dbs/db4/opticonnect is a SAP Parameter attribute which is used to control Opticonnect usage information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
This parameter specifies whether Opticonnect is used instead of TCP/IP
if the application server and database server are not on the same
See SAP Parameter Documentation for full SAP documentation for this profile parameter.