[asterisk-users] Pickup application

[nik600]

I am trying to configure the pickup.

This is my dialplan:
exten => _57.,1,Pickup(${EXTEN:2})

So, when i call for example 57333 Asterisk tries to pick up the call
ringing on 333

The problem is that it works only with internal calls!

For example, if i call 333 from 334 and while 333 i ringing i try to
dial 57333 it works.

If i call an external number that via dialplan dials 333 dialing 57333 i got:

Executing [57333 at from-internal:1] Pickup("SIP/200-08432290", "333") in new stack
[Feb 16 09:20:46] NOTICE[7586]: app_directed_pickup.c:159 pickup_exec:
No target channel found for 333.


Where am i wrong?
Thanks