COTP (ISO 8073) is running on the host and may be part of an ICCP server, MMS application, or substation automation device that uses IEC61850 / UCA.
Description
The ICCP stack (and other protocols such as MMS and IEC 61850) include ISO 8073 (RFC 905) at the Transport Layer. ISO 8073 specifies the Connection Oriented Transport Protocol (COTP) that uses a pair of user configurable 16-bit numeric, or in some cases ASCII string values, to identify client endpoints called Transport Service Access Points (TSAPs). Note that ICCP by itself does not offer protection against eavesdropping, spoofing, man-in-the-middle, and similar attacks.
Solution
Either limit traffic to this port to authorized hosts or upgrade to Secure ICCP, which protects the basic protocol with SSL / TLS encryption and digital certificates.