support earphone, one high-quality earphone (with microphone) is attached. support sip, iax2. support 2 sip servers and 1 iax2 server running at the same time. support 3 settings storage, switch by keypad. support major g7.xxx ( 711a/u,723,729¡­) codec. call hold, call forward, call transfer. e.164 dial plan and customized dial rules. configurable jitter buffer size. 80 groups incoming & outgoing calls memory reviewed¡¢stored. phone book with 100 groups memory. user define ring tone, call id display. static/dynamic wan-ip-addressing, support pppoe. safe mode provide reliability. support poe (power over ethernet). adjustable user password and super password. configure file download, upload and update/upgrade by ftp,http and tftp. interface 1 x wan; 1 x lan; 1 audio port