Integrated Ethernet switch , Multiple VoIP protocol support. Class 2 PoE , 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. IEEE 802.1p , IEEE 802.1Q (VLAN) , Type of Service (ToS). Acoustic echo cancellation (AEC) , Comfort noise generation (CNG) , HD Voice , Packet loss concealment (PLC) , Voice activity detection (VAD). Key Expansion Module Max Qty. The item "Polycom VVX 311 6 Line SIP VoIP Business Media Phone" is in sale since Wednesday, August 29, 2018. This item is in the category "Business & Industrial\Office\Telecom Systems\Business Phone Sets & Handsets". The seller is "konecobuildingservices" and is located in Sanford, Florida. This item can be shipped to United States.