[asterisk-users] SIP_HEADER() read-only

[Vincent Regnard]

Hi,

Having checked the documentation for SIP_HEADER:

pitux-exercice15*CLI>
   -= Info about function 'SIP_HEADER' =-

[Syntax]
SIP_HEADER(<name>)

[Synopsis]
Gets or sets the specified SIP header

I thought I could write some info in SIP_HEADER to retrieve them later.

But when I try to write to it:

exten => s,n,Set(SIP_HEADER(DN)=toto)
exten => s,n,NoOp(Sip DN ${SIP_HEADER(DN)})

Write is refused:

2006-08-02 16:16:09 VERBOSE[5224] logger.c:     -- Executing 
Set("SIP/220-aa94", "SIP_HEADER(DN)=toto") in new stack
2006-08-02 16:16:09 ERROR[5224] pbx.c: Function SIP_HEADER is read-only, 
it cannot be written to
2006-08-02 16:16:09 DEBUG[5224] pbx.c: Function result is '(null)'


Is this function really read-write ? Is there something I could check or 
modify to achieve my goal (writing to sip header) ?
Is there a switch somewhere to allow to write to it ? Any global or 
channel variable or parameter to set for that ?

Thanks for your help and comments.

I run asterisk 1.2.4.