One of the most interesting aspects of I
2
O is a mechanism called peer-to-peer communications. Championed by Xpoint Technologies, which gave the technology to the I
2
O Special Interest Group, it lets two or more devices transfer data between themselves with little or no involvement on the part of the OS or main processor. This enables a new category of "brilliant handlers" that run on an I/O processor (IOP). For example, a peer-to-peer hardware device module (HDM) might monitor block-storage data tr
affic to implement disk mirroring. It could also copy recently modified files from a hard drive to a backup tape. A peer-to-peer OS-specific module (OSM) provides OS information, such as file system type, to the HDM so that it can set up the transfers. Additionally, the OSM acts as a traffic cop to monitor file access rights and supervise the transfer. The peer-to-peer specifications did not make it into the I
2
O 1.5 release, but they will be provided as an addendum later. They will become part of version 2.0, which is due out in March 1998.
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