ringtone on spa942

hello,

i need a diferent call from inside and outsite on my pbx
i found solution, to add n=Office in Alerf-Info field in extension
this is ok, and works with spa942( with firmware 5.1.15 wasn't working)

but how can i add this setup for all extension , i can add it manualy, but this isn't good idea

if i add it in ibound route with did/cid any/any it isn't working,

have someoune similar problem

thanks