The following numbers should not be assigned within a domain because they are reserved for system functions.
Restricted Numbering |
|
00-99 | Reserved for internal use |
411 | Directory Information Service |
911 | Emergency |
988 | National Suicide Prevention Lineline |
700-709 | Used for Dynamic Call Parking Queues |
900-999 | Reserved due to 911 system feature |
5000 | Unregistered Login to VMail (prompted for acct no and password) |
5001 | Registered Login to VMail (prompted for password only) |
5002 | Hot Desking Sign In |
7000-7999 | These are unusable as extension numbers because they conflict with the 7+extension rule to transfer a call directly to voicemail |
9900-9999 | System Features |
Best Practice Dial Plan |
|
100-599 | User Extensions |
800-899 | User Extensions |
1000-4999 | User Extensions |
5003-6999 | User Extensions |
8000-8999 | User Extensions |