How an IP phone works
An IP telephone converts voice into digital data packets and transmits them over the network using VoIP. It registers with a SIP server or a virtual PBX and receives an extension number.
Compared to an analogue telephone, an IP telephone also offers:
- BLF (Busy Lamp Field) - display of colleagues' status directly on the screen or indicator buttons
- Conference calls with multiple participants directly from the device
- Direct transfer to another branch or number with a single button press
- Display of caller number and name (CLIP)
Who is an IP phone suitable for?
Employees who prefer a physical device over a software application will appreciate an IP phone:
- Reception and customer service - a physical telephone is more ergonomic for all-day calling
- Offices with fixed workstations - the telephone remains on the desk; there is no need to wear a headset
- Companies transitioning from ISDN - users are accustomed to physical devices and do not wish to change their habits
IP telephones are manufactured in a range of versions: from simple devices with basic functions to manager models featuring large touch displays and dozens of programmable buttons.
What to watch out for when choosing an IP phone
Before purchasing, verify compatibility with your PBX: not every IP phone supports all features of a specific cloud exchange, particularly BLF and advanced call forwarding.
Further follow:
- PoE (Power over Ethernet) - power supply via network cable; eliminates the need for an electrical socket at each telephone
- HD Voice support - The G.722 codec significantly improves speech intelligibility during calls.
- Backup in case of internet outage - An IP phone does not work without internet; consider setting up a default forward to a mobile number.
On virtualni-ustredna.cz, standard SIP phones operate without complex configuration, simply enter the server address and login credentials.
Frequently Asked Questions
Do I need a special telephone line for an IP phone?
No, the IP telephone connects to a standard network socket (LAN). You do not need a telephone socket, an ISDN connection or any special cable, just access to the company network.
What is PoE and why is it important for IP phones?
PoE (Power over Ethernet) enables powering an IP telephone directly from the network cable. This eliminates the need for a power socket at each workstation, simplifying both installation and relocation of phones.
Can I use my existing company number on an IP phone?
Yes, the phone number is assigned to the extension at the central office, not to the physical device. The number remains the same when replacing the device or switching to a different telephone.