It seems that this application is using a lot of ports. I don't understand what you wrote 1st about "telnet".
Found this thread about a similar problem:
socket: All ports in use
They talk about of no further available ephemeral ports, which are for temporary connections. The network options command
no can limit the range of them. Check the man page for
no about
tcp_ephemeral_high and
tcp_ephemeral_low. Maybe it the application is not working correct and opening/using too many ports for communication.
There could also be a hint in the documentation about this software what OS parameters they'd like to have when running their app.