Linksys NSS4000 Series Administrator's Manual page 157

Chapter
9
Network Storage System (NSS) Administrator Guide
Striping: A method of concatenating multiple disk drives into one logical storage unit. Striping
involves partitioning each drive's storage space into stripes which may be as small as one sector
(512 bytes) or as large as several megabytes. These stripes are then interleaved round-robin, so that
the combined space is composed alternately of stripes from each drive. In effect, the storage space
of the drives is shuffled like a deck of cards. The type of application environment, I/O or data
intensive, determines whether large or small stripes should be used.
T
Terabyte (TB): For data storage capacity usage, terabyte is equal to 1024 gigabytes.
TFTP (Trivial File Transfer Protocol): A simple file transfer protocol used to transfer small files
between hosts on a network. TFTP works like a very basic form of FTP.
TLS: Transport Layer Security. A security protocol from the IETF that is based on the Secure Sockets
Layer (SSL) 3.0 protocol developed by Netscape. TLS uses digital certificates to authenticate the user
and the network. The TLS client uses the public key from the server to encrypt a random number and
send it back to the server. The random number, combined with additional random numbers
previously sent to each other, is used to generate a secret session key to encrypt the subsequent
message exchange.
U
UPnP: Universal Plug and Play. A family of protocols from the UPnP Forum that automatically
configure devices, discovering services and providing peer-to-peer data transfer over an IP network.
Like Zeroconf, UPnP uses link-local addressing for IP assignment and provides service discovery.
Unlike Zeroconf, UPnP uses a different protocol. If a device does not have an IP address and there is
no DHCP server in the network, UPnP employs link-local addressing to create an IP address.
Software such as Windows Media Connect uses UPnP to stream audio and video over the network.
Several UPnP standards are employed including the Simple Service Discovery Protocol (SSDP) for
finding devices and UPnP AV Architecture, MediaServer and MediaRenderer for streaming. UPnP
can open router ports to let a device, external to the network, contact a network device.
UPS: Uninterruptible Power Supply. A device that provides battery backup when the electrical power
fails or drops to an unacceptable voltage level. Small UPS systems provide power for a few minutes;
enough to power down the computer in an orderly manner, while larger systems have enough
battery for several hours.
V
Virtualization: The creation of a virtual (rather than actual) version of something, such as an
operating system, a server, a storage device or network resources. The Linksys NSS refers to
virtualization as a way of aggregating storage between devices. Virtualized storage occurs when
storage is exported to the network as a disk drive or an array and is then imported by a master
NSS. The master NSS then uses the newly imported storage to create a single JBOD.
VLAN: Virtual Local Area Network (LAN). A logical group of user stations, servers, and other
network devices that appear to be on the same LAN, regardless of their physical location. You can
use the MAC addresses or IP addresses to interconnect the workstations on the LAN. You can access
and control the switches directly from a console port or via the LAN using IP.
Chapter 9: Glossary
155