EPABX Programming

History of the Intercom System

Real-Life Examples of Intercom Systems

Types of Intercom Systems

1. Wired Audio Intercom

A wired audio intercom is the traditional type of intercom system that uses physical cables to connect all intercom stations. It provides clear and reliable two-way voice communication without requiring an internet connection. Because of its stability and low maintenance, it is widely used in offices, schools, hospitals, and factories.

2. Wireless Intercom

A wireless intercom communicates using radio frequency (RF) or Wi-Fi instead of cables. It is easy to install and can be moved from one location to another, making it ideal for temporary installations or places where running cables is difficult. Wireless intercoms are commonly used in homes, warehouses, construction sites, and events.

3. Video Intercom

A video intercom combines voice communication with live video. It includes a camera, microphone, speaker, and display, allowing users to see and talk to visitors before granting access. Video intercoms improve security and are commonly installed in apartments, homes, offices, and gated communities.

4. IP Intercom

An IP intercom uses an Ethernet network or the internet to transmit voice and video. Since it operates over an IP network, it can communicate across multiple buildings or even remote locations. IP intercom systems support high-quality audio and video and can integrate with CCTV, access control systems, and IP PBX solutions. They are widely used in corporate offices, hospitals, airports, and universities.

5. SIP Intercom

A SIP intercom is an IP-based intercom that uses the Session Initiation Protocol (SIP) to communicate with VoIP phones and IP PBX systems. It allows users to make calls between SIP devices and can be easily integrated into existing business telephone networks. SIP intercoms are commonly used in hotels, offices, smart buildings, and large organizations.

6. Paging Intercom

A paging intercom is designed for one-to-many communication. Instead of speaking to a single person, it broadcasts announcements through multiple speakers simultaneously. Paging intercoms are commonly used for public announcements, emergency notifications, and general communication in schools, hospitals, shopping malls, and factories.

7. Door Entry Intercom

A door entry intercom allows visitors to communicate with people inside a building before entering. The system usually includes a call button, microphone, speaker, and sometimes a camera. Many door entry intercoms also allow users to remotely unlock doors, making them popular in homes, apartments, offices, and commercial buildings.

8. Industrial Intercom

An industrial intercom is specially designed for harsh and noisy environments such as factories, mines, power plants, and oil refineries. These systems are built with rugged, weatherproof equipment and powerful speakers to ensure clear communication even in challenging conditions. Many industrial intercoms also include emergency call buttons and alarm integration for worker safety.

Benefits of an Intercom System in Organizations, Schools, Colleges, and Hospitals

1. Benefits in Organizations

An intercom system enables employees to communicate instantly without using mobile phones or external telephone lines. It improves coordination between departments such as Reception, HR, Accounts, Sales, and Management. This reduces response time, increases productivity, and lowers communication costs. Intercoms also support visitor management and internal announcements, making office operations more efficient.

2. Benefits in Schools

In schools, an intercom system allows the principal or administration to make announcements to classrooms quickly and clearly. It is useful for emergency alerts, timetable changes, exam notifications, and general information. Teachers can also communicate with the office without leaving their classrooms, improving both safety and operational efficiency.

3. Benefits in Colleges

Colleges use intercom systems to improve communication across departments, administrative offices, libraries, laboratories, and hostels. Staff can coordinate academic and administrative activities more efficiently. Intercoms are also valuable for campus-wide announcements, emergency communication, and managing events, helping ensure smooth daily operations.

4. Benefits in Hospitals

In hospitals, intercom systems provide fast communication between doctors, nurses, reception, laboratories, pharmacies, and emergency departments. During medical emergencies, staff can immediately request assistance, reducing response times and improving patient care. Intercoms also support public announcements, visitor guidance, and coordination between different hospital units.

Overall Benefits of an Intercom System:

Provides fast and reliable internal communication.
Reduces telephone and mobile communication costs.
Improves teamwork and coordination.
Saves time by enabling instant communication.
Supports emergency communication and safety.
Enhances operational efficiency and productivity.
Can integrate with paging systems, access control, CCTV, and IP PBX systems.
Improves customer, student, and patient service through quicker response times.

Summary:

An intercom system is an essential communication tool for organizations, schools, colleges, and hospitals. It enables quick internal communication, increases efficiency, improves safety, and helps staff coordinate their work more effectively while reducing communication costs.

Deployment Locations of an Intercom System

An intercom system can be deployed in many types of buildings and facilities where fast, reliable internal communication is needed. Below are the most common deployment locations.

1. Offices and Corporate Buildings

Intercom systems are installed in reception areas, management offices, conference rooms, and different departments to enable quick communication between employees and improve office productivity.

2. Schools

Schools deploy intercom systems in the principal’s office, classrooms, staff rooms, libraries, laboratories, and playgrounds. They are used for announcements, emergency alerts, and communication between teachers and the administration.

3. Colleges and Universities

Intercom systems are installed in administrative offices, lecture halls, laboratories, libraries, hostels, security offices, and campus buildings. They help coordinate academic activities and provide campus-wide communication.

4. Hospitals

Hospitals use intercom systems in reception areas, emergency departments, nurse stations, operating theaters, ICUs, wards, laboratories, pharmacies, and administrative offices. They enable rapid communication for patient care and emergency response.

5. Hotels

Hotels install intercom systems at the reception desk, guest rooms, housekeeping offices, kitchens, restaurants, security rooms, and management offices to improve guest service and staff coordination.

6. Residential Apartments

Apartment buildings deploy intercom systems at the main entrance, security gate, reception, parking area, and individual apartments. Residents can communicate with visitors and remotely unlock entrance doors.

7. Factories and Industrial Plants

Industrial intercom systems are installed in production floors, control rooms, warehouses, maintenance departments, loading docks, and security checkpoints. They provide reliable communication in noisy working environments.

8. Shopping Malls and Retail Stores

Intercom systems are used at customer service desks, security rooms, management offices, warehouses, billing counters, and retail floors for staff communication and public announcements.

9. Airports and Railway Stations

Airports and railway stations deploy intercom systems in control rooms, ticket counters, boarding gates, platforms, security checkpoints, and information desks to coordinate staff and make public announcements.

10. Government Buildings and Banks

Government offices and banks install intercom systems in reception areas, executive offices, customer service counters, security rooms, and server rooms to improve communication and security.

Summary:

Intercom systems are deployed wherever people need fast, secure, and reliable internal communication. Common deployment locations include offices, schools, colleges, hospitals, hotels, apartments, factories, shopping malls, airports, railway stations, banks, and government buildings, helping improve communication, coordination, safety, and operational efficiency.

What is EPABX Programming?

Why is EPABX Programming Needed?

What Does EPABX Programming Include?

Extension Programming – Creates, modifies, and manages extension numbers for users, allowing internal communication within the organization.

Trunk Programming – Configures external telephone lines such as PSTN (FXO), SIP Trunks, ISDN, or GSM gateways for incoming and outgoing calls.

Incoming Call Routing – Determines how incoming calls are routed to specific extensions, ring groups, IVR menus, or voicemail.

Outgoing Call Routing – Controls how users make external calls, including trunk selection, call restrictions, and least-cost routing.

Class of Service (COS) – Defines the calling permissions and restrictions for each extension, such as Local, STD, ISD, or Internal-only calling.

Ring Groups – Groups multiple extensions so they ring simultaneously or in a specific sequence when a call is received.

Call Forwarding – Automatically redirects incoming calls to another extension, mobile number, or voicemail based on predefined conditions.

Call Transfer – Allows an active call to be transferred from one extension to another using blind or attended transfer.

Call Pickup – Enables one extension to answer a ringing call from another extension within the same pickup group.

Auto Attendant (IVR) – Automatically answers incoming calls and provides voice menu options to route callers to the appropriate department.

Voicemail – Allows callers to leave voice messages when an extension is busy, unavailable, or does not answer.

Caller ID Configuration – Configures the display of incoming caller information and sets the outgoing caller ID for extensions or trunks.

Speed Dial – Stores frequently dialed telephone numbers for quick and easy access using short dialing codes.

Paging – Broadcasts announcements to selected extensions, paging speakers, or all users within the EPABX system.

Conference Calling – Allows three or more participants to communicate in a single conference call.

Time and Date Settings – Configures the system clock, date, time zone, and daylight saving settings for accurate call records and scheduled operations.

Backup and Restore – Creates backup copies of the EPABX configuration and restores them when required after system failure or maintenance.

Security Settings – Protects the EPABX system by configuring administrator passwords, extension permissions, toll restrictions, and user authentication.

System Maintenance – Monitors system health, performs firmware upgrades, checks logs, restarts services, and diagnoses system faults to ensure reliable operation.

How is EPABX Programming Performed?

2. PC Software Programming:

Description:

Some EPABX systems require dedicated programming software provided by the manufacturer. The software communicates with the EPABX through USB, Serial, or LAN.

Advantages:

Full access to advanced features
Faster configuration
Easy backup and restore
Suitable for large systems

Example:

A technician uses NEC PCPro software on a Windows computer to configure a new EPABX installation.

3. Serial Console Programming

Description:

Older EPABX systems can be programmed through a serial (RS-232) connection using terminal software on a computer.

Advantages:

Reliable for legacy systems
Direct communication with the EPABX
Useful when network access is unavailable

Example:

A technician connects a laptop to the EPABX using a serial cable and configures the system through a terminal application.

Skills Required for EPABX Programming

Common EPABX Programming Used in 90% of Offices

1. Extension Programming

Extension Programming is the process of creating and managing extension numbers for each telephone connected to the EPABX system. Every employee is assigned a unique extension number that allows internal communication without using an external telephone line. The administrator can also assign extension names, enable or disable extensions, and configure analog or IP telephones.

Real Example:
An office has 20 employees. The administrator assigns:

Reception – 200
Manager – 201
Accounts – 202
HR – 203

Employees can call each other by simply dialing the extension number.

2. Trunk Programming

Trunk Programming configures the external telephone lines that connect the EPABX to the public telephone network. These trunks may include PSTN (FXO), SIP Trunks, ISDN, or GSM gateways. Proper trunk programming ensures reliable incoming and outgoing calls.

Real Example:
A company has two BSNL telephone lines and one SIP Trunk. All three trunks are configured so users can make and receive external calls.

3. Incoming Call Routing

Incoming Call Routing determines where incoming calls should be directed after they arrive at the EPABX. Calls can be routed to a receptionist, an extension, a ring group, an IVR, or voicemail depending on the organization’s requirements.

Real Example:
During office hours, all incoming calls are routed to Reception (Extension 200). After office hours, the calls are automatically forwarded to voicemail.

4. Outgoing Call Routing

Outgoing Call Routing controls how users make external calls and which telephone line is used. It also allows administrators to restrict unauthorized calls and optimize telephone costs.

Real Example:
Employees dial 0 before making an outside call. The EPABX automatically selects an available BSNL line or SIP Trunk.

5. Ring Group Programming

Ring Group Programming allows multiple extensions to ring simultaneously or in sequence whenever a call is received for a department. This ensures that important calls are answered quickly.

Real Example:
The Sales department includes extensions 210, 211, and 212. When a customer calls Sales, all three extensions ring at the same time.

6. Class of Service (COS)

Class of Service (COS) defines the calling permissions for each extension. Administrators can allow or restrict local, national (STD), international (ISD), and mobile calls based on the user’s role.

Real Example:
Reception staff can make only local calls, while the General Manager is allowed to make international calls.

7. Call Forwarding

Call Forwarding automatically redirects incoming calls to another extension, mobile number, or voicemail when the original extension is busy, unavailable, or unanswered.

Real Example:
When the Manager leaves the office, all calls to Extension 201 are automatically forwarded to the Manager’s mobile phone.

8. Auto Attendant (IVR)

An Auto Attendant, also known as an Interactive Voice Response (IVR) system, automatically answers incoming calls and provides callers with menu options to reach the appropriate department.

Real Example:
“Welcome to ABC Company. Press 1 for Sales, Press 2 for Support, Press 3 for Accounts.”

The caller is automatically connected to the selected department.

9. Time and Date Settings

Time and Date Settings configure the system clock, calendar, and time zone. Accurate time settings are essential for call logs, voicemail timestamps, scheduled operations, and reports.

Real Example:
After installing the EPABX, the administrator sets the correct date and time so that all call records display accurate timestamps.

10. Caller ID Configuration

Caller ID Configuration enables the display of incoming caller information and configures the outgoing caller ID presented to external parties.

Real Example:
When a customer calls the office, the employee’s telephone displays the customer’s phone number before the call is answered.

11. Call Transfer

Call Transfer allows an active call to be moved from one extension to another without disconnecting the caller. It can be performed as a blind transfer or an attended transfer.

Real Example:
A customer calls Reception asking for the Accounts department. The receptionist transfers the call directly to Extension 202.

12. Backup and Restore

Backup and Restore protects the EPABX configuration by saving all programming settings. If the system is reset, upgraded, or replaced, the saved configuration can be restored quickly.

Real Example:
Before upgrading the EPABX firmware, the administrator creates a complete backup. If any problem occurs during the upgrade, the previous configuration can be restored within minutes.

13. Speed Dial:

Speed Dial allows frequently used telephone numbers to be stored in the EPABX system for quick and convenient dialing. Instead of entering the complete telephone number every time, users can dial a short code to automatically call the stored contact. Speed Dial can be configured as System Speed Dial (available to all users) or Personal Speed Dial (available to a specific extension).

Real Example:
The Reception extension stores frequently used numbers such as suppliers, customers, the courier service, and the branch office. Instead of dialing 03324567890, the receptionist simply dials Speed Dial Code 001.

14. Hotline (Hotline / Off-Hook Dialing):

Hotline is a feature that automatically dials a predefined extension or external telephone number as soon as the user lifts the handset or after a preset delay. The user does not need to dial any digits manually. This feature is commonly used for emergency phones, reception desks, security offices, hospitals, and help desks.

Real Example:
A telephone installed at the factory entrance is programmed with a hotline. When a visitor lifts the handset, the EPABX automatically calls the Reception (Extension 200) without requiring any number to be dialed.

15.Call Back on Busy Feature:

The Call Back on Busy feature allows a user to receive an automatic callback when a busy external line (Junction Line) or a busy internal extension becomes available. This eliminates the need to repeatedly dial the same number and improves communication efficiency.

When all Junction (CO) Lines are busy, the user dials 0 to access an outside line. If a busy tone is heard, the user presses # and replaces the handset. As soon as any one of the busy junction lines becomes free, the PBX automatically rings the user’s extension once. If the handset is picked up within 10 seconds, the user is immediately connected to the available external line.

Similarly, if an Extension is busy, the caller dials the required extension number. After hearing the busy tone, the caller presses # and hangs up. Once the called extension becomes free, the PBX simultaneously rings both the calling and called extensions. If both users answer within 10 seconds, the PBX automatically connects the call without requiring either user to dial again.

This feature is especially useful in offices, hospitals, hotels, schools, and other organizations, where employees frequently encounter busy lines. It saves time, reduces repeated dialing, and ensures that important calls are connected as soon as the required line or extension becomes available.

Example 1: Busy Junction Line (External Call):

Suppose an office has 8 BSNL CO Lines, and all eight lines are currently in use. Mr. Rahul, working at Extension 603, wants to make an external call. He dials 0 to access an outside line but hears a busy tone because no CO line is available. Instead of trying again and again, he presses # and hangs up. After about a minute, one of the CO lines becomes free. The PBX automatically rings Extension 603. Rahul picks up the handset within 10 seconds, and the PBX immediately connects him to the available outside line, allowing him to dial the desired telephone number.

Example 2: Busy Extension (Internal Call):

In a company, the Reception (Extension 601) needs to speak with the Accounts Department (Extension 605). The receptionist dials 605, but the extension is busy because the Accounts staff is already on another call. Instead of repeatedly dialing, the receptionist presses # and hangs up. A few minutes later, when Extension 605 becomes free, the PBX automatically rings both Extension 601 and Extension 605 at the same time. As soon as both users answer within 10 seconds, the PBX automatically connects their call without requiring the receptionist to dial 605 again.

16. What is Memory Dial:

Memory Dial is a PBX feature that allows frequently used telephone numbers to be stored in the system or telephone memory. Instead of dialing the complete phone number every time, the user can call the stored number using a short code or memory location. This saves time, reduces dialing errors, and improves productivity, especially in offices where the same numbers are called repeatedly.

Real Example:

Suppose a company frequently calls its Head Office at 033-24567890. Instead of dialing the entire number each time, the administrator stores it in Memory Location 01. Now, whenever an employee needs to call the Head Office, they simply dial the assigned memory code (for example, 01 or the programmed feature code), and the PBX automatically dials 033-24567890.

Another example is a hospital where the ambulance service, police station, and fire department numbers are stored in memory. During an emergency, staff can dial a short memory code instead of the full telephone number, allowing them to connect quickly.

What is Extension Programming?

Extension Programming is the process of configuring and managing each extension in an EPABX system. It allows the administrator to assign extension numbers, set user permissions, and customize telephone features according to the needs of different users or departments. Through extension programming, every telephone connected to the PBX can be configured to perform specific functions, ensuring efficient and secure communication within the organization.

Each extension can be programmed with different settings such as outgoing call permissions, incoming call handling, call forwarding, call waiting, do not disturb (DND), extension passwords, and class of service (COS). For example, a receptionist may be allowed to answer and transfer all incoming calls, while a finance department extension may be restricted from making international calls. This flexibility helps organizations control telephone usage and improve productivity.

Example: In a company, Extension 601 is assigned to the Reception, 602 to the Sales Department, and 603 to the Manager. The Reception extension is programmed to receive all incoming calls and transfer them to other departments. The Sales extension is allowed to make local and STD calls but cannot make ISD calls. The Manager’s extension is programmed with full calling privileges, including conference calling, call forwarding, and unrestricted external dialing. This customized configuration of each telephone is known as Extension Programming.

Extension Programming is an essential part of EPABX administration because it helps organize communication, improve security, reduce unnecessary telephone expenses, and ensure that every employee has access only to the features required for their job responsibilities.

What is Trunk Programming?

Trunk Programming is the process of configuring the external telephone lines (Trunks) connected to an EPABX system. It allows the administrator to define how incoming and outgoing calls are handled through CO lines, PRI, SIP trunks, or GSM gateways. Through trunk programming, the PBX can control which trunk is used for outgoing calls, how incoming calls are routed, and what permissions or restrictions apply to each trunk.

Trunk programming includes settings such as trunk type, trunk numbering, caller ID, outgoing call routing, incoming call routing, trunk access permissions, dial plans, and call restrictions. These settings ensure that external telephone lines are used efficiently, securely, and according to the organization’s communication requirements.

Example: A company has 8 BSNL CO Lines connected to its EPABX. The administrator programs Trunk 1–4 for the Sales Department and Trunk 5–8 for the Accounts and Management Departments. Incoming calls on Trunk 1 are automatically routed to the Reception (Extension 601), while outgoing calls from the Manager’s extension are given priority to use Trunk 8. This configuration of external telephone lines is called Trunk Programming.

Trunk Programming is an essential part of EPABX administration because it helps manage external telephone lines efficiently, improves call routing, reduces communication costs, enhances security, and ensures that incoming and outgoing calls are handled according to the organization’s communication policy.

What is Incoming Call Routing Programming?

Incoming Call Routing Programming is the process of configuring how incoming external calls are handled in an EPABX system. It allows the administrator to define the destination of calls received from CO lines, PRI lines, SIP trunks, or GSM gateways. By programming the incoming call routing, the PBX can automatically direct calls to a specific extension, receptionist, department, ring group, or IVR (Auto Attendant) without requiring manual intervention.

Incoming Call Routing Programming includes settings such as assigning incoming trunks to specific extensions, configuring IVR menus, defining operator destinations, setting ring groups, and creating different routing rules for business hours, after-office hours, or holidays. These settings ensure that every incoming call reaches the correct destination quickly and efficiently.

Example: A company has 8 BSNL CO Lines connected to its EPABX. The administrator programs CO Line 1 to ring the Reception (Extension 601), CO Line 2 to ring the Sales Department (Extension 602), and CO Line 3 to play a welcome message (IVR). The IVR says, “Press 1 for Sales, Press 2 for Support, or Press 3 for Accounts.” Based on the caller’s selection, the PBX automatically routes the call to the appropriate department. This configuration process is called Incoming Call Routing Programming.

Incoming Call Routing Programming is an essential part of EPABX administration because it ensures that incoming calls are directed to the right person or department, reduces response time, improves customer service, minimizes missed calls, and provides efficient call management for the organization.

What is Outgoing Call Routing Programming?

Outgoing Call Routing Programming is the process of configuring how an EPABX system routes outgoing calls through different external telephone lines (trunks). It allows the administrator to define which trunk, such as a CO Line, PRI Line, SIP Trunk, or GSM Gateway, will be used based on the dialed number, call type, extension, or department. This programming helps optimize trunk usage, reduce telephone costs, and ensure reliable communication.

Outgoing Call Routing Programming includes settings such as assigning trunk access to extensions, creating dial plans, defining trunk priority, setting call restrictions, and selecting different routes for local, STD, ISD, or mobile calls. These rules ensure that outgoing calls are automatically sent through the most appropriate and cost-effective telephone line.

Example: A company has 4 BSNL CO Lines, 1 PRI Line, and 1 SIP Trunk connected to its EPABX. The administrator programs the system so that local calls are routed through the CO Lines, STD calls are routed through the PRI Line, and ISD calls are routed through the SIP Trunk to reduce communication costs. The Sales Department is allowed to use only CO Lines, while the Manager’s extension has permission to use all available trunks. This configuration process is known as Outgoing Call Routing Programming.

Outgoing Call Routing Programming is an important part of EPABX administration because it ensures that every outgoing call uses the correct trunk, balances traffic across available telephone lines, reduces communication expenses, prevents trunk congestion, and improves the overall efficiency of the telephone system.

What is COS Programming?

COS (Class of Service) Programming is the process of assigning different calling permissions and restrictions to extensions in an EPABX system. It allows the administrator to control what each extension is allowed to do, such as making local, STD, ISD, or international calls, accessing specific trunk lines, or using advanced PBX features. COS Programming helps improve security, control telephone expenses, and ensure that employees use the telephone system according to their job responsibilities.

With COS Programming, different extensions can be assigned different levels of access. For example, a receptionist may have permission to make all types of outgoing calls, while a general employee may only be allowed to make local calls. Similarly, the manager’s extension may have unrestricted access to all telephone services, including conference calling, call forwarding, and international dialing.

Example: Consider a company with four extensions. Extension 601 (Reception) is assigned COS Level 1, allowing Local, STD, and ISD calls. Extension 602 (Sales) is assigned COS Level 2, allowing only Local and STD calls. Extension 603 (Accounts) is assigned COS Level 3, allowing only Local calls. Extension 604 (Store Room) is assigned COS Level 4, which permits only internal extension-to-extension communication and blocks all external calls. This assignment of different calling privileges to different extensions is called COS Programming.

COS Programming is an important part of EPABX administration because it prevents unauthorized telephone usage, reduces communication costs, enhances security, and ensures that every user has the appropriate level of telephone access required for their role in the organization.

What is Ring Group Programming?

Ring Group Programming is the process of configuring a group of extensions in an EPABX system so that multiple telephones ring simultaneously or in a predefined sequence when an incoming call is received. It allows the administrator to assign several extensions to a single group, ensuring that calls are answered quickly even if one user is unavailable. Ring Group Programming is commonly used in reception desks, sales departments, customer support teams, and call centers.

Through Ring Group Programming, the administrator can decide which extensions belong to a particular group and how the calls will be distributed. Depending on the PBX model, calls may ring all extensions at the same time (Simultaneous Ring) or one extension after another (Sequential Ring) until someone answers the call.

Example: A company has a Sales Department with three employees using Extensions 602, 603, and 604. The administrator creates a Sales Ring Group containing these three extensions. When a customer calls the Sales number, all three telephones ring simultaneously. The employee who answers first receives the call, while the other telephones stop ringing. If the PBX is configured for sequential ringing, the call first rings Extension 602; if there is no answer, it automatically rings Extension 603, and then Extension 604.

Ring Group Programming is an important EPABX feature because it reduces missed calls, distributes incoming calls efficiently among team members, improves customer response time, and ensures that calls are answered promptly even when some employees are busy or away from their desks.

What is Call Forwarding?

Call Forwarding is an EPABX feature that automatically redirects an incoming call from one extension to another extension, mobile number, or voicemail when the original extension is busy, unanswered, or unavailable. It ensures that important calls are not missed and that callers can always reach the appropriate person.

Call Forwarding can be configured in different ways depending on the organization’s requirements. Common types include Call Forward Always, where all incoming calls are forwarded immediately; Call Forward on Busy, where calls are forwarded only when the extension is already in use; Call Forward on No Answer, where calls are forwarded if the user does not answer within a specified time; and Call Forward on Unreachable, where calls are redirected if the extension is offline or unavailable.

Example: In an office, the Manager uses Extension 605. When the manager is in a meeting or away from the desk, the administrator programs Call Forwarding so that all calls to Extension 605 are automatically forwarded to the Assistant’s Extension 606. As a result, customers and employees can still communicate with the office without experiencing missed calls. Similarly, if Reception (Extension 601) does not answer within 20 seconds, the PBX can automatically forward the call to the Sales Department (Extension 602).

Call Forwarding is an essential EPABX feature because it improves communication efficiency, reduces missed calls, ensures business continuity, increases customer satisfaction, and allows organizations to manage incoming calls more effectively.

What is Barge-In?

Barge-In is an advanced EPABX feature that allows an authorized extension, usually the administrator or supervisor (such as Extension 601 or 602), to enter an ongoing telephone conversation. The administrator can either listen silently (monitor) or join the conversation as a third participant (conference), depending on the PBX configuration. This feature is mainly used for call monitoring, employee training, quality assurance, and emergency situations.

In an EPABX system, Barge-In can be used on both Junction Lines (external calls) and Extension Calls (internal calls). To monitor an external call in progress, the administrator dials #71. To monitor or join an internal extension call, the administrator dials #77 followed by the extension number. Only authorized users are permitted to use this feature to maintain security and privacy.

Example: Suppose Extension 603 is talking to an important customer on an external BSNL line. The Sales Manager at Extension 601 wants to monitor the conversation to ensure that the customer is receiving proper service. The manager dials #71, and the PBX allows the manager to listen to or join the ongoing call. Similarly, if Extension 603 is speaking with Extension 605, the administrator can dial #77 603 to monitor or join that internal conversation.

Barge-In is an important supervisory feature because it helps managers monitor call quality, provide real-time assistance during important conversations, train employees, resolve customer issues quickly, and improve overall communication standards within the organization. It should only be used by authorized personnel in accordance with company policies and applicable privacy regulations.

Note:

Because Barge-In allows someone to monitor or join ongoing calls, it is usually restricted to administrator or supervisor extensions (such as 601 and 602) and should only be used according to the organization’s policies and applicable privacy laws.

What is Call Pick-Up?

Call Pick-Up is an EPABX feature that allows a user to answer a ringing call from another extension without physically going to that telephone. This feature is especially useful when the intended user is away from their desk, ensuring that important calls are not missed. A user simply dials the call pickup code from their own extension, and the PBX connects them to the ringing call.

Call Pick-Up can be configured for individual extensions or pickup groups. In Individual Call Pick-Up, a user answers the call ringing on a specific extension by dialing a feature code along with the extension number. In Group Call Pick-Up, any member of the same pickup group can answer a ringing call by dialing only the pickup code, without specifying the extension number.

Example: Suppose the telephone at Extension 603 (Accounts Department) is ringing, but the employee is away from the desk. A colleague at Extension 604, sitting nearby, notices the ringing phone. Instead of letting the call go unanswered, the colleague dials the Call Pick-Up code from Extension 604. The PBX immediately transfers the ringing call to Extension 604, allowing the colleague to answer the customer’s call on behalf of the Accounts Department.

Call Pick-Up is an important EPABX feature because it reduces missed calls, improves customer service, allows team members to assist one another, and ensures that incoming calls are answered quickly even when the intended user is unavailable.

In this PBX, the Call Pick-Up code is #9. When a user dials #9, the PBX automatically connects them to the highest-priority ringing or waiting call. The system follows a predefined priority order to determine which call should be picked up first.

Real Example:

Suppose Reception (Extension 601) receives an important customer call, but the receptionist is away from the desk. The telephone at Extension 601 continues ringing. An employee sitting at Extension 603 notices the ringing phone and dials #9. The PBX immediately picks up the ringing external call and connects it to Extension 603, allowing the employee to answer the customer’s call without going to the reception desk.

Call Pick-Up is an important EPABX feature because it reduces missed calls, improves customer service, allows employees to assist each other, and ensures that high-priority calls are answered as quickly as possible.

Emergency Conference Call

Emergency Conference Call is an EPABX feature that allows one extension to instantly call all extensions in the system at the same time. By dialing the emergency code, the PBX makes every extension ring simultaneously. When users answer their phones, they are automatically connected into a single conference call, allowing everyone to communicate together. This feature is mainly used for urgent announcements or emergency situations.

In this PBX, the Emergency Conference Call code is #88. When any extension dials #88, the PBX sends a ringing signal to all connected extensions. As users answer the call, they are automatically joined to the conference. No manual dialing or call transfer is required.

Example: Suppose there is a fire alarm in an office building. The administrator at Extension 601 immediately dials #88. Instantly, all extensions such as 602 (Sales), 603 (Accounts), 604 (HR), and 605 (Manager) start ringing. As soon as everyone answers their telephones, they are connected into the same conference call. The administrator announces, “Attention everyone, please evacuate the building immediately using the nearest emergency exit.” All employees hear the announcement at the same time.

This feature is especially useful in offices, hospitals, schools, hotels, factories, and warehouses, where an urgent message must be delivered to all staff members simultaneously. It enables fast communication, reduces response time during emergencies, and ensures that important information reaches everyone without delay.

What is Conference Call?

What is Do Not Disturb (DND)?

Do Not Disturb (DND) is an EPABX feature that temporarily prevents incoming calls from ringing a particular extension. When an extension is in DND mode, other users cannot call that extension, allowing the user to work without interruptions. This feature is useful during meetings, presentations, or when the user does not wish to receive calls.

In this PBX, a user can activate DND by dialing #83 from their extension. Once DND is enabled, the extension will not receive incoming calls. According to the manual, to cancel DND, simply lift the handset. After lifting the handset, the extension returns to Normal Mode and can receive calls again.

Real Example:

Suppose the Manager (Extension 605) is attending an important online meeting and does not want to be disturbed by incoming calls. Before the meeting starts, the manager dials #83 to activate Do Not Disturb mode. Now, if the Reception (Extension 601) or any other employee tries to call Extension 605, the call will not ring on the manager’s telephone. After the meeting is over, the manager simply lifts the handset, which automatically cancels DND mode. The extension then returns to Normal Mode, and incoming calls can be received again.

The Do Not Disturb (DND) feature is useful in offices, hospitals, hotels, and conference rooms, where users may need uninterrupted time for meetings, confidential discussions, or focused work. It helps reduce interruptions, improves productivity, and ensures that users can control when they receive telephone calls.

What is Day Mode and Night Mode?

Day Mode and Night Mode are EPABX operating modes that allow the system to use different call handling settings during office hours and after office hours. The PBX stores two separate sets of programming—one for Day Mode and another for Night Mode. By switching between these modes, the administrator can automatically change how incoming calls are routed without reprogramming the system.

In this PBX, the administrator can switch the system to Day Mode by dialing #20 and to Night Mode by dialing #21. The default setting is Day Mode. Each mode can have different call routing, ringing extensions, operator settings, and other call-handling rules.

Real Example:

Suppose a company works from 9:00 AM to 6:00 PM. During office hours, the administrator keeps the PBX in Day Mode by dialing #20. In this mode, all incoming calls are routed to the Reception (Extension 601), where the receptionist answers and transfers calls to different departments.

At 6:00 PM, when the office closes, the administrator changes the PBX to Night Mode by dialing #21. Now, instead of ringing the reception desk, all incoming calls are automatically routed to the Security Office (Extension 610) or to the Manager’s Extension (605), since the receptionist is no longer available. Some organizations may also configure Night Mode to play a recorded message such as “Our office is currently closed. Please call during business hours.”

Day Mode and Night Mode are important EPABX features because they allow organizations to handle calls differently during business and non-business hours, improve customer service, reduce missed calls, and ensure that incoming calls always reach the appropriate destination based on the time of day.

Disallowed Number Programming (Call Restriction Table)

Disallowed Number Programming is an EPABX feature that allows the administrator to block specific telephone numbers or number prefixes from being dialed by selected extensions. It is used to prevent unauthorized or expensive calls, such as mobile, STD, ISD, or premium-rate numbers. This feature helps organizations control telephone expenses and improve communication security.

In this PBX, the Disallowed Number Table is used only for extensions whose Junction Dialing Control value (L) is set to 4. The table contains 16 memory locations (01–16), and each location can store the first four digits (prefix) of a telephone number that should be blocked. Whenever a user with L = 4 dials a number starting with one of these stored prefixes, the PBX automatically rejects the call.

Example: Suppose a company wants to prevent employees from calling mobile numbers that begin with 9876. The administrator stores the prefix 9876 in Location 01 of the Disallowed Number Table using the programming command #*0000 + 41 01 9876#. Now, any extension with L = 4 that tries to dial 9876543210 or any other number starting with 9876 will not be able to make the call. Similarly, different prefixes can be stored in the remaining locations to block other types of telephone numbers.

Disallowed Number Programming is an important EPABX feature because it prevents unauthorized telephone usage, reduces communication costs, protects company resources, and ensures that employees can make only the calls permitted by the organization’s telephone policy.

Programming Command:

To store a blocked number prefix:

				
					#*0000 + 41 QQ ABCD#

				
					#*0000 41 01 9876#

What is Door Phone Programming?

Door Phone Programming is an EPABX feature that allows a Door Phone (Door Intercom) to be connected directly to the PBX. When a visitor presses the door phone button, the PBX rings the assigned extensions, allowing users inside the building to communicate with the visitor before opening the door. This feature improves security and convenience in offices, apartments, hospitals, schools, and factories.

In this PBX, one Door Phone can be connected. The Door Phone uses two wires, which are connected to any extension port from 601 to 605. After the physical connection, the administrator must program that extension as the Door Phone extension. This is done by dialing #*0000 + 80 N#, where N = 1 to 5, representing Extensions 601 to 605. If the administrator wants to use that extension as a normal telephone again, the Door Phone setting can be removed by dialing #*0000 + 800#.

The PBX also allows the administrator to decide which extensions will ring when someone presses the Door Phone button. This is called Door Phone Ring Assignment. By using the command #*0000 + 82 N#, up to three extensions (excluding the Door Phone extension itself) can be assigned to ring. If required, all Door Phone ring assignments can be cleared by dialing #*0000 + 82#.

Example: Suppose a company installs a Door Phone at the main entrance and connects it to Extension 605. The administrator programs Extension 605 as the Door Phone using #*0000 + 805#. Then, the administrator assigns Reception (601), Security (602), and Manager (603) to ring whenever a visitor presses the Door Phone button by programming #*0000 + 821#, #*0000 + 822#, and #*0000 + 823#. When a visitor arrives and presses the Door Phone button, all three assigned extensions ring. The receptionist answers the call, speaks with the visitor, and then allows entry if appropriate.

Door Phone Programming is an important EPABX feature because it enhances building security, allows visitors to communicate with staff before entering, ensures that multiple users can respond to door calls, and provides a convenient and professional access control solution.

What is Flexible Extension Numbering?

Flexible Extension Numbering is an EPABX feature that allows the administrator to change the default extension numbers according to the organization’s requirements. Instead of using the factory default extension numbers, custom numbers can be assigned to make the telephone system easier to use and manage.

By default, the PBX assigns extension numbers from 601 to 608. This means the first extension is 601, the second is 602, and so on up to 608. Users can call each other by dialing these extension numbers immediately after installation.

The PBX also supports 1-digit, 2-digit, 3-digit, and 4-digit extension numbering. This feature is called Flexible Numbering because the administrator is free to create a numbering plan that matches the company’s needs. For example, a small office may use 1 to 8, while a large company may use 1001, 1002, 1003, etc.

Example: Suppose an office has eight employees. Initially, their extension numbers are 601, 602, 603, 604, 605, 606, 607, and 608. The administrator decides to simplify the numbering and changes them to 1, 2, 3, 4, 5, 6, 7, and 8. Now, instead of dialing 605, employees only need to dial 5 to call that extension. Similarly, in a large organization, the administrator may change the numbers to 1001, 1002, 1003, 1004, and so on, making the numbering consistent with the company’s internal telephone plan.

Flexible Extension Numbering is an important EPABX feature because it allows organizations to customize extension numbers, simplifies internal communication, supports future expansion, and makes the telephone system easier for employees to remember and use.

What is Flexible Extension Numbering Programming?

Flexible Extension Numbering Programming is an EPABX feature that allows the administrator to change the default extension numbers to custom numbers according to the organization’s requirements. Instead of using the factory default extension numbers (601–608), the administrator can assign new extension numbers that are easier to remember and better suited to the company’s internal numbering plan.

The PBX supports 1-digit, 2-digit, 3-digit, and 4-digit extension numbers. New extension numbers can be assigned within the range of 11 to 6999. Different extensions can have different digit lengths if required. However, the new extension number cannot begin with 0, 7, 8, or 9, because these digits are reserved for PBX functions such as trunk access, feature codes, and programming commands.

Before assigning new extension numbers, the administrator can reset all existing flexible numbering by dialing #*0000 + 9000#. This command clears all custom extension numbers and restores the PBX to its default numbering (601–608).

To change a single extension number, the administrator uses the command #*0000 + 9 N ABCD#, where N represents the last digit of the original extension number printed on the MDF panel, and ABCD represents the new extension number. The physical extension port does not change; only the dialing number changes.

If all extension numbers need to be changed in sequence, the PBX provides a shortcut programming command. By dialing #*0000 + 9000 L K#, the administrator can automatically assign sequential extension numbers. Here, L represents the number of digits (3 or 4), and K represents the first digit of the new numbering plan. For example, if L = 3 and K = 2, the extensions become 201, 202, 203…208. If L = 4 and K = 2, the extensions become 2001, 2002, 2003…2008.

Example: Suppose an office wants to replace the default extension numbers 601–608 with 101–108. The administrator programs each extension individually using the Flexible Numbering command. After programming, employees will dial 101 instead of 601, 102 instead of 602, and so on, while the physical wiring on the MDF remains unchanged.

Flexible Extension Numbering Programming is an important EPABX feature because it allows organizations to create a customized extension numbering plan, simplifies internal communication, supports future expansion, and makes extension numbers easier for employees to remember and use.

Before assigning new extension numbers, the administrator can reset all previous flexible numbering by dialing:

				
					#*0000 + 9000#

Where:

0000 = Programming Password
9 = Flexible Numbering Command
N = Last digit of the original extension number
ABCD = New extension number

Here, N always refers to the original MDF extension number, not the new number. Even after changing the extension number, the physical port on the PBX remains the same.

Example 1

Suppose you want to change:

601 → 101

Since the last digit of 601 is 1, dial:

				
					#*0000 9 1 101#

Now, users will dial 101 instead of 601.

Example 3

Suppose you want to change:

608 → 2008

Dial:

				
					#*0000 9 8 2008#

Now, Extension 608 becomes 2008.

What is Automatic Sequential Numbering?

Automatic Sequential Numbering is an EPABX feature that automatically assigns new extension numbers in a continuous sequence. Instead of changing each extension number one by one, the administrator can use a single programming command to renumber all extensions automatically. This saves time and simplifies the numbering process, especially when many extensions need to be renumbered.

In Automatic Sequential Numbering, the administrator specifies only two values: L and K. Here, L defines the length of the new extension numbers (3 digits or 4 digits), while K defines the first digit of the new numbering plan. After these values are entered, the PBX automatically assigns the remaining extension numbers in sequence.

Example: Suppose the default extension numbers are 601 to 608, and the company wants to change them to 201 to 208. Since the new extension numbers contain 3 digits, L = 3. Because the numbering starts with 2, K = 2. The administrator dials the programming command once, and the PBX automatically changes the extension numbers as follows:

601 → 201
602 → 202
603 → 203
604 → 204
605 → 205
606 → 206
607 → 207
608 → 208

Similarly, if the administrator selects L = 4 and K = 2, the PBX automatically assigns 2001, 2002, 2003…2008 to the extensions.

Automatic Sequential Numbering is a useful EPABX feature because it reduces programming time, eliminates manual configuration errors, maintains a consistent extension numbering plan, and makes it easier to manage large telephone systems.

How Do I Enter L and K?

In the EPABX programming manual, L and K are not actual keys on the telephone keypad. They are variables (placeholders) used to represent numeric values. When programming the PBX, you must replace L and K with the appropriate numbers before dialing the command.

The value of L represents the length of the new extension numbers. If you want all new extension numbers to have 3 digits, then L = 3. If you want all new extension numbers to have 4 digits, then L = 4.

The value of K represents the first digit of the new extension numbering plan. For example, if you want all extension numbers to start with 2, then K = 2. If you want them to start with 1, then K = 1. The first digit can be 1, 2, 3, 4, 5, or 6, but it cannot be 0, 7, 8, or 9.

Example: Suppose you want to change the default extension numbers 601–608 to 201–208. Since the new numbers contain 3 digits, L = 3. Because the new numbers start with 2, K = 2. Therefore, instead of dialing L and K, you dial the actual numbers:

				
					#*0000 9000 32#

				
					#*0000 9000 41#

This automatically changes the extension numbers to 1001, 1002, 1003…1008. Thus, L and K are only symbols used in the manual—they should always be replaced with the required numeric values when entering the programming command.

Automatic Sequential Numbering Command Explanation:

The command #*0000 9000 32# is used to automatically change all extension numbers in the EPABX to a new sequential numbering plan. Instead of programming each extension individually, the administrator can use this single command to renumber all extensions automatically.

The #* at the beginning of the command tells the PBX that the user wants to enter Programming Mode. It informs the system that the following digits are programming instructions rather than a normal telephone number.

The 0000 is the default programming password. It authenticates the administrator before allowing any changes to the PBX configuration. If the password has been changed, the administrator must enter the new password instead of 0000.

The 9000 is the programming code for Automatic Sequential Numbering. This command tells the PBX to automatically assign new extension numbers to all extensions in sequence without requiring individual programming.

The digit 3 represents the value of L (Length). It specifies that all new extension numbers will contain 3 digits. If 4 is entered instead, the PBX will create 4-digit extension numbers.

The digit 2 represents the value of K (Starting Digit). It specifies that all new extension numbers will begin with the digit 2. As a result, the PBX automatically generates extension numbers such as 201, 202, 203, 204, 205, 206, 207, and 208.

The final # indicates the end of the programming command. After receiving this symbol, the PBX processes the command and saves the new extension numbering plan.

Example: Suppose the default extension numbers are 601 to 608, and the administrator wants to change them to 201 to 208. By dialing #*0000 9000 32#, the PBX automatically changes the numbering as follows:

601 → 201
602 → 202
603 → 203
604 → 204
605 → 205
606 → 206
607 → 207
608 → 208

This feature saves time, reduces manual programming, and ensures that all extension numbers are assigned in a consistent sequence.

What is Direct Junction Access (Hot Line to Junction)?

Direct Junction Access, also known as Hot Line to Junction, is an EPABX feature that automatically provides an outside telephone line (CO Line/Junction Line) as soon as the user lifts the handset. In this mode, the user does not need to dial 0 or any other trunk access code before making an external call. This feature is commonly used for reception desks, security offices, or departments that frequently make external calls.

When an extension is programmed for Hot Line to Junction, lifting the handset immediately connects the extension to a free Junction Line, and the user hears the external dial tone. If the user wants to make an internal extension call, they must first dial * after lifting the handset. The PBX then changes the dial tone from the external line to the internal dial tone, allowing the user to dial another extension.

To enable Direct Junction Access for a specific extension, the administrator dials #*0000 + 20 N#, where N is the last digit of the original extension number. For example, to enable this feature for Extension 605, the command is #*0000 205# because the last digit of 605 is 5.

If the administrator wants all extensions to receive a Junction Line immediately after lifting the handset, the command is #*0000 20#. After this programming, every extension automatically receives an outside line without dialing any access code.

To disable this feature for a specific extension and return it to Normal Mode, the administrator dials #*0000 21 N#. To return all extensions to Normal Mode, the command is #*0000 21#. In Normal Mode, users must first dial the trunk access code (such as 0) before making an external call.

Example: Suppose the Reception (Extension 601) handles customer calls throughout the day. The administrator enables Hot Line to Junction for Extension 601. Now, whenever the receptionist lifts the handset, the PBX immediately provides a free BSNL line, and the receptionist can dial an outside telephone number directly. However, if the receptionist wants to call the Manager (Extension 605), they must first lift the handset, dial *, wait for the internal dial tone, and then dial 605.

An important note is that if all extensions are configured in Hot Line to Junction Mode, the normal programming method changes. To enter Programming Mode, the administrator must first lift the handset, dial * to obtain the internal dial tone, and then dial #*0000 followed by the required programming command.

Direct Junction Access (Hot Line to Junction) improves efficiency by allowing users to make external calls more quickly, reducing the number of dialing steps and making communication faster for departments that primarily handle outside calls.

What is Hot Line to Extension?

Hot Line to Extension is an EPABX feature that automatically connects an extension to a pre-programmed extension as soon as the user lifts the handset. The user does not need to dial any extension number manually. This feature is commonly used in places such as reception desks, security offices, hospitals, and help desks, where users frequently need to contact the same person or department.

When an extension is programmed in Hot Line to Extension Mode, lifting the handset immediately starts a call to the assigned extension. However, if the user wants to call a different internal extension, they must first dial * after lifting the handset to obtain the PBX’s internal dial tone. After hearing the internal dial tone, they can dial any desired extension number.

To enable Hot Line to Extension for a specific extension, the administrator uses the following programming command:

				
					#*0000 + 883 N XXXX#

				
					#*0000 883 1 605#

				
					#*0000 884 N#

				
					#*0000 884 1#

After this programming, Extension 601 will no longer automatically call Extension 605 when the handset is lifted.

Real Example:

Suppose a hospital has a Nurse Station (Extension 601) and a Doctor’s Office (Extension 605). The hospital wants every call from the nurse station to reach the doctor immediately without dialing an extension number.

The administrator programs Extension 601 in Hot Line to Extension Mode with Extension 605 as the destination.

Now, whenever the nurse lifts the handset, the PBX automatically calls Extension 605. If the nurse needs to call another department, such as Accounts (Extension 603), they simply lift the handset, dial * to get the internal dial tone, and then dial 603.

Important Note:

If all extensions are programmed in Hot Line Mode, the normal programming procedure changes. To enter Programming Mode, first lift the handset, dial * to obtain the internal dial tone, then dial #*0000 followed by the required programming command.

Hot Line to Extension is a useful EPABX feature because it provides instant communication with a frequently contacted extension, reduces dialing time, eliminates dialing errors, and improves response time in offices, hospitals, hotels, and other organizations.

What is Redial?

Redial is an EPABX feature that allows an extension user to automatically dial the last outside telephone number that was called. Instead of dialing the complete number again, the user simply uses the Redial code, and the PBX calls the last dialed number. This feature saves time and is useful when the called party is busy or the call was accidentally disconnected.

When a user makes an external call and later wants to call the same number again, they do not need to remember or re-enter the entire telephone number. The PBX stores the last dialed number in its memory, and the user can recall it using the Redial feature.

Real Example:

Suppose Extension 601 calls the customer at 9876543210. The customer does not answer. A few minutes later, the receptionist wants to call the same number again. Instead of dialing 9876543210 again, the receptionist simply uses the Redial feature, and the PBX automatically dials the last number.

CCL Redial Code:

On most CCL EPABX models, the Redial code is: ##

What is Call Waiting

Call Waiting is a standard PBX feature that allows an extension user to receive notification of a second incoming call while they are already engaged in another conversation. Instead of sending the second caller a busy tone, the PBX holds the new call in a waiting state and alerts the user with a beep tone, flashing LED, or display message on the telephone. The user can choose to continue the current conversation, place the first caller on hold and answer the waiting call, switch between the two calls, or ignore the new call. This feature helps ensure that important calls are not missed and improves communication efficiency in an organization.

Real Example:

Imagine an office where the receptionist uses Extension 101 on the PBX system. While speaking with Customer A, Customer B calls the same extension. The PBX generates a call waiting tone to inform the receptionist of the second incoming call. The receptionist can finish speaking with Customer A, or place Customer A on hold and answer Customer B. After completing the second conversation, the receptionist can switch back to Customer A. This allows both callers to be handled without disconnecting the first call or giving the second caller a busy tone.

When you hear a call waiting tone during a conversation, press the FLASH or RECALL key to answer the second call. The first call is automatically placed on hold. Press the FLASH/RECALL key again to switch back to the first caller. On IP phones, use the Answer or Swap soft key instead.

What is Call Hold?

What is Call Park?

Call Park is a PBX feature that allows a user to place an active call in a temporary parking location, where it can be retrieved from another extension. Unlike Call Hold, which can usually be resumed only from the same phone, a parked call can be picked up from any authorized extension by dialing the assigned park code.

Example:
A receptionist receives a call for the Sales Manager but does not know where the manager is. The receptionist parks the call and announces, “Please pick up the parked call on Park 701.” The Sales Manager dials 701 from any office extension to retrieve the call.

Note: The exact feature codes (such as *6, 701, etc.) are configurable and may differ depending on the PBX programming. The installer or system administrator can change these codes.

How to Use Call Park (PBX):

Answer or make a call.
Press the Call Park key or dial the Call Park feature code.
The PBX assigns a Park Number (for example, 701).
Inform the other user of the park number.
From any authorized extension, dial the Park Number (701) to retrieve and continue the call.

What is Call Hunt?

What is Call Toggle?

Call Toggle is a PBX feature that allows a user to switch between two active calls without disconnecting either call. While talking to one caller, the other call is automatically placed on hold. The user can switch back and forth between the two calls whenever required.

Example:

Extension 101 is talking to Customer A. During the conversation, Customer B calls Extension 101. The user answers the second call, and Customer A is automatically placed on hold. By using the Call Toggle feature, the user can switch between Customer A and Customer B without ending either call.

Difference Between Call Toggle and Conference Call:

Call Toggle: The user can talk to only one caller at a time, while the other caller remains on hold.
Conference Call: All participants can talk to each other at the same time in a single call.

Call Toggle Procedure:

Call Toggle allows a user to switch between two active calls without disconnecting either caller. While speaking to one party, the other party is automatically placed on hold. The user can press Flash + 1 to switch between the two calls whenever required.

Procedure

Step 1:
While talking to the first caller, place the call on Hold. The caller will hear music on hold.

Step 2:
Dial the second extension number. The second extension will start ringing.

Step 3:
When the second party answers, speak with them as required.

Step 4:
To switch between the two calls, press Flash, then dial 1. The current caller will be placed on hold, and you will be connected to the other caller.

Step 5:
Repeat Flash + 1 whenever you want to switch between the first and second callers.

Step 6:
When the conversation is finished, simply hang up the handset to end the call.

Music on Hold (MOH)

Music on Hold (MOH) is a PBX feature that plays music or a recorded announcement to a caller while the call is on hold. Instead of hearing silence, the caller hears music or a company message until the call is resumed. Music on Hold provides a professional calling experience and assures the caller that the call is still active.

Example:

A customer is speaking with Extension 101. The user needs to consult Extension 102, so they place the customer on hold. While waiting, the customer hears background music or a recorded message such as, “Thank you for calling ABC Company. Please stay on the line.” After the consultation is complete, the user returns to the customer, and the conversation continues.

How to Set Up Music on Hold:

To use Music on Hold, the PBX must have either a built-in music source or an external music input. If an external music source is used, connect a compatible music player, mobile phone, or computer to the PBX’s Music on Hold (MOH) port. Once connected and configured, the PBX will automatically play the music whenever a call is placed on hold.

Note: The exact setup procedure depends on the PBX model and manufacturer.

What is Make Set Busy?

Programming the PBX

				
					#*0000

				
					#*0000

What is Allowed Table?

Table Programing

				
					#*0000 + 43 QQ ABCD#

				
					#*0000 4301 9831#

Clear the Entire Allowed Table

				
					#*0000 43#

Example:
To clear Location 01:

				
					#*0000 4301#

Note: The Allowed Table contains 16 locations, and each location stores one allowed number prefix. Extensions assigned to Dialing Control Level (L = 0) can dial only the numbers that match the prefixes stored in this table.

Auto Attendant Programing

Auto Attendant:

Auto Attendant is a PBX feature that automatically answers incoming calls and plays a recorded voice message. It guides callers to the appropriate extension without requiring a receptionist to answer the call. This feature improves call handling and provides a professional greeting for callers.

Example:
A customer calls your office. Instead of the phone ringing at the reception, the PBX answers automatically and plays: “Welcome to ABC Company. Please dial the extension number you require.” The caller then dials 101 for Sales or 102 for Support.

Types of Auto Attendant Messages:

The PBX supports three recorded messages:

Welcome Message (10 Seconds): Played when a caller first connects to the PBX.
Busy Message (5 Seconds): Played when the selected extension is busy.
No Answer Message (5 Seconds): Played when the selected extension does not answer within the specified time.

Example:
If a caller dials Extension 101 and it is busy, the PBX plays the Busy Message. If no one answers the call, the PBX plays the No Answer Message before ending or redirecting the call.

How to Enable Auto Attendant Programing:

To enable Auto Attendant for a junction, enter the following command:

				
					#*0000 + 10 J#

Where:

*#0000 = Programming Password
10 = Auto Attendant Enable Command
J = Junction Number (1 or 2)

Example:

To enable Auto Attendant for Junction 1

				
					#*0000 101#

Result:
Incoming calls on Junction 1 will be answered automatically by the PBX, and the Welcome Message will be played.

How to Disable Auto Attendant (Direct Ring):

To disable Auto Attendant and return the junction to Direct Ring mode:

				
					#*0000 + 11 J

Result:
Incoming calls will ring directly on the assigned extension without playing any recorded message.

How to Record an Auto Attendant Message:

To record an Auto Attendant message, first lift the handset of a programming extension (such as 601, 602, 603, or 604). Then enter the programming password and dial the recording command:

				
					#*0000 + 12 M#

Where:

0000 = Default Programming Password
12 = Record Message Command
M = Message Type
- 1 = Welcome Message
- 2 = Busy Message
- 3 = No Answer Message

Example:

To record the Welcome Message, dial:

				
					#*0000 121#

Recording Procedure:

Lift the handset of a programming extension (601–604).
Dial the recording command (for example, #*0000 121#).
Wait for the first confirmation beep.
After the beep, start speaking clearly. Your voice will be recorded.
When you hear the second beep, the recording has finished automatically.
Hang up the handset.

Example Message:

After the first beep, you can record a message such as:

“Welcome to ABC Company. Please dial the extension number you require.”

The PBX will play this recorded message automatically whenever a caller reaches the Auto Attendant.

Important Note:

According to the manual, the caller can dial extension numbers such as 101, 102, etc. However, the Operator Extension (for example, 101, 601, or another extension) and the Junction Landing destination are configured in a different programming section of the manual.

That section has not been provided yet. It will usually contain the Operator Assignment or Junction Landing Programming settings.

Once you share that page, I can explain the complete Auto Attendant call flow, including exactly where the call goes after the Welcome Message and how to configure each step.

Auto Call Back Programing

Auto Call Back is a PBX feature that automatically calls the user back when a busy junction line or busy extension becomes available. Instead of repeatedly dialing the same number, the user can activate Auto Call Back, and the PBX will notify the user when the line is free.

Example:

Extension 101 tries to call Extension 102, but 102 is busy. The user dials # after hearing the busy tone and hangs up. When Extension 102 becomes available, both extensions ring automatically. When both users answer within 10 seconds, the PBX connects the call.

Auto Call Back from a Busy Junction Line:

If all junction (CO) lines are busy, the user can request an automatic callback. After dialing 0, if a busy tone is heard, dial # and hang up. When any junction line becomes available, the PBX rings the extension once. The user must answer within 10 seconds to be connected to the free junction line.

Example:

Extension 101 dials 0 to make an outside call, but all junction lines are busy. The user dials # and hangs up. When a junction line becomes free, Extension 101 rings. The user answers within 10 seconds, and the PBX automatically connects the outside call.

Auto Call Back from a Busy Extension:

If the called extension is busy, the user can activate Auto Call Back by dialing # after hearing the busy tone. When the busy extension becomes available, both the calling and called extensions ring simultaneously. If both users answer within 10 seconds, the PBX automatically connects the call.

Example:

Extension 101 calls Extension 102, but 102 is busy. After hearing the busy tone, the user at 101 dials # and hangs up. When Extension 102 becomes free, both 101 and 102 ring at the same time. After both users answer, the PBX automatically connects the call.

Auto Call Disconnection Programing

Auto Call Disconnection is a PBX feature that automatically disconnects an outgoing junction (CO line) call after a predefined time limit. This feature helps control call duration and prevents users from making excessively long outgoing calls.

Example:

Extension 101 is programmed with a 10-minute call limit. When the user makes an outgoing call, the PBX automatically disconnects the call after 10 minutes. This feature applies only to outgoing junction calls and does not affect incoming calls.

Programming Procedure:

To set the automatic call disconnection time:

				
					#*0000 + 6 NN TT#

Where:

NN = Last two digits of the extension number.
TT = Call duration in minutes (01–99).

Example:

To disconnect outgoing calls from Extension 101 after 10 minutes:

				
					#*0000 60110#

Explanation:

6 = Auto Call Disconnection Feature
01 = Extension 101 (last two digits)
10 = Disconnect the call after 10 minutes

Result:
Every outgoing call made from Extension 101 will be automatically disconnected after 10 minutes.

Cancel Auto Call Disconnection:

To remove the time limit:

				
					#*0000 + 6 NN 00#

Example:

To cancel the time limit for Extension 101:

				
					#*0000 60100#

Result:
Extension 101 can make outgoing calls without any automatic disconnection.

Important Note:

✅ This feature applies only to outgoing junction (CO line) calls.
❌ It does not apply to incoming junction calls.
Default Setting: No call time limit is applied unless it is programmed.

Barge-In Programing

Barge-In:

Barge-In is a PBX feature that allows an authorized extension to join or monitor an ongoing call. In this PBX, only Extension 601 and Extension 602 are authorized to use this feature. They can listen to or join a conversation between an extension and a junction (CO line) or between two extensions.

Example:

A customer is talking to Extension 101 on Junction 1. The manager at Extension 601 wants to monitor or assist with the conversation. Using the Barge-In feature, Extension 601 can join the call and listen or speak in the conference.

Barge-In to a Junction Line:

To listen to an active Junction (CO) Line, dial:

#7J

Where:

#7 = Barge-In command.
J = Junction Number.
- 1 = Junction 1
- 2 = Junction 2

Example:

To monitor Junction 1:

#71

Result:
Extension 601 or 602 will be connected to the active call on Junction 1. The user can listen to the conversation and, depending on the PBX configuration, may also speak in the conference.

Barge-In to an Extension:

Command:

				
					#77 Extension Number

Where:

#77 = Barge-In command for an extension.
Extension Number = The extension that is currently on a call.

Example:

To monitor Extension 101:

				
					#77101

Result:
Extension 601 or 602 will join the ongoing call of Extension 101 and can listen to or participate in the conversation.

Real Example:

Suppose:

Extension 101 is talking to a customer on Junction 1.
The manager is using Extension 601.

The manager dials:

#71

The PBX connects Extension 601 to the active call on Junction 1.

Or, if the manager wants to monitor Extension 101 directly, they dial:

				
					#77101

The PBX connects Extension 601 to the ongoing conversation of Extension 101.

Important Note:

Only Extensions 601 and 602 are authorized to use the Barge-In feature.
J always represents the Junction Number (1 or 2).
This feature is typically used by supervisors, managers, or administrators to monitor calls, provide assistance, or join an active conversation.

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EPABX Programming

Table of Contents

History of the Intercom System

Real-Life Examples of Intercom Systems

Types of Intercom Systems

What is EPABX Programming?

Why is EPABX Programming Needed?

What Does EPABX Programming Include?

How is EPABX Programming Performed?

Conclusion:

Skills Required for EPABX Programming

1. Telephony Fundamentals

2. Extension Programming

3. Trunk Configuration

4. Call Routing

5. Class of Service (COS)

6. Auto Attendant (IVR)

7. Voicemail Configuration

8. Networking Knowledge

9. SIP Protocol

10. IP Phone Configuration

11. Cabling Skills

12. Call Features Configuration

13. Troubleshooting Skills

14. Manufacturer-Specific Programming

15. Backup and Restore

Common EPABX Programming Used in 90% of Offices

1. Extension Programming

2. Trunk Programming

3. Incoming Call Routing

4. Outgoing Call Routing

5. Ring Group Programming

6. Class of Service (COS)

7. Call Forwarding

8. Auto Attendant (IVR)

9. Time and Date Settings

10. Caller ID Configuration

11. Call Transfer

12. Backup and Restore

13. Speed Dial:

14. Hotline (Hotline / Off-Hook Dialing):

15.Call Back on Busy Feature:

Example 1: Busy Junction Line (External Call):

Example 2: Busy Extension (Internal Call):

16. What is Memory Dial:

Real Example:

What is Extension Programming?

What is Trunk Programming?

What is Incoming Call Routing Programming?

What is Outgoing Call Routing Programming?

What is COS Programming?

What is Ring Group Programming?

What is Call Forwarding?

What is Barge-In?

What is Call Pick-Up?

Emergency Conference Call

What is Conference Call?

What is Do Not Disturb (DND)?

What is Day Mode and Night Mode?

Disallowed Number Programming (Call Restriction Table)

What is Door Phone Programming?

What is Flexible Extension Numbering?

What is Flexible Extension Numbering Programming?

Real Example:

Example 1

Example 3

What is Automatic Sequential Numbering?

How Do I Enter L and K?

Automatic Sequential Numbering Command Explanation:

What is Direct Junction Access (Hot Line to Junction)?

What is Hot Line to Extension?

Real Example: