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Can key telephone systems be used multiple times i

Started by bellsystem, June 29, 2017, 11:37:26 AM

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Victor Laszlo

Since the assumption is that only one, or no more than a few, people will be talking on any one line at one time, there will not be any "deterioration of quality" other than lower volume due to more load on the circuit. if one person is the usual number using a line, there will be no deterioration.

There is a minimum amount of wiring, cabling, and cross-connecting in any system. It is not complicated, just expandable and repetitious.



Keep it simple ... you want MADN MCR/MCA.  You have 5 phones -- they all ring on one number.  You answer that phone, and the other 4 are locked out.  The next call to the same number rings those 4, and the process continues.  The lamps on the other phones go out.

Is that what you want?  There's also MADN SCR with privacy and without.

You just need the 1A2 -- the CO can do this MADN part.

Look for

Multiple Appearance Directory Number
Single Call Arrangement or Multiple Call Arrangement.


No, that's not what I want. If there is another call to one of those five lines, it should not ring another multi-line phone. They should hear a busy signal and get off the line.

I might want call waiting on 1005 or 1010/1110 ( but not both ), but only on that line. I'm still a big fan of the busy signal!

I just be able to answer an incoming call from any of those ML or primary phones. But there is only going to be one line per extension.


You want to be able to take a call from any line on any phone.  1A2 cannot do MADN SCA w/ Privacy Lockout.  Option 11 can do that.  You're asking old technology to do what it can't do.  You can't put call waiting on a 1A2 line.


I re-read what you said.  If you have 5 lines and 5 phones on 2565s in a square config, you cannot make the other 4 busy.  You push Line 1 to answer and you want keys 2, 3, 4, and 5 to become busy?

The other phones will see a line in use indication on 1 and can tap in to your call on 1A2

What you are talking about, 1 line with 5 appearances? That's one number.  So why do you need multi-line phones?


I didn't recommend 1A2. Others did.

You're still misunderstanding. Each key on each of the multiline phones is a different number. You can't use a different multiline phone to make a different call using the same line however. That number would be busy. The other lines on the ML phones would be completely different lines.


Yes you can.  MCA causes the lamps to go out on the remaining appearances.  How do you think ACD and call centers work?  You're gonna give people 5 phone numbers and then tell them, if this is busy, call that.  If that is busy, call the 3rd, and so on.

The CO hunts, or they use CFB, or they use MCA.

The PSTN is dead and nobody complained, they used Rotatone.  I thought collectors, and I am one, were knowledgeable or worked in the industry.

My goal is to support everything and make everything work.  It's ok to like the old stuff, but it's not gonna work right on voip which is all you are gonna have left if Verizon and AT&T have their way.

Victor Laszlo

QuoteI thought collectors, and I am one, were knowledgeable or worked in the industry.

Most of the folks on this forum are "civilians" who enjoy the styles and aesthetics of old rotary phones. There are some of us who cross the line from employee to collector, and then to the more complicated role of advisor and operator of key systems and EM switches.

Some of your messages seem to indicate a need for more education in how the subscriber equipment end of the industry works.  I don't mind teaching you, as I have done for a hundred other people, how 1A2 works. But it's a course of study that cannot ever be done by typing on a forum. It takes an open mind and the ability to use the right words. It is a building-block type of education, which is delightful, to me, to teach, as long as the student has the right motivation.


When you continue to be misunderstood, then you have to consider that you haven't explained your design ideas well enough.  Now, I admit, I won't follow this hypothetical trolling, but it does not appear you have a real plan.  It seems like an ever moving target.

A successful telecommunication system must exhibit simplicity and reliability to the users.  This was one, not the only, of the governing principles of the Bell System by which they built their monopoly and avoided government intervention.  This was even more important than subscriber set styling and similar fashionable criteria in which other companies usually excelled.

Complex signaling and condition indications detract from the core task of enabling communication between two or more people. You will find that, while you bask in your technical wizardry, no one around you will use your system.  They will use their smartphone, point to a name in the directory, and be connected with a touch of the screen.   No dial pulses, no misdialing, no operator, no person-to-person request, because all communication is soon person-to-person and almost instantaneous.

Read what Bellcore, the technical successor to Bell Telephone Laboratories, wrote in 1997 (Notes on the Networks, Bellcore SR-2275, Section 14, p.22):


Service Enabling Technologies — Simplifying the User Interface

     A common complaint of the 1990's has been that many of the new telecommunications
technologies and/or services are too complex and difficult to use. In some cases, the
services are used infrequently and the user forgets the instructions for the service or device.
Telephone services have not been exempt from this criticism. The number of telephone
services being deployed has exploded in recent years, and many services have not only their
own service activation codes, but their own particular service characteristics as well.

     The user interface to the telephone network, on the other hand, has not kept pace with these
developments until recently. This interface has not significantly changed since Dual-Tone
Multifrequency (DTMF) Touch-Tone signaling was introduced into the network in the
1950's. Telephone users have had a limited and non-intuitive interface to navigate,
consisting of ten numbers, two abstract symbols, and an unforgiving momentary signal
called the "flash hook." For services that require a "flash hook," such as Call Waiting and
Three-Way Calling, the user must depress the "flash hook" for between 300 and 1100
milliseconds (ms). Some people find this a difficult task and refrain from using the service.

     Two technical advancements in network interface technology have emerged that are
making new telephone and information services not just easier to use, but actually more
useful to the subscriber. One interface uses a visual screen-based approach, while the other
interface uses the recognition of human speech as its basis. These new network interface
technologies are the Analog Display Services Interface (ADSI) and Voice Activated
Dialing/Voice Activated Network Control (VAD/VANC).

     ADSI builds on the network interface developed for the Caller Identity Delivery (CID)
services: Calling Name Delivery (CNAM), Calling Number Delivery (CND), and Calling
Identity Delivery on Call Waiting (CIDCW). ADSI allows specialized Customer Premises
Equipment (CPE), with a screen display and soft-key capabilities, to interact with the
subscriber's network service software to provide visual menus and options that the user can
select with the touch of a button.

     VAD/VANC takes a different, audible approach. VAD/VANC does not require new or
specialized CPE but uses the emerging voice recognition technologies to act on the user's
wishes. This could make dialing and using complex services as easy to use as saying "Call
Forward to Mom's."

==end quote==

The point is the simplification aspect, and not that ADSI and VAD, for example, have revolutionized anything, they haven't, the computer did that, but that communication has always tended toward making it easier to communicate, not promulgate old, expensive technologies.  If it weren't for the stone-age analog loop plant, we could be talking today with crystal clear, music-quality like sound. ADSI of the 1990s, has been transformed into fully digital touch-screens interfaces on desk and hand-held devices.

So, I don't understand this activism to preserve ancient technology that is expensive, hard to maintain anymore, and utterly obsolete.  Nobody wants to dial by pulses; The goal is to hang a picture on the wall and enjoy the view, not enjoy using the hammer. But if you do want to just the latter, then go and do it on your own wall and on your own time, and don't make everyone else pay for it.

If you actually do pay $0.15 for long-distance, then be advised that it is priced to not use it, so they can finally retire all that copper in the ground, because that probably doesn't pay for the cost of maintaining old stuff anymore.

Nobody wants to use a key system anymore either, or a step-switch.
It is fine to appreciate old technology, collect it, use it for teaching, socialize about it, etc., all those activities that collectors do, as they do in the radio world, the automobile world, and so many other areas of human experience, but don't hold everyone else back with silly activism to preserve land line, pulse dialing, etc.

The television industry did the right thing.  They set a deadline to turn off the old, flip on the new, and television has never been better, and no one cries about 80 pound lead-filled wood boxes with glass screens anymore.

The same is overdue for the old telephone network. The activism is better spent toward ensuring five or six nines for IP technology by the minds and hands that know how to achieve such reliability, technically and politically; that is the future of the telephone folks.  The network core is already 100% Ethernet, packet-switched.
Finish it.


Again you misunderstood.

I am not giving anyone five numbers. Each number has a different purpose, as I outlined in my original post. If the number they call is busy, they call again later,

The key system is so the five lines in particular with the most incoming calls can be easily accessed throughout the house. It sounded simple in my head.


HI Guy's and Gal's
Let's bring this to and end, We have two people that are using this space for a argument, this is not the place. 98% of the members are PHONE collectors, NOT
key system or Switching collectors, also this is WAY over their head's. I have read all post regarding the Analog, 1a2 topic. I see both sides, and also agree to some degree with both sides, My suggestion is for Bell system and Dominic is to chat out side of this forum.  Bell system, Please understand that they replies to you questions are from Long time telephone tech's, Please spend some time researching on the internet to have a better understanding, There is a lot to learn about the old telecommunication's industry, Dominic we understand that you don't' like the old sxs and WE equipment  please give it a rest.       


After input from members and discussion of this topic, it was decided that it be re-launched on the public side but locked to further replies - the discussion is closed. Even though this topic was not moving forward to an end (solving the initial topic question) and filled with many replies considered off topic,  it was pointed out that some of the replies contained useful information in themselves.

One of the reasons this has happened was the large number of ad hominem replies and pointed attacks on another member's knowledge, understanding and/or credibility in telephony. Another reason was topic digression, numerous tangents and red herrings taking the discussion far afield from the initial topic question.

With the topic stalled and the discussion becoming contentious, it was decided to end the discussion but to make what was posted available to those who participated and anyone in the future who may find any of the information within useful. It was re-launched in its entirety with nothing deleted, modified, changed or added other than this explanation.

Going forward, this re-launch also make all if the useful information within available to any member who would like to take it upon themselves to extract that information and place it into a document or topic in logical order including an index and glossary for future reference. This summary can be placed where ever appropriate on the forum.

In the future, topics will be watched more closely for digression and contentious replies than in the past. This forum is here to help people, to teach new members, to exchange ideas, to correct errors, to show off phones and to discuss phones or phone systems in a civil and friendly manner.

There is no room for attitude.