This device is suitable for personal usage.  It is quite cheap.

Features:

• Support IAX2, H323, MGCP, SIP
  
• Support G.711, G.723.1, G.729, GSM
  
• DHCP support for LAN or Cable modem
  
• PPPOE support for ADSL or Cable modem
  
• Set phone by HTTP web browser(IE6.0) or Telnet
  
• Upgrade by FTP
  
• Dynamic voice test
  
• CNG(Comfort noise generation)
  
• G.168/165 compliant 16ms echo cancellation
  
• Tone generation and local DTMF re-generation according with ITU-T
  
• E.164 dial plan and customized dial rules

For more informations, please visit: http://www.iaxtalk.com

Order it online: http://iaxtalk.com/index.php?main_page=product_info&products_id=4&zenid=52ae54725bef2da0452587b569f82802