Efficient time-sensitive printing

Thanks for reading and considering the question, and for your help.

Presently, a HP network printer is connected to the router. Hplip is used on Linux, OSX comes with its own driver, etc. And they print. But this is very efficient. People are standing by waiting for minutes before the printer starts to print. A way to process print jobs much faster is desired. Is there a way to ask the router to send all print jobs immediately to the printer? I think this is a job process issue? Is there a package to help with such?
Thanks a lot.

If the printer and user PCs are on the same LAN, the router isn't even involved other than as a layer 2 bridge. The PCs are talking to the printer directly with TCP data which the router doesn't even parse.

@mk24 you're right. Thank you. How can I change this, and hand over print jobs to the router from the clients. I assume the router will do a much better job at processing jobs faster. Thanks a lot.

You did not mention which particular HP laser printer you have...
Also, how much memory is installed in the laser printer?
If the printer has a slot to add more memory, adding memory may help it process complex print jobs faster.

@cesarvog will check but I don't think the model of the printer matters. This is a question of protocol and priority, and deployment as noted by @mk24 . But I agree that more RAM instead of the stock will help. However, I'd rather try a solution direct from the router first, and see how things improve. I just don't know how :smile:

printing wouldn't get any faster, if you move the print jobs around, rather the opposite, assuming printer's the bottleneck.

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@frollic, surely, there must be a way to prioritise certain jobs, QoS from the router does this job, for example, by prioritising certain packets. I'm hoping to do the same for printing. But can you support your statement with some references? I do not make any assumptions, partly the reason why not providing more ram as suggested by @cesarvog is not the way to go, for now. So for now, passing all print jobs to the router would be a way forward. But again, how :slight_smile: Someone here must have done this.

Why would you assume that? How do you think inserting an additional device between where the print job is coming from and the printer would make things better?

Again, why are you thinking this is a way forward? Currently the print job goes from the originating device directly to the printer. You want to insert a device in the middle of this and think that'll speed it up? Assuming there's even a suitable package available on OpenWRT.

Oh, it does, believe me.
Depending on the model, it could support many different features not supported by simpler, more affordable printers. Also, the processing unit (CPU) and engine (motor, fusor, etc...) would be more capable (meaning more pages per minute output) on higher end printers, which support duplex printing and other higher end capabilities. Memory also makes quite a difference on the processing of printer jobs. Some printers, only support raster images, others can print PDFs directly, it all depends on the printer model (aham... capabilities...).

@krazeh thanks. I get your point. Speaking of package, I found this: https://openwrt.org/docs/guide-user/services/print_server/p910nd

Pretty sure this is to allow you to connect a printer directly (i.e. via USB) to the router and then have devices attached to the network be able to print using that printer. It's not an alternative to a printer connected directly to the network.

This is intended to emulate an HP Jetdirect interface which was sold ages ago to allow parallel printers to be used on a network (yes, I'm that old). Your HP brand network printer already contains hardware that acts as a built-in Jetdirect.

Before implementing any "solution", you should investigate what the rootcause of this long delay is. Only if the rootcause is something that can be influenced by the router, a solution implemented on the router will have success.

Knowing the exact printer model could help in finding a solution.

What is the exact timing of a printjob, from clicking "Print" or "OK" until the printer starts the printing? (fill in the xx:xx; min:sec)

  • 00:00 Click "Print"
  • 00:01 Computer displays "Printing..."
  • xx:xx Computer finished printing
  • xx:xx Printer displays "Receiving data/print job"
  • xx:xx Printer heats up the fuser drum (maybe /maybe not visible from the outside)
  • xx:xx Printer starts to print

Have you searched the net already for something like "< printer model > OSX slow printing / long waiting / long delay"?

Have you asked your question already in an HP / OSX forum?

That would be within the print driver, and I would assume most people would select the prioritize me check box, once they realize other print jobs have it set.

From a print server point of view, a print out might be a binary blob, there's nothing to analyze or trigger.

To be able to work with priorities, you need something tangible, user ID, IP, separate queues, or whatever.

I'd get a new, faster printer, for priority jobs, or for round robin.

I will do get to it and do this.

No

No.

Many thanks.

@frollic @cesarvog @tmomas @mk24 @mk24 Thanks to you all. Word has it, it's an HP 2025DN with standard RAM, which I think is 256, last time I saw it.

21 ppm, and duplex capable.
That's not very fast, using duplex probably make it even slower (10 ppm ?) - those low end printers print the whole front page first, output the paper sheet, then suck it back in again, to print on the back.

Is it the CP2025dn? (color laser printer)
If so, it comes standard with only 128MB of RAM, which can be upgraded to 384MB max, by adding 256MB of memory in a single 144pin DDR2 DIMM slot.
Having said that, it's specs on B&H Photo says the following:

Print Speed	Black & color: up to 21ppm
First page out (letter):
Black: as fast as 17.2 sec (ready mode), as fast as 17.6 sec (low power mode)
Color: as fast as 17.7 sec (ready mode), as fast as 18.2 sec (low power mode)

source: [https://www.bhphotovideo.com/c/product/669706-REG/HP_Hewlett_Packard_CB495A_ABA_CB495A_Color_LaserJet_CP2025dn.html/specs](CP2025dn at B&H Photo)

Also, this review https://www.tonerbuzz.com/blog/printer-review-hp-color-laserjet-cp2025dn/ says it's not the fastest around these days.

@cesarvog @frollic @krazeh @tmomas @mk24 without getting distracted, how does a printer slows down with time? I can understand how a computer or router will, but a printer gets print jobs, that it process and prints. The jobs we can say have remained the same, text and images. Perhaps I'm dead wrong here. Back to the issue: is the conclusion then that the printer is old and slow? But before we answer that, I'd do as @tmomas suggests.

good idea... if it slows down with time... it's related to it's internal buffers / memory etc.

this is the whole principle behind server based spools... caching print jobs so the printer does not have to handle that...