Whenever a dynamic connection is agreed upon, each path manager involved sends an “add connection” control record to systems not involved in the connection over all other NJE lines. The add connection control record is used by receiving path managers to determine best paths to nodes within the network. Each NPM node forwards the add connection control records. If a connection is already known (CES indicates that the control record received is not new), the record is ignored and not forwarded to other network nodes.

Disconnections are promulgated to the members of the network using a “subtract connection” control record. Disconnections may cause nodes formerly reachable via the disconnected line to no longer be available to the system. In this case, dependent connections are automatically determined by each system experiencing the disconnection or receiving the subtract connection control records.

Add and subtract connection control records may be blocked in the buffer with reset and concurrence control records. This is common when a new trunk is established and complete pictures of the network are traded by the systems involved, or when a disconnect is received by a JES. See Networking Connection Control Records (NCCR) in NJE Transfer Units for the format of the control records.