不能將同一 CID 注冊兩次，道理很簡單，

當別人打這一號碼，which provider handle your call?
so settings for line2 should be:
registration: NO,
ans call without registration: yes,
call without registration: yes,
By the way you can use GoogleVoice# as your CID to voipdiscount. this is bullet proof tested.

after update the info for line2 should be: offline.