[asterisk-users] problem with transfer application (REFER)

[nik600]

I'm experiencing some problem using the transfer()
application,expecially when a call in received from a queue.
I'm using Asterisk 1.4.22.1

This is my scenario:

; this is the piece of code in extensions.conf that place the call in
the queue when 1111 is called
exten => 1111,1,Answer
exten => 1111,n,Queue(2000|t)

;this is the piece of code that calls the user test when 2222 is called
exten => 2222,1,Dial(SIP/test)

; this is the piece of code that transfer the call using REFER
exten => 3333,1,Transfer(SIP/endpoint at x.y.z.t)

Calling 1111 the call is placed on the queue, and then answered from a
member (SIP/test), when the member try to transfer the call to 3333
the call ends with an error every time.

Calling 2222 the call is placed directly to the user SIP/test, when
the user try to transfer the call to 3333 SOMETIMES the call ends with
an error.

Sometimes asterisk says:

> Auto fallthrough, channel 'SIP/xxxxxxxxxx' status is 'ANSWER'

and sometimes it says

> Auto fallthrough, channel 'SIP/xxxxxxxxxx' status is 'UNKNOWN'

Can you help me to guess the problem?
I've read that the REFER implementation in the transfer application is
not complete, is it true?
Is there any procedure / configuration to use a complete and stable
implementation of the REFER functionality?

Thanks to all in advance

-- 
/*************/
nik600
http://www.kumbe.it