TCP/IP Port Number
The initialization parameters TCP.LISTEN and TCP.API.LISTEN provide the best method for defining a single port or multiple ports for IBM® Connect:Direct® to listen to and accept incoming TCP/IP connection requests. You can define a single port for establishing a listen task, or define multiple ports by establishing a list of IP address and port number combinations. Multiple port listening allows IBM Connect:Direct to accept incoming traffic from a variety of addresses.
Single Port TCP/IP Listen
IBM Connect:Direct implements a standard TCP client/server architecture. Each IBM Connect:Direct node in the TCP/IP network can function as both the client and the server simultaneously.
The server establishes a connection with the TCP/IP network and waits for session requests from other IBM Connect:Direct clients. When a session request is received and validated, the server accepts the connection to the client.
The IBM Connect:Direct client requests a session that is established through the TCP/IP network to a IBM Connect:Direct server. When the session is accepted by the server, a dynamic port is assigned by the network. This dynamically assigned port is used for the actual data transfer. When the data transfer is complete, the port is released back to the network and the session is terminated.
IBM Connect:Direct uses a predefined TCP/IP port number for both client and server. This port is defined in TCP/IP as a TCP service and requires the same port for all IBM Connect:Direct TCP/IP nodes in your network. Refer to your TCP/IP implementation documentation for how to define TCP servers. If you cannot use the predefined TCP/IP port, you can override it for both the client and server.
This initialization parameter defaults to port number 1364.
Client Override Port Number
The client override port number is coded on the adjacent node record in the second positional parameter. The IBM Connect:Direct client requests sessions to the IBM Connect:Direct server through this port. The port number coded on the adjacent node record is used by client functions only and does not change the port number used by the server functions. You must code the network map entry in your network map in order to use the override port number.
Server Override Port Number
The server override port number is coded in the TCP.LISTEN initialization parameter. The IBM Connect:Direct server waits for a IBM Connect:Direct client request on this port. The initialization port number is used by server functions only and does not change the port number used by the client functions.
Multiple Port TCP/IP Listen
IBM Connect:Direct accepts incoming traffic from a variety of addresses. The initialization parameters TCP.LISTEN and TCP.API.LISTEN support both IPv4 and IPv6 protocols. They also allow for a list of IP address and port number combinations.
The first address defined in the parameter becomes the local or default address. Up to eight different addresses/ports can be defined for each server.
For information about multiple port listening in a IBM Connect:Direct/Plex environment, refer to A New IBM Connect:Direct/Plex Environment.