We are new to IP phone firmware upgradation (Sorry if it is a re-post of previous question(s)).
Recently we have bought a cisco 7942G IP phone.
It currently has SIP 42.9-0-2SR1S firmware loaded on it.
We do not see any option to configure a SIP Proxy where we can provide SIP Server (Asterisk PC/Device) IP address (with current firmware on it) to register it with Asterisk.
Do we need to upgrade the SIP firmware to any latest versions?
If yes, to which version we should be updating it?
It would be of great help if you advice us on what are files we need to have in the tftpboot directory apart from the firmware (like SIP Default.conf, SIP.cnf.xml, CTLSEP.tlv, etc) for the upgradation.