Re: Digital switch over query

The message <1238264524_5197@xxxxx>
from J G Miller <miller@xxxxxxxx> contains these words:

On Sat, 28 Mar 2009 15:46:46 +0000, Johnny B Good wrote:
> Not according to the manual.

So much for the accuracy of customer reviews at Amazon then ;)
And this product, is as far as I am aware, no longer in production.

> Which you can do with pretty well all such modem/routers.

Well one would hope so ;)

> A router doesn't need to be upgraded to gigabit speeds, especially when
> it is only used to act as a gateway router to link your lan to the
> internet via a sub-100Mbps line.

Indeed -- you only need a gigabit router if you have gigabit NICs in your
PCs and need to shift gigabytes of data from one machine to another very
quickly. 100 Mbps appears to be adequate for most needs, even playing
video files from one machine on another machine.

I'm not sure, but it seems you're using router as a synonym for
ethernet switch(ing hub). The two are very distinct 'animals'. Whilst
they both provide interconnectivity for network connected devices, the
switch merely acts as a high performance intelligent hub for devices
operating in the same sub-net address range. The (gateway)router acts as
a bridge between two different subnets, in this case, the internet (WAN
- Wide Area Network) and your LAN (local area network).

> To upgrade the lan to GBit ethernet, you need only add a Gbit ethernet
> switch and, if necessary, upgrade the NICs in the PCs that are intended
> to enjoy the benefit of gigabit lan speed

But to take full advantage, I understood that all devices on the
LAN must support jumbo frames, and you also need at least CAT 5e cables.

Not strictly true unless you need _all_ devices to operate at the best
possible gigabit speed. I don't think there have been any gigabit
switches manufactured in the last 4 years or so that _don't_ support
jumbo frame working. You can quite happily mix 10, 100 and 1000 mbps
devices connected to a modern gigabit switch and get the maximum speed
possible out of whatever combination of link connections that arise in
such a mixed environment.

If a jumbo enabled gigabit device connects to a non jumbo capable
device, the (intelligent) gigabit switch will repackage the data packets
appropriately and the connection will proceed at the slower speed
imposed by the constraints of an MTU value of 1500 or less (well, that
seems to be the case using a Netgear 8 port Gigabit ethernet switch I
have in my LAN).

Regarding the ethernet cabling, provided it is to cat5 spec (all 8
wires properly connected pin for pin - not crossover) it should be fine.
Ethernet cables purchased over the last ten years or so should be to the
cat5 spec anyway. More recently purchased cables are more likely to be
cat6 spec so, apart from substandard or faulty cabling, there shouldn't
be any problem with the gigabit upgrade.

> In any case, no ADSL2+ wireless modem/router is likely to have a
> Gbit ethernet switch built in (not impossible, just unlikely at
> this time).

Hence one of my reasons for suggesting a separate single port ADSL2+ modem
line the Linksys AM200, which is then connected to the router of choice.

> There is no "One Best Solution" for any network setup. Each individual
> case needs to be considered on its own merits.

I have not intended to, nor sought to repudiate that truism.

> with networking kit, at least there _is_ some choice!

Yes, and for those who are not aware, there is an excellent comparison and
review site at

<http://www.smallnetbuilder.COM>

That's an interesting link. I've just spent the last hour or so
investigating some articles on creating high performance NAS boxes and
test results for FreeNAS (which I currently use) and the Ubuntu server
edition OS (of which I'm currently downloading both the 32 and 64 bit
ISO images to give it a whirl on a test machine since, on the same
hardware they reviewed, it seems to outperform FreeNAS by a 2:1 margin
on writes and an extra 15% on reads!).

Ubuntu is based on Debian Linux and the last time I tried this OS to
run a fileserver, its performance rather left me cold and other freely
available server OSes had issues of their own, hence my settling on
FreeNAS for the past couple of years.

FreeNAS is based on OpenBSD rather than a Linux distro, but these two
branches of the Unix family are quite closely related. However, despite
FreeNAS's excellent webGUI based management interface, I've had a
nagging feeling that file copying performance really aught to be better
than the 20MB/s writes and 26MB/s reads that I'm currently seeing when
copying gigabyte sized files.

Now that I've got MD5 checksum verified ISO images of the Ubuntu server
OS, I'll check out the FreeNAS project page for the latest update just
in case any such update happens to address the indifferent performance
before I experiment with the Ubuntu server on my test machine ( I do
rather like FreeNAS's webGUI interface, it's become rather like an old
friend ;-).

That link has provided me with some interesting stuff to do over the
next few days... I might be gone for some time. ;-)

--
Regards, John.

Please remove the "ohggcyht" before replying.
The address has been munged to reject Spam-bots.

.

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