| Loudspeaker | No |
| Caller display | No |
| SIP-Standard (Session Initiation Protocol) | No |
| ISDN Port | No |
| Ethernet connection | No |
| USB | No |
| Bluetooth | No |
| Release date | 11 Apr 2006 |
| H.323 VoIP-Protocol | No |
| IP Phone | No |
| System Phone | No |
| Recording System | Digital Announcement |
| Hands-Free Functionality | No |
| Polyphonic ringtones | No |
| SMS function | No |
| Backlight illumination | No |
Retell 540 Pro Answering Machine reviews
- 11 Apr 2006
- Digital Announcement
