Short for Sender Policy Framework, an extension of SMTP that stops e-mail spammers from forging the “From” fields in an e-mail. As SMTP itself does not carry an authenticating mechanism, the SPF extension provides the authentication scheme by specifying which computers are authorized to send email from a specific domain. In order to use SPF, the domain sending e-mails must establish an SPF record that is published in DNS records. When the e-mail passes through the DNS server, it is compared to the SPF record for that domain to determine if the sender is indeed authorized to transmit e-mails from that sender’s address. If the e-mail comes from a domain that is not authorized, the DNS server will not forward the e-mail to the expected destination.
SPF is one method that can be used to stop spam from being sent using unauthorized domain names. However, it should be noted that SPF only stops the spammer from forging the “From” field in the e-mail and does not stop the spammer from sending e-mails from a domain in which it is a member.
SPF was formerly called Sender Permitted Form, but the name was later changed while the abbreviation remained the same.
Acronym for Service Profile Identifier, a number that identifies a specific ISDN line. When you obtain ISDN service, your telephone company assigns a SPID to your line. Part of the initialization procedure is to configure your ISDN terminal adapter to use this SPID. Most telephone companies in the U.S. use the Generic SPID Format, which […]
Short for single point of failure, a generic phrase for any component of a system that upon failure will cause a malfunction in the entire system. A SPOF can be a hardware or electrical component or a software component. Each time a system expands (e.g., adding a workstation to a network or adding a new […]
SPN, short for service principal name, is the name by which a client uniquely identifies an instance of a service. If you install multiple instances of a service on computers throughout a forest, each instance must have its own SPN. A given service instance can have multiple SPNs if there are multiple names that clients […]
Short for Sequenced Packet Exchange, a transport layer protocol (layer 4 of the OSI Model) used in Novell Netware networks. The SPX layer sits on top of the IPX layer (layer 3) and provides connection-oriented services between two nodes on the network. SPX is used primarily by client/server applications. Whereas the IPX protocol is similar […]
- Structured Query Language (SQL)
Abbreviation of structured query language, and pronounced either see-kwell or as separate letters. SQL is a standardized query language for requesting information from a database. The original version called SEQUEL (structured English query language) was designed by an IBM research center in 1974 and 1975. SQL was first introduced as a commercial database systemin 1979 […]