Very professional and knowledgeable. It was easy to work with them at all levels. They were flexible in accommodating our meetings etc and provided valuable inputs. KCOM's role was very critical in the success of Broker Migration. A very successful engagement & RDG team looks forward to working with them in future

Paroma Choudhury
Project Manager, Rail Delivery Group


The Rail Delivery Group (RDG) brings together the companies that run Britain’s railway into a single team with one goal; to deliver a better railway for you and your community. All the passenger and freight rail companies are members of the RDG, as well as Network Rail and HS2.

They provide services and support to enable their members to succeed in transforming and delivering a successful railway, benefiting customers, taxpayers and the economy. They also provide support and give a voice to freight and passenger operators, as well as delivering important national ticketing, information and reservation services for passengers and staff on behalf of member companies.

The challenge

RARS is a modern Rail Availability and Reservation platform which replaced the National Reservations System (NRS) and delivered a major step-change for the Rail Industry through the improved functionality it offers.

The RARS2 programme was led by the Rail Delivery Group who completed a smooth transition from NRS onto RARS2 in October 2020.

RDG’s consumers were experiencing challenges when connecting to the NRS broker service, an AWS-hosted solution that integrated with the multi-channel mainframe NRS system, using a legacy Multiprotocol Label Switching (MPLS) network connection with latency issues. This had the potential to adversely impact their future revenue streams through a loss of ticket sales brought about by poor customer experience.

The solution

In October 2020, the KCOM team successfully implemented an innovative networking solution which allowed train operators with existing AWS infrastructure to migrate away from the MPLS to leverage AWS native connectivity instead.

Each consumer uses a unique weighted Amazon Route 53 DNS record to route traffic to their dedicated AWS PrivateLink endpoint. Using the legacy MPLS network only as a secondary route should the primary route fail.

AWS PrivateLink endpoints are mapped to the NRS system channels via new AWS Network Load Balancers (NLBs), so the existing NLBs used by the MPLS connection can be deprecated.The solution was deployed as Infrastructure as Code (IaC) using AWS CloudFormation.

VPC flow logs were configured and used in conjunction with CloudWatch Contributor Insights to help diagnose complex networking issues. Logging, telemetry, and dashboarding leverage Amazon CloudWatch to rapidly assist with any operational matters.

KCOM use native AWS cost analysis tools in conjunction with CloudHealth to understand AWS resource utilisation, provide cost-saving recommendations based on over-performing resources, and suggest changing compute instances when newer instance types are released.

Results / Benefits:

RDG and the seven train operators have realised the following benefits as a direct result of implementing the solution in AWS:

  • Performance. The solution has reduced the response time when compared with the MPLS connection, with up to a 70% improvement being observed.
  • Reliability. The solution has improved the reliability of the connection when compared to the MPLS connection.
  • Reduced complexity. The solution simplifies management of the multi-tenant architecture, negating the need to configure an Internet gateway, VPC peering connections, or manage VPC Classless Inter-Domain Routing (CIDRs) blocks.
  • Security. The solution enables connecting in a secure and scalable manner; network traffic does not traverse the Internet, reducing exposure to brute force and distributed denial-of-service (DDoS) attacks, along with other threats. Using private IP connectivity so that services function as if hosted directly on private networks. Using AWS native controls, we precisely control who has access to specified services.
  • Observability. Leveraging AWS-native services unlocks an unprecedented level of end-to-end infrastructure observability from a single solution.

KCOM has proven to be a knowledgeable and dedicated supplier during the implementation of the AWS solution and Broker Migration for RARS. The ability to work collaboratively as well as the support and flexibility shown throughout the process have been critical in its success.

Nadine Rajkumar
Senior Service Manager, Rail Delivery Group