wireless - terminology & advice?

I'm ashamed to admit I'm getting very confused :-( I'd be grateful
for advice on some probably naive questions.

Wired networks I'm happy with, and have a home LAN using a freebsd box
as router with 3 NICs for cable modem, and two LAN segments
192.168.0/24 and 192.168.1/24. All works very nicely.

However, the 192.168.1 segment is intended mainly for senior son's
bedroom, and eventually junior's too. I've been wondering whether to
poke holes in walls and ceilings, or go wireless.

But I'm finding the functionality and names confusing. I assume an
access point plugs into an existing network to give wireless access -
but to how many clients? And if a bridge converts a machine with
ethernet port to wireless, then how does a bridge differ from an
access point?

But getting to the crunch, if I want to add multiple wireless-ethernet
machines onto an existing wired segment, what's the minimum kit needed
to do this? AFAICT it's a router (but ignore the WAN connection and
router functionality -- should this be an access point???) connected
to the LAN segment, plus usb or pci card for each machine.

And looking futurewards, what if I wanted to add a new wired segment
with a wireless link to the existing wired segment - what bits of kit
should I be looking at?

As I said, confused! Thanks in advance for any advice.

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"Mike Scott" <(E-Mail Removed) k> wrote in
message news:(E-Mail Removed)...

Hi Mike,

> I'm ashamed to admit I'm getting very confused :-( I'd be grateful
> for advice on some probably naive questions.

I'm also on a learning curve here, but I sense I'm slightly ahead of you. I
could be wrong, as I've yet to implement a wireless network. I'm also quite
confused about bridging, as I'll explain. Perhaps we can help each other.

> But I'm finding the functionality and names confusing. I assume an
> access point plugs into an existing network to give wireless access -
> but to how many clients? And if a bridge converts a machine with
> ethernet port to wireless, then how does a bridge differ from an
> access point?

Most wireless networks work as a hierarchy, with Wireless Access Points
(meaning wireless server) and clients. This is "infrastructure" mode, as
opposed to "ad hoc" mode which is just clients in a P2P arrangement.

I think performance suffers when there are a lot of ad hoc clients,
presumably because every client must maintain a link with every other client
and the number of such links quickly rises. When there's an access point,
each client connects directly only to the single access point, thereby
adding one connection per client.

A wireless bridge connects wired ethernet to wireless. I think such a device
then typically acts as a wireless client, and consequently typically
connects to an WAP in infrastructure mode.

The wireless parts of wireless routers act solely as WAPs, but stand-alone
WAPS can often be configured to adopt a different role. Such roles include
acting as a bridging client, point to point bridges (which I think means
dedicating both ends to a single connection), and point to multipoint
bridges. I suspect that last one means that every link then acts as an P2P
ad hoc client with the other bridges and they cannot talk to a WAP.

Finally, I think that some client bridges can only connect only one device
on the wired side, but others can be connected to a switch and thereby
connect multiple devices.

God, it's complicated! And I haven't even mentioned repeaters, or the
security of WEP and WPA.

> But getting to the crunch, if I want to add multiple wireless-ethernet
> machines onto an existing wired segment, what's the minimum kit needed
> to do this? AFAICT it's a router (but ignore the WAN connection and
> router functionality -- should this be an access point???) connected
> to the LAN segment, plus usb or pci card for each machine.

You need to connect a WAP to your router or, equivalently, replace your
router with a wireless router. Everything else is a client (eg PCI card,
PCMCIA card, USB adaptor or multirole WAP configured as a client) configured
for infrastructure mode and connects directly only with the WAP, and
indirectly with everything else.

> And looking futurewards, what if I wanted to add a new wired segment
> with a wireless link to the existing wired segment - what bits of kit
> should I be looking at?

You'll then need a bridging client, ie either a dedicated device or a
configured multirole WAP.

But be warned, I've never used or configured a wireless device so I could be
talking nonsense.

--
Richard Boyce
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