What is SEAL IPP Interface?¶
Once upon a time ...¶
... print data had to be transferred from a client to the SEAL Systems output management system.
It was necesary to send special information beneath the print data about
- which output device should be addressed?
- which paper has to be used?
- color or black-n-white?
- folding?
- ...
So header files were born and attributes like
PLS_PLOTTER=pdfout
were associated to the print data.
Transfer Protocols (knets/franss)¶
In early days of network printing, existing protocols like LPR were not able to
fit all demands, so knets and franss services were implemented.
These services use proprietary protocols to send print data and associated attributes to the output management system.
But they are insecure and non-standard, so system administrators are not happy with opening firewall ports for those protocols.
IPP - Internet Printing Protocol¶
In 1999 the Internet Printing Protocol was proposed (RFC 2567), based on HTTP/1.1.
This protocol allows to send arbitrary attributes beneath the print data and can easily be secured by TLS.
It is the de facto standard for network printing.
SEAL IPP Interface¶
Sending print data and attributes to existing SEAL Systems output management systems is possible by IPP header attributes. The required header files are build using valid IPP extensions.