Yealink SIP-T31 in Nairobi, Kenya is a two-line VoIP phone with HD audio quality, Gigabit Ethernet speed, and PoE support. Yealink SIP-T31 features Yealinkâs Smart Noise Filtering technology crystal clear sound quality. Yealink SIP-T31 is intended to be familiar to users with two-line keys and a backlit display. HD audio performance means professional communications from the handset, full-duplex speakerphone or wired headset. The phone supports Yealink EHS headsets. Yealink SIP-T31 supports the open SIP communications protocol interoperable with VoIP phone systems and services. The phone supports two SIP lines and has a powerful chip to improve performance designed to last. The Yealink T3 Series of IP Phones feature unified firmware across the series to simplify the deployment, maintenance, and updating of the fleet