Well, I am assuming that calls to US are coming in on a GW in US, and calls to UK are coming in on a GW in UK. If that is the case then it's simple, assuming the GWs are collecting 4 significant digits, assign a Calling Search Space to US GW that only has access to US phone partition, and do the same for all other locations.
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.