Integrated Ethernet switch , Multiple VoIP protocol support. Class 4 PoE , Lightweight Directory Access Protocol (LDAP) , Network Address Translation (NAT). DNS , HTTP , HTTPS , IP , Link Layer Discovery Protocol - Media Endpoint Discovery (LLDP-MED) , RTCP , RTP , SNTP , SRTP , TCP , TFTP , UDP. Power Over Ethernet (PoE) Support. Differentiated Services (DiffServ) , IEEE 802.1p , IEEE 802.1Q (VLAN) , Type of Service (ToS).Acoustic echo cancellation (AEC) , Comfort noise generation (CNG) , HD Voice , Voice activity detection (VAD). Support Details Full Contract Period. The item "NEW Polycom VVX 501 12 Lines PoE SIP VoIP Business Media Phone (2200-48500-025)" is in sale since Tuesday, March 07, 2017. This item is in the category "Computers/Tablets & Networking\Home Networking & Connectivity\VoIP Home Phones". The seller is "tuksycom" and is located in California. This item can be shipped worldwide.