A SCSI card, network card, hot-swap adapter card, serial adapter card, or VGA adapter that plugs into an appliance expansion slot.
A device that performs a well-defined function and is easy to install and operate.
A security step performed by NetCache. If protocol authentication is enabled, NetCache requires users to provide a user name and password before servicing any Web requests.
Mechanism that triggers e-mail messages from the customer site to Network Appliance Technical Support or another specified e-mail recipient when a problem or potential problem occurs with the NetCache appliance.
See Classless Inter-Domain Routing.
A type of network routing that uses the network mask instead of the address class to determine the destination network. NetCache access controls can be specified in CIDR format.
A terminal that is attached to a NetCache appliance's serial port and is used to monitor and manage the operation of the NetCache appliance.
A small file sent by a Web server containing information about a particular Web page. This information is generally used to maintain user-specific information and to adjust the appearance of a particular page accordingly, allowing for more personalized content. However, a Web page with a cookie attached to it requires special attention by NetCache, and might be uncacheable.
RAID degraded mode is the operating mode of a NetCache appliance when a disk is missing from the RAID array or the batteries on the NVRAM card are low. The missing disk or batteries should be replaced as soon as possible.
Public key encryption algorithm that uses 56-bit keys. DES is widely used for data encryption to secure communication over the Internet.
A number assigned by the NetCache appliance to each disk when it probes the disks at boot time.
A shelf that contains disk drives and is attached to the NetCache appliance.
A method by which computers connected to a TCP/IP network can identify each other, using known DNS servers as telephone books in which to look up other machines.
An Ethernet interface card.
A SCSI card, NVRAM card, network card, hot-swap card, or console card that plugs into a NetCache appliance expansion slot.
Slots on the system board in which you insert expansion cards.
Asystem in which the disk drives are exposed for easy access.
See also internal disk tray system.
An FDDI interface card.
An FDDI adapter that supports a fiber-optic cable.
An FDDI adapter that supports a twisted-pair cable.
The component of a news server that accepts news feeds from other news servers. The Feeder server might be on the same computer as other news server software components or it might be on a different computer.
A host's FQDN consists of its host name and its domain name, separated by a period. For example, the host euler, located in the domain netapp.com, has an FQDN of euler.netapp.com.
A disk installed in the NetCache appliance that can be used to substitute for a failed disk. Before the disk failure, the hot spare disk is not part of the RAID disk array.
Adding, removing, or replacing a disk while the NetCache appliance is running.
A query the NetCache appliance sends to a Web server in order to verify the consistency of an object, that is, to determine whether the object has been modified.
A closed system in which the disks are not easily accessible.
See also external disk tray system.
The method by which a hierarchy of NetCache appliances communicate with each other. A derivative of the User Datagram Protocol, ICP enables NetCache to query other caches for individual Web pages.
Lightweight Directory Access Protocol server. LDAP is a client-server protocol for accessing a directory service. NetCache can be configured to point to an LDAP server for authentication of user requests.
A live stream is a streaming media presentation occurring in real time, like the news program that you watch on your television set. Some organizations record a live media stream and then broadcast the media stream to their employees or customers at a specified time. All users who have requested the media stream see the same media stream at the same time. Users are not able to rewind or fast-forward a live media stream.
See also stream, on-demand stream, streaming media, and streaming media presentation.
Client host responsible for sending automatic e-mail to Network Appliance Technical Support when certain NetCache appliance events occur.
An option when booting a NetCache appliance from the system boot diskette. Maintenance Mode provides special commands for troubleshooting the hardware and system configuration.
The MD5 algorithm, created by RSA Data Security, Inc., is a checksum generation for use in security applications. Common uses include verifying the integrity of system files and password checking.
ASCII files that describe the information that the SNMP agent sends to network management stations.
The streaming media control protocol used in Windows Media Technologies (WMT) 3 & 4 streams. MMS is a proprietary protocol owned by Microsoft.
See also streaming media.
See Multipurpose Internet Mail Extensions.
See Microsoft Media Streaming protocol.
A set of definitions and specifications describing the various kinds of information that can be sent across the Internet (video, audio, and so on) and the methods used in their transmission. Every Web browser sends a block of information, called a MIME header, to a server when requesting a Web page. The server, in turn, sends back a MIME response header, as well as the page. Many types of information can be passed in these MIME headers, such as the type of browser used and the last time the Web page requested was modified.
An Ethernet, FDDI, or ATM adapter.
Client workstation on a network that uses a third-party application to process information.
A NetCache appliance that was configured to accept news requests from clients and to be able to fetch requested news data from a news server or another NetCache appliance that connects to a news server.
Network News Transfer Protocol. A news transmission protocol for the Internet. NNTP can be used to transport news from one host to another. Also, newsreader software can use NNTP to access the news database on a server host. One great advantage that NNTP has over UUCP, which preceded NNTP for news transport, is that an NNTP host receiving multiple newsfeeds generally receives only one copy of each article.
Nonvolatile random access memory. Static random access memory that is made into non-volatile storage by having a battery permanently connected.
See also SVRAM.
A previously recorded media stream that users can request at a time most convenient to them. Users can rewind and fast-forward on-demand media streams. Also called video on demand (VOD).
See also stream, live stream, and streaming media.
Adapter card that contains the NetCache appliance's NVRAM cache.
Disk on which parity information is stored for the RAID-4 disk drive array. Used to reconstruct data in failed disk blocks or on a failed disk.
Power-on self-tests run by the NetCache appliance right after the power is turned on.
Request issued by a browser specifying that the proxy agent fetch the original object from the source and not a cached copy.
The default mode of operation for NetCache. In this mode, the cache serves all users who set up their browsers to use NetCache as their proxy. While acting as a proxy, NetCache also caches Web pages requested by users, greatly decreasing response time for subsequent requests for the same Web page, as well as greatly decreasing total network bandwidth usage.
See also Web accelerator, streaming accelerator.
Redundant Array of Independent Disks. A technique that protects against disk failure by computing parity information based on the contents of all the disks in the array. The NetCache appliance uses RAID Level 4, which stores all parity information on a single disk.
Remote Authentication Dial-In User Service. RADIUS is a client-server protocol for accessing a directory service. NetCache can be configured to point to an RADIUS server for authentication of user requests.
The component of a news server that obtains the data that the news cache requests from the news storage device such as a NetApp filer. When the news cache does not have requested news in its cache, it connects to the Reader server component of the news server, through NNTP. The Reader server might be on the same computer as other news server software components or it might be on a different computer.
RTSP is the streaming media control protocol used in RealNetworks G2 and Apple QuickTime 4 streams. RTSP is an open protocol.
See also streaming media.
A feedback protocol that provides quality of service information to the streaming server. The RTCP feedback mechanism periodically describes the state of the network so the streaming server and client can negotiate the optimum bit rate for current network conditions. By default, RTCP uses UDP for transport.
Public key encryption algorithm that uses 2048-bit keys. RSA is widely used in public key cryptography to create matched public and private key pairs for data encryption. Data encrypted with the public key can be decrypted only with the private key, and data encrypted with the private key can be decrypted only with the public key.
See Real-Time Transport Control Protocol.
See Real Time Streaming Protocol.
Expansion card that supports the SCSI disk drives.
The number of a disk drive on the SCSI chain (0 to 6).
The full address of a disk, consisting of the disk's SCSI adapter number and SCSI ID (for example, 9a.1).
SecureAdmin is a NetCache security feature that enables you to administer NetCache in a nontrusted environment using an encrypted exchange of information between NetCache and a client. SecureAdmin supports the Secure Sockets Layer (SSL), and the Secure Shell (SSH) protocol options. SSL can be enabled to secure HTTP transmissions, or SSH can be enabled to replace Telnet and RSH clients and provide confidential NetCache administration.
Protocol that is a standard method for replacing Telnet and RSH sessions to secure encrypted communication over the Internet.
Protocol that is a standard method for secure, encrypted communication over the Internet. By encrypting the data on the sending end before it is sent out over the Internet, users can be reasonably assured that unauthorized parties intercepting their information cannot read it. Secure forms of the Network News Transport Protocol (NNTP) and Secure HTTP (HTTPS) can be proxied by NetCache.
An expansion card for attaching a terminal as the console on the NetCache appliance.
An ASCII or ANSI terminal attached to a NetCache appliance's serial port. Used to monitor and manage NetCache appliance operations.
NetCache process that gathers status and diagnostic information and forwards it to network management stations.
Name that is used as a password by the SNMP manager to communicate with the NetCache SNMP agent.
User-defined process that monitors a specific occurrence on the NetCache appliance, for example, a trap that monitors the disks on a NetCache appliance.
The process of delivering a unique stream to multiple clients simultaneously. Splitting reduces the number of requests sent across the network to the streaming server.
See also stream and streaming media.
A streaming media file being transmitted over a network. Streams are of two types, live and on-demand.
See also live stream, on-demand stream, streaming media, and unique stream.
A NetCache appliance that caches content from one or more streaming servers that you identify. A streaming accelerator provides that content to clients that request it. To the outside world, the streaming accelerator is the streaming server. In contrast, when NetCache runs as a streaming media cache, it acts as an agent for the media player.
A term used to describe media files that begin playing while they are being transmitted over the network to the media player on the client computer. In contrast, conventional Web files must be downloaded entirely before the user can view them. Commonly requested types of streaming media are video and audio. Streaming media also includes interactive media, cartoon-like animations, panoramic data, and more.
A specially configured NetCache appliance that intercepts client requests for streaming media. When a streaming media cache is deployed between clients and a streaming media server, streaming requests that would otherwise have been sent directly to the streaming server are sent to the cache. NetCache satisfies client requests by delivering cached or split streaming media content directly to users.
See also splitting, stream, streaming media.
A general term used to describe the delivery of live or on-demand streaming media. A streaming media presentation can consist of multiple unique streams.
See also stream.
Semi-volatile random access memory. SVRAM uses a part of main memory as if it is NVRAM.
See also NVRAM.
A Web object's Time To Live (TTL) is the time limit on how long a copy of that Web object remains in the cache before NetCache verifies the object with the originating Web server. An object's TTL is often determined by an explicit expiration time included in the MIME header of the object itself. If the object does not include an expiration time, NetCache calculates a default TTL for the object.
In streaming media, the streaming server's process of dropping a consistent number of video or audio frames to try to make the data being delivered to the client stream more efficiently during playback.
See also streaming media.
A stream is unique if the connection speed, media type, or thinning parameters are different from another stream that is part of the same streaming media presentation.
See also stream and streaming media.
A means of transferring information over a network, such as the Internet. It forms the backbone of the InterCache Protocol (ICP) used by NetCache to communicate with other caches in a hierarchy.
Write Anywhere File Layout. The file system designed for NetApp appliances to optimize write performance.
A Cisco router running WCCP 2.0 software.
A NetCache appliance that caches content from one or more Web servers that you identify. A Web accelerator provides that content to clients that request it. To the outside world, the Web accelerator is the Web server. In contrast, when NetCache runs as a Web cache, it acts as an agent for the browser.
An intermediary server that accepts requests from clients and forwards them to a Web server or services the request from its own cache. A Web cache acts as an agent for the client browser.
Copyright © 1994-2002, Network Appliance, Inc. All rights
reserved.
Part No. 210-00317
File: glossary.htm
Last updated: 11/12/02 16:57:28