Basic:

• Provides handset with its own extension number but no direct dial (DDI) capability
• Allows handset to make outgoing calls
• Offers integration of 'Click-to-dial' functionality with VoIP website phonebooks
• Call recording can be enabled (if supported)
• Intercept ('pick-up') unanswered colleagues calls

Standard:

• Provides all Basic-level functionality
• Allows handset to have an external DDI number
• Allows handset to be part of a hunt group

Enhanced:

• Provides Basic and Standard functionality
• Adds voicemail for the handset's extension
• Enables Point-to-Point video conferencing to take place on suitable handsets
• Offers 'Soft phone' capability for the phone

Deluxe:

• Offers all Enhanced-level functionality
• Links up to three additional handsets with a Deluxe handset