A print server is a device or software that manages print jobs and distributes them to one or more printers on a network. Instead of connecting a printer directly to a single workstation, a print server allows multiple users to share printers across the network. This centralized approach reduces hardware costs, simplifies management, and gives administrators control over print queues and user access.
Print servers can be dedicated hardware devices, software running on a Windows or Linux server, or functionality built into network-capable printers themselves.
How Network Printing Works
When a user prints a document on a network, the following process occurs:
- The application sends the print job to the local print spooler
- The spooler forwards the job to the print server
- The print server adds the job to the printer's queue
- The print server sends the job to the printer when ready
- The printer renders and prints the document
The print spooler is a service that manages print jobs in a queue, allowing users to continue working while documents print in the background. On Windows, the Print Spooler service handles this function.
Printing Protocols and Ports
Several protocols enable network printing, each suited to different environments.
RAW printing on port 9100 is the most common method for network printers. It offers fast, direct communication with minimal overhead. You may also see it called the HP JetDirect or AppSocket method.
IPP (Internet Printing Protocol) on port 631 is becoming the modern standard, supporting features like encryption, authentication, and detailed job status reporting. When IPP runs over TLS it's referred to as IPPS, still on port 631. IPP is the foundation of CUPS printing on Linux and macOS.
LPD/LPR (Line Printer Daemon / Line Printer Remote) on port 515 is a legacy protocol from the Unix world. The LPD service runs on the print server or printer and accepts jobs sent by LPR clients.