In BDT, a node at one end of each file-to-file connection must be designated global while the other node is designated local.¹ Because a node may take part in many sessions, it may be global for some sessions and local for others. A node cannot be described as global or local by itself. A node is global or local only with respect to another node.

A global node of a given session has a queue where transactions involving the two nodes are kept until they are scheduled, executed, and finally purged. For example, if a session exists between node A and node B, and node A is the global node for that session, then transactions involving file transfers between A and B are queued and scheduled at A. This is regardless of the direction of data flow. Because A keeps the queue and does the scheduling, it may require more machine resources and more experienced operators than node B. This may be offset by the fact that B could be a global node for some other session pair.

You must designate the global and local relationship of each node by using the T=LOCAL parameter of the BDTNODE initialization statement (described on page BDTNODE—Define Session Characteristics between Home and Remote Nodes).

There are several ways to approach the planning of global-local relationships, as described on the following pages.