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802.11 RF Amp
MikeLRoy writes "Linksys has announced a signal amp, to be available soon, for their wireless ap's/routers. While many people have been using commercial rf amps hacked onto their ap's, linksys now has a commercial solution!" I wonder when ISPs are going to stop soft-pedaling the anti-NATing provisions in their terms of service.
And I'm not even a SpeakEasy customer. I wish RoadRunner would implement similarly "with-it" policies...
"BSD: Free as in speech. Linux: Free as in beer. Windows 10: Free as in herpes." --Man On Pink Corner in #52607549.
Actually, this device increases the RX sensitivity and power as well as that of the TX, thus giving a greater range regardless of what you have in your laptop.
Erm, no... it's a signal amp... so if you stick it halfway between a laptop and a wireless AP, it will amplify the signal from both. It's just like using a repeater in a cabled network.
"If at first you don't succeed, lower your standards."
Because this device emmits at the FCC max, something most APs do not. Yeah, this thing would rock inside a Pringles can, but it's likely even the worst designed can will put the setup over the limit.
Get yours here!
Karma: Censored (mostly affected by decency laws)
I dumped my Comcast cable modem for SpeakEasy DSL just about a year ago, and I've never been happier with an ISP.
I've never had an outage, I can (and do) run servers in my house to handle my own mail, www, etc. Their phone reps are courteous and don't suffer total brain shutdown when I mention the magic sentence, "I'm using a Mac."-- not that I've needed support beyond a little help sorting out a password issue when I wanted to configure the INCLUDED dial-up access in case I needed it.
When I needed an additional IP address last year, I called them up and had one in a couple minutes. I just upgraded my service from 608K down/128K up to 1.5M down/384K up, and it was not a hassle at all. Since my employer chips in $50/month of my ISP charges, this higher speed service now costs me $40 per month, the same I was paying a year ago for my cable modem with all of its restrictions.
To all Slashgeeks who are able: If you have a choice, go with SpeakEasy-- you won't regret it!
~Philly
LOL ok yea it's posible allthough doubtfull any DSLM worth it's salt dosent forward DHCP responce packets in from the CPE and dosent forward DHCP requests out to the CPE end either. If a small ISP has missed bridge configuration 101 (Yes most DSLAM's especialy cheap ones are simply bridges) but in my state at least the DSLAM is actualy the Telco's the small ISP gets a single ATM connection into there cloud and PVC's are setup for each port to there router generaly running PPPoE to that router. The first thing you do after you get it working is get it secure (yea I know it's nice ot say secure first but for a small company working is normaly more of a priority than secure) BTW if you were to actualy worry about this they shouldent allow windows boxes turn on ICS the wrong way and you have a DHCP server on your cable modem / DSL. Oh Cable modems may have more of an issue with this they would have to filter at the cable modem or the head end (I dont think any of the cable modems can receive on there transmit frequencies at the same time so any modem to modem connection need to pass through the head end? Would like to be corrected if I'm wrong on this I dont nroamly deal with this low end gear :)
No sir I dont like it.
That's not entirely true. If the signal going FROM the hub to the laptop are strengthened, the data transmission would definately be improved, but in most cases, one can also improve the "reception" capability of the hub by boosting the recieving antenna gain. But by the same token, these systems run full duplex (transmit and recieve at the same time), so if the transmitter is boosted, it COULD concievably de-sensitize the reciever.
Not sure of the exact machanisms IF the hub actually transmits and recieves at exactly the same time, but now that I think about it, perhaps not (being digital - it COULD be simplex).
If you've even been near a powerful FM or even a TV transmitter, and try to use an FM radio, you would be hard pressed to pick up anything else BUT the FM transmitter.
RF can get into ANYTHING... as a 1st class FCC license holder, and former Chief Engineer of a 25KW FN station, I know only too well what RF can do. Ask your food, when you take it out of the Microwave oven.
1 watt actual power
4 watt ERP (with the antenna)
This is somewhat easy to find people that are extremely likely to be NAT'ing actually, usually with no extra hardware than what the ISP already has.
You can look at the source port of the packet (going from the customer to wherever, i.e. ingress to the ISP's network), to be fairly confident that the customer is NAT'ing their traffic.
Most NAT implimentations change the source port to a very high port number (usually in the 60,000+ range) when they translate (along with changing other info). You can probably be fairly safe to log anything above 40k (although some research into what more popular 'ethernet routers' that do NAT use for port ranges would be prudent). Normal traffic for most implimentations of a TCP/IP stack won't typically source off of ports that are reserved for NAT'ing, so again, you can be fairly sure they are NAT'ing if you 'catch' them (enough to call them to ask them about it anyway.. that way if they aren't, you don't shut down a paying customer for no reason).
On a cisco, you can setup an extended access list applied to the interface the traffic is hitting, with logging enabled to see who is NAT'ing, see if it continues for a while, and if it does, you can be fairly assured they are NAT'ing traffic.
Mind you, there are many ways around this for some implimentations of NAT (i.e. changing the port range NAT'd packets source off of), but for average Joe User hooking up an 'ethernet router' that does NAT, they could be caught fairly easily by this (and other methods that work in conjunction with this).
(this is just a brief summary, don't blame me if it isn't detailed enough).
A while ago on slashdot there was breathless coverage of a Linksys hardware 'hack' that raised their 30mw AP to 100mw. Some knowledgeable RF engineer took a look and it *was* putting out 100mw - 31mw in channel, and 69 mw of crap spattered all over 2350 - 2550 MHz. All that 'hack' accomplished was giving more ammunition for those satellite radio folks that want to regulate the ISM band.
Instead of building a 100mw radio with good sensitivity, Linksys is building a cheesy amp to go with their cheesy AP.
If you genuinely need some amplification I've used YDI.com and Teletronics.com amps in the 250mw to 1 watt range and not had much trouble with any of them. RFLinx or RFLynx(sp?) has come out with a 750mw amp for $200, but I haven't tried that product yet.
FYI half of the reason to deploy an amp is for the LNA (low noise amplifier) effect - besides boosting output they pump up the return signal by 10 - 14 dB. There is a real call for a 150mw output amp with a solid LNA for client side problems, but that is a story for another day.
I am very easy to get along with, but I don't have time to waste being nice to people who are being stupid. -Theo
Actually, like puzzled (12525) posted: "FYI half of the reason to deploy an amp is for the LNA (low noise amplifier) effect - besides boosting output they pump up the return signal by 10 - 14 dB."
Give him the karma. And mods, why the hell are you modding up this post's parents, and it's parent's parent?
The amp doesn't go halfway between anything, and you don't need a similar device on the other end.
-Berj
What I wish linksys would allow in the firmware was a mac address allow list. Right now you can only set mac addresses to block from the WAP. Kinda stupid if u ask me, why not list the mac addresses you want to allow. I know that they can be spoofed, but it makes it just THAT much harder
RF signal of this type can carry 30 miles very easily, until it hits something that has a strong adsorbtion rate at 2.4Ghz something very uncommon and non-abundant like..... water...
you haven messed very much with wifi or anything in the microwave range have you.
I have a 1 watt transmit amp on each end of a 23 DBi gain dish link... IT WILL NOT FIRE THROUGH A TREE because of the adsorption rate of water. I wished I could burn through a tree but I cant not even with the huge power (as far as wifi is concerned) I am using... (shhhh dont tell the FCC I'm violated every fricking law with this expieriement)
it will NOT travel 30 miles, it will NOT kill everything or cause huge problems for anything but low end gear that barely works anyways... (your car keyfob/car alarm opener for example.. it dont matter who makes it they are low grade junk in regards to the RF functions of it.)
I can show you at least 5 houses that have a field strength at least 10 times that of anything you could buy in 802.11b equipment... and it's because of MICROWAVE OVENS that are old and leaky..
please dont fearmonger... these tiny toys that linksys are selling wont hurt anything... and 95% of those out ther eamplifying any of their 802.11 gear are not capable of doing it anywhere remotely correct to get anything but a marginal gain.. Hell some of these people are using the worse feedline and antenna designs that are attenuating more than they gain...
stop worrying... the no-code ham licenses has more of a chance at ruining the airwaves than amplifying 802.11 traffic.
Do not look at laser with remaining good eye.
It is just a repeater. It doesn't broadcast at any greater strength than your typical 802.11b access point, all it does is repeat whatever it picks up, thus increasing the range.
The logic goes that you have to certify with a known antenna, so if you use standard connectors anybody could hook up a different antenna and make the device noncompliant...
and yes, it sounds screwy to me too, but those are the rules
I think you are confused as to what an amp is and what it does and doesn't do.
An amplifier takes raw signal (including noise) and amplifies the power on it in the direction it is set to amplify. There are bidirectional amplifiers to do it in both directions.
Amps are best placed as close to the antenna as possible to reduce loss and noise. As a signal travels across cable, noise and loss increase. Thus, a short "jumper" cable is ideal to connect the antenna to the amp.
Putting an amp on one side of the communication pathway will improve the signal and perhaps the distance a bit. The biggest improvement will be in the quality of the wireless link at the far reaches of the original signal.
To greatly improve distance, it is absolutely necessary to amplify on both ends. The end goal is to improve your signal to noise ratio. The weaker your signal from the other end, the worse that ratio becomes.