 Yealink SIP-T21P E2 |  Yealink SIP-T23G |  Yealink SIP-T27G |  Yealink SIP-T29G | |
| Lines | 2 | 3 | 6 | 16 |
| Display | 2.3" graphicalLCD | 2.8" graphicalLCD | 3.66" graphicalLCD | 4.3" color LCD |
| Line Key | 2 | 3 | 8 | 10 |
| Memory Key | 0 | 0 | 21 (3 pages of 7 keys) | 27 (3 pages of 9 keys) |
| EthernetPorts | 2 x 10/100 | 2 x Gigabit | 2 x Gigabit | 2 x Gigabit |
| IntegratedPoE | Yes | Yes | Yes | Yes |
| PSU included | Yes | Yes | Yes | Yes |
| USB | No | No | 1 x 2.0 | 1 x 2.0 |
| Bluetooth | No | No | Optional Adapter BT40 | Optional Adapter BT40 |
| WiFi | No | No | Optional Adapter WF40 | Optional Adapter WF40 |
| ExpansionModule | No | No | 6 x EXP20 | 6 x EXP20 |