s of iSCSI adapters. They combine the functional- ity of both categories (that of a NIC with that of a storage HBA). iSCSI adapters work with block- level data and perform the required segmentation and processing on the adapter card with the assistance of TCP/IP processing engines. The produced IP packets are then transmitted across the IP network. This allows the creation of full-fledged IP-based SANs without adversely affecting the host or server CPU. STORAGE VIRTUALIZATION Before we discuss some of the lower-level details, we must briefly mention the concept of storage virtualization, which is another state-of-the-art technology trend that is also contributing to the explo- sive growth of storage networking and depends on high-performance network storage processors. If we consult an industrial definition, such as the definition provided by Trebia Networks (www. trebia.com), storage virtualization is the "separation of the logical view of data storage from the actual underlying physical devices." If a storage infrastructure can arrive at that level of sophistication, then all physical storage is a shared pool of storage capabilities that can be used to service changing stor- age needs in an enterprise or organization. This can include, but is not limited to, online capacity expansion and reprovisioning. It is argued that the true potential of SAN can be maximized if IP stor- age is embraced by organizations and if equipment that supports storage virtualization is deployed. Virtualization software is first used to collect data that may be originating from different types of storage devices. These devices can be SAN-attached devices, network-attached devices, or devices that are attached on a server. The virtualization software then consolidates all of this gathered data into a common pool that can be monitored, managed, supervised, and administered for broad use from a single console. The term storage virtualization is widely used by several vendors, but each vendor approaches the issue differently: Some vendors