sundance-communications.com/forum Forums General General Telephone & Systems Information analog/digital/IP - How to recognize

Okay, back in March of '05 there was a discussion on part of what I'm inquiring about and I went through all of it.

Here's the problem. I need to know how to differentiate between the three types of phones mentioned above.

I've learned that an analog phone and analog line would be indicated on the back of the phone by seeing the REN and that analog lines were two wire and digital were two-pair or four wire. Yet, IP phones are two-wire connected.

I believe I've also learned that all phones must be converted to analog whether their signals are transferred via digital or analog for the quality of what we hear. Am I okay so far?

And, I know I can take a two-wire connector and plug it into a four wire connector and the phone will work AND the features but I won't be able to program it which confuses the issue of plugging an analog phone into a digital network. I realize we are talking about the phone itself due to the draw of current, BUT I am trying to convey a more simplistic approach to understanding what is going on when someone is shown just a phone and how would they know if it was digital, analog or, IP and how to hook it up?

Also, someone mentioned that if there is a display then the phone is digital which if we understand that concept to mean there are four wires than how are two wires used on IP phones to get a digital signal?

So, if anyone can help clarify this, I would surely appreciate it.

Oh, I was also told that since we are installing these on a ship it is just better to refer to phones as analog or digital due to their being connected to analog or digital circuit packs and that's why they want to make sure they know the difference although few really know the difference when asked.

as simple as I can

two pairs does not mean digital it just indicates hybrid in other words the analog portion is on the center pair and the digital signal is on the outer pair. some systems can accept either the hybrid phone or analog but not many can do that.

ip phones require and ip address and only work on "data ports", yes they use two pair but then again so does a pc. they do however connect with an 8p8c or (ed is gonna jump me) rj45 mod plug were the regular phones use an rj11 or 6p4c connector.

as for telling the difference because some systems only use 1 pair and only handle digital phones.

they are just going to have to take your word as the gospel because seeing a ren is not the only indicator and neither is the display with the advent of caller id and so many "house phones" having big displays now.

I suggest taging you station jacks as analog and digital eg: 1-analog 1-digital or 1-anlg 1-dig

final note yes all signals to phones do get converted back to analog at some point but were is not going to be something your customer understands.

I bet if you ask nice Ed will get the soap box out :p

Allow me to add a couple of things:

First of all, it would be helpful to know what system/version you are using, since every manufacturer uses their own proprietary format or protocol.

Second, "digital" phones are your switches manufacturer's proprietary sets - they will have Lucent, Mitel, whatever on them along with a model number. Use that and check your documentation.

Also, not all proprietary phones use two pairs - Mitel phones for example, only use a single pair for TDM (Time Division Multiplexing) or COV (Control Over Voice) protocols.

You can tell IP phones because you paid way too much for them

Best way to check, aside from knowing your product, is to plug in a buttset or analog phone and see if you get dial tone. you won't get it on anything but analog.

Best thing to do is to learn to use a toner and trace the circuit from the jack all the way back to the switch and identify the card it's connected to - then you'll know.

Hope this helps.

jsaxe

I appreciate the help. I am working on delivering the curriculum associated with a Definity System on ships. And, there are several hundred different types of phones being used. That is why I am trying to come up with some generic way of explaining this difference when we are in a classroom setting vice being able to trace out the circuit.

Not at all without merit but again these kids are far away from their ships and I don't get to see or know exactly what each has nor the time to explain each one.

That is why I am trying to streamline the delivery of explaining the three so we are all on the same page instead of just bits and pieces which cause so much confusion.

I would like to say that if it could be put in a simple phrase or explanation it would sound something like this;

There are three types of phone sets for telephone systems.
1) Analog - these are your everyday telephones that can be used at your house or apartment. They come from many different manufactures, some have displays some don't.
2) Digital Proprietary sets - these can be used only on the systems the manufacturer allows. They are Analog or Digial circuitry sets.
3) IP - These are Digital and are Proprietary but, they utilize an existing Data Network to operate.

Now as far as the wiring aspect to telephones in land-based systems they use anywhere from 1 pair to 4 pair to operate. There is NO scheme of 1 pair is analog, two pair is digital,...etc.
Minimum numbers of pairs to a jack should be 2 pair on a USOC type jack unless the manufacturer states differently and also they way they are wired maybe different than another manufacturers. Common cable is 4 pair in a single jacket, either catagory 3 or 5,6 and is run in a homerun fashion.
These jackets may be PVC or Plenum, Teflon, or OSW sheathing.
Basic troubleshooting steps would be to use a Toner & Wand on the cabling for continuity.

WRichey, your'e busted!

Folks, I have to agree with everything said so far in this post. There just isn't a canned or simple answer. This technology is so commonplace to us who are involved in phones every day, that when someone asks a simple question like this one, we can't come up with an answer!

I will try to ponder this to see if there's some way to give you an answer that is "understandable by all" if possible. Snoopy, your post is actually a very good one. A very simple question with a very complicated answer.

I agree with wrichey.
Ed your soap box awaits you.

Here..............................I will even put a wheelchair ramp to it.

We only deal with Avaya equip. (Partner, Magix and IP Office).

Partner system feature phones use 2 pair. Pins 2 and 3 on a 4 conductor jack, pins 4 and 5 on a 8 conductor. (or the middle pair as we call it) would be analog and is what the dial tone runs on. The outer pair or pins 1 and 4 on a 4 conductor jack or 3 and 6 on a 8 conductor jack is digital and is what makes the features of the phone work like the display ect.
Now you can also hook a regular analog phone to a Partner system and it only uses the inside pair or analog if you will.

Now on a Magix if you are using 44XX series phones you will only use the inside pair and it will be digital. But on a Magix you can also put analog phones if you have an analog card in the system and those phones also would just use the inside pair, but it would be analog.

On the IP Office you can use analog,digital or IP phones. Digital and analog would work same as on a Magix, but the IP phones need a connection just as if there was a PC hooked to the other end. Wired on 568a or 568b config or the standard of your preference.

Hope this helps in some way

Maybe I am being very simple minded, but seems like if he used only IP phones (vendor optional) that he would make his wiring simple. Guests could use any connection in their rooms for either a phone or computer. No guessing. The IP phones just need to be registered to the phone system and could be carried anywhere on the ship with the guest???

If they have the time it might be worth making an Excel spreadsheet of all the rooms. If you are using multiple cable locations indicat that on the sheet and tag the outlets. Best thing to do is to learn to use a toner and trace the circuit from the jack all the way back to the switch and identify the card it's connected to and add that to the spread sheet also. Some people use the standard of a 4 plug outlet set up with the top left a digital phone, top right an analog and the bottom 2 are data connections. You really need to establish a standard wiring scheme. The test set, toner and wand are a must for any phone or data work. It will save you many countless hours of work.

Thank you all for the help although it might be wise at this point to say that I'm not asking this for a small business or home but for the military and their ships. In fact, when I pointed out the phones in some homes were digital they said they couldn't be because home phones are analog and when I explained that the signal coming in was analog though there could easily be an A/D converter in it for subsequent digital use they gave me that "deer in the headlight" look.

For instance, there are over 5000 people on an aircraft carrier and as many as 3500 different types of voice terminals and for those of you working for AVAYA we are using some of your equipment as well and they are calling the 8400 series the digitals and most others analog so, marking them all, albeit handy, isn't feasible at this point after having countless numbers of people installing/working on them.

I get arguments about features on analog and digital phones and if the buttons are programmable they have to be digital and so on and I'm beginning to think I'm discussing Greek ethics.

I hope that soap box holds up because you may be up there a while as it seems there are countless individuals trying to figure this out and all have several theories but no good approach to understanding what is going on.

To those helping me - have a Happier New Year than those before!