Are Public Switched Telephone Network (PSTN) Lines Still the Best Failover Option?

Most of us still remember the sounds of an analog modem connecting to the ISP or back to the corporate office. These nostalgic sounds are a thing of the past as broadband connections have pushed PSTN lines further away from the norm.

For some, a PSTN line is still a reality, especially in scenarios where a slow connection is better than no connection. PSTN lines are still used for remote management of IT infrastructure in cases of disaster recovery. For example: A branch office has gone completely offline… In this case it is important to identify if the cause of failure is a misconfigured VPN connection, other configuration changes causing unforeseen results, or if the broadband connection is down and it’s time to call the ISP.

In today’s Blog, we will review why PSTN lines are still being used for failover and some of the misconceptions associated as to why switching to another alternative failover method can be a complicated task.


Why are PSTN lines still in use?

PSTN lines are still in use because the technology has been around for a long time and the solution simply works. A dial up connection might be finicky, but give it a little bit of time and it will sort itself out. Besides this, the following reasons play a big part:

  • For a console, analog connection speed is acceptable
  • Some end devices, specifically in older branch offices only support analog modem connections
  • It provides a simple method of implementing a Point-to-Point communication
  • Analog Modems are still supported by vendors
  • Analog Technology is vendor neutral
  • Other communication options might not be stable enough or even available in the specific region
  • Some existing infrastructure management solutions offer solutions which can manage both the infrastructure management and the fallback connection of a single device

Overall PSTN lines have provided a stable and secure method of connectivity over the years, so why change? The pressure to change has increased over the years as ISP’s have updated their hardware and broadband connectivity. It has become cumbersome for phone companies to offer analog lines to end users. Analog solutions require additional maintenance and cabling costs, resources which can be better utilized by the ISP’s on more profitable, technologically advanced solutions. It has become increasingly difficult to get a PSTN line installed and in some areas, PSTN lines are no longer available. Line quality has also become an issue as noise affects speed and reliability. To decrease noise levels requires active maintenance of the older, legacy equipment and technology.

Another obstacle is fewer manufacturers produce replacement parts and the number of available modems by different vendors is very short as most devices are OEM products. On a recent project, we had difficulty finding a working modem which could handle the noise; We tested multiple modems all with the same result. We managed to find two modems that solved the customers line noise dilemma, neither was under $100.

It is only a matter of time, where even the last few implementations will have to be changed to alternative connection methods.


Alternative Connection Methods

Rented/Dedicated connection

This option would be the closest to a PSTN line in the sense that it can provide a real point to point connection. For most customers, this option will be far too expensive, especially if we are looking at redundant connections for disaster recovery scenarios. Although this solution provides a point to point connection, it also runs through the same exchanges as the normal broadband connection. Only a few will actually have their own cable going to every branch office. This means there is some shared infrastructure which increases risk and could potentially expose the data going over the cable. Based on this, most customers would still run a site to site VPN to secure the connection.

Backup Broadband Connection (Secondary ISP)

This solution is typically easier to implement, but can be very costly as it may require a completely new line to be brought into the building. The advantage is the second line can be used for other failover scenarios. In any case, a VPN solution is necessary to establish point to point security between the sides.

Mobile Broadband (Cellular Connectivity)

This solution is the easiest to implement and is used by most customers. Mobile broadband devices are available for a variety of devices and offer wide spread support from vendors. Taking the commitment by most countries and ISPs to expand their mobile broadband offerings in their regions, the coverage and availability will increase even further over the next few years. The question is, which version will be available in which region? The first real mobile broadband was introduced in 2001 with 3G and with a roll-out of 5G in planned for 2020, we will have at least three different versions available. All need to be supported by the hardware. Regardless of the mobile broadband version, a VPN solution is required here as well.


Now, what does this all mean for existing disaster recovery infrastructure management scenarios? For one, existing PSTN, solutions still work, but their time is limited, as challenges with replacement parts and availability of the actual line through the ISP’s will increase. Alternatives exist, but solutions will consist of at least 2 main parts; The actual broadband connection and a VPN solution. This means we have the option to invest in two or more individual appliances which will manage the broadband connection, VPN and the infrastructure management or invest in an infrastructure management solution which offers everything in one appliance.

Investing in multiple devices has the advantage that standardized hardware can be deployed on all sites this means small sites needed the same infrastructure as a large site, requiring the same administrative overhead, space and power, which can become very costly and non-scalable.

Infrastructure Appliances which support different broadband connections, VPN’s and infrastructure management protocols exist, but the appliances themselves are not the complete solution. The connection of these devices through broadband means they are exposed for long periods of time to the internet, and have security risks. The solution should be selected with the idea in mind that it is secure today, (capable of running secure operating system versions, cyphers, VPN and firewalls) and in the future. It should have enough flexibility built in to support upcoming connectivity options, management and security requirements while supporting current IT management standards.


The Solution: Open Infrastructure Management with Nodegrid

The Nodegrid Family of products are the ideal solution for maintaining maximum connectivity, with support for all of the alternative connection methods listed above; Nodegrid utilizes multi-routing tables to assign connectivity for a secondary broadband connection, comes equipped with provider agnostic cellular connectivity capabilities, and makes the migration from PSTN lines to alternative connection methods quick and easy. Nodegrid Manager software is up-to-date with security protocols, allows for automation and scripting, and provides a vendor neutral software-defined approach to infrastructure management, all of which allow for an unmatched level of flexibility, automation, and security. ZPE’s combination of modern hardware and built-in support for various connectivity methods, paired with the powerful Nodegrid Manager software results in a centralized and secure management platform with maximum uptime and reliability at the core.

For more information regarding the Nodegrid family of products and failover connectivity capabilities, give us a call or send us an email – We’d love to hear from you.

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