CUSTOM_HEADER

 [vici]

exten => _X.,1,Noop(******making the call******)

exten => _91NXXNXXXXXX,1,AGI(agi-set_variables.agi)

exten => _91NXXNXXXXXX,n,NoOp(Customer phone number ${phone_number})

exten => _X.,n,Set(CUSTOM_HEADER_VALUE=${UNIQUEID})

exten => _X.,n,SIPAddHeader(X-Your-Custom-Header: ${CUSTOM_HEADER_VALUE})

exten => _X.,n,Dial(SIP/${trunk}/${EXTEN})

[a2b]

exten => _X.,1,Noop(******receiving call******)

exten => _X.,n,Noop(Custom SIP Header Value: ${SIP_HEADER(X-Your-Custom-Header)})

exten => _X.,n,Set(CDR(userfield)=${CUSTOM_HEADER_VALUE})