In a XenDesktop/XenApp environment, print jobs can take two routes, they are:
- Through the client
- Through a network print server
When locally attached printers are used, print jobs are routed through the ICA channel and are compressed. When Client printers are used, the print job must be routed through the client.
When network based printers are used, print jobs are routed directly from the XenApp server to the printer. Print jobs can be routed through the client for network based printers if there are trust issues or the driver is not available. Printing using this method results in uncompressed traffic .
The Direct connections to print servers policy can be used to configure servers and virtual desktops to print directly to print servers. If this setting is misconfigured, the print job may traverse the WAN 3 times!
- Print Job sent to client via ICA
- Print Job sent to Print Server, uncompressed
- Print Job sent to Printer, uncompressed
Generally, when printing over a WAN it is ideal to have print jobs routed through the client, if this is not possible, or to provide additional control, configure QoS (and multi-stream ICA if required).