Just confirming what I think I already know. If I use a phones external mask via route pattern that would get overridden by the RL/RG if something was specified there. If I specify at the gateway, that will take the ultimate precedence over everything. I have a 3905 which does not have the ability as a feature to modify the line appearance. I need the 5 digit extension listed per site but masked as the primary DID for that site for all outbound calls. The big problem comes in that it is a centralized dial plan and there is only one T1 PRI group. FXOs are only used for 911.
I tried to use transforms but the route pattern and gateway override them so no dice there. Any other thoughts? I guess I could completely redesign a separate dial plan for just the 3905s but that would require some decent configuration. I've thought about translation patterns but that is the same thing as redoing the route patterns for them. Getting rid of the 3905s is not an option since there are already so many in place. Any thoughts on how to get around CUCMs nature to override the external mask that farther away from the phone you get?