laser-lovers@uw-beaver (01/22/85)
From: imagen!geof@su-shasta.arpa I've been asked to clear up the situation on accounting and Imagen TCP-IP printers. Printers with the serial communications option tell the spooler process how many pages were printed for each job that the spooler has sent. This allows the spooler to do proper accounting. There is currently no accounting support for the TCP-IP/Ethernet communications option. We intend to support accounting in the future. Some accounting support will appear with the next major release of the TCP-IP software. We have not yet scheduled this release. There are some users who simulate accounting on TCP printers by monitoring the number of "Printing Page N" messages that are printed on the console between "Job Finished" messages. This is a hack (or clever technique, if it works for you), and we don't expect it to be sufficient for our users, but it might explain some of the confusion on the list. In the future, printers will be accessible via a new tcp-based protocol, which will be called ``Transport2'' (In case you didn't know, the current protocol is called transport1). Transport2 will allow the sender of a document to wait around until a job is finished and get a final count of pages from the printer. This will solve accounting problems for users who only communicate with the printer via trusted spoolers. The general problem of accounting is harder to solve. A distributed printer can be sent data by many entities on the network. Some of them are allowed to use the printer, some are not. Some are trusted to pass on accounting information, some are not. In general, the entity that sends a file to be printed is not necessarily the entity that should receive the accounting information for the job. A real solution the this problem would require encryption, key distribution, authentication servers, and so on. We intend to estimate a solution to the problem by allowing the user to configure a particular communications channel (which might be a serial line or might be a TCP connection to a given host-port combination) into the printer. All accounting data passes down this channel, which is presumably connected to a trusted host. The trusted host collects accounting information for all the hosts using the printer. Possible embellishments to this scheme could allow the trusted host to preview job information and use it to implement access control for the printer. Again, I can't say exactly when all this will arrive. However, trust that we recognise and are working on the problem. We welcome your input. Feel free to send me any suggestions that you think will help (I think that direct mail is better than laser-lovers for this sort of thing). - Geof Cooper imagen!geof@shasta.arpa