SIP phones, either physical or software based, offer distinct advantages in a modern communication setup. Not surprisingly they are favored by most users.
Traditional analog phones can't be plugged directly into your IP network since they have analog RJ11 connectors instead of IP ports.
To address this you will need to purchase an ATA - Analog Telephony Adaptor. The ATA has both an IP port and RJ11 (or other analog) connections.
It acts as a bridge between the IP network and the analog phone, converting digital data to analog signal and vice-versa.
The VoIP features that the analog phone will be able to perform depends on the ATA itself. Most basic functions will be covered. Advanced users or those dealing with large call volume may require an actual SIP phone.
An ATA can also be used for connecting other analog devices like a fax machine or a Door Phone. These may have an RJ45 connection used for analog data transmission.
Not only a good ATA is cheaper than a basic SIP phone, but business grade models usually comes with at least two analog ports for connecting two or more analog devices, making it an even more economical solution.
If the office location of your analog phones is not near an IP port, an ATA that can connect over Wi-Fi will easily solve that. However, a physical IP connection should provide a better call quality and is inherently more secure.
When planning to buy an ATA you should take into consideration that it can have two types of analog ports. FXS port stands for Foreign Exchange Station and provides connection between the ATA and analog faxes, phones, or other analog devices. FXO port stand for Foreign Exchange Office and provides connection between the ATA and traditional analog copper telephone lines (knows as POTS - Plain Old Telephone Service).
You would need FXO ports in your ATA if your office uses any analog telephone lines to connect to the PSTN (Public Switched Telephone Network) or if the premises already has some copper wiring. In this case the FXO ports can bridge your VoIP equipment with the PSTN or the copper lines. Otherwise, if you just need to connect analog devices to your VoIP network, FXS ports will suffice.
Once you connect the analog phones to the ATA they still need to be configured to recognize the relevant server and user settings. With some ATAs this can be done by the process of auto-provisioning.
If auto-provisioning is not available you would need assign a line or extension to the analog phone from the Telebroad PBX admin. You would then login to the ATA's own IP interface with its own admin password, enter the IP address of your PBXellent server, and the username and the SIP password assigned to the phone. Call the phone line you assigned. If the analog phone rings, you have just successfully connected it to an IP phone system.
It is also possible to use an ATA to connect analog emergency service device such as alarms, elevators, fire suppression etc. However, this is strongly advised against since that ATA introduced an extra point of failure.