Configuring TCP/IP on CICS Transaction Server for z/OS

CICS® Universal Client can send ECI requests over TCP/IP to CICS Transaction Server for z/OS® V2.2 and later. To perform this configuration:
  1. Set the SIT parameter TCPIP=YES.
  2. Install the following:
    • CICS-supplied transient data queue CIEO, in group DFHDCTG
    • Transaction CIEP in group DFHIPECI
    • Program DFHIEP in group DFHIPECI
  3. Define the TCP/IP address and host name for the z/OS system. By default they are defined in the PROFILE.TCPIP and TCPIP.DATA data sets.
  4. Add a TCP/IP listener to CICS. Use the following CEDA command to define a TCPIPSERVICE in a group:
    CEDA DEF TCPIPSERVICE(service-name) GROUP(group-name)
    Ensure that the group in which you define the service is in the startup GRPLIST, so that the listener starts when CICS is started. Key fields are explained as follows:
    POrtnumber
    The port on which the TCP/IP service listens.
    PRotocol
    The protocol of the service is ECI.
    TRansaction
    The transaction that CICS runs to handle incoming ECI requests. Set it to CIEP.
    Backlog
    The number of TCP/IP requests that are queued before TCP/IP starts to request incoming requests.
    Ipaddress
    The IP address (in dotted decimal form) on which the TCPIPSERVICE listens. For configurations with more than one IP stack, specify ANY to make the TCPIPSERVICE listen on all addresses.
    SOcketclose
    Whether CICS should wait before closing the socket after issuing a receive for incoming data on that socket. NO is recommended for ECI connections, to ensure that the connection from the Client daemon always remains open.
    ATtachsec
    Specifies the level of attach-time security required for TCP/IP connections.
  5. Use the following command to install the TCPIPSERVICE definition:
    CEDA INS TCPIPSERVICE(service-name) GROUP(group-name)