Normally codecs have SSH on by default, Telnet however is typically disabled. However, since you said you have access to the system via the remote, you can find the NetworkServices settings in the advanced configuration section of the OSD menu. If the HTTP/S services are already on, than something else might be an issue, such as something between you and the system that is preventing you from accessing it, like a firewall in your network. Worse case you could try to factory reset the codec and see if that resolves it, but that is worse case since it will clear all your configurations and set the codec completely back to default settings.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.