Figure 4.4 Distributed deployment model.
The distributed model combines elements of the branch and centralized deployment models. In this model, SNA Server computers are deployed both in a central location near the SNA host and in the branch LANs near the clients. Typically, the computers located near the host are linked by a high-performance connection, such as channel-attachment. These link services are then made available for distribution to the branch SNA Server computers using the Distributed Link Services, a feature that allows an SNA Server to share configured link services with other SNA Server computers. When implemented, the branch-based servers communicate with the SNA host via a virtual link service over a routable WAN protocol, such as TCP/IP.