FAQ/Why does my snom display "SIP disabled"

From Snom User Wiki

Answer

There are several reasons possible:

1. Concerns only snom360: The license file was not delivered with FW Versions < 4. You will need to request a valid license file from us. Please proceed to this FAQ article.
2. Your phone has one of the following MAC addresses which are not supported by former firmware versions:
   • snom300:
     • 00041328XXXX
     • 0004132DXXXX
     • 0004132FXXXX
     • 00041334XXXX
   • snom320:
     • 00041327XXXX
     • 0004132CXXXX
     • 00041331XXXX
     • 00041335XXXX
   • snom360:
     • 00041329XXXX
     • 0004132BXXXX
   • Workaround: Please use one of the following firmware versions instead:
     • FW releases 6.2.21 or 6.5.20
     • FW releases greater than 7.3.26: see also here