How to recover lost extension.conf file?

I need help badly!!!

I by accident overwrite the extension.conf using extension.conf.sample. How can I get the extension.conf recovered? What choice to I have other than reinstall the whole thing?

I have a pretty simple set up right now. A analog card with 12 dahdi ports, 5 of them from-internals, and 7 of them from-pstn.

Can anyone help me to recover/recreate the extension.conf? Please.

I tried to delete all the extensions and re-create them, that does not seem to help at all. The extension.conf timestamp seems being updated, but its contents are not changing at all.

The phone connected to the analog ports can hear dial tone. But when I dial any number, for example, “1”, it will be busy tone. With these message in the full log file:

[Dec 31 12:19:25] VERBOSE[6503] chan_dahdi.c: – Starting simple switch on ‘DAHDI/1-1’
[Dec 31 12:19:27] VERBOSE[6503] pbx.c: – Executing [[email protected]:1] Dial(“DAHDI/1-1”, “dahdi/8,60,m(default)”) in new stack
[Dec 31 12:19:27] WARNING[6503] app_dial.c: Unable to create channel of type ‘dahdi’ (cause 0 - Unknown)
[Dec 31 12:19:27] VERBOSE[6503] app_dial.c: == Everyone is busy/congested at this time (1:0/0/1)
[Dec 31 12:19:27] VERBOSE[6503] pbx.c: – Executing [[email protected]:2] Hangup(“DAHDI/1-1”, “”) in new stack
[Dec 31 12:19:27] VERBOSE[6503] pbx.c: == Spawn extension (from-internal, 1, 2) exited non-zero on ‘DAHDI/1-1’
[Dec 31 12:19:27] VERBOSE[6503] chan_dahdi.c: – Hungup ‘DAHDI/1-1’