A few things...

JSamuel · 17th March 2006

1. Anyone know the 'free' range broadcasting frequencies you're allowed to use without paying in south london? Something about 835.0 Mhz to 86*.0 Mhz? Can't find it on google - admittedly, didn't look hard - this is about audio devices.

2. I was using a new laptop which had Messenger Service enabled, and got a random from an unknown source in a building I was working in awhile ago saying that someone was capturing my wireless packets? Can the WPA-PSK encryption be cracked once you have sniffed a few million packets? Or should I notify the company I was using the laptop for and say to be careful?

XILO-Matt · 17th March 2006

Quote:

Originally Posted by KeepItReal

1. Anyone know the 'free' range broadcasting frequencies you're allowed to use without paying in south london? Something about 835.0 Mhz to 86*.0 Mhz? Can't find it on google - admittedly, didn't look hard - this is about audio devices.

2. I was using a new laptop which had Messenger Service enabled, and got a random from an unknown source in a building I was working in awhile ago saying that someone was capturing my wireless packets? Can the WPA-PSK encryption be cracked once you have sniffed a few million packets? Or should I notify the company I was using the laptop for and say to be careful?

1) No idea

2) I'm using WPA2-PSK with a set key rotation. I would assume that this rotation stops the "cracking" of a set passphrase.

Hiding your SSID is also recommended.

Andrew · 17th March 2006

In short, yes WPA-SK can be cracked. Its more tough than WEP though (you can crack WEP under a minute if you know what your doing). There are *tons* of other factors though (unfortunately as part of my uni degree, we had to make wireless nic's from scratch - was a major PITA).

We personally use the following:
1) MAC address whitelisting
2) SSL Certificate authentication (each machine gets its own .crt installed that the network looks for before allowing access).

We also limit the IP range from the DHCP server to the number of machines we have authenticated, though its not *that* much of a diference, I recommend it

JSamuel · 17th March 2006

Cheers folks.
They have alot of walk-in-walk-out users, so I doubt they'd like the MAC filtering idea if they don't have someone 'technical' there to quickly add someone. Same with the DHCP, they have a few 'always there' and about 10 IPs free, so it's pretty much free-hunting.

Andrew,
How did you get that SSL cert thing up? That's obviously not just within the router then is it?

It should be ok with WPA-PSK and key rotation

- As you can tell, not a wireless person, only set up a few basic wireless networks, based on one or two wireless routers with WEP or basic WPA-PSK...

AdamC · 17th March 2006

Quote:

How did you get that SSL cert thing up? That's obviously not just within the router then is it?

You'll need more than your standard home-grade access point if you planning on doing anything which is incredibly secure.

anderson · 17th March 2006

My guess if I am not mistaken is Andrew may have a hardware firewall between the wireless router and the core network.

But I may be wrong

JSamuel · 17th March 2006

Quote:

Originally Posted by aTech

You'll need more than your standard home-grade access point if you planning on doing anything which is incredibly secure.

Nah, Not rock solid.
Just not being a wireless guru (or guru in general

) just was a tad worried about the fact I got a really random Messenger notice.

The company has the connection downstairs, and it's sorta like a converted house (best to describe it) and it then serves the whole building, which is ground (about 10 PCs and a few laptops) then 1st floor, about the same, then top, about 5 PCs.

Not sure,
I'll just say they should keep to WPA-PSK and rotate keys,
and perhaps try and do MAC filtering. Unless someone s****s the MAC (no idea how easy that would be wirelessly?) when that machine logs off...

JSamuel · 17th March 2006

Probably not the place for it...
But:

Got the wireless mic system up and running, put it on 850mhz (see what happens, no clashes or complaints so far - google's meant to be my friend, but it's not telling me what I wanna know!) but when the transmitter is turned off, base station puts out some bloody awful noise, at about +5db over the level of signal when the transmitter was on... It's rather odd... I googled this, someone said something about 'squelch' ? Which I also googled, but this thing doesn't have any settings for it - any tips anyone? Apart from 'well, keep it on'

Rebuke · 18th March 2006

I do theatre technical stuff in my spare time, so have some knowledge of radio mics etc - what model do you have and I can probably tell you where the squelch setting is?

As for frequencies, it's not hard to find, just google for 'radio mic frequencies uk' and the first result gives you want you want - 850 is not a legal frequency to use, the ones you can use are 863-865mhz.

JSamuel · 18th March 2006

Alex,
Called the UK devision of the company, Sennheizer (sp?) and they told me that the manual I got was outdated, but the model is fine, and told me how to raise the squelch db to 5 (out of possible 40) which gets rid of it. Works fine now.

863-856.
Doesn't leave me that many options... since we've got places nearby who are within range, and we've heard them over ours, and they've heard us over theirs. Perhaps going to have to ask them to give up a frequency for our additional mic :|