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Odd Question - RJ45 2

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percent

IS-IT--Management
Apr 27, 2004
176
US
I have two linksys wireless routers bridged the routers have a four port switch built-in would it be possible to cable two cords that go from RJ-45 to RJ-11(I guess I would just cable it like a 10base straight thru cable) plug the phoneline in one side and a phone in the other - is there any way to make this work - when I mentioned the routers if I was able to do this then I wouldn't have any computers plugged into the router

 
If I understand your question correctly you'd like to extend your phoneline using the wireless routers.

If that is what you are asking the answer is no. The Wireless access point (WAP) only knows about Ethernet (Layer 1) and IP (Layer 2). Some know about some other Layer 2 protocols such as Appletalk, but not all. These are all datacom specs.

If you had a VOIP gateway connected to the phone line, and were using VOIP phones, this might work, but even in that case performance would be marginal in that there is no QOS on wireless.

There are "wireless" phone line extenders that actually extend the phone line over the AC power lines. These are not great for modems but probably ok for voice (never used one myself). These are widely avaialble through consumer electronics store - you could probably search around online for a "telephone line extender".

Best of luck.
 
Hey guys,
Powerline phone extenders are usually claimed at 56k modem operation, and we've tested them to 44,000bps, so they're not bad. Percent, stick to those kinds of options, a VoIP gateway would set you back quite a bit, definitly more then getting a new telephone jack installed in your desired location.

Trevor Farren
Metrotech Telecom Inc.
 
I was just curious
Since they have ethernet over phonelines I thought why couldn't you have phoneline over ethernet exspecailly since ethernet is 4 pair



%, 2004

 
Ethernet is a pretty innocuous, low-voltage medium, and while POTS lines are considered low voltage, they actually have a lot of current and voltage when ringing, etc, and they're analog. So it's best not to plug phone stuff into Ethernet stuff, eventhough the pinouts will not line up...

The Phone/Ethernet/Phone question:

It seems to be easier to turn data ino analog into data, than it is to turn anlog into digital into analog, but I guess it depends on who you ask.

I'm hoping that wasn't all very cryptic. Sorry.

:)

Trevor Farren
Metrotech Telecom Inc.
 
thats just cabling. You can run phones over ethernet cabling. You just cant put a switch in the mix. It's two different formats- one digital, one analog.
 
sorry...repying to percent's last post...
quote: "ethernet over phonelines I thought why couldn't you have phoneline over ethernet"

 
MetroMan thanks that answered my question - I just thought it would be a nice feature being able to transfer phone data over 802.11x - Guess I will just let that bit of curiousity stay in the back of my head
 
I did a search and found out why digital to analog works better than analog to digital
it is almost impossible to compensate for the number of possible values that analog can have where as digital has a set number of values

(digital to analog)so transfering a set number of values over a line without a limit is easy

(analog to digital)and transfering an almost unlimited set of values over a line with a limit means that you will loose some data

I thought I would post my finding just incase anyone in the future has a similar question
[src]
[/src]

%, 2004

 
Percent, why don't you just use a cordless telephone set ? They are pretty inexpensive these days !
 
I have a cordless phone - I was just wondering if it was possible - you can send a 802.11x signal pretty far with a directional antenna - but with a cordless you have a small radius - and you couldn't use a powerline phone extender if the locations weren't on the same electric circuit
 
Hey percent, analog versus digital is very tricky. A standard phone conversation digitzes very well with Pulse Code Modulation or PCM, but it's due to the narrow bandwith of voice used on the phone. You would be amazed at the bandwith that the telcos have to prvide between radio stations and their stereo FM towers. I wasn't trying to dumb it down earlier, I just type on the computer so slowly, that it's best for me to simplify!!! ;-)

-t-

Trevor Farren
Metrotech Telecom Inc.
 
The real issue is that the wireless access point is a data device. The fact it happens to use RJ45 connectors and Ethernet is immaterial. It could just as well use USB, firewire, or even RS-232.

In fact, it is very unlikely it passes raw Ethernet data, more likely it pass IP data only.

If you send it anything other than IP data fed over Ethernet ain't nothin gone to happen.

BTW one rather odd thing about POTS (plain old telephone service) is that in addition to being able to handle 300 to 3 kHz audio, and 90 VAC 20 Hz ringing, it must be able to pass DC.

An analogy - if you took the analog output of your VCR and fed it into the digital inputs of your computer monitor nothing will happen, even though they happen to both use coax cables with RCA plugs on them.

I hope this helps!

 
my wireless access points run linux - it is possible to modify the way the ethernet devices are controlled but I do not have any experience in programming for hardware -
do you think maybe you can point me in the direction of a program that can do this - if there is one - I have searched sourceforge no luck

(I'm not crazy when I say my access point run linux - linksys released the source code for their newer routers - and its linux - I run a modified version of the firmware from sveasoft - I can ssh in to the router - run commands - load programs into the ram and run them)
just wanted to make sure yall didn't think I was crazy
)

%, 2004

 
Are you now asking if a program will allow the routers to pass dial tone? I doubt it. As ISDNman kind of said: you are dealing with apples and oranges.

Your other quote: "ethernet over phonelines I thought why couldn't you have phoneline over ethernet"... just to be clear: when people do Ethernet over phone lines there is no converting from digital signal to analog. They are merely using the additional pairs that exist in phone cabling to carry the digital data. Ethernet actually only runs on two pairs, and phone cables typically have 3-4, with only 1 pair being used for analog dial tone. It is bad practice to do so, but that is what most people are talking about when they say they ran their Ethernet over their phone lines.
 
I think we should just end this topic because I will never get the answer I want - even though I beleive it is possible(it would just take alot of work)

[I will just try to figure out a way to do this myself - maybe there is another wireless standard I'm not aware of, maybe I'll look into modifing my 2 mile handradios althought there is nothing secure about them]

[This Post is Offically Ended]
 
Right statsmanRCDD, it IS possible by using an appropriate device to turn your analog POTS signal into digital and vice versa. But is not anything remotely close to splitting out pairs of a 4 pair cable to share different services.

VOIP would definitely work (though not particularly well unless you added some custom QOS system to the router). Some other protocol (including raw Ethernet packets) would require that the router pass the appropriate protocol (*this* could be handled by custom software, if needed.

Actually you can do VOIP using a couple of outdated computers running "Asterix" which is an open source PBX that suports VOIP. But in that case you'll need proper cards for the two Asterix machines to handle the A/D conversion and again it won't be particularly cheap. You'd need one FXS carc and one FXO card for each line to be extended.

I honor Percent's request and stop replying now....
 
Trevor,
Could you give me some products I can look at for the phone extender? either radio or electrical line.
On a google search I found dtk.de, but it seems to be an OEM product.
I have my TV in a corner I can't run a phone line to without major surgery to the walls, and I want pay per view which requires a phone (modem) link from the cable box.
Thanks
 
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