any open ports you have and see if 
the speed hardwired is "good enough" for your purposes.

I was trying to figure out if you were 802.11b, 802.11g, or 802.11n in 
your wireless stuff, but I don't see the device you use for wireless 
listed.  The different types would make a TON of difference, and if 
you're mixing 802.11g and 802.11b devices, your network slows (by 
design) considerably.

Remember, 802.11 is half-duplex.  It also only can implement CSMA/CA 
instead of CSMA/CD, so collisions are relatively "expensive" time-wise. 
  Lots of machines online and asking for bandwidth at the same time will 
mean slower and slower speeds.

Also, note that USR has a warning out about the 8200 doing Path based 
MTU discovery not working on many networks that block ICMP message types 
needed for it.


They default to 576, which isn't very optimal these days... they say to 
set it manually instead of relying on Auto if you're experiencing 
problems related to a small MTU size.  (Easy enough to try.)

Final thought... do you have traffic passing through the hub when going 
from machines to your NAS at the same time as other things on the hub 
are using bandwidth... like do you have a teen on the VoIP phone all the 
time?  It probably won't make a HUGE difference, but you might consider 
replacing that with an inexpensive switch... instead of a hub.

I'm all about "cheap"... think about it this way... most businesses 
handle hundreds of desktops with 10/100 switches that have gigabit 
uplinks to a master "closet" somewhere in the building.  10/100 
full-duplex is "plenty fast" for most activities.

Also... make sure you're looking for performance specs for that NAS on 
the Net, and see if anyone is complaining.  Many of them are 
under-powered as far as CPU goes (Apple's new one for Time Machine 
backups is particularly bad, I hear), and the bottleneck isn't the 
network at all... it's the device.  Sometimes the only way to prove this 
would be pushing some files using the same file xfer protocol to the 
same Ethernet port the NAS is on, but use a laptop or something... and 
see if the network can go faster than the NAS.

I can bet that Gig-E would definitely outpace the little cheap NAS 
box... thus, it's probably not worth paying for until you can prove the 
NAS can go that fast... maybe visit a friend who has "too much money" 
and Gig-E everywhere and see if you can push files from one of his 
machines into the NAS at Gig rates... if not... you'll know you saved 
some money not buying Gig gear.

Nate WY0X

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