Incredible function and a great value. The GW0220 has two network ports. It is comparable to GW0120 except that this unit has a PSTN port. It has all the requirements of meeting the needs for a small and medium enterprise, and consistently delivers clear voice sounds. It also has reliable fax calling through its implementation of internationally recognized standards for voice and data networking. *Asterisk Supported. 

Echo elimination: G168
Fax Support: T.38
NAT transversal: support STUN client
Supports SIP info, DTMF Relay, RFC2833
Supports voice gain setting, jitter buffer
SIP domain, SIP authentication (none, basic,MD5), DNS name of server, peer to peer
Voice activity detection (VAD) and comfort noise generation (CNG)
SIP support for dual public server
Can connect to public server and private SIP server at the same time

Calling Functions and Features

Web and telnet configuration
Call forward/transfer/holding/waiting
Flexible dialing map
Caller ID identification
Supports hotline
Empty calling no. reject service
Black list for rejected authenticated call
Do not disturb
Supports conference

Network Functions and Features

PPPoE for xDSL,DHCP Client on WAN
SNTP Client, 802.1p/q, Diffserv
Network tools in telnet server. Includes ping, trace route and telnet client

Maintenance and Management

Supports boot monitor
Can upgrade firmware through boot monitor
Can upgrade firmware and configuration file through HTTP, FTP, TFTP
Can config through Web, keypad and Telnet
Support Syslog