Gets the specified SIP header from an incoming INVITE message.
Since there are several headers (such as Via) which can occur multiple times, SIP_HEADER takes an optional second argument to specify which header with that name to retrieve. Headers start at offset
Please observe that contents of the SDP (an attachment to the SIP request) can't be accessed with this function.
number- If not specified, defaults to
This documentation was imported from Asterisk Version Unknown