SIP v1 (RFC2543), v2 (RFC3261)
SIP server/proxy redundancy
NAT Traversal: STUN mode
IP assignment : static/DHCP/IEEE802.1X/open VPN
HTTP/HTTPS web server
Time and date synchronization by SNTP
DNS-NAPTR/DNS-SRV(RFC 3263)
QoS: 802.1p/Q tagging (VLAN), Layer 3 ToS DSCP
TLS(Transport Layer Security), SRTP, ZRTP
HTTPS certificate manager
AES encryption for configuration file
Digest authentication using MD5/MD5-sess
IEEE802.1X/OpenVPN
IPv4/IPv6 , LLDP/CDP/DHCP VLAN