SNA NETWORK FLOW CONTROL.

Transitory bottleneck conditions can occur in communications networks. Proper flow control is required to prevent these from leading to deadlock or severe performance problems through storage depletion or other causes. This paper offers an informal description of network flow control needs and the virtual route flow control introduced in SNA 4. 2, with emphasis on the underlying reasons for the methods. Priority traffic, small networks, situations with poor performance, and networks with both SNA 4. 2 and earlier level nodes are special cases treated within the virtual route control framework.