Port Monitoring feature is to allow the users to monitor TCP/IP based servers for protocol types that are unknown to PATROL for Internet Servers.
 Any service existing on any single TCP port can be monitored.PATROL for Internet Servers can be used to connect to local or remote Telnet servers to perform any type of command to measure the response against expected results. PATROL for Internet Servers reports the services’ availability, response time, down time, and content validity of the service response.

Use the port monitoring feature to:
- Define both TCP/IP-based (excluding Telnet) and Telnet sessions
- Define simple sessions using a KM dialog or define more complicated sessions such as sending an actual mail message using a definition file
- Use the Telnet option to log into any local or remote server, on any platform, and then, issue one or more commands of your choice
- Use the Telnet option to track the availability of services such as NIS (user login) and NFS (user home directories)
- Verify the return content for validity

Port monitoring is configured based on the service that has the port opened. During the configuration users need to supply a read or write arguments depending on the needs. Network administrator should know which arguments to use.

The read/write to port works as follows:
If the application of the port is sending data,  configure the port to read, then the data the application sent will be written to the portContent parameter.
If the application is waiting for data, then open a WRITE session, and whatever user write in the field next to the "WRITE" will be written to the port.
When users write to the port, it goes to the port, if the port is belong to an application that waits for data then the application will get the data.
Examples available on below link:
https://docs.bmc.com/docs/display/pki90/Portmon+TCP+IP-based+session+example
https://docs.bmc.com/docs/display/pki90/Portmon+telnet+example

Users can also configure Content check criteria and Alarm if content expression - match or do not match.

Is possible also to check the availability of the port only. To do this, select this as a TCP (not telnet) port, and in the configuration, instead of selecting to "read", select to "write", using a short character string of "hhhhhh" (the character string characters are not significant).

The ISM KM will send this character string to the port, and if it finds that it successfully wrote the string to the port, it was able to consider the port as online.  The listener running on the port should ignore these characters, however at least send back a favorable response that this port is up and running to Internet Server Manager.