Are You Ready for the PSTN Switch-off?

For over 7 years, the PSTN and ISDN switch-off dates have been fast approaching for companies in the UK. Despite this, around 33% of SMEs still say they haven’t prepared for the change. While moving away from familiar communication and connectivity infrastructure can be a daunting prospect for many brands, it’s not something today’s organisations can afford to delay.

By 2023, the “Stop Sell” order for ISDN and PSTN solutions will be implemented, making it impossible to access new functionality connected with these technologies. By 2025, BT has announced the two technologies will be eliminated completely, forcing all organisations in the UK to shift towards a more agile, cloud-based environment. 

The switch off of ISDN/PTSN technology represents the most significant change to take place in the telecoms industry for the last 30 years. For many companies, it will prompt a radical transformation in the way their teams access the internet, phone lines, and existing “connected” tools. 

So how do you prepare for such a massive transition?

The team at Resonate joined forces to provide a step-by-step guide to everything business leaders need to consider when migrating away from ISDN and PSTN in the next few years.

Here are the key steps recommended by:

  • Harkirat Degun, Product Director
  • Adnan Safdar, Principal Solutions Architect
  • Sat Bhooi, Programme Manager

Step 1: Understand what the ISDN/PTSN Switch-off Is

The first step in a successful migration strategy is understanding exactly what the ISDN/PTSN switch-off means to modern businesses. Although BT has been promoting this switch-off for several years, 83% of organisations in 2021 still said they didn’t know when their services would be disappearing, and 77% said they haven’t prepared for any disruption the switch-off may cause. 

The ISDN/PTSN switch-off is the planned roadmap for removing ISDN and PSTN line technologies from circulation throughout the whole of the UK by the end of 2025. While the change is primarily facing UK companies today, ISDN and PSTN technologies are gradually phasing out throughout the world too. Once these technologies are removed, phone lines will need to be moved to a digital network, leveraging the “Internet Protocol” format. 

While the official switch-off date is set for 2025, it’s worth noting Openreach has also implemented a “Stop Sell” data for September 2023. After this time, UK telecom companies will not be able to deliver new services on PSTN technologies.  

Although the switch-off may seem like a daunting prospect to business leaders, it does have a number of benefits to offer. The traditional technology offered by PSTN, and ISDN is no longer fit-for-purpose at a time when we’re increasingly relying on global, fast-rate communications. Broadband connections delivered through the IP environment will allow companies to achieve a higher level of scalability, redundancy, and quality in their communications. 

Step 2: Determine what the Switch-Off Means to You 

Once you have a clear view of what the PSTN/ISDN switch-off is, and when it’s happening, the next stage is understanding which technologies in your organization are likely to be affected. Some people assume this transition will only affect their traditional “copper” phone lines. However, all of the services that use the conventional phone line network will be affected. Because PSTN supports connectivity options like FTTC and ASDL broadband, you may need to change your entire network strategy when the switch-off takes place. 

To ensure you’re implementing the right plan for migration, and avoiding disruption wherever possible, it will be crucial to conduct a full audit of your current communication system. In other words, explore what your technology infrastructure looks like today, and highlight all of the services which may be influenced by the PSTN/IDSN switch-off. 

The most common voice-connected services likely to be affected by the switch-off include:

  • Fax systems
  • Telecare and critical care systems
  • Phone system “PBX” (Public Branch Exchange) services
  • DECT (Digital Enhanced Cordless Telecommunications)
  • Powered lines (Lift lines)
  • Alarm systems with phone system connectivity
  • Security systems connected to PSTN/IDSN technology
  • Telemetry systems
  • Payment lines and terminals (EPOS, ATMs, and PDQs)
  • Non-served premise solutions

Step 3: Plan for Migration: Considering Your Technology Choices 

The next step in planning for your migration away from PSTN and IDSN technology is determining how you’re going to make your transition. There are a few options to choose from, both from a connectivity perspective and in relation to voice services. 

For your connectivity, you may need to switch away from FTTC and ASDL broadband to one of the following:

  • Full fibre: Full fibre functionality is currently being rolled out throughout the United Kingdom. By 2025, 85% of the UK will be equipped for gigabit broadband. The remaining 15% should be implemented by the end of 2030. 
  • SOGEA: SOGEA is Single Order Generic Ethernet Access, which offers companies the equivalent of FTTC broadband, without telephony. Voice services are not supported.
  • SOFAST: Similar to SOGEA, this solution works for companies currently using the G.Fast connectivity solution for rapid download speeds.

For your voice services, you’ll be able to choose between either moving your entire communication ecosystem online, maintaining a portion of your on-premises technology or working with a specialist on-premises technology provider for “Private Automatic Branch Exchange” services.

When assessing your options, make sure you consider:

  • Your technology strategy: Are you planning on shifting into the cloud rapidly, starting with a hybrid environment and ramping up, or maintaining most of your equipment on-premises?
  • Resources: Do you have the talent and technology available in-house to manage the switchover yourself, or will you need a partner to assist you with the process?
  • Processes: Which everyday business processes will need to evolve after the switchover? Will you need to transition from fax to email, for instance?
  • Business continuity: How will you ensure your phone services and connectivity lines remain accessible in the case of emergency situations?
  • Budget: Do you want to maintain some of your existing investments to save money, or are you willing to spend more to migrate completely?
  • Change management: How will you process the change in a way that supports rapid adoption, and keeps your team informed every step of the way?
  • Security: How can you ensure the data lines you implement for connectivity and communications remain secure as you transition into the digital landscape?

Step 4: Assess the Considerations of Each Transition Strategy

When choosing the ideal migration plan for your switch away from PSTN and ISDN, it’s worth remembering that each potential option comes with its own considerations and challenges to be aware of. 

Today, the majority of companies are moving directly into the cloud, to access a greater level of agility, flexibility, and freedom. However, cloud transitions can be expensive and time-consuming for some brands. Similarly, staying on-premises may seem to save you money in the short term, but could cost you more in terms of maintenance in the long term. 

Cloud Adoption

If you decide to move your communications system into the cloud, you’ll adopt technology which allows your phone and PCs to connect to a router, into the SIP environment. The Session Initiation Protocol technology will manage multimedia communications on your behalf, allowing you to seamlessly make calls around the world through the internet. 

Before switching to cloud, think about:

  • Adoption: How easy it will it be for employees to switch to a cloud environment? Are they already familiar with certain cloud tools, or will they need additional training?
  • Migration strategy: Will you implement all of your new systems at once, or roll new functionality out one piece at a time to streamline the process?
  • Communication endpoints: Can you continue to use your existing endpoints with SIP and VOIP, or do you need to upgrade to new solutions?
  • Legacy dependencies: Are there any legacy tools you can’t transition into the cloud? How will you deal with these as part of your process?
  • Vendors and porting: Which vendors will you be working with for your SIP trunking technology and your new communications network?

Hybrid Migration

In a hybrid migration, you can continue to use your conventional PBX, and leverage a range of analogue and digital phone networks. However, you should also be able to expand your connections to the internet using the SIP landscape and IP protocols. Think about:

  • SBCs and voice gateways: How will you connect your existing technology to the internet using gateways and session border controllers?
  • Interoperability: Will your existing communication tools work alongside the cloud-based tools you want to adopt? Can you integrate different services?
  • Adoption: Where will employees need additional training and support for the transition?
  • Endpoints: Do you need to purchase new headsets and tools to accommodate the transition?
  • Vendors and porting: Who will be responsible for maintaining the connection between your legacy tools and the IP network?

On-Premises Solutions

While some companies may find staying on-premises to be the best solution for maintaining high levels of security and control, this can be the most problematic option for long-term functionality. Ultimately, you won’t be able to maintain a fully on-premises environment, as you will need to connect your technology to the internet. 

The considerations here are mostly the same as those used by people considering a “hybrid” strategy. However, you’ll also need to think about how much it’s going to cost to upgrade, manage and maintain the ageing technology in your landscape. Infrastructure and hardware costs can also be a significant concern for those staying on-premises. 

Step 5: Test and Migrate

Once you’ve considered all of the points of your migration process, the next step is rolling out your migration. Decide whether you’re going to start with a site-based or functionality-based migration, or whether you want to roll everything out at once. Generally, it’s a good idea to create a step-by-step strategy where you can roll simple changes out gradually, and make alterations as you go.

Implement pilot plans to test user adoption, and group functionality into buckets so you can ensure everything in your new system works according to plan. Remember to test for resilience and security too and keep your team members up to date at every stage of the migration. 

If you need more help planning for your ISDN/PTSN switch-off strategy, you can watch the full webinar recording from the Resonate team here.

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