from misdn.conf

[intern]
; define your ports, e.g. 1,2 (depends on mISDN-driver loading order)
ports=1,2
; context where to go to when incoming Call on one of the above ports
context=from-pstn
msns=*


from extension.conf


[from-pstn]
include => from-pstn-custom                     ; create this context in extensions_custom.conf to include customizations
include => ext-did-direct               ; MODIFICATOIN (PL) put before ext-did to take precedence
include => ext-did
include => from-did-direct              ; MODIFICATOIN (PL) for findmefollow if enabled, should be bofore ext-local
exten => fax,1,Goto(ext-fax,in_fax,1)