Yealink SIP-T53W IP Phone - Corded - Corded/Cordless - Wi-Fi, Bluetooth - Wall Mountable, Desktop - Classic Gray - VoIP - IEEE 802.11a/b/g/n/ac - Caller ID - Speakerphone - 2 x Network (RJ-45) - USB - PoE Ports - Monochrome - SIP, RTCP XR, LDAP, SIP v2, NAT, STUN, DHCP, PPPoE, SNTP, UDP, TCP, ... Protocol(s):