As far as real advantages, all I can think of is that most so called "digital" systems use one pair for each station as opposed to the much inferior "non-digital" which uses two. A single pair can be used because the audio signal is not analog however the disadvantage is that you cannot use standard T/R devices but there are ways around this with some systems.

So this is really just a design issue with no real advantage from one to the other.

-Hal

This has to be more than you wanted to know.

Phone lines
Analog lines, also referred to as POTS (Plain Old Telephone Service), support standard phones, fax machines, and modems. These are the lines typically found in your home or small office. Digital lines are found in large, corporate phone systems.
How do you tell if the phone line is analog or digital? Look at the back of the telephone connected to it. If you see "complies with part 68, FCC Rules" and a Ringer Equivalence Number (REN), then the phone and the line are analog. Also, look at the phone's dialpad. Are there multiple function keys? Do you need to dial "9" for an outside line? These are indicators that the phone and the line are digital.
A word of caution. Though digital lines carry lower voltages than analog lines, they still pose a threat to your analog equipment. If you're thinking of connecting your phone, modem, or fax machine to your office's digital phone system, DON'T! At the very least, your equipment may not function properly. In the worst case, you could zap your communications tools into oblivion.
How? Let's say you connect your home analog phone to your office's digital line. When you lift the receiver, the phone tries to draw an electrical current to operate. Typically this is regulated by the phone company's central office. Since the typical proprietary digital phone system has no facilities to regulate the current being drawn through it, your analog phone can draw too much current—so much that it either fries itself or in rare cases, damages the phone system's line card.
Perhaps the most effective use of the digital versus analog technology is in the booming cellular market. With new phone activations increasing exponentially, the limits of analog are quickly being realized. Digital cellular lets significantly more people use their phones within a single coverage area. More data can be sent and received simultaneously by each phone user. Plus, transmissions are more resistant to static and signal fading. And with the all-in-one phones out now—phone, pager, voice mail, internet access—digital phones offer more features than their analog predecessors.
Analog's sound quality is still superior—as some users with dual-transmission phones will manually switch to analog for better sound when they're not concerned with a crowded coverage area—but digital is quickly becoming the norm in the cellular market.
You may have an analog phone at home and call your next door neighbor with the same type of phone but you are still connecting thru a digital switch. You can buy LP's but the amplifier is digital.

That's exactly what I get sometimes from a prospective customer. We mainly sell Avaya and they will compare it to Panasonic. They'll say Panasonic is digital, it says so right on it. It HAS to be better. How come Avaya isn't digital? I then tell them what I said above and they look at me like I'm crazy.

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Originally posted by gkar:
Also, look at the phone's dialpad. Are there multiple function keys? Do you need to dial "9" for an outside line? These are indicators that the phone and the line are digital.

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Nortel makes proprietary phones with multiple lines that work with the DMS100 switch that are analog phones. These P-phones use 8khz ASK for signaling.

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Originally posted by gkar:
I think the industry stopped producing analog switches in 1975.

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But forget all that, other than what I mentioned above in my first post what difference does it make???

I just emailed you....check your email

I will say it again, Run away really fast from those people.

No it is still a digital switch but those ports are analog. And the digital phones you hook up to the digital ports are digital... Partner does not have digital ports for the sets nor does it have digital sets....So the partner system is not..... again is not a digital system.......
The talk path on a partner system is the wb/bw pair the data and power for the set is the wo/ow pair... If you have a talk path on a seperate pair of wires it is not a digital system... with a digital system you have a data stream on one pair.... There are digital systems that use a second pair to power the phones... but do not use it as a talk path. Above posts have already answered the question "which is better"

Walter
Valentine Systems
25 years in business and going strong...

Hybrid/EKT systems do use digital signalling for setup, features, lights, and buttons, but the voice stays analog on a separate pair from your mouth through the switch to another phone or CO line. They use (typically) the blue pair for voice and the orange pair for signalling. This can roughly be compared to a 1A2 system, where the line buttons and lights are controlled by different wires than the voice.

Digital/DKT systems convert your voice from analog to digital inside the phone and transmit it as digital from the phone through the switch to another digital phone, or convert back to analog in the CO card. Analog phones (2500 sets) on these systems connect to an analog card that does the analog to digital conversion on the card before going into the switch. They only use one pair from a digital phone to the switch.

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Originally posted by hbiss:
As far as real advantages, all I can think of is that most so called "digital" systems use one pair for each station as opposed to the much inferior "non-digital" which uses two. A single pair can be used because the audio signal is not analog however the disadvantage is that you cannot use standard T/R devices but there are ways around this with some systems.
-Hal

[This message has been edited by hbiss (edited March 27, 2005).]

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I'm not familiar with Siemens or Alcatel. Does a one pair (T/R?) analog set have all the functionality (such as line buttons etc) as the digital sets or are they basically single line sets with no line appearances and you use hook flash and dial codes? This is all I have ever seen.