Telephony 101: On Voice Mail

Some people love voice mail, many just hate it. Many are apparently so egotistical, they think it’s not worth listening to 2 minutes of a voice based message than a generic email.

People also think email is better, but do you know the history of voicemail?

if the answer is no, lets go down memory lane of Voice Mail.

Voicemail is often assumed to be an electronic answering machine on a server. While it’s true, its origins was almost similar to sending a letter or an email, just with spoken word.

The first indication of such language was in printed publications in 1877. A famous man named Thomas Edison with an invention called the phonograph. For the Gen-X audience and older, this is basically a record player. Millenials are probably familiar to just be cool for the latest trend. While it was well known for songs, the ability to record spoken word, as a way to replace letter writing had the possibility. The “voice mail” language was in the lexicon by the 1910s.

While the answering machine was invented in the 1960s, the ability to install these would be so cost prohibitive, and worse, a wiring nightmare. In the early 1970s, Motorola introduced pagers that provided one way voice messages that would be answered by an “answering center” (this in 2017 is completely archaic with the advent of digital telephony, automated attendants, in fact the size of these answering centers were the size of contact centers, which was not existent at the time.) These pagers used UHF signals and were often used for volunteer fire fighters, etc. In this sense, this could be considered as a voice message.

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The Makings of a Telephone Museum, part two

This video has a faster time lapse and I have been able to get all 500/2500 (except for the ITT and other WE black set) to ring through a trick I learned through Jason with a coverage-answer-point, hunt group and coverage-group function on the Definity console. I’ll post that at a later time. But please enjoy this hard work that took nearly a near from idea to completion!

Repost: Nortel Logic-1 Analog Telephone

I follow Joe The UCX Guy’s blog, he posted yesterday a picture featuring his father working in a federal office from the early 1990s. The phone pictured is a Nortel SL-1 telephone from the mid 1970s. It’s quite interesting in Avaya Blue, legacy sets lasted much longer than say Avaya Red. Any Dimension or Horizon telephone was scrapped off many desktops by that same time, and yet the original “wedge” SL1 sets were common place even into the 90s.

Apparently in the same post, his father passed away on Wednesday. In some of his posts in recent months of Nortel sets at area hospitals, he mentioned about his sick father. I typically wouldn’t go this far in discussing other sites and the people involved, but I have had off-web communications with Joe and therefore I feel its worth sharing and giving a tribute.

So out of tribute and to go along with the Avaya Blue theme, here is a video I made last winter showing an analog set similar to the one linked. Basically this is a repost from another one back at that same time.

History of Nortel Digital PBX Systems, Part 3

Nortel rang the new year in 1990 with yet another improvement to their Meridian 1 PBX just as AT&T tried to an arranged marriage with the System 75 and 85 PBX systems with a new name called Definity, and IBM’s salesforce who probably thought a 2564 was the only best office telephone and wasn’t able to tell from tip and ring as they couldn’t get the ROLM CBX 9751 to take off.

By this point technology had gratefully improved, as consumers were listening to CDs or tapes, many having color TV, using PCs that were already a generation or two old; and people were ditching the leased phones to ones they could buy off the shelf at a Phone Center Store (if they were still around.)

January 1990 was no different for Northern, they added yet more features in Rls 15. Here it goes

X11 Release 15 (1/90)

  • Busy Lamp Field Enhancement: Displays, in addition to the busy/idle status of system users, the reason for user absence and an alternate extension number to utilize.
  • Coordinated Dialing Plan Routing Enhancement: Provides more flexibility to network dialing plans and alternate routing by allowing incoming DID calls to be routed over CO, WATS, and TIE trunks when a distant steering code is used.
  • Flexible Feature Codes: Provides customers the ability to define their own access codes for system features.
  • Remote Call Forward: Allows all incoming calls to a station to be automatically forwarded to a pre-selected number that may be remotely defined.
  • Time Forced Disconnect: Permits a customer to specify the maximum duration of a call permitted on a trunk route basis.
  • Call Forward No Answer Second Level for Message Waiting: Allows an SFA class of service to be defined on telephones with a Message Waiting Allowed (MWA) class of service. A message waiting indication can be activated at the originally dialed DN for Second Level CFNA calls terminating at a message center.
  • Recorded Announcement Enhancements: Provide compatibility with associated RAN equipment that permit message lengths of 512 seconds.
  • Console Presentation Group: Provide greater flexibility to the Multi-Tenant feature by allowing attendant consoles to be defined at the tenant level rather than the customer level.
  • Attendant Alternative Answering: Allows any call presented to a console loop key to be forwarded to a customer-defined directory number when the attendant is not available to answer.

Hotel Feature Enhancements:

  • Enhanced CCOS: Adds additional levels of restrictions.
  • Automatic Wake-up: Extends the number of automatic wake-up calls from 100 to 500 in a five minute period.

Telemarketing Enhancements:

  • Network ACD (NACD): Uses ISDN PRI or ISL hardware to quickly and efficiently route calls to available agents within a network of SL-1 systems.
  • Enhanced Overflow: Allows customers to optimize resources and service level by adding more flexibility in defining call overflow patterns within the system.
  • ACD Screen Enhancements: Provide new display messages on associated M2216 digital telephones that give agents and supervisors clear and simple instructions for feature activation.
  • Network ACD Remote Targets
  • Network Message Center
  • International PRA
  • Extended P. E. (Superloop)
  • Enhanced Conference, TDS, & MFS
  • Superloop Administration

If you missed the boat in Release 15 within the first months of 1990, why just go with Rls 16 instead?

X11 Release 16 (6/90)

Business Features:

  • Allows customers to send route dialed 0, 00, or 011 calls over different routes. Benefit: Customers can route local 0 calls differently from international 0 calls.
  • Attendant End-To-End Signaling: Enables a console attendant to send Dual Tone Multi-frequency (DTMF) code through an established outgoing connection.  Benefit: Allows the attendant to access digital paging systems, digital dictation devices, and Meridian Mail.

Hospitality Features:

  • Guest Entry of Auto Wake-Up: Allows hotel guests to program wake-up requests directly from their hotel telephones. In a business setting, employees can program a reminder call from their set, and the system will call the user at the designated time with a reminder call.
  • Multi-Language Wake-Up: Permits a hotel to provide wake-up calls in a guest’s preferred language. Up to six customer-definable languages can be configured on a per room basis.
  • Meridian Hospitality Voice Services: Provides voice mail services to hotel guests by linking, Meridian Mail, the Property management System, and the Meridian 1.  Benefit: Allows guests to handle their own calls and thereby minimizing staff requirements.

ACD Enhancements:

  • Supervisor Control of Queue Size: Configures ACD DNs so that when a queue meets or exceeds its overflow threshold, calls can be selected to receive a busy tone or to be routed into the queue.  Benefit: Saves operation costs for 800 service by reducing the number of calls waiting in queue.
  • 500/2500 Single Line ACD Set: Allows 500 or 2500 type telephone sets to be used as ACD Agent sets.  Benefit: Facilitates support of off-premise and part-time agents and saves money by reducing hardware costs.

Networking Enhancements:

  • Trunk Optimization (Before Answer): Allows the Meridian 1 to automatically reconfigure trunk routes before answer for redirected calls (Call Forward All Calls/Call Forward No Answer, Call Forward Busy, Call Forward Hunt). For example, if a call is placed from location A to location B, then redirected before answer to location C, this enhancement drops the A to B and B to C connections, reestablishing a direct connection between A and C.  Benefit: Saves money by avoiding unnecessary use of ISDN PRI or ISL channels/trunks.
  • Network Call Redirection: Extends Hunt and Busy capabilities networkwide, using a Meridian 1 network connected via either ISDN Primary Rate Interface or ISDN Signaling Link Private Networks. The originally dialed number, the connected number, and the reason for redirection (busy or hunt) are displayed.
  • AT&T Connectivity: Supports Meridian 1 Integrated Service Access (ISA) call-by-call service when the Meridian is connected to an AT&T 5ESS central office switch via ISDN PRI. This feature allows the Meridian 1 to exchange information with the network on a call-by-call basis about services required for each incoming call.
  • In-Band Automatic Number Identification: Allows a carrier such as MCI or Sprint to send the Meridian 1 the calling party’s 10 digit telephone number via standard digital trunks (T-1).  Benefit: This feature allows customers to receive ANI digits without having the Inter-Exchange carriers’ ISDN facilities in place.
  • Public Switched Data Service (PSDS): Also known as switched digital service, allows Meridian 1 users to transmit and receive 56 kbps data over T-1 circuits or at 64 kbps over an ISDN PRI channel. PSDS is offered by local phone companies and long distance carriers and allows the Meridian 1 to interwork with other PBXs data units supporting the PSDS feature. Meridian 1 customers can use this feature for building data transfer, videoconference, group IV facsimile, and access to the high-performance applications.
  • Meridian Link

While there could’ve been a perceived lull at NT, they were busy improving the M1 PBX to meet FCC requirements as they list below. Nearly a year and a half later, they introduce the next release.

X11 Release 17 (1/92):

Release 17 was introduced in January 1992. It included a PBX enhancement to meet new FCC regulations, Equal Access compliance, and introduced new business and hospitality features/enhancements to satisfy customer requirements.

Business Features:

  • 500/2500 Line Disconnect: Provides disconnect supervision to 500/2500 line ports that are connected to outboard processors such as an automated attendant or Voice Response Unit.
  • Name Display for DNIS: Enables a name to be associated with a DNIS number. It displays the product line, company name, department, and other information associated with the incoming call to help ACD agents personalize and customize call answering.
  • Faster I/O: Introduces a TTY “Host Mode” which ensures that output of the data associated with a TTY user type will be directed to a single TTY with an optimum baud rate.

Hospitality Features:

  • Maid ID: Allows a maid to enter a one- to four-digit identification number which is then sent to the Property Management System. Benefit: Helps management track maid whereabouts, performance, and room status such as occupancy, cleaning status, and the readiness of hotel rooms thus providing an increased level of customer service.
  • VIP Auto Wake-up: Routes Automatic wake-up calls for designated guests to an attendant who can provide personalized wake-up service.
  • Hospitality Screen Enhancements (Special Applications Display): Supports screen capabilities for Meridian Modular Telephones to guide users through Automatic Wake Up sequences, Maid ID, Message Registration, and Room Status Operations.

Regulatory Compliance:

  • FCC Compliance: With Release 17, Northern Telecom complies with the new FCC Part 68.314 to return answer supervision signals to the Public Switched Network on Direct Inward Dial (DID) calls.

Call Center Enhancements:

  • ACD Report Control: Allows customers to select specific ACD DNs to include in ACD-C1, ACD-D, ACD-MAX, and Meridian MAX reports. ACD Report Control is configurable on a per queue basis, allowing Call Center managers to focus on critical report information.
  • Call Detail Recording Enhancements (CDRE): Enables Meridian systems with Feature Group D to capture Feature Group D ANI in Normal and Start Records for incoming Feature Group D calls.

Networking Enhancements:

  • Feature Group D (Inbound to Meridian 1): Allows the Meridian 1 to receive Multi-Frequency (MF) Signaling from Equal Access End Offices and perform the same functions as an Inter-Exchange Carrier Switch, providing corporate networks with high-quality long distance services such as using the private corporate network as the long distance carrier, routing to any long distance carrier of choice, receiving ANI information where ISDN PRI has not been implemented, and requiring mandatory user authorization codes.
  • NARS/BARS Enhancement – Local Termination: Enhances Network Alternate Route Selection (NARS) and Basic Alternate Route Selection (BARS) capabilities. Local termination allows separate 911 emergency services for campus-like network environments.
  • ISA/Call by Call Service Selection Enhancements: Dynamically allocates calls by call and service type. ISA enhancements support InWATS calls to all station types, including ACD DNs, support private trunk types for DMS-100 systems, and support Service Identification and Incoming Digit Conversion for all trunk types (TIE, COT, DID, WATS).
  • Network Name Display: Displays caller and called party names in ISDN networks between Meridian 1s and Meridian Digital Centrex.
  • T309 Timer: Operates in conjunction with T309 timers on DMS-100/250 and AT&T 5ESS Central Offices and Inter-Exchange Carrier switches to maintain active network calls if a D channel interruption is less than 90 seconds. After 90 seconds the T309 timer expires, releasing active calls.
  • D-Channel Error Reporting and Monitoring: Provides diagnostic messages whenever the D channel is established or released.
  • Network Call Trace and Call Diagnostic: Transports vital network call information from each tandem node back to the originating node, providing network administrators with information for testing and maintaining network setup and function integrity.
  • Backup D-Channel to DMS-100/250 and AT&T 4ESS: Provides redundancy for the D Channel Handler Interface, switching to a second ISDN Primary Rate Interface span if the primary link fails.

Meridian Link Enhancements: Meridian Link Release 2 supports the following features in the LAPB Pass Through mode. (Release 3 will support the features in X.25 environments.) These capabilities are included in existing Meridian Link software and require the appropriate Software Utility Packages on the Meridian Link Module.

  • Feature Invocation Messages: Allows the agent to activate frequently used ACD set features. The host application can activate and deactivate Make Set Busy/Make Set in Service, Ready/Not Ready, and Log-in/Log-out. Associated Sets can also access Call Forward and Message Waiting features.
  • Feature Notification Message:  Notifies the host whenever an agent activates the Make Set Busy/In Service Feature.

X11 Release 18 (1993)

  • ISDN BRI: Standard interface for connecting data terminals and telephones to the Meridian 1. Developed based on the CCITT and ANSI standards to allow terminal portability, uniform feature activation, and simplified application development for third-party developers.
  • Remote Virtual Queuing (RVQ): ISDN feature that uses ISDN PRI or ISDN Signaling Link to allow queuing for network calls when trunking facilities are blocked or busy.
  • Off-Hook Alarm Security (OHAS): Telephones with this class of service are intercepted when the dial tone/interdigit timer expires or a digital set is forced out of service when the line cord is cut or damaged. Benefit: Helps customers recognize potential emergency situations in correctional and hospitality settings.
  • Call Detail Recording (CDR) Answer Supervision on Ground Start Trunks: Generates accurate CDR records for ground-start trunks. CDR records start recording when the receiving party answers the call rather than when the trunk is seized. Benefit: Enables customers to control costs.
  • Overlay Cache Memory: Stores up to 32 system overlays in cache memory, a protective memory, allowing customers to quickly access frequently used overlays.
  • Multiple Appearance DN Redirection Prime (MARP): Ensures the consistent activation of call redirection parameters such as Hunt, Call Forward All Calls, Call Forward Busy, and Call Forward No Answer.
  • Hold in Queue for Interactive Voice Response (IVR): Allows callers waiting to be answered in an ACD Queue to be connected to the voice processing services of IVR equipment of Meridian Mail Voice Menus. Caller receives IVR treatment while they retain their place in the ACD queue.
  • Alternate Call Answer: Lets agents place Individual Directory Number (IDN) calls on hold to take a higher priority ACD call. Also allows ACD agents to place IDN calls on hold and not receive ACD calls.
  • Dialed Number Identification Service (DNIS) Name Display Enhancements: Retains DNIS name and number during call modifications such as conference, transfer, and no hold conference when the call reverts to a two-party call.
  • Meridian Communications Adapter (MCA): Asynchronous/synchronous data card that fits into Meridian Digital Telephones to permit simultaneous voice and data transmission up to 64 Kbps.
  • Data Port Hunting: Allows up to 255 data ports to be configured as trunks in data port trunk routes when using the Data Access Card. The route can be programmed to step to another data port route if all route members are busy.
  • Modular Telephone Relocation: Automates the Automatic Set Relocation (ASR) feature by reducing the number of manual steps needed to relocate a set.

It’s interesting the MCA was released so late in the sharing serial data with electrical telephone lines. This was common back before the days of Ethernet and TCPIP and when everyone used Terminals to do their work.

History of Nortel Digital PBX Systems, Part 2

By 1982, the system’s software was renamed X11, starting with Release 1. Northern Telecom was in an innovative spree, if you were at ROLM, AT&T you’d be mouthing “holy crap.” In the early 80s, NT released a new version of the PBX close to a year and by the end of the 80s, a new release came every 6 months.

Similar to Voice over IP, digital telephony was limited similar to the old SXS or Crossbar type of electromechanical PBX systems, but quickly proved otherwise.

Because I am not familiar with the Meridians, if you are a Nortel fanboy, you’ll probably get it.

X11 Release 1 (11/82)

  • Mini CDR
  • Network Class of Service
  • Automatic Set Relocation
  • Attendant Administration
  • History File
  • Attendant Overflow Position
  • Attendant Overflow Position Busy
  • Basic Alternate Route Selection (BARS)
  • BARS Traffic Measurement
  • Network Alternate Route Selection (NARS)
  • Coordinated Dialing Plan
  • Priority Queuing
  • Flexible Call Back Queuing
  • Off-Hook Queuing
  • Network Authorization Codes
  • Conditional Data Dump
  • Expanded Trunk Groups
  • Multiple Loop Directory Numbers

X11 Release 2 (6/83)

  • ACD Package D: Provides comprehensive administration capability that includes status displays, reports, and load management functions.
  • Call Park: Provides the capability for attendant or station user to place a call in a held state (park) where it can be retrieved by dial access from any console or telephone set in the system.
  • Recorded Overflow Announcement: Allows incoming calls that are delayed in answering by the attendant to be routed to a recorded message notifying the caller accordingly.
  • Flexible Code Restriction: Allows the customer to specify whether stations with toll-denied class of service will be allowed or denied access to outgoing trunk routes based on specific number patterns and/or the number of digits dialed.
  • Speed Call – Enhancement: Allows the creation of a System Speed Call list (or lists) from access by any assigned station set irrespective of any class-of-service restrictions.
  • System Speed Call
  • IMS Software
  • Network Traffic Measurement
  • Network Control / Signaling
  • Network Queuing
  • Network Speed Call
  • New Flexible Code Restriction
  • ACD-D Auxiliary Processor Link
  • Trunk Group Busy Enhancement
  • Flexible Call Forward – No Answer
  • Conference Control
  • Bulk Data Load
  • Agent Log-in/Log-out/Walk-away
  • RAN Improvements
  • Extended Agent Observe
  • Reporting Enhancements
  • Audible Message Waiting
  • ESN Enhancements
  • ETN Switch Compatibility
  • Traveling Class of Service
  • Manual Trunk Maintenance
  • 100 Test Line Termination
  • Loop Around Termination
  • Routing Control
  • CDR Enhancement

X11 Release 3 (10/83)

  • Stored Number Redial: Allows telephones and attendant consoles to store one previously dialed number of 4 to 31 digits in length for automatic redialing.
  • Outgoing Trunk Hunting: The outgoing trunk hunting feature allows the choice of linear hunting, the last available trunk on a trunk route, round-robin hunting, where the system distributes outgoing trunk calls among the members of a route.
  • Network Call Transfer: Minimizes the use of access Tie lines in the connection between Meridian 1 switches when calls are transferred and provides improved transmission performance because of the reduced number of access Tie lines involved in a transferred call on the SL-1 network.
  • Called Party Disconnect Control: Allows the Meridian 1 to be the controlling party for disconnect of incoming calls on CO, FX, CCSA, DID, TIE, WATS, Mode, and CAMA trunks.
  • Secretarial Filtering: Allows a set to have calls forwarded to a second set and the second set can, if necessary, transfer calls back to the first set even if it remains in the call forward mode.
  • SL-1 Tone Detector
  • ACD/CDR Q Record
  • Log-in/Log-out SL-1 Sets
  • Management Reports
  • 15 Minute Reporting Option
  • DID/TIE/CCSA Route Reporting
  • Quiet Agent Observe
  • Restricted Agent DN
  • BARS NCOS – Enhancement
  • TGAR/TARG Capability for ESN
  • Satellite Link Control
  • ACD-D Internal Route Change
  • End of File Mark Enhancement
  • Password Enhancement
  • Enhanced 911 Interface

Wow, E911 for the mid 80s. That’s just impressive. The competition must’ve been embarrassed. Maybe not so much given it took till the 90s for E911 to be everywhere.

X11 Release 4 (1/84)

  • Flexible Hotline: Provides the capability to assign any single predetermined destination to be automatically rung from an associated 500/2500 telephone when the latter goes off-hook.
  • Deluxe Hold: Adds two capabilities for calls placed on hold in multiple-appearance (single-call arrangement directory number environments:
  • Individual Hold: indicates only those calls placed on hold on SL-1 telephones in a multiple-appearance single call arrangement. When a user puts a call on hold, normal hold (winking) is indicated at that telephone only. A slow flicker is shown at all other telephones with the multiple appearance.
  • Exclusive Hold: allows users with multiple-appearance DNs to place calls on hold under the control only of their particular telephone. All other appearances of the DN do not indicate the held call and are excluded from entering it.
  • Automatic Line Selection: Allows the SL-1 telephone to automatically select a line in a prioritized order when the handset is lifted.
  • 500 Set Features: Provides rotary dial access to the Speed Call, Call Forward, and Permanent Hold features.
  • Distinctive Ringing: Allows calls over specified trunk routes to distinctively ring stations as opposed to the standard audible signaling arrangement.
  • Integrated Voice Messaging System (IVMS): Expanded previous SL-1 capabilities to include voice store and forward (VSF) messaging.
  • Autovon Interface
  • Autovon CDR
  • Flexible Line Lockout
  • BARS/NARS 1 + Dialing
  • Variable Trunk Seizure
  • CDR Charge
  • Double Density Line & Trunk Cards
  • Line Preference Enhancement
  • Network Enhancement

X11 Release 5 (1/85)

  • PBX Interface (DTI/CPI): Provides a 24-multiplexed digital connection for voice and/or data from a Meridian 1 to a digital DS-1 facility.
  • Departmental LDN: Allows up to four different departments to be identified by their own specific listed directory number.
  • Data Port Hunting: Allows up to 128 data access modules to be assigned in a trunk group
  • Call Register Enhancement: Allows a separate logical memory page to be assigned to both call registers and trunk timing blocks, thereby increasing the number of call registers from 1200 to approximately 1500.
  • Meridian SL-1 XN Memory Expansion:  Increases the amount of memory available on the SL-1XN in the areas of Program Store and Protected Data Store.
  • Enhanced End to End Signaling (EES): Allows a telephone to send and receive DTMF codes, thereby extending the EES capability to internal PBX calls and incoming trunk calls.
  • Incoming Trunk Group Exclusion: Associated with the BARS/NARS feature, provides the capability to deny the routing of incoming trunk calls to specific prefix codes.
  • Multiple DID Office Code Screening for NARS: Supports on-net to off-net conversion for sites that have varying numbering schemes.
  • Offnet Number Recognition for BARS/NARS: Removes the need to use two additional CO trunks to terminate a call at a company-owned location.
  • Privacy Override: Allows multiple-appearance, single-call-arrangement directory numbers assigned to SL-1 telephones to have class-of-service control of privacy.
  • ESN AT&T/EPSCS Interface
  • Optional Outpulsing Delay
  • ACD Log-Out Enhancement
  • ACD Reports Enhancement
  • Message Waiting Lamp Testing
  • ADM Trunk Hunting Enhancement
  • ROM Enhancement

X11 Release 7 (12/85)

  • Station Category Indication (SCI): Allows the attendant to selectively answer internal calls in accordance with a predetermined priority status.
  • Controlled Class of Service (CCOS): Formally introduced for the Hotel/Motel industry, was applied to the business environment to allow a station’s level of access to the external network to be changed to a pre-determined system level using a controlling SL-1 telephone.
  • Automatic Trunk Maintenance: Provides a means of periodically testing network resources by measuring facility loss and noise parameters to prevent under-utilization due to poor performance of service outage. Associated hardware to provide tone detection capabilities was also introduced.
  • Multi-Tenant Service: Allows each of the 32 customer groups within the Meridian SL-1 to be partitioned into 512 tenants to facilitate resale of services.
  • Meridian Digital Telephones
  • Meridian M3000 Touchphone
  • Flexible Line Lockout
  • CDR Enhancements
  • DISA Enhancements

X11 Release 8 (6/86)

  • Last Number Redial (LNR): Allows users to simple redial the last number dialed without having to key in the digits again.
  • Pre-translation: Provides a means of utilizing Speed Call lists to implement a flexible dialing plan.
  • Supervisory Console: Allows one attendant in each customer group to function in a supervisory capacity when the associated console is placed in a position-busy mode.
  • 63 Attendant Consoles: Allows 63 attendant consoles for each customer group compared to the previous fifteen*.
  • BARS/NARS Enhancement: Extends the previous three- or four-digit translation mechanism to eliminate potential routing conflicts when utilizing the BARS/NARS feature.
  • Station to Station Call Waiting: Allows internal calls to enter the call waiting state via a new station class of service.
  • Digital Trunk Interface (DTI): Extends DTI functionality to additional Meridian systems including MS, NT, and XT.
  • Command and Status Link
  • Command and Status Link Alpha
  • Fast Tone & Digit Switch

* So much for that maximum 32 attendant consoles on that System 85 huh? Dammit!

X11 Release 9 (6/87)

  • Trunk Verification from Stations:  Provides the capability for a classmarked 2500 set to seize a particular trunk within a trunk group, receive dial tone, and outpulse digits to complete a call to a remote maintenance site. This feature is used as part of a PPC-based Network Management system to allow physical testing of each trunk in a network.
  • New Distinctive Ringing: Offers the ability for stations to have a distinctive ring to distinguish various call types. The distinctive ringing is enabled for specific trunk groups.
  • Meridian M2317 Digital Display Telephone
  • ESN Access to ADM/MDM Trunks
  • 16 Port 500/2500 Line Card
  • Print Routing – Enhancement

X11 Release 10 (1/88)

This software release introduced new business opportunities in key vertical markets, such as lodging, health care, telemarketing, and the federal government. In addition, Generic X11 Release 10 culminated the development program, embarked on in 1984, to recombine the Hotel/Motel Generic (X37) into a single stream business offering. Thus, users in the lodging environment utilized features formerly only available to the business segment, and vice versa. Generic X11 Release 10 introduced a total of 18 new feature options, partitioned typically for vertical markets, but additionally available to all users of this software base.

Hospitality/Health Care:

  • Automatic Wake Up
  • Room Status
  • Message Registration
  • Property Management System Interface
  • Background Terminal

Federal Systems Telemarketing:

  • Station Loop Pre-emption – ACD Enhancements
  • Line Load Control
  • Dialed Number Identification Service

General Business:

  • Call Party Name Display
  • CFNA/Hunt by Call Type
  • Call Forward No Answer 2nd Level
  • 500/2500 Conference Enhancement
  • Do Not Disturb Enhancement
  • Malicious Call Trace
  • Internal CDR
  • Auxiliary Processor Link
  • ACD Timed Overflow
  • Enhanced Hotline

X11 Release 12 (12/88)

Generic X11 Release 12 was introduced in November 1988 to offer another subset of powerful features to Meridian SL-1. ISDN Primary Rate Interface (PRI) capability was made available as well as console and ACD enhancements, further data networking flexibility, specific features for Health Care and Hotel markets, additional business feature offerings and memory expansion for the Meridian SL-1 ST all combined to bring new services. The following features were provided with this release:

  • Incoming DID Digit Conversion
  • ACD-D Auxiliary Security
  • Directed Call Pick Up
  • ACD Priority Agent
  • Enhanced Music
  • Meridian SL-1 ST Memory Expansion
  • Overlay 10/11 Enhancements
  • Multiple Background Overlay Programs
  • Night Service Time of Day
  • Attendant CPND Enhancement
  • Call Number Information Message
  • M2317 Enhancement – English/French
  • CDR Enhancement
  • ADM Trunk Hunting – Enhancement
  • ACD Enhancement

X11 Release 13 (3/89)

The availability of X11 Release 13 in March 1989 added numerous additional business features and system enhancements. The existing four-digit numbering scheme was expanded to accommodate up to a seven-digit dialing plan to alleviate potential conflicts with directory number assignments. The expanded numbering plan also met the needs of large single system applications that may otherwise exhaust their numbering capacity.

Expanded software parameters addressed the requirements for additional networking routing capabilities with the BARS, NARS, Autovon, and Coordinated Plan features. Other feature parameters expanded included additional Call Pickup Groups, Speed Call lists, Group Call Members, and Multiple Appearance Directory Numbers.

In addition, other enhancements to existing features included Distinctive Ringing for Dial Intercom, Speed Call/Auto Dial with Authorization Code using one key stroke, and an enhancement to the Call Party Name Display.

  • Network Call Party Name Display (NCPND): Provides networkwide visual display of name and number over PRA facilities.
  • Display of Non-PRA Calls: Uses the trunk route access code and member number instead of CLID on the terminating telephone set display when network calls are routed over non-ISDN facilities.
  • Call Redirection/Call Forward All Calls Enhancements: Provide information updates for both the calling and called telephones display for CLID and NCPND under those calling conditions.
  • Back-up D Channel: Provides redundancy for the D-Channel Handler Interface (DCHI) circuit card with automatic switchover, if necessary, to the backup unit in the event of failure.
  • ISDN Application Protocol: Provides interworking to facilitate message exchange between Meridian SL-1 and the DEC computer to support applications such as telemarketing, message desk, and support center operations.
  • Call-By-Call Service
  • Calling Line Identification in CDR
  • ISDN Signaling
  • ISDN Primary Rate Access
  • ISDN Signaling Link
  • Advance ISDN Features
  • Inter-Exchange Carrier
  • Software Capacity Expansion
  • Directory Numbering Plan
  • Call Pick Up Group
  • Speed Call Lists
  • Group Call Members
  • Trunk Route Members
  • Trunk Group Access Restrictions
  • Multiple Appearance DNs
  • NARS/BARS Route List Entries
  • CDP Route List Index
  • CDP Route List Entries
  • CDP NCOS Groups
  • CDP Steering Codes

X11 Release 14 (12/89)

  • Software Capacity Expansion: Extended the upper-limit parameters on the following features:
    • Private Line Routes
    • Dial Intercom Groups
    • Trunk Routes
    • Customer Groups
    • Network Authorization Codes
    • Pre-translation Groups
  • Centrex Switchhook Flash: Facilitates the emulation of the SL-1 as a key system behind a Centrex switching office to permit call transfer
  • No Hold Conference: Allows a station user to set up a conference call without losing voice contact with the original party such as in an emergency call.
  • Audible Reminder of Held Calls: Extends to proprietary telephone, the Permanent Hold capability on 500/2500 telephones of alerting users periodically of the held call situation.
  • Night Key for DID Digit Manipulation: Permits different call treatments to be implemented either after hours or during specific times during normal business hours.
  • ISDN Enhancement:
  • Network Call Redirection
  • Network Ring Again for 500/2500 Sets
  • ISDN Signaling Link Enhancements
  • Audible Tone for ACD Observe
  • Data Agent Log-In
  • Flexible Incoming Tones

If you thought this was an exhaustive list, wait till the 1990s. Their PBX just kept growing and growing!

History of Nortel Digital PBX Systems

From Nortel’s old website, I was able to access through the Internet Archive, Nortel was unusually very open to the software history of their PBX systems. The copyright likely is owned by Avaya, and all rights reserved to them, originally © Nortel Networks 1999-2009.

All of Nortel’s PBX were in succession from the first release called Software Generic 101 in 1975 leading up to Communication Server 1000, with almost the 30th revision.

Unlike the old Nortel page, I’m starting with the oldest first, then newest

Software Generic 101 (1975)

From a software point of view, Generic 101 was introduced to support the SL-1L system. In addition to many standard features and services inherent in the system, optional software packages provided multi-customer and advanced SL-1 set features. Multi-customer was unique in that it allowed a single SL-1 system to serve up to 32 different customers, each with independent feature complements, numbering plans, and peripheral equipment. The advanced feature package provided Auto Dial, Call Forward, Override, Ring Again, Speed Call, and Voice Call /capability to the SL-1 telephone user. The typical application of the SL-1L system was in the 100 to 1000 line range.

Remember in 1975, the Meridian name didn’t exist. It went by a clunky named called the SL1 or for Stored Logic. There were suffix model numbers but they weren’t easy to tell apart like an Option 11 from Option 81. Nortel did have a reputation for being Nerdtel.

X02 (1976)

Generic X02 was introduced in 1976 to form the base for the SL-1VL system. The software added a number of feature enhancements over the initial system capability and was adapted to the SL-1L as Generic 102.

X03 (1977)

  • Call Detail Recording: Allows the recording, on a per call basis, of details related to incoming and outgoing calls such as the calling and called parties, time, and duration. Downstream processing of the collected data permits usage reports to be generated.
  • Recorded Announcement (RAN): Provides an interface to a Recorded Announcement machine and the capability of flexibly defining the intercept treatment for various call situations.
  • Time and Date: Provides the capability of displaying and modifying the system time and date from the attendant console.
  • Do-Not-Disturb: Provides the capability for the attendant to make any individual directory number appear busy to incoming calls while maintaining it free for originating calls.
  • End-to-End Signaling: Allows use of the SL-1 electronic telephone on an established outgoing connection to utilize the push-button dial pad to effect Digitone end-to-end signaling.

Digitone (was their analog telephony solution, the circuit cards, perhaps single line sets – and the description to refer to any non digital telset, since Touch Tone still was a registered trademark of AT&T.)

X04 (1978)

  • Automatic Number Identification (ANI): Provides the facility to automatically identify a station originating an outgoing toll call and to send this information by Multi-Frequency (MF) signaling to a central office toll-ticketing system.
  • Route Selection for ANI: Works in conjunction with the ANI feature to route toll calls automatically over predetermined trunks.
  • Automatic Route Selection (ARS): Provides automatic selection of least expensive and efficient trunk routes under software control for outgoing calls.
  • Remote Peripheral Equipment (RPE): Increases the range of the multiplex loop between the CE and PE by using T-1-type carrier facilities.
  • Do Not Disturb Group: Allows the attendant to place a group of directory numbers into a Do-Not-Disturb mode so that they appear busy to all incoming calls, but free to originate calls.
  • Make Set Busy: Allows an SL-1 telephone user to busy out the set for incoming calls to all DN appearances but free to originate calls.
  • Office Data Administration System

I hate to defend Nortel, but supporting ANI in 1978 was truly innovative and the concept of ARS, which most digital PBX systems’ basic necessity to work.

X05 (1979)

In 1979, due to varying demand for software features, a split occurred in the Software Generic to address specific market segments. Business Generic X04 formed the foundation for the separate generic streams to evolve. X05 was introduced at this time as the premium Business Generic adding the following capabilities:

  • 2500 Set Features: Provides a subset of features, formerly available only to SL-1 telephones, to be utilized on 2500-type single line sets. By dialing an octothorpe key (#) and a single digit access code, 2500-type telephones can access the features listed below:
    • Call Forward all calls
    • Speed Call (User and/or Controller)
    • Permanent Hold
  • Digit Display Sets: Provides for the display of information relative to normal call processing and feature activation on any SL-1 telephone equipped with a digit display.
  • Dial Intercom: Allows stations to be accessed by abbreviated dialing and arranged into separate intercom groups within the SL-1 system.
  • Direct Inward System Access (DISA): Allows selected users to access the SL-1 from the external public network by dialing a special directory number from any Digitone-type telephone.
  • CDR Charge Account Code: Allows a charge account code to be entered before dialing or during an established call to allow billing of calls to other than station directory numbers.
  • Authorization Code: Allows selected users to temporarily override the access restriction assigned to any station or trunk by entering an authorization code.
  • Centralized Attendant Service: Allows customers with multiple locations to centralize their attendant services at a single facility.
  • ARS Priority Queuing: Provides an improvement to the ARS feature by introducing a flexible class-of-service assignment of the one of four priority levels or the access of least-cost routes by each user.
  • Basic ACD: Provides a means of sharing service among a group of answering positions such that calls are served in the order of their arrival. A number of administration capabilities are available for effective agent/supervisor communication. The flexibility of providing stand-alone ACD, combined PABX service, or a split among the two can be configured utilizing a single system.
  • Message Center: Allows an incoming call to be automatically routed to a message center if not answered at the original destination. A message waiting indication alerts the station user, who can then access the center for message retrieval.
  • Automatic Handsfree Answerback
  • Group Call

We’re still in the days when people saw TV on rabbit ears, many TV shows in film, people were listening to Top 40 on the very warm AM band and Jimmy Carter can’t figure out basic economics and I can’t understand how AT&T was asleep during all this innovation. While they innovated, there was a Northern stigma was just how much jargon they had in addressing the technology.

X07 (1979)

In 1979, due to varying demand for software features, a split occurred in the Software Generic to address specific market segments. Business Generic X04 formed the foundation for the separate generic streams to evolve. Generic X07 was aimed specifically at the Hotel/Motel communications management market and included the following features:

  • Room Number Correlation
  • Angle Digit Access to Special Services
  • Message Waiting
  • Vacant Room Restriction
  • Supervisory Attendant Console
  • Toll Terminal Access
  • Music-On-Hold
  • System Call Park
  • Room Status
  • Controlled Class-of-Service
  • Recorded Overflow Announcement


X09 (1980)

Software Generic X09 was introduced in 1980 to support the SL-1 XL and additionally provide enhancements to the ACD feature by adding load management and administration and report capabilities

  • ACD Package B
  • ACD Package C
  • Music Package
  • CDR Forced Charge Account

Load management in today’s modern context was an supplemental app, or a service that would run semi separate to the actual PBX. Supposedly programming Meridians you have “load” prompts, because software to program would be in different types of disks that you wouldn’t have running at all times (only because hard drives were limited – even more limited for a PBX setup.) Since hard drives and flash ATA drives, the load command would just simply allow you to go to a certain screen you need to go to.



Northern Telecom (Nortel) SL-1 & Porche Promotional Video

Another YouTube find recently was a video produced by Nortel back in the mid to late 1980s featuring a top of the line car companies of that time.

In this promotional video, it was produced before the Meridian 1 (1989 or so) and it featured the beginnings of ISDN before the ISDN got it’s name. Porche at the time was based in the Western part of the country, with a North American office and an operations office in Nevada with another plant in North Carolina. These plants used the Meridian SL-1 PBX that had the ability to use digital trunking to link up all the facilities and link their IBM mainframe system. This type of marriage would allow customers calling Porche to get screen pops and get customer information in a short period of time. If someone wanted to call another person at the other facility, the name and number would appear (“feature transparency”.)

I am not an expert of the Nortel ecosystem, but the SL1 platform was ridden with random letters for the various hardware/software capacities, and I do not know Nortels fully, so I can’t explain it.


What’s interesting is the full screen graphic that appears at the end of this clip. It was produced by their Santa Clara, California operations. Who would know that operations would become Avaya, and become the headquarters 30 years later? I’d take the cold, dark, least disastrous are of Jersey before working in the Crazy California anyday!


This virtual museum will feature pictures from central offices. A central office is where the hub of the public switched telephone network or PSTN meets and acts as the electronic operator by connecting the call from your home or office to connect to the other party on the other side. These switches are both very physical and very virtual between the millions and millions of wires (in this specific case) that connect to a bunch of mainframe telephone carrier systems that are probably as big as your Frigidaire in your kitchen, the only difference is it carries up to a few thousands of lines in the cabinet and its respective drawers within them. Then the software in the system does the all the magic of hooking up the call whether its down the street or across the country meanwhile these same systems are capable of providing voicemail, services like 3ways, call waiting and calling line ID (CLID or “Caller ID”) services to the customers.  (This is a very Cliff Notes version of central offices – I think a Glossary will be in order soon!)

So, lets start a series by showing today’s set of photos includes photos I had taken on a trip to New York in April. In Lower Manhattan, near their government center, there is a huge tower that has no windows. Normally that’s the sign its a central office. Why they don’t have windows? They don’t need them. In fact, windows could bring in unneeded heat in the summer or the unnecessary arctic temperatures in the winter time.

Verizon Central Office, Manhattan, NY

The Verizon Central Office in Lower Manhattan in New York City

This central office was built when the Bell System still virtually owned the U.S. phone business, the New York counterpart was known as New York Telephone. In the 1984 breakup, NYT joined into the New England Telephone, and the parent company was known as NYNEX (New York New England EXchange), though they operated on separate networks, bureaucracies, union groups etc. New York had more Nortel (Northern Telecom) switches, while in most parts of New England operated the 5ESS switches.

In the mid to late 1990s, NYNEX merged with Bell Atlantic (which operated New Jersey Bell, the Bell companies in PA, Maryland, D.C., Virgina and for the most part of the Mid Atlantic region. The merger took the Bell Atlantic name and the New York/England bell names would disappear. The company had renamed itself Verizon by the year 2000 (without any acquisition by that point.)

The corporate offices are right down a few blocks on Pearl Street, that is the location of the corporate headquarters. I’ll save that for another post.

Like I mentioned earlier, the New York Bell was and is still mostly a Nortel (previously Northern Telecom or NT) using their Digital Multiplex System DMS series of switches, I’m quite positive, I will double check and correct if necessary.

Central Offices: Verizon Lower Manhattan, NY