It must be a thankless task running a railway network. Via timetables you can control the scheduling of trains, through signalling systems you can prioritise which trains move first and their path through your network, and you can change this dynamically and route trains around failures. You tread a fine line between enforcing revenue collection with barriers and train staff or putting passenger convenience first, opening yourself up to revenue loss. But no matter how much you invest in your infrastructure and how well you manage it, what really matters to your passengers (customers) is the experience of their individual journeys – the journeys you can’t see. All you can see are the complaints on social media platforms when something on a journey goes wrong.

Rail passengers do not access your core train management systems to optimise their experience, they use journey planner apps to find the best way to navigate your complex infrastructure. These apps react in real time, telling you which train to take, when you need to change, estimating your arrival time and putting each rail passenger more in control of their own experience.

Sessions equivalent to journeys

Looking at IP networking, the network manager (whether in a service provider or an enterprise) again has a raft of tools to route packets, choose priorities, enforce security and monitor the infrastructure performance via packet loss, delay, jitter etc.  But the purpose of all of this is to enable better flows of information between end-users and applications in order to optimise the individual sessions which are the IP Networking equivalent of individual rail journeys.

SD-WAN gives an additional level of control, you can create overlay networks using IPsec tunnels, you can group application traffic by application type and apply rules, which route the traffic for these applications over the best routes based on network performance. However, the creation and management of tunnels comes with drawbacks and overheads and like the managers of railway networks who can’t manage journeys, you are not seeing and optimising the individual flows – the sessions.

The technology set to revolutionize how networks are provided and managed

There is therefore a potential for a new technology called Session Smart Routing to revolutionise how networks are provided and managed. This new technology does two key things; first it eliminates the need to build and maintain an overlay network of IPsec tunnels and secondly it routes individual sessions – taking key information from the originating and terminating IP address and the session application identifier to determine the best route for that user and that session at that time.

The elimination of IPsec tunnels brings a host of benefits to scalability and efficiency. Traditional SD-WANs create a mesh of tunnels, but in large networks they cannot be pre-configured to enable any-to-any networking, where interconnection between 100 sites needs 10,000 simultaneous tunnels and between 1000 sites would need around a million tunnels, hence large SD-WANs are constructed in hub and spoke architectures – driving up costs and driving down performance. Tunnels are also inefficient – especially for “short packet” applications like voice where the tunnel overhead can often double the bandwidth needed for the same end-user experience.

Tunnels encrypt everything, regardless of whether the traffic they are carrying is already suitably encrypted, such as traffic to and from O365 for example. Managing tunnels is processor hungry, leading to larger and more expensive boxes at each site. Furthermore, with growing use of infrastructure as a service cloud-based offerings such as AWS and Azure, not only does processing power cost, but traffic-out is charged by the bit so tunnels to the cloud drive up costs big time.

Routing by session is the second key benefit. Perhaps surprisingly this makes the central management and control interfaces easier and more intuitive. At set up, the manager of the network instructs the central controller (conductor) as to which end-users (hence which IP addresses) are allowed to access which applications, and also where these applications are hosted. This information is then distributed and held at each router. The Session Smart Routers then act on the first packet of every new session to determine whether it is allowed to be set up, and the best path for it to use between the network of Session Smart routers.  Requests that initiate new application access which is not allowed are just ignored – traffic is in effect black-holed – creating a deny-by-default / zero trust routing architecture. Abstracting the setting of policies to the real-world terminology of end users and applications (referred to as tenants and services) makes policy determination, set-up and management far simpler than the design a meshed tunnel network and deployment of routing rules by application type to this network. However, perhaps the key here is that using this technology you are routing, managing and optimising performance of what really matters to end users – their session.

Whilst it may be a long while until train networks are optimised and managed for each individual journey, IP network managers can benefit from Session Smart Routing today. The technology has been developed by a US-based software company called 128 Technology. It has been deployed widely across diverse customer sets, for example in a 10,000-site retail branch network in the US, to optimise latency and performance for a satellite network provider in Africa and to link between operational and administrative locations for the US military. The company was bought late last year by Juniper who are now providing this capability through a growing range of their reseller/distributer network world-wide.

Have a question? Get in touch!

This is yet another example of a technology which enables a competitive internet-based wide area network offering to compete with traditional MPLS and “traditional” SD-WAN solutions. Here at Brodynt we can offer you a single point of contact to quote, order, provide, manage and bill an internet-based underlay, while you focus on utilising new technologies such as Session Smart Routing to drive up customer experience whilst driving down customer costs.

You are always welcome to drop us an e-mail to and one of our Account Managers will be happy to assist you! Alternatively, engage in a discussion by leaving a comment below!