Hi,
We had this issue as well and found that in most cases it was caused by the way the caller-ID for missed calls was presented, so that if users pressed dial without using edit dial first they dial 911.
We implemented a workaround first by removing the 911 route pattern and adding the 9.911 route pattern. Next, we are now in the works to add a translation profile to the gateways to add the 9 for an outside line to the caller-ID.
BTW, we sufferd the same in our EU countries where the emergency number is 112 and I just tested the translation profile with succes for these sites.
Here is the config for the Netherlands, similar one should be possible for the US I guess (have not yet tested it):
!
voice translation-rule 2
rule 1 /\(^.........$\)/ /00\1/
rule 2 /\(^..........$\)/ /000\1/
rule 3 /\(^...........$\)/ /000\1/
rule 4 /\(^............$\)/ /000\1/
rule 5 /\(^.............$\)/ /000\1/
rule 6 /\(^..............$\)/ /000\1/
rule 7 /\(^...............$\)/ /000\1/
!
voice translation-profile AddLeadingZero
translate calling 2
!
dial-peer voice 100 pots
translation-profile incoming AddLeadingZero
incoming called-number
direct-inward-dial
!
With this in place users can just press dial on missed calls without accidentally dialing the 112 emergency number :-)
Hope this helps,
Leo
