Reddit reviews Grandstream Enterprise IP Phone GS-GXP2140 (4.3" Color Display, POE, Power Supply Not Included)

Dual switched auto-sensing 10/100/1000 Mbps Gigabit Ethernet ports with integrated PoE4 line keys with up to 4 SIP accounts, 5 programmable context sensitive softkeys, 5 navigation/menu keys11 dedicated function keys for : MESSAGE (with LED indicator), PHONEBOOK, TRANSFER, CONFERENCE, HOLD, HEADSET, MUTE, SEND/REDIAL, SPEAKERPHONE, VOLRJ9 headset jack (allowing EHS with Plantronics headsets), USB, extension module portSupport for G.729A/B, G.711/a-law, G.726, G.722 (wide-band), and iLBC, in-band and out-of-band DTMF (in audio, RFC2833, SIP INFO)