Hi,
it is possible to change the default settings by modifying the configuration file "lightstreamer_conf.xml", that you can find in <LS_HOME>/conf directory (where LS_HOME is the path where you installed the Lightstreamer server). In order to change the default listening TCP port, you must replace the original settings in the <port> element under the "HTTP/HTTPS SERVER CONFIGURATION" block at the beginning of the file.
If your requirement is to have both Lightstreamer and IIS listening on port 80, you should consider to deploy them into different hosts, because TCP does not allow to bind more than one process on the same port.
Alternatively, you could also consider to plug two different network interfaces in the same host with two different IP addresses, allowing you to bind each process on its own listening interface on the same port 80. To do that, you have to properly configure the <listening_interface> element in the configuration file with the IP address of the network interface you assign to Lightstreamer server instance.
Could you please give us more details about your scenario in order to identify the deployment strategy that fits your requirement best?
Regards,
Gianluca
