PWG> Print Number minutes

PWG> Print Number minutes

PWG> Print Number minutes

Su Ling suling at
Sun Apr 10 22:05:00 EDT 2005


Sorry for the delayed response as we are not quite aware of the PWG workflow or procedure on handling BOF. Now we would reply:

1. What is the process for assigning numbers?
Let’s look at an example that IBM wants a printer number for the advertisement of IBM X31 PC. So IBM sends to the administrator of PNS server the following email: 

“IBM wants a print number for an ads. 

IBM requirement that PNS server executes: 
If PNS server receives this printer number from any printers, reply with the following IBM message.

IBM message:
This is print number service. 
The document title is “IBM X31 PC”.
The document is at PS3 format with A4 paper size 
If the printer is in China, get document at
Else get document at “

According to the email, the PNS administrator assigns and replies a number such as 88991111 to IBM, stores above IBM message in the PNS server, and let the PNS server execute above IBM requirements straight. 

2. What is the protocol between the printer and PNS?
The communication protocol may be a very simple one. That is, the printer retrieves a simple message from PNS. 
For example, the printer sends to PNS a simple request, like “I want the message for print number 88991111”. So the PNS reply with the message registered by IBM to the printer. It is the printer to take up the responsibility to interpret the message and get the document from document server like HTTP server. However we may develop and use more complicated PNS server. 

3. How do devices register with the PNS server?

The device (printer/keypad) does not register with the PNS server. That is, PNS does not keep any information of devices (printers/keypads).

4. What are the security / authentication requirements? Public vs. private documents. (e.g., random print number entry) 

The PNS is similar to DNS in functionality. We know there are no security / authentication requirements between the computer and DNS. We think that there are also no security / authentication requirements between the printer and PNS, as PNS server just tells where and how to get the document.

If a user wants to sends his credit number to PNS to get the URL of the bank, the printer should be able to identify that the number is a credit card number, and to remove sensitive data, but to keep the bank identity information, for example, change credit number 1111,1122,3333,4444 to 1111,1100,0000,0000. The PNS server still is able to use the remainder credit number to get the URL of the bank.

However, there are security / authentication requirements between the printer and the server, like HTTP server, that stores the document. The security depends on the existing protocols used between printer and document. For example, if the server is HTTP type, the security is guaranteed by the secure methods used in the HTTP protocol.
For example, PNS stores the IBM’s message of the print number 88991111:
This is print number service. 
The document title is “IBM X31 PC”.
Get document at with input parameters
Print Number = 88991111
Printer Language = ?
Paper Size = ?
Location = ?
Password=? and is encrypted by the public key “1234
After a printer receives the message, it prompts to the user for password. And then the printer may get the document by: PrintNumber=88990001, PrinterLang=PS3/PCL5, PaperSize=A4, Location=USA/Postcode11011/according to ip address, Password=EncryptUserPassword. 

Have to say that we do not know the security technology very well. 

5. The documents explain well the benefits.  What are the costs? (random "dialing", security, wrong number prints large document) 

We suggest following three measures to avoid “random dialing and wrong number”. 

For example, a user wanted to enter 88991111 to print the ad of IBM X31 PC, but he wrongly enters 88991112, which by chance is the ad of HP LaserJet 1300. As the printer has the wrong number 88991112, so it gets from the PNS server the message of 88991112, which includes a title “HP LaserJet 1300”. The printer generally has a small one or two lines LCD module, so the LCD prompts the tile “HP LaserJet 1300” to the user, and the user cancel the request of print before the printer downloads the HP ad (measure 1). 

When we enter a wrong phone number in the phone set, we hang up the line after we talk with receiver”. It is similar to this. If the printer does not have a LCD, the printer starts to print the document. As the user is standing in the front of the printer, as soon as he reads the first page, he may immediately press the cancel button of the printer (measure 2). 

If a printer is high-speed, after you read the page one, it is printing the page ten. In such case, the printer is designed such that after it prints the first page, it stops and prompts “continue?” in the LCD, or waits a few such as 10 seconds for user to read the first page before it continues to print following pages (measure 3).   

6. International issues (numbers are inherently global, URLs are not). 

The print number may be global or local.
For example, the number 88992222 is assigned as local number to three companies in different countries such as American, China and Singapore.
So the administrator of PNS server receives three messages from these companies in different countries.
And the printer gets the following messages from PNS server for the number 88992222; or PNS server selects one of them according to the printer’s ip address:
 If the printer is in the American, use

 If the printer is in the China, use

 If the printer is in the Singapore, use

By referring to the location of printers, we can let a number become a local one. Local numbers have more benefit in printing account statements (case 3). We think that people can manage the numbers well by studying current telephone number technology. 

7. What is the namespace?  Is this a world-wide service? 

We prefer that PNS, like DNS, provides the world-wide service. 

8. What is the lifetime of a PNS number? Scope? Duration? Are PNS numbers intended to be durable while URLs may change? 

The lifetime of a PNS number should be depended on the service it relates.
I boldly guess that if a PNS number is for advertising, its lifetime can range from a few weeks to permanent. If a PNS number is for temporary printing for travelers and students, like our case 2, its lifetime is less than weeks. In both cases, we can reuse the numbers.
When URL changes, the print number may not change.

9. In particular environments, the idea might be useful.
To be unique and durable, numbers will have to be very long. At some point, very long numbers are harder to recall and deal with than URLs. (e.g., IP numbers vs. DNS names) 

“In particular environments, the idea might be useful”. We can guess that the idea is mainly for some identified applications and environments, and the number will not become very long.
If we have a worry that number goes very long, this worry means that there are high demands on the print number, we do not expect such demands to happen so quickly.

10. Case 2 seems like “follow-me printing” already done by (ex PrinterOn); and have you heard of "Internet Number" from Japan? 

We were not able to get more information on their technologies. We may possibly be only one of the promoters of the idea.

11. What do you already have working? 

We are developing the demo software of using print number within the office LAN and Internet. We prefer not to embark on developing the software product by ourselves if we have any other alternative.

12. “Print Number” (the company) should participate in the PWG to move the idea forward.

Although we are doing something for the ideas, we are aware of our limitations, experience and capability, and we prefer not to involve in the standardization of the idea. We were planning to attend your Tokyo meeting, since some personal reasons we still will not go to the meeting in this time. If PWG thinks that the public will benefit from this idea, please try to standardize the idea, and prepare to vote the BOF without our attendance at the meeting.
We did file our first patent application for the idea in March 1, 2004. If PWG wants to standardize the idea, we will early sign PWG letter of Assurance according to the PWG requirement. If some members may have other related requirements and want to settle them in the beginning, we also would like to let them be done early.
Please, PWG, move the idea forward, if the idea can “help make good network printing possible”.


Su Ling

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