This should be added/registered to CUCM as 3rd Party SIP Phone. follow the below guide for configuration assistance/example. https://support.spectralink.com/sites/default/files/resource_files/1725-86980-000_C2.pdf     Regards, Venkatesh.  

how did you confirm that the CUCM is not working when you cant access it both via web and CLI.

seems like the MTP is not getting allocated here: we would see something as "countChange=1"next to the MTP if its allocated successfully and we don't see it here,    you can collect the below information from gwy to isolate further or try restarting ...