Routing Background IBM's networking architecture has evolved considerably as computing in general has evolved away from domination by centralized computing solutions to peer-based computing. Figure 37-1 illustrates the concepts addressed in this chapter in the context of a traditional SNA environment. IBM SNA Session Connectors IBM SNA session connectors are used to bridge address spaces when sessions traverse multiple address spaces.
Boundary functions reside in subarea nodes and map between subarea and peripheral address spaces.
SNI gateways act as bridges between SNA networks, accepting data from one network and transmitting it to the appropriate destination in another network. APPN intermediate nodes perform intermediate routing within APPN networks. Refer to Figure 37-1 for the relative position of a session connector in a traditional SNA environment. TGs are comprised of one or more SNA links and their assigned transmission priorities. Multi-link TGs, which provide added reliability and bandwidth, are used to bundle multiple physical links into a single logical SNA link.