What Is ISDN And How Does It Work?

ISDN is a circuit-switched telephone network system that was widely used in the past to transmit data, voice, and signaling over a digital line. It was developed to replace outdated landline technology. 

Integrated Services Digital Network ( ISDN) was well known for providing better speeds and higher call quality at a lower price than traditional phone lines. But with time, BT declared in 2015 that it would cease buying ISDN lines in 2020 and terminate ISDN completely in 2025. 

Thus, in today’s digitalized world, businesses prefer more modern communication technologies than ISDN to streamline business communication. ISDN has become outdated technology with the introduction of more reliable VoIP technology, mobile networks, sip trunking, etc. 

This blog provides everything about ISDN. It further elaborates on VoIP and SIP technologies. 

So, let’s get started. 🚀

Understanding of ISDN in detail

ISDN, or Integrated Services Digital Network, is a set of communication standards provided by telephone carriers that transmit data, phone calls, video calls, and other network services using digital transmission over the circuits of the traditional Public Switched Telephone Network. 

Analog phone networks were unreliable for making long-distance connections. They were prone to frequent malfunctions and caused interruptions during business phone calls. 

To address these issues, BIT introduced ISDN in 1986. It replaced traditional landlines with digital lines, adding new features and capabilities that were not available with the classic telephone system. The transition to digital lines improved voice quality, reliability, and the ability to integrate advanced communication features. 

In present times,  cable modems, DSL, and WAN connections for broadband internet access have replaced ISDN. Even so, it serves as a backup in case the primary lines fail. 

How Does ISDN Work?

ISDN (Integrated Services Digital Network) transmits voice, data, and other services over traditional copper telephone lines using digital technology instead of analog signals.

Some key elements of ISDN operation include:

• The phone line can handle multiple connections at the same time by dividing it into numerous digital channels.
• Data, audio, and signaling information are transmitted using digital channels.
• There are two main types of ISDN interfaces: BRI (Basic Rate Interface) and PRI (Primary Rate Interface). The BRP has 2 B channels for data/voice and one 1D channel for signaling, operating at 144kbps. On the other hand, PRI has 23 or 30 B channels operating at 1.544 Mbps. These technologies combine circuits to transmit digital information. 
• POTS (Plain Old Telephone Service) line, assigned a phone number, and a modem setup is required to access the network. 

How To Setup ISDN?

Here are the simple steps to set up an ISDN service.

Step 1: A functional Plain Old Telephone Service (POTS) line is necessary. 

Step 2: Verify your serial ports in step two. 

Step 3: Install the modem driver on your computer.

Step 4: After that, set up the digital modem. 

Step 5: Use the correct phone number to connect the modem. 

Step 6: Configure the various phone lines to connect at the speed you want. 

Step 7: Use the modem to dial the number supplied by your ISP. 

Step 8: If you are unable to connect to a high-speed internet connection, set your modem to BONDING. BONDING  allows the modem to dial up both numbers simultaneously. 

Setting up an ISDN service can be quite time-consuming since its effectiveness relies heavily on the current physical infrastructure. Any minor errors or hiccups in the system can disrupt internet access. Due to these challenges, the ISDN process is being gradually phased out. 

Advantages of ISDN

In areas without high-speed internet, some people still use ISDN to get online. However, ISDN for internet access is mostly being replaced by other options. The other advantages of ISDN include: 

1. Faster Transmission

ISDN can transfer data more quickly than its predecessors, such as traditional telephone systems and early T1 digital systems. It can transmit data at 128 kbps over the same phone circuits, while normal phones transmit data only at 2.4 kbps.  

2. Better Quality Signal

In addition to quicker data transmission, the lines that run through the ISDN also transmit better-quality signals. Both the internet connection and voice conversation have improved in quality and frequency of disruptions in the telecommunication field. 

3. Multi-Purpose Cables

The telephone network ISDN lines are of great use for businesses that allow multiple types of information, such as voice, video, fax, and data, to be transmitted simultaneously over the same cable. This helps employees multitask effectively and be more productive. 

4. Various call management features

ISDN has a range of useful phone call features. These advanced features streamline business communication and include call forwarding, directed call pickup, Caller ID, three-way calling, message waiting indicator, and more. 

Difference between ISDN and DSL

The differences between ISDN and DSL are:

What are the types of ISDNs?

Let’s discuss the different types of ISDNs in detail.

• BRI (Basic Rate Interface): BRI is an ISDN configuration commonly used for home and small enterprise connections for streamlined business communication. It has two data-bearing channels, the B channels, and only one signaling delta channel, the D channel. Both channels transmit information but work independently of each other. 
• PRI (Primary Rate Interface): PRI, which consists of one D channel and multiple B channels, provides a better connection, more reliable service, and faster speed. Thus, it is commonly used in large organizations with higher communication demands. It can be adjusted for speeds up to 2.94 Mbps.
• B-ISDN (Broadband ISDN Line): Broadband ISDN is a modern interface that operates independently of copper cables. It is specifically engineered to meet current communication requirements and utilizes fiber optic cables. For this service, we need transmission channels with speeds faster than PRI.

What Are The Alternatives To ISDN?

Today, each organization is in search of a quick and efficient communication technology to reach customers across the globe with minimal setup. If you intend to improve your business’s productivity, you will be glad to know that other options can be substituted for ISDN for enterprises. 

Now, let us discuss all of them in greater detail.

I. VoIP

VoIP, also known as IP technology, is a better option for businesses than ISDN. It eliminates costly traditional telephone charges and enables people to connect via a broadband Internet connection from anywhere at any time. 

VoIP functions similar to ISDN in voice communications but offers more flexibility and expandability. It eliminates the need for expensive hardware implementation, maintenance, and upgrade costs. 

II. SIP trunking

SIP trunking, which stands for Session Initiated Protocol, is a virtual phone line that allows you to make local and international calls over the Internet by consolidating data across channels. It also lets a company’s phone system connect to the public phone network using the Internet instead of traditional phone lines.

III. Mobile Networks

A Mobile or cellular network is a telecommunication network that enables wireless communication using mobile phones or tablets. It is also considered one of the best alternatives to ISDN due to its increased accessibility, advanced features, and improved call quality. 

IV. Digital Subscriber Line (DSL)

DSL is a modem technology and a cost-effective option for internet connectivity. It offers high-speed internet access to homes and businesses without the need for a separate dedicated line. Such high-speed internet access ensures smooth communication and allows for faster downloads and browsing. 

How to switch from ISDN to Hosted VoIP? 

1. Planning and preparation

When conducting business, it’s essential to outline your goals clearly, set a realistic budget, and find a reliable technology provider. Consider both your own needs and those of your target audience when assessing how technology can support your objectives. Your business’s success is closely tied to the technology you choose; having a technology partner who understands your goals and target audience can significantly benefit your business.

• Business goals: Before adopting VoIP, consider if it matches your objectives. For basic functions, any VoIP provider will do. For more features, switch to a better provider.
• After identifying your company’s goals, prepare a budget. One major consideration you may have to factor in may be the cost determined by your VoIP deployment. Web-hosted systems are the least expensive since they run natively on cloud servers.
• Finding the right technology partner: Once you have set out a parameter of the amount of money you are willing to spend, try to find someone within your current peer group who has some technical competency and understanding of the business you are in. They should be able to avail services all the time, be in a position to understand their client’s needs to the letter, and operate the new updates. Do not hesitate to ask for trials so that you are assured they meet your needs.

2. Switching to VoIP

Once you’ve finished the hard part of strategizing, switching to VoIP is pretty straightforward. Here are a few things to think about: check your internet connection, look into different VoIP service providers, and make a plan for training and supporting your employees. Let’s discuss them in detail. 

• Access new features

VoIP offers you a number of cutting-edge capabilities that are necessary for you to stay competitive, in contrast to conventional phone systems. Call queuing, conference, forwarding, bridging, and merging are among the capabilities that are available to you.

• Connect the system with your hardware

VoIP doesn’t need dedicated hardware. It functions using the Internet, providing complete location independence. VoIP can connect to Bluetooth speakers, desk phones, Bluetooth headsets, and softphones.

• Train your staff

Give your staff training materials so they may become familiar with the recently implemented system. A reputable VoIP provider will supply sufficient resources for educating your staff about the VoIP system. You don’t need to worry, though, as 67% of staff members believe using VoIP systems to handle calls to be simpler.

A Comparison of ISDN Service and VoIP

Let’s see the key difference between the ISDN service and the VoIP system. 

Why Switch From ISDN to VoIP?

When comparing these two communication solutions, VoIP performs far better than ISDN. Let’s examine the benefits of switching to VoIP from ISDN. 

A. Increased accessibility

Voice over Internet Protocol (VoIP), also known as IP technology, allows individuals or businesses to make voice calls from any location using the Internet. It enables them to manage inbound and outbound calls across their preferred channels effectively. VoIP call software further facilitates remote work. 

B. Reduced cost

With VoIP, startups can save up to 90% on their costs. Setting up a landline phone system costs $50 per line. In contrast, Dialaxy VoIP pricing starts at $20 per user per month, cutting call costs by over 50%. Therefore, businesses aiming to boost their profitability should transition from ISDN to VoIP.

The initial cost of VoIP is high but in the long run, the business can significantly increase the ROI.

C. Improved voice quality

Call quality on traditional phone lines is good. However, when making calls abroad, the quality degrades. With a steady internet connection, VoIP constantly ensures improved call quality while making national or international calls. 

D. Additional features

VoIP is loaded with modern features not available in traditional telephony systems. These features improve business communication. Here is a list of VoIP’s advanced features. 

• Call waiting
• Call queuing 
• Call forwarding
• Voicemail
• Caller ID
• Call conference
• Unified communications
• Video conferencing 

Conclusion

ISDN is a set of communication standards serving as a vital voice and data communication technology. It transmits both data and voice over a digital line. It was designed to move outdated landline technology to digital because it was unreliable for long-distance calls. It has a reputation for providing better speeds, more features, and higher call quality at a lower cost than traditional connections. 

However, with advancements in IP technology, ISDN’s significance has diminished. In today’s digitalized world, many telecom providers and countries favor modern communication options like VoIP, DSL, or fiber optics over ISDN services. This is because these technologies are cheaper, faster, more reliable, and future-proof. 

FAQs

What are the advantages of ISDN?

The advantages of ISDN are:

1. It provides a higher data transfer rate. 
2. It is up and running faster than other modems. 
3. Digital signals are broadcast through telephone lines. 
4. It offers multiple digital services that operate through the same copper wire. 

What are the limitations of ISDN?

They are:

1. Limited Bandwidth
2. Higher cost
3. Decreased availability 
4. Complex setup
5. Scalability issues

Why is ISDN being switched off?

Despite once being considered groundbreaking, ISDN has become outdated with the emergence of more sophisticated technologies like VoIP. As a result, BT has decided to shut it down instead of investing more money in maintenance.

How many lines are in ISDN?

ISDN consists of two lines: the B channel, which carries data, and the D channel, which carries signaling and control data. For more data capacity, ISDN can handle additional B channels.

What are the main types of ISDN?

The main types of ISDN are the Basic Rate Interface (BRI) and Primary Rate Interface (PRI).