Furuno Felcom 250 Service Manual page 162

Nickname
When registration in the SIP and registration of the client
Handset have been completed, " " will be displayed in Reg.
column. It may take approx. 1 min (Max.) until the mark is
displayed after the registration was completed.
Reference)
Register / edit the Handset extension Number and Password from the Web MMI
1) Open the "Device" menu.
2) If you click "Auto detect," the IP addresses and the software Ver. for the detected
Handset and Incoming indicator will be displayed.
When receiving an extension call
4-16
4.3 Registering the Handset in the SIP Server
Caller's extension
number