安全可靠
* SIP v1 (RFC2543), v2 (RFC3261)
* SIP TLS, SRTP加密
* HTTP/HTTPS/FTP/TFTP
* ARP/RARP/ICMP/NTP/DHCP
* DNS SRV/ A Query/NATPR Query
* STUN, 会话刷新(RFC4028)
* DTMF模式: In-Band, RFC2833和SIP INFO
* SIP TLS, SRTP加密
* HTTP/HTTPS/FTP/TFTP
* ARP/RARP/ICMP/NTP/DHCP
* DNS SRV/ A Query/NATPR Query
* STUN, 会话刷新(RFC4028)
* DTMF模式: In-Band, RFC2833和SIP INFO













