If you want to use different clients with different ports to connect to the service, you can achieve it by the following steps:
1) Start your vrep service with command ./vrep.sh -gREMOTEAPISERVERSERVICE_19997_FALSE_TRUE -h /path/to.ttt
You can change 19997 to other numbers. This command allows you to start a service use different port.
2)In your remote api code, use the port number 19997, and you can connect to the service 19997 by the same port number they use.
In my code, I start the vrep use 19997 to 20003, so I have 7 vrep service. And it is possible to control these 7 service by using the right port number in the remote api.