IAX Trunk Caller ID name reset

I have 4 PBXs that are connected by IAX trunks directly to each other. The PBXs have extension ranges that overlap extension ranges on the other PBXs (there is extension 1001 on all 4 PBXs).

If 1001 calls 1002 on another PBX, the called PBX resets the caller id name to the name of the 1001 on the called PBX. So a person thinks they are answering a call from John in the next office when it is really Jane in the office across town.

I fixed my issue by adding the last line below to extensions_additional.conf. Where would I add this so that it is not erased when FreePBX is reloaded?

include => macro-user-callerid-custom
exten => s,1,Set(AMPUSER=${IF($[“foo${AMPUSER}” = “foo”]?${CALLERID(number)}:${AMPUSER})})
exten => s,n,GotoIf($["${CHANNEL:0:5}" = “Local”]?report)
exten => s,n,GotoIf($["${CHANNEL:0:3}" = “IAX”]?report)

you don’t say what version you are running BUT… there is a notice in almost all versions at the top stating very clearly to NOT edit that file…

See http://freepbx.org/configuration_files and it will give you information and directions on the proper file or files to edit that will allow this change to stick.