Linksys NSS4100 Cisco NSS4000 and NSS6000 Series Network Storage System Admini - Page 188

Glossary of Storage-related Terms and Acronyms D 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. Linksys Small Business NSS4000 and NSS6000 Series Network Storage System Administration Guide 180