Calling a SIP with phpagi

good morning,

i would like a help about calling a SIP phone from phpagi code.

i ve tried this : $agi->agi_exec(“DIAL SIP/$sip”);

but when the asterisk is running i have like that

agi->executing(/var/lib/asterisk/ivr.agi) ---- DIAL SIP sip@service without calling the sip phone.

thinks for your help