Printing in Engineering Computing

erick@uwaterloo.ca

Printing Overivew

Engineering Computing maintains print queues for 45 printers across the Faculty of Engineering.

Print jobs from workstations are sent to eng-mmserve, a Windows 2003 server which authenticates the user against nexus.  Client printer drivers are also stored on eng-mmserve.  Once the job is ready to print, it is sent via LPR to engprint, a FreeBSD machine which manages the print spooling and accounting.  Engprint uses LPRng, XAS and locally written software to manage the printing process. 

Nexus  group policy objects (GPOs) are used to install networked printer drivers on Nexus computers.  Laptops and standalone computers can easily find and connect to any Nexus or ADS printer using our web based printer connection tools: laptopprint for Windows, and omniprint for Mac and Unix/Linux.

Details

Nexus GPOs are used to install printer drivers at login time.  Printers used in  student labs are automatically deleted at logout time, so the users will not collect printers with every room their physically visit.

We found that configuring the print queue at server.uwaterloo.ca works best.  However, it has the unfortunate effect of obscuring the print queue name in some Windows applications because the server name is so long.

Printing is limited to 250 MB per job, a number chosen to fairly share the printers and the server.

Our LPRng system is configured to check the user’s XAS account for any funds before printing.  Some preprocessing is also done on each job to determine the format  of the output (eg. 11x17 or envelope).  When jobs are sent to public printers incapable of that format, or which would require manual access to insert paper of that size, the job is deleted and Email notification of the problem is sent to the user.

Jobs sent in pure text are formatted and printed at four cents per side.

Postscript or PCL jobs are 8 cents per single sided page, 12 cents duplex.

We have the ability to charge different users different rates, or no charge. 

Print jobs can be enabled by user groupings and station groupings, or prevented by user groupings or station groupings.

Post-printing Email can be sent or not.

‘Out-of-paper’ or ‘printer down’ messages are sent to blackberries and other Email systems.  The message is repeated every 24 hours if the problem is not fixed.

Queue status and paper status are available on the web.  Users can view queues and delete jobs.  Various wall mounted displays show the queue and paper status.

The system is capable of supporting a release monitor, but we are not using any.

The ability to cancel active jobs depends on the printer model.  For HP we use SNMP to quickly cancel jobs.

On many printers we implement a feature to display the userid who owns the current job.

Both PostScript and PCL devices are supported.  Some devices do not have 64 bit drivers.

Many printer vendors are trying to add value with drivers that want to talk directly to the hardware during installation to query feature sets.  These are often trickier to initially install, but then work fine in production.  The HP universal driver is in this category, it uses SNMP to query the device at installation time. 

We use XAS accounting and have a few XAS card swipe stations.  We would really like to have eCommerce to  put money on XAS.

We log page counts and other statistics.

We think our differential accounting for duplex printing is helping encourage responsible paper use. Over the past year, 13.5% of all student print jobs are double-sided.  15% of all sheets of paper (student jobs only) are double sided.

Our annual number of pages printed has decreased over time.

Some users print pdfs which either crash printers or cause them to timeout.  Trying Ghostscript to view the PDF displays errors too.  These buggy PDFs are not common.  We  have not located the source yet, we think it may be Latex originated PDFs.

Host based printers exist, they do not go through our print queues.  We prefer to use network printers.

Laptop users can configure printing using laptopprint for Windows, and omniprint for Mac and Unix/Linux.  Both utilities were on the Minuwet post-login page.  They are temporarily available at: http://www.eng.uwaterloo.ca/~erick/software/wirelessprint/ until minuwet is reactivated.

Both laptopprint and omniprint present all printers in ADS and Nexus.  The PC version automatically installs the drivers and makes the connections. Omniprint lists the exact commands the user must enter to install the printer.