Classic Wide Area Networks (WAN)

Connecting users to business services and applications located in another site, be it another office, a Data Centre or the cloud, requires a wide area network (WAN). Classically, this would generally have been delivered using either:

  • Dedicated network links such point-to-point lease lines or service-provider delivered MPLS
  • Internet connections, using VPNs for security
Classic Wide Area Networks (WAN)

Pros and Cons of Classic WAN

Dedicated Network Links/MLPS


Fast – latency across dedicated links is far lower than using the internet, so sensitive applications like voice and real-time video work well, especially when quality of service is enabled.

Reliable – dedicated links tend to be more reliable, both in terms of their availability across the year, and also the level of performance across them. This means less risk for a business.


Cost – dedicated links are expensive, and the the cost is doubled if you need a primary and backup line to ensure your users can work if a link fails.

Flexibility – dedicated links are usually very slow to deploy, taking 90+ days to install, and also take time to move, should the need arise.

Visibility – Getting visibility of what links are in place, how they are performing and what capacity they are running can be difficult and time consuming, particularly as the number of sites grows.

VPN over the Internet


Cost – Internet links are far cheaper than a dedicated link with the equivalent bandwidth.

Flexibility – If you’re opening a new site, a VPN solution will allow you to connect to it easily as long as it has an internet connection.


Reduced Performance – latency across an internet link will be greater than over an equivalent dedicated link. The internet doesn’t support quality-of-service, so users may experience issues with latency-sensitive applications.

Less Reliable – internet links are often less reliable than dedicated links, in terms of availability and performance. This increases the risk for a business.

Visibility – Getting visibility of what links are in place, how they are performing and what capacity they are running can be difficult and time consuming, particularly across multiple sites.

What is SD-WAN?

SD-WAN (Software-Defined Wide Area Networks) is the next generation of WAN technology, provided by vendors such as Cisco (SilverPeak), Palo Alto (Prisma & PAN-OS), Fortinet (FortiGate NGFW) and Versa (Secure SD-WAN).

It allows you to utilise the existing WAN technologies that best fit your requirements, whilst providing next-generation levels of security, manageability and visibility.

For example, rather than requiring a primary and backup MPLS link, you could implement a single MPLS link in a site, and provide a far less expensive direct internet link as the backup. This would allow you to direct your latency-sensitive application data over the expensive but reliable MPLS link, while other traffic was directed over the cheaper internet link, whilst still providing automatic failover in case of a failure of either of these links.

What is SD-WAN?

Challenges of building a WAN

Defining the requirements is key, but often challenging. Understanding what features and capabilities the network needs to support underpins the solution and will make the difference between success and failure.

The SD-WAN market has been in flux for a number of years. The amount of vendors has continued to grow and includes several  SD-WAN specialists, as well strong offerings from all of the big players in networking and security. Selecting the correct vendor for this potentially large, long term investment is key as they all have strengths and weaknesses, so mistakes at this stage could have dire results.

Once the vendor has been selected, designing the new solution also brings challenges, including identifying the points of interconnect to existing services such as cloud resources and data centers, and determining how the new solution will integrate into the office networks.

Finally, the implementation of the new solution, and migration of offices and services to it, need careful consideration in order to minimise costs whilst ensuring that users’ access to business applications and services is not affected.

Our approach and benefits

We are always led by understanding the requirements of our clients. Fundamental to every engagement, we collaborate with you to help you to determine what is important, both now and in future.

Once the requirements are understood, we use our extensive experience in the field to identify and design the correct solution and then finally implement it, navigating the complexities of the migration from the previous solution.

Our experience in designing and implementing wide area networks and SD-WAN solutions allows us to select the solution that meets your requirements, and then navigate the potential pitfalls to ensure that the solution is deployed successfully.

SD-WAN: How to Improve Security & Performance blog post

SD WAN - Our approach and benefits

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