Cisco 6921 Unified IP PhoneCisco 6921 Unified IP PhoneHeadset support: RJ9 interface to optional headset allows customers to enjoy additional options for place and receiving callsCodec support: G.711a, G.711, G.729a, G.729b,G.729ab and iLBC audio-compression codecs are supported.Network features: Network features include Cisco Discovery Protocol and IEEE 802.1 p/q tagging and switching.Speakerphone: Full-duplex speakerphone allows for flexibility in placing and receiving callsVideo Communications: Requires Cisco Unified Video Advantage 2.2 and the VTIII camera for support.Network features: Network features include Cisco Discovery Protocol and IEEE 802.1 p/q tagging and switching.Additionally ethernet switch: The phone has a 10/100BASE-T Ethernet connection through two RJ-45 ports, one for the LAN connection and the other for connecting a downstream Ethernet device such as a PC.Get more information about this product from here
