Following the US example of BITNET, which was already using IP circuits since 1986, in 1991 EARN decided to reorganize its NJE routing following a plan formulated by the EARN Routing Project Group. The new routing plan was based on the segmentation of the network into regions, similar to BITNET 2. The criteria followed for the division was based on parameters such as the density of nodes, traffic, and need of services in the area. The regions were connected through a set of Core Sites with virtual NJE links among themselves, forming a full mesh network, and with a virtual link to a US BITNET 2 core site. The plan was approved by the EARN Executive and Board committees, implementation started by mid 1991, and in 1992, once Ebone was up and running, it became possible for EARN to migrate most of its traffic over TCP/IP lines and improve performance by reducing the load on key backbone sites. The full mesh configuration was achieved in September 1992.

This paper describes the plan and offers a picture of its implementation at the beginning of 1992.