Data Transmission Network (DTN) HS2

The HS2 Data Transmission Network (DTN) will provide network transport services and specific central service functions necessary for the reliable operation of trains on HS2.

The DTN shall fulfil the following high-level requirements: • Provision of a Critical network for safety-related connected sub-systems: DTN-Critical • Provision of a Protected network (DTN-P), distinct from the critical DTN network, connecting non-safety-related subsystems. • Provision of a secure, geo-redundant external interface via a De-Militarized Zone (DMZ). DTN acts as the aggregator for internet and cloud connectivity from its DMZ. The DTN DMZ also acts as the interface to Network Rail to connect HS2 rail systems to Conventional Rail services hosted in Network Rail's telecoms network. • Provision of the DMZ, including central compute and servers, protected by internal and external security perimeters. • Provision of a Master Clock System, providing accurate clocking internally and to connected subsystems with Precision Time Protocol (PTP) with boundary clock functionality, Synchronous Ethernet (SyncE), and Network Time Protocol (NTP). • Provision of other services include: DHCP, DNS, AAA authentication, Network Management System (NMS) for supplied operational systems. • Provision of optical and electrical SFP (where required) to facilitate the above inter-connectivity.