LPRng

Wyman Eric Miles

In the beginning, UNIX printing was nothing more than a line printer attached to a serial port. The system was rugged, reliable, and the points of failure were known. As printers became network aware, they could be placed near their users without the need for a nearby print server. Berkeley LPR, long the mainstay of UNIX printing, struggled to keep pace with printer technology. Maintaining a large network of printers spread over an entire campus became increasingly difficult.

The UNIX vendors created their own variations on the theme. The Solstice printing software has undergone major revisions with each new release of Solaris. Berkeley LPR is continually improved but still suffers from some of its early flaws.

At Rice University, we maintain an academic network that enjoys heavy use 24 hours a day, 7 days a week, year round. In response to the varied needs of class work and faculty printing, we've deployed upwards of 50 different printers across our 40-acre campus. Some labs have several HP printers that we'd like to operate as a single gang to distribute the load. Other labs have various types of printers, each supporting several different kinds of media: letterhead, legal, drilled, and tabloid papers. Our operations center has several Tektronix color printers that provide resume, transparency, glossy-film, and architectural-size color poster prints. We've recently added two new printers for high-volume drilled, collated, and stapled work. Under our previous printing system, Berkeley LPR under SunOS 4, maintaining such an infrastructure was time consuming. Without LPRng, which we started using two years ago, our older printing system was unreliable and inflexible to the degree that some of our fancier equipment would be an unthinkable addition.<>