I have a phone which has registered with Asterisk server. I powered cycle the phone. After the phone comes up again, the phone re-registers to my Asterisk server. If I make a call, the server responds with 503 on fist call. After the first call, everything works fine. I check server log which says:
SIP/2.0 503 Server error
Via: SIP/2.0/UDP 192.168.7.221:54910;branch=z9hG4bK4219157283;received=192.168.7.221
From: sip:6062@192.168.7.56;tag=1066332949
To: sip:6015@192.168.7.56;tag=1066332949
Call-ID: 4113312960@192.168.7.221
CSeq: 972910190 INVITE
User-Agent: Asterisk PBX
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Supported: replaces
Contact: sip:6015@192.168.7.56
Content-Length: 0
X-Asterisk-HangupCause: Normal Clearing
X-Asterisk-HangupCauseCode: 16
Does the server need to clear up previous data when the server gets the first “invite”
What I can do to resolve this issue? How can I fix this issue?