I have an SL2100 with 2 x sip trunks all working as expected, today I increased my sip trunk channels to 4 and change 10-68 number of ports from 2 to 4. However I cannot access the additional trunks, and only the original 2 can be access by pressing the trunk access code.

Is there any other setting that needs to be changed to enable them. If I have two lines in use and try an incoming call the sl2100 responds with busy tone?