XMLDefault.cnf.xml should contain:
<Default> <callManagerGroup> <members> <member priority="0"> <callManager> <ports> <ethernetPhonePort>2000</ethernetPhonePort> <mgcpPorts> <listen>2427</listen> <keepAlive>2428</keepAlive> </mgcpPorts> </ports> <processNodeName></processNodeName> </callManager> </member> </members> </callManagerGroup> <loadInformation6 model="IP Phone 7970">SIP70.9-2-1S</loadInformation6> <authenticationURL></authenticationURL> <directoryURL></directoryURL> <idleURL></idleURL> <informationURL></informationURL> <messagesURL></messagesURL> <servicesURL></servicesURL> </Default>
Just as a FYI, i'm reading reports that there are (or were) issues registering with the v9 sip firmware, I can't find the v8 firmware for download anywhere! I did find v9.3.1, try upgrading the phone to that if the above doesn't help: https://1drv.ms/u/s!AusdiKa87-PC6f9ZZ-RpAdVn9GkHuQ
To upgrade the firmware, use the XMLDefault.cnf.xml file posted here and the SEP001956A3C492.cnf.xml file posted here.
You will need to find SIP70.9-2-1S in both files and replace with SIP70.9-3-1SR4-1S to upgrade the firmware.
If that doesn't work, throw the thing in the bin and get yourself a native SIP phone. ;-)