It is not unusual for a person using a mobile user equipment to wish to access computing resources. For example, a person traveling may wish to access computing resources of an enterprise network associated with the traveler's regular place of business. Because of concerns about security, the enterprise network may be protected by a “firewall,” a system that is intended to prevent unauthorized and undesired access to the enterprise network. For example, the firewall may deny access except from specific “trusted” devices.
If a traveling user with a notebook computer that is trusted by the network wishes, for example, to print a document that is stored on the enterprise network to a printer outside the firewall, the user may download the file to the trusted notebook computer, and then send the file from the notebook computer to the printer in a separate transaction not implicating the firewall.
However, many people use devices such as a wireless e-mail device or a “smart phone” with e-mail or text messaging capability that does not allow the downloading of a document for printing. It is a common experience to receive an e-mail with an attached document, and be unable to open or read the attachment because the mobile device does not have sufficient memory capacity or display capability to handle the attachment.
One solution to this problem is “print by reference,” in which the user sends to a print server associated with the printer a reference to a document that is to be printed, which may be in the form of a network address such as an internet URL and a filename, and the print server retrieves the document directly from the enterprise server, bypassing the limited capability of the mobile device. However, with a strong firewall there may be no way of permitting the print server to retrieve the file through the firewall.