You are recommended to reserve as many ports belonging to z/OS® Communications
Server as you need for CICS® Web support, and to ensure that CICS Web support
has exclusive use of those ports where possible.
- For HTTP, the well known (or default) port number is 80, and for
HTTPS, the well known port number is 443. You should take care
to resolve conflicts with any other servers at the same IP address that might
use the well-known ports.
- Application programmers may use port numbers from 1024 to 32 767
for nonstandard servers. Ports below 1024 are the well known port
numbers which are architected by IANA for particular functions, so except
for the HTTP port 80 and the HTTPS port 443, these should not be used for CICS Web
support. SSL and non-SSL requests must use separate ports.
- To reserve a port on which CICS Web support listens for incoming client
requests, you can specify the PORT statement or the CICS job name in the PROFILE.TCPIP data
set, as described in z/OS Communications Server: IP Configuration Reference,
SC31-8776.
- The maximum length of any queue of requests for a TCP/IP port on
which a program is listening is controlled by the SOMAXCONN parameter in the
PROFILE.TCPIP data set. CICS listens on a TCP/IP port, so you must coordinate
the value of this parameter with the value chosen for the BACKLOG parameter
in the TCPIPSERVICE definition.