Sir,
While running test case 203, initially it sends an INVITE with a contact set to sip:sc%40sip%63ert@192.168.1.61:6500;%6C%72.
After the call is answered it sends an ACK with a contact field set to sip:sc@192.168.1.61:6500.
So consequently while we try to terminate a call, the contact will be sip:sc@192.168.1.61:6500. But whereas terminate is expecting sip:sc%40sip%63ert@192.168.1.61:6500;%6C%72.
 
So we tried adding the earlier contact to the ACK at line number 83
i.e.
ack = self.createRequest("ACK", trans=message.transaction)
co = ack.getParsedHeaderValue("Contact")
co.uri.username = "sc%40sip%63ert"
co.uri.params.append("%6C%72")
ack.setHeaderValue("Contact", co.create())

So now the test case is passed successfully.

Please clarify whether we are correct. Thanks in advance.

Regards,
VidhyaBoopalan,
Corent Technology.