The RiOS (Riverbed Operating System) that runs on Steelhead appliances seems to have been built on the top of a linux kernel. If we can assume this then here is an explanation of the TAP interfaces under linux:
Explanation found there (more details on the faq page): http://vtun.sourceforge.net/tun/faq.html#1.2
The TAP is a Virtual Ethernet network device.
TAP driver was designed as low level kernel support for
Ethernet tunneling. It provides to userland application
- /dev/tapX - character device;
- tapX - virtual Ethernet interface.
Userland application can write Ethernet frame to /dev/tapX
and kernel will receive this frame from tapX interface.
In the same time every frame that kernel writes to tapX
interface can be read by userland application from /dev/tapX
"Apurva Dave, director of product marketing at Riverbed, toldInternetNews.com that RiOS uses a Linux kernelas a base and then Riverbed hardens it and adds network acceleration optimization features on top."
yes that is what my riverbed SE told me also