I would strongly suggest you upgrade your Communications Manager as I dont belive version 4.0 even supported SIP trunking, it was added in version 4.1 to my recollation. We are on version 8.6 now, with many/many/many changes to SIP since version 4.X.
Also, ideally you would want a CUBE (border element) and I would either use 28XX, or idelly 29XX router for that.
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.