gtpc1m0iTransmission Control Protocol/Internet Protocol

Sample Transmission Control Protocol/Internet Protocol Network

TCP/IP builds an interconnection of networks that provides universal communication services.

The service performed by TCP/IP support is transparent to the application and is comparable to services performed from other platforms.

An application can be either a client, server, or both, depending on whether the application requests or provides a service. Program TPF servers with special consideration to reduce resource usage and to handle messages most effectively. Figure 7 shows the TPF system as the host with two IBM 3172 Model 3 offload devices.

The following steps correspond to the numbers in Figure 7:

  1. The TPF host is connected to both token-ring and fiber distributed data interface (FDDI) networks through the IBM 3172 Model 3 Interconnect Controller with the Offload program, and is able to forward or receive data from clients on any connected network.
  2. Parallel or Enterprise Systems Connection (ESCON) channels connect the TPF host to the IBM 3172 Model 3 Interconnect Controller.
  3. Each TPF host can connect to more than one IBM 3172 Model 3 Interconnect Controller.

    The IBM 3172 Model 3 Interconnect Controller with the Offload program allows the TPF system to communicate with remote TCP/IP hosts through socket application program interface (API) functions. See Socket Overview for a detailed description of sockets.

  4. The 3172 Model 3 Interconnect Controllers send information packets between local area networks (LANs) and the TPF host processor. IBM recommends that all 3172 Model 3 Interconnect Controllers are connected to the same local area network (LAN). The 3172 Model 3 Interconnect Controller can connect to the following LANs:
  5. Routers distribute information packets of data directly when the destination and source are on the same TCP/IP network or indirectly when the destination and source are on two different networks.
  6. The information packets are routed to the Internet.

Figure 7. Network Overview