Reserved Number Space

he following numbers should not be assigned within a domain because they are reserved for system functions.

Restricted Numbering
00-99 Reserved for internal use


Customer Service

911 Emergency


Used for Dynamic Call Parking Queues


Unregistered Login to VMail (prompted for acct no and password)


Registered Login to VMail (prompted for password only)


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


User Extensions

800-899 User Extensions
1000-4999 User Extensions
5003-6999 User Extensions
8000-8999 User Extensions
9000-9899 Special Extensions (Example : Cloud Extension that forward to a cell phone, Fax Users, call routing, call queues and auto attendants)

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