Ninja Pro Features:

• Touch-tones [DTMF]
• 6 Lines
• separately adjustable Ringtone, Speaker and Microfon
• Line Hold
• Line Transfer
• Further inquiry with Line Transfer
• Blind Transfer of a call
• Do Not Disturb
• Inbound Call 'Ignore'
• Inbound Call forwarding to an internet voicebox
• Inbound Call forwarding to a local voicebox
• 6 Party Conferencing [IP & PSTN]
• Auto-conference
• Multiple SIP Proxy Registration
  [10 Proxies]
• Dial/ Redial/Hangup
• Auto-answer
• Dynamic CODEC Selection
• Caller ID [SIP ID]
• Call Timer
• Silence Threshold
• Backspace/Clear/Delete
• Mute
• Microphone & Speakers Levels
• Microphone & Speakers Meters
• Redial
• Recent Calls Dialed, Received, missed 
• Individual Ringtones
• Individual Voicebox messages 
• Contact manager  
• Changeable Skins
• 6 lines for simultaneous calls
• Intuitive user input interface & menu. Easy to to navigate and manage.
• G.711a/G711u/PCM/G726 16 to 40 / GSM/Speex/iLBC included. [G.729 or G723 available on inquires with a co brand or private lable]
• NAT/Firewall support 
• Adjustable and fixed SIP and RTP ports for better firewall support  
• Supports Windows 98/NT4/ME/2000/Win2003/XP/VISTA
• DNS SRV configuration property supported