if 1000 devices are homed to a subscriber (any time devices are more than 500), definitely that server requires 2 gigs. Even more is better. I guess these servers can go up to 4 gigs or 6 gigs. If your publisher is also running CM service, that requires 2 gigs. If its not having its callmanager service enabled, you can have your publisher with 1 gig.
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.