What Is a Fax Server?

A facsimile machine, or fax machine, scans a document and transmits a copy of the document over a telephone line or an Internet protocol (IP) network. The digital scan of the document is printed at the recipient's location to create a facsimile of the original document. This one-to-one sending works well for small offices with short documents, but larger organizations or organizations sending longer documents often require a system to send multiple documents sequentially or simultaneously. They need a fax server.

General Definition

A fax server is a software or software and hardware combination that can process, send and receive a number of fax documents. It is usually installed on an organization's local area network (LAN) and is set up to send faxes for any person on the network. A fax server also receives faxes and routes the fax, usually via email, to the intended recipient.

Telephone-based Servers

Some fax servers are attached to one or more telephone lines. If the server is only attached to a single phone line, it schedules fax delivery sequentially and sends the faxes only when the server is not receiving a fax transmission. If a fax server is connected to multiple telephone lines, it can send and receive multiple faxes at the same time.

IP-based Servers

Some fax servers send their data as Internet protocol (IP) data to a receiving IP fax machine or server. Because data travels over the public Internet, telephone lines aren't required for IP-based fax servers. Because IP based servers don't require telephone lines, they do not incur long distance telephone charges.

Hybrid Traditional and IP Servers

Some fax servers are systems that combine both telephone line based fax with IP-based fax. They send faxes via IP to servers and machines that support IP fax and fall back to telephone delivery for all other faxes.

Future of Fax Servers

Many fax servers are currently being configured to use IP, traditional telephone lines and Voice Over IP (VOiP) to transmit data. VOiP is an advantage because it combines the cost savings of IP-based fax with the flexibility of sending faxes over traditional telephone lines. Traditional fax transmissions using VOiP often do not incur the same long distance charges as traditional faxes over telephone lines.