|
|
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Apache
The most common web server (or HTTP server) software on the Internet. Apache is an open-source application originally created from a series of changes ("patches") made to a web server written at the National Center for Supercomputing Applications, the same place the Mosiac web browser was created.
Apache is designed as a set of modules, enabling administrators to choose which features they wish to use and making it easy to add features to meet specific needs inlcuding handling protocols other than the web-standard HTTP.
ASCII -- (American Standard Code for Information Interchange)
This is the defacto world-wide standard for the code numbers used by computers to represent all the upper and lower-case Latin letters, numbers, punctuation, etc. There are 128 standard ASCII codes each of which can be represented by a 7 digit binary number: 0000000 through 1111111.
ASP -- (Application Service Provider)
A organization (usually a business) that runs one or more applications on their own servers and provides (usually for a fee) access to others. Common examples of services provided this way include web-based software such as Calendar systems, Human Resources tools (timesheets, benefits, etc.), and various applications to help groups collaborate on projects.
Atom
An evolving protocol for syndication and sharing of content.
Atom is being developed as a succesor to and improvement over RSS and is more complex than RSS while offering support for additional features such digital signatures, geographic location of author, possibly security/encryption, licensing, etc.
Like RSS, Atom is an XML-based specification.
back to top
Backbone
A high-speed line or series of connections that forms a major pathway within a network. The term is relative as a backbone in a small network will likely be much smaller than many non-backbone lines in a large network.
Bandwidth
How much stuff you can send through a connection. Usually measured in bits-per-second (bps.) A full page of English text is about 16,000 bits. A fast modem can move about 57,000 bits in one second. Full-motion full-screen video would require roughly 10,000,000 bits-per-second, depending on compression.
Baud
In common usage the baud rate of a modem is how many bitsit can send or receive per second. Technically, baud is the number of times per second that the carrier signal shifts value - for example a 1200 bit-per-second modem actually runs at 300 baud, but it moves 4 bits per baud (4 x 300= 1200 bits per second).
Blog -- (weB LOG)
A blog is basically a journal that is available on the web. The activity of updating a blog is "blogging" and someone who keeps a blog is a "blogger." Blogs are typically updated daily using software that allows people with little or no technical background to update and maintain the blog.
Postings on a blog are almost always arranged in chronological order with the most recent additions featured most prominently.
It is common for blogs to be available as RSS feeds.
bps -- (Bits-Per-Second)
A measurement of how fast data is moved from one place to another. A 56K modem can move about 57,000 bits per second.
Broadband
Generally refers to connections to the Internet with much greater bandwidth than you can get with a modem. There is no specific definition of the speed of a "broadband" connection but in general any Internet connection using DSL or a via Cable-TV may be considered a broadband connection.
Browser
A Client program (software) that is used to look at various kinds of Internet resources.
Byte
A set of Bits that represent a single character. Usually there are 8 Bits in a Byte, sometimes more, depending on how the measurement is being made.
back to top
Certificate Authority
An issuer of Security Certificates used in SSL connections.
CGI -- (Common Gateway Interface)
A set of rules that describe how a Web Server communicates with another piece of software on the same machine, and how the other piece of software (the ?CGI program?) talks to the web server. Any piece of software can be a CGI program if it handles input and output according to the CGI standard.
cgi-bin
The most common name of a directory on a web server in which CGIprograms are stored.
Cookie
The most common meaning of "Cookie" on the Internet refers to a piece of information sent by a Web Server to a Web Browser that the Browser software is expected to save and to send back to the Server whenever the browser makes additional requests from the Server.
Depending on the type of Cookie used, and the Browsers' settings, the Browser may accept or not accept the Cookie, and may save the Cookie for either a short time or a long time.
Cookies might contain information such as login or registration information, online "shopping cart" information, user preferences, etc.
When a Server receives a request from a Browser that includes a Cookie, the Server is able to use the information stored in the Cookie. For example, the Server might customize what is sent back to the user, or keep a log of particular users' requests.
Cookies are usually set to expire after a predetermined amount of time and are usually saved in memory until the Browser software is closed down, at which time they may be saved to disk if their "expire time" has not been reached.
Cookies do not read your hard drive and send your life story to the CIA, but they can be used to gather more information about a user than would be possible without them.
CSS -- (Cascading Style Sheet)
A standard for specifying the appearance of text and other elements. CSS was developed for use with HTML in Web pages but is also used in other situations, notably in applications built using XPFE. CSS is typically used to provide a single "library" of styles that are used over and over throughout a large number of related documents, as in a web site. A CSS file might specify that all numbered lists are to appear in italics. By changing that single specification the look of a large number of documents can be easily changed.
back to top
DHTML -- (Dynamic HyperText Markup Language)
DHTML refers to web pages that use a combination of HTML, JavaScript, and CSS to create features such as letting the user drag items around on the web page, some simple kinds of animation, and many more.
DNS -- (Domain Name System)
The Domain Name System is the system that translates Internet domain names into IP numbers. A "DNS Server" is a server that performs this kind of translation.
Domain Name
The unique name that identifies an Internet site. Domain Names always have 2 or more parts, separated by dots. The part on the left is the most specific, and the part on the right is the most general. A given machine may have more than one Domain Name but a given Domain Name points to only one machine. For example, the domain names:
matisse.net
mail.matisse.net
workshop.matisse.net
can all refer to the same machine, but each domain name can refer to no more than one machine.
Usually, all of the machines on a given Network will have the same thing as the right-hand portion of their Domain Names (matisse.net in the examples above). It is also possible for a Domain Name to exist but not be connected to an actual machine. This is often done so that a group or business can have an Internet e-mail address without having to establish a real Internet site. In these cases, some real Internet machine must handle the mail on behalf of the listed Domain Name.
back to top
Email -- (Electronic Mail)
Messages, usually text, sent from one person to another via computer. E-mail can also be sent automatically to a large number of addresses.
Ethernet
A very common method of networking computers in a LAN.
There is more than one type of Ethernet. By 2001 the standard type was "100-BaseT" which can handle up to about 100,000,000 bits-per-second and can be used with almost any kind of computer.
back to top
FAQ -- (Frequently Asked Questions)
FAQs are documents that list and answerthe most common questions on a particular subject. There are hundreds of FAQs on subjects as diverse as Pet Grooming and Cryptography. FAQs are usually written by people who have tired of answering the same question over and over.
Fire Wall
A combination of hardware and software that separates a Network into two or more parts for security purposes.
FTP -- (File Transfer Protocol)
A very common method of moving files between two Internet sites.
FTP is a way to login to another Internet site for the purposes of retrieving and/or sending files. There are many Internet sites that have established publicly accessible repositories of material that can be obtained using FTP, by logging in using the account name "anonymous", thus these sites are called "anonymous ftp servers".
FTP was invented and in wide use long before the advent of the World Wide Web and originally was always used from a text-only interface.
back to top
GIF -- (Graphic Interchange Format)
A common format for image files, especially suitable for images containing large areas of the same color. GIF format files of simple images are often smaller than the same file would be if stored in JPEG format, but GIF format does not store photographic images as well as JPEG.
back to top
Hit
As used in reference to the World Wide Web, ?hit? means a single request from a web browser for a single item from a web server; thus in order for a web browser to display a page that contains 3 graphics, 4 ?hits? would occur at the server: 1 for the HTML page, and one for each of the 3 graphics.
Host
Any computer on a network that is a repository for services available to other computers on the network. It is quite common to have one host machine provide several services, such as SMTP (email) and HTTP (web).
HTML -- (HyperText Markup Language)
The coding language used to create Hypertext documents for use on the World Wide Web. HTML looks a lot like old-fashioned typesetting code, where you surround a block of text with codes that indicate how it should appear.
The "hyper" in Hypertext comes from the fact that in HTML you can specify that a block of text, or an image, is linked to another file on the Internet. HTML files are meant to be viewed using a "Web Browser".
HTML is loosely based on a more comprehensive system for markup called SGML.
HTTP -- (HyperText Transfer Protocol)
The protocol for moving hypertextfiles across the Internet. Requires a HTTP client program on one end, and an HTTP server program (such as Apache) on the other end. HTTP is the most important protocol used in the World Wide Web (WWW).
Hypertext
Generally, any text that contains links to other documents - words or phrases in the document that can be chosen by a reader and which cause another document to be retrieved and displayed.
back to top
IMAP -- (Internet Message Access Protocol)
IMAP is gradually replacing POP as the main protocol used by email clients in communicating with email servers.
Using IMAP an email client program can not only retrieve email but can also manipulate message stored on the server, without having to actually retrieve the messages. So messages can be deleted, have their status changed, multiple mail boxes can be managed, etc.
IMAP is defined in RFC 2060
IP Number -- (Internet Protocol Number)
Sometimes called a dotted quad. A unique number consisting of 4 parts separated by dots, e.g.
165.113.245.2
Every machine that is on the Internet has a unique IP number - if a machine does not have an IP number, it is not really on the Internet. Many machines (especially servers) also have one or more Domain Names that are easier for people to remember.
IPv4 -- (Internet Protocol, version 4)
The most widley used version of the Internet Protocol (the "IP" part of TCP/IP.)
IPv4 allows for a theoretical maximum of approximately four billion IP Numbers (technically 232), but the actual number is far less due to inefficiencies in the way blocks of numbers are handled by networks. The gradual adoption of IPv6 will solve this problem.
IPv6 -- (Internet Protocol, version 6)
The successor to IPv4. Already deployed in some cases and gradually spreading, IPv6 provides a huge number of available IP Numbers - over a sextillion addresses (theoretically 2128). IPv6 allows every device on the planet to have its own IP Number.
back to top
Java
Java is a network-friendly programming language invented by Sun Microsystems.
Java is often used to build large, complex systems that involve several different computers interacting across networks, for example transaction processing systems.
Java is also used to create software with graphical user interfaces such as editors, audio players, web browsers, etc.
Java is also popular for creating programs that run in small electronic devicws, such as mobile telephones.
Using small Java programs (called "Applets"), Web pages can include functions such as animations,calculators, and other fancy tricks.
JavaScript
JavaScript is a programming language that is mostly used in web pages, usually to add features that make the web page more interactive. When JavaScript is included in an HTML file it relies upon the browser to interpret the JavaScript. When JavaScript is combined with Cascading Style Sheets(CSS), and later versions of HTML (4.0 and later) the result is often called DHTML.
JDK -- (Java Development Kit)
A software development package from Sun Microsystems that implements the basic set of tools needed to write, test and debugJava applications and applets
JPEG -- (Joint Photographic Experts Group)
JPEG is most commonly mentioned as a format for image files. JPEG format is preferred to the GIF format for photographic images as opposed to line art or simple logo art.
back to top
Meta Tag
A specific kind of HTML tag that contains information not normally displayed to the user. Meta tags contan information about the page itself, hence the name ("meta" means "about this subject")
Typical uses of Meta tags are to include information for search engines to help them better categorize a page.
You can see the Meta tags in a page if you view the pages' source code.
MIME -- (Multipurpose Internet Mail Extensions)
Originally a standard for defining the types of files attached to standard Internet mail messages. The MIME standard has come to be used in many situations where one cmputer programs needs to communicate with another program about what kind of file is being sent.
For example, HTML files have a MIME-type of text/html, JPEG files are image/jpeg, etc.
mod_perl
An add-on for the Apache web server software, mod_perl makes it possible to use the Perl language to add new features for the Apache server, and to increase the speed of Perl applications by as much as 30 times.
back to top
PDF -- (Portable Document Format)
A file format designed to enable printing and viewing of documents with all their formatting (typefaces, images, layout, etc.) appearing the same regardless of what operating system is used, so a PDF document should look the same on Windows, Macintosh, linux, OS/2, etc. The PDF format is based on the widely used Postcript document-description language. Both PDF and Postscript were developed by the Adobe Corporation.
Perl -- (Practical Extraction and Report Language)
Perl is a programming language that is widely used for both very simple, small tasks and for very large complex applications.
During the 1990s it became the de-facto standard for creating CGI programs. Perl is known for providing many ways to accomplish the same task, with "there's more than one way to do it" being something of a motto in the Perl community.
Because it is so easy to perform simple tasks in Perl it is often used by people with little or no formal programming training, and because Perl provides many sophisticated features it is often used by professionals for creating complex data-processing software, including the "server-side" of large web sites. Perl does not provide significant support for creating programs with a graphical user interface.
PHP -- (PHP: Hypertext Preprocessor)
PHP is a programming language used almost exclusively for creating software that is part of a web site. The PHP language is designed to be intermingled with the HTML that is used to create web pages. Unlike HTML, the PHP code is read and processed by the web server software (HTML is read and processed by the web browser software.)
PNG -- (Portable Network Graphics)
PNG is a graphics format specifically designed for use on the World Wide Web. PNG enable compression of images without any loss of quality, including high-resolution images. Another important feature of PNG is that anyone may create software that works
with PNG images without paying any fees - the PNG standard is free of any licensing costs.
POP -- (Point of Presence, also Post Office Protocol)
Two commonly used meanings:
Point of Presence and Post Office Protocol.
A Point of Presence usually means a city or location where a network can be connected to, often with dial up phone lines. So if an Internet company says they will soon have a POP in Belgrade, it means that they will soon have a local phone number in Belgrade and/or a place where leased lines can connect to their network.
A second meaning, Post Office Protocol refers to a way that e-mail client software such as Eudora gets mail from a mail server. When you obtain an account from an Internet Service Provider (ISP) you almost always get a POP account with it, and it is this POP account that you tell your e-mail software to use to get your mail. Another protocol called IMAP is replacing POP for email.
Port
3 meanings. First and most generally, a place where information goes into or out of a computer, or both. E.g. the serial port on a personal computer is where a modem would be connected.
On the Internet port often refers to a number that is part of a URL, appearing after a colon (:) right after the domain name. Every service on an Internet server listens on a particular port number on that server. Most services have standard port numbers, e.g. Web servers normally listen on port 80. Services can also listen on non-standard ports, in which case the port number must be specified in a URL when accessing the server, so you might see a URL of the form:
gopher://peg.cwis.uci.edu:7000/
This shows a gopher server running on a non-standard port (the standard gopher port is 70).
Finally, port also refers to translating a piece of software to bring it from one type of computer system to another, e.g. to translate a Windows program so that is will run on a Macintosh.
Protocol
On the Internet "protocol" usually refers to a set of rules that define an exact format for communication between systems. For example the HTTP protocol defines the format for communication between web browsers and web servers, the IMAP protocol defines the format for communication between IMAP email servers and clients, and the SSL protocol defines a format for encrypted communications over the Internet.
Virtually all Internet protocls are defined in RFC documents.
back to top
Router
A special-purpose computer (or software package) that handles the connection between 2 or more Packet-Switched networks. Routers spend all their time looking at the source and destination addresses of the packets passing through them and deciding which route to send them on.
RSS -- (Rich Site Summary or RDF Site Summary or Real Simple Syndication)
A commonly used protocol for syndication and sharing of content, originally developed to facilitate the syndication of news articles, now widely used to share the contents of blogs.
RSS is an XML-based summary of a web site, usually used for syndication and other kinds of content-sharing.
There are RSS "feeds" which are sources of RSS information about web sites, and RSS "readers" which read RSS feeds and display their content to users.
RSS is being overtaken by a newer, more complex protocol called Atom.
RTSP -- (Real Time Streaming Protocol)
RTSP is an official Internet standard (RFC 2326) for delivering and receiving streams of data such as audio and video.
The standard allows for both real-time ("live") streams of data and streams from stored data.
back to top
Search Engine
A (usually web-based) system for searching the information available on the Web.
Some search engines work by automatically searching the contents of other systems and creating a database of the results. Other search engines contains only material manually approved for inclusion in a database, and some combine the two approaches.
Security Certificate
A chunk of information (often stored as a text file) that is used by the SSL protocol to establish a secure connection.
SEO -- (Search Engine Optimization)
The practice of designing web pages so that they rank as high as possible in search results from search engines.
There is "good" SEO and "bad" SEO. Good SEO involves making the web page clearly describe its subject, making sure it contains truly useful information, including accurate information in Meta tags, and arranging for other web sites to make links to the page. Bad SEO involves attempting to deceive people into believing the page is more relevant than it truly is by doing things like adding inaccurate Meta tags to the page.
Server
A computer, or a software package, that provides a specific kind of service to client software running on other computers. The term can refer to a particular piece of software, such as a WWW server, or to the machine on which the software is running, e.g. "Our mail server is down today, that's why e-mail isn't getting out."
A single server machine can (and often does) have several different server software packages running on it, thus providing many different servers to clients on the network.
Sometimes server software is designed so that additional capabilities can be added to the main program by adding small programs known as servlets.
Servlet
A small computer program designed to be add capabilities to a larger piece of server software.
Common examples are "Java servlets", which are small programs written in the Java language and which are added to a web server. Typically a web server that uses Java servlets will have many of them, each one designed to handle a very specific situation, for example one servlet will handle adding items to a "shopping cart", while a different servlet will handle deleting items from the "shopping cart."
SMTP -- (Simple Mail Transfer Protocol)
The main protocol used to send electronic mail from server to server on the Internet.
SMTP is defined in RFC 821 and modified by many later RFC's.
Spam (or Spamming)
An inappropriate attempt to use a mailing list, or USENET or other networked communications facility as if it was a broadcast medium (which it is not) by sending the same message to a large number of people who didn?t ask for it. The term probably comes from a famous Monty Python skit which featured the word spam repeated over and over. The term may also have come from someone?s low opinion of the food product with the same name, which is generally perceived as a generic content-free waste of resources. (Spam® is a registered trademark of Hormel Corporation, for its processed meat product.)
Spyware
A somewhat vague term generally referring to software that is secretly installed on a users computer and that monitors use of the computer in some way without the users' knowledge or consent.
Most spyware tries to get the user to view advertising and/or particular web pages. Some spyware also sends information about the user to another machine over the Internet.
Spyware is usually installed without a users' knowledge as part of the installation of other software, especially software such as music sharing software obtained via download.
SQL -- (Structured Query Language)
A specialized language for sending queries to databases. Most industrial-strength and many smaller database applications can be addressed using SQL. Each specific application will have its own slightly different version of SQL implementing features unique to that application, but all SQL-capable databases support a common subset of SQL.
A example of an SQL statement is:
SELECT name,email FROM people_table WHERE contry='uk'
SSL -- (Secure Socket Layer)
A protocol designed by Netscape Communications to enable encrypted, authenticated communications across the Internet.
back to top
T-1
A leased-line connection capable of carrying data at 1,544,000 bits-per-second. At maximum theoretical capacity, a T-1 line could move a megabyte in less than 10 seconds. That is still not fast enough for full-screen, full-motion video, for which you need at least 10,000,000 bits-per-second. T-1 lines are commonly used to connect large LANs to theInternet.
T-3
A leased-line connection capable of carrying data at 44,736,000 bits-per-second. This is more than enough to do full-screen, full-motionvideo.
TCP/IP -- (Transmission Control Protocol/Internet Protocol)
This is the suite of protocols that defines the Internet. Originally designed for the UNIX operating system, TCP/IP software is now included with every major kind of computer operating system. To be truly on the Internet, your computer must have TCP/IP software.
Telnet
The command and program used to login from one Internet siteto another. The telnet command/program gets you to the login: prompt of another host.
TLD -- (Top Level Domain)
The last (right-hand) part of a complete Domain Name. For example in the domain name www.matisse.net ".net" is the Top Level Domain.
There are a large number of TLD's, for example .biz, .com, .edu, .gov, .info, .int, .mil, .net, .org, and a collection of two-letter TLD's corresponding to the standard two-letter country codes, for example, .us, .ca, .jp, etc.
Trojan Horse
A computer program is either hidden inside another program or that masquerades as something it is not in order to trick potential users into running it. For example a program that appears to be a game or image file but in reality performs some other function. The term "Trojan Horse" comes from a possibly mythical ruse of war used by the Greeks sometime between 1500 and 1200 B.C.
A Trojan Horse computer program may spread itself by sending copies of itself from the host computer to other computers, but unlike a virus it will (usually) not infect other programs.
back to top
URI -- (Uniform Resource Identifier)
An address for s resource available on the Internet.
The first part of a URI is called the "scheme". the most well known scheme is http, but there are many others. Each URI scheme has its own format for how a URI should appear.
Here are examples of URIs using the http, telnet, and news schemes:
http://www.matisse.net/files/glossary.html
telnet://well.sf.ca.us
news:new.newusers.questions
URL -- (Uniform Resource Locator)
The term URL is basically synonymous with URI. URI has replaced URL in technical specifications.
URN -- (Uniform Resource Name)
A URI that is supposed to be available for along time. For an address to be a URN some institution is supposed to make a commitment to keep the resource available at that address.
back to top
Virus
A chunk of computer programming code that makes copies of itself without any concious human intervention. Some viruses do more than simply replicate themselves, they might display messages, install other software or files, delete software of files, etc.
A virus requires the presence of some other program to replicate itself. Typically viruses spread by attaching themselves to programs and in some cases files, for example the file formats for Microsoft word processor and spreadsheet programs allow the inclusion of programs called "macros" which can in some cases be a breeding ground for viruses.
back to top
Web page
A document designed for viewing in a web browser. Typically written in HTML. A web site is made of one or more web pages.
Website
The entire collection of web pages and other information (such as images, sound, and video files, etc.) that are made available through what appears to users as a single web server. Typically all the of pages in a web site share the same basic URL, for example the following URLs are all for pages within the same web site:
http://www.baytherapy.com/
http://www.baytherapy.com/whatis/
http://www.baytherapy.com/teenagers/
The term has a somewhat informal nature since a large organization might have separate "web sites" for each division, but someone might talk informally about the organizations' "web site" when speaking of all of them.
Wi-Fi -- (Wireless Fidelity)
A popular term for a form of wireless data communication, basically Wi-Fi is "Wireless Ethernet".
Worm
A worm is a virus that does not infect other programs. It makes copies of itself, and infects additional computers (typically by making use of network connections) but does not attach itself to additional programs; however a worm might alter, install, or destroy files and programs.
WWW -- (World Wide Web)
World Wide Web (or simply Web for short) is a term frequently used (incorrectly) when referring to "The Internet", WWW has two major meanings:
First, loosely used: the whole constellation of resources that can be accessed using Gopher, FTP, HTTP,telnet, USENET, WAIS and some other tools.
Second, the universe of hypertext servers (HTTP servers), more commonly called "web servers", which are the servers that serve web pages to web browsers.
back to top
XML -- (eXtensible Markup Language)
A widely used system for defining data formats. XML provides a very rich system to define complex documents and data structures such as invoices, molecular data, news feeds, glossaries, inventory descriptions, real estate properties, etc.
As long as a programmer has the XML definition for a collection of data (often called a "schema") then they can create a program to reliably process any data formatted according to those rules.
back to top
200 - Is a browser code that signals that the website page was opened successfully.
301 - Is a browser code that signals a directory was requested instead of a file. The server substituted an index.htm file
302 - Is a browser code that signals a temporary redirection to another page/location.
403 - Is a browser code that means the browser understands what to do, but can't do it for some reason.
404 - Is a browser code that means the requested web address cannot be found.
500 - Is a browser code that means there was an error in displaying a webpage.
506 - Is a browser code that signals ASP is not enabled for the domain name.
507 - Is a browser code that means there is likely an error with the coding of a ASP page.
400 Bad Request - The Apache Web server allows site managers to override the standard error page that is served for specific errors by number. This error, 400 bad request, means that a request for a URL has been made but the server is not configured or capable of responding to it. This might be the case for URLs that are handed-off to a servlet engine where no default document or servlet is configured, or the HTTP request method is not implemented.
401 Unauthorized -Your IP address or the username/password you entered were not correct. Your request was denied as you have no permission to access the data.
402 PaymentRequired - The data is not accessible at the time. The owner of the space has not yet payed their service provider.
405 Method Not Allowed - Your IP address or the username/password you entered were not correct. Your request was denied as you have no permission to access the data.
OR The server was unable to serve the data that was requested.
406 Not Acceptable - The document that has been requested either no longer exists, or has never existed on the server.
407 Proxy Authentication Required - The browser has not been authenticated on the required proxy server to access the data. This error is probably most commonly returned by content filters/parental controls.
408 Request Timeout - The browser has not been authenticated on the required proxy server to access the data. This error is probably most commonly returned by content filters/parental controls.
409 Conflict - Too many requests for the same file at one time.
OR
There is a conflict with an established software rule. (ie: you are trying to copy over a file with an older version, or you do not have permissions to delete a file)
OR
This could be caused by a DNS issue.
410 Gone - This is like a 404 error in that the document requested is not on the server, however this differs in that the server 'knows' that the file used to be there and 'believes' that the file may be back, so it returns 410 rather 404.
411- Length Required: Your Web server thinks that the HTTP data stream sent by the client (e.g. your Web browser or our CheckUpDown robot) should include a 'Content-Length' specification. This is typically used only for HTTP methods that result in the placement of data on the Web server, not the retrieval of data from it.
412- Precondition Failed: Your Web server thinks that the HTTP data stream sent by the client (e.g. your Web browser or our CheckUpDown robot) included a 'Precondition' specification which the server detected was not met.
413- Request Entity Too Large: Your Web server thinks that the HTTP data stream sent by the client (e.g. your Web browser or our CheckUpDown robot) was simply too large i.e. too many bytes. What constitutes 'too many bytes' depends partly upon the operation being attempted. For example a request to upload a very large file (via the HTTP PUT method) may encounter a ceiling on upload file size set by the Web server.
414- Request- URI Too Long: Your Web server thinks that the HTTP data stream sent by the client (e.g. your Web browser or our CheckUpDown robot) contains a URL that is simply too large i.e. too many bytes.
Typically Web servers set fairly generous limits on length for genuine URLs e.g. up to 2048 or 4096 characters. If your URL is particularly long, you can usually try shorter variations to see roughly where the limit is. If your long URL is indeed valid, then the Web server may need to be reconfigured to allow your URLs through. Understand that Web servers have to set some reasonable limit here, because they have to deal with badly programmed clients trying to give them huge garbage URLs.
415- Unsupported Media Type: Your Web server thinks that the HTTP data stream sent by the client (e.g. your Web browser or our CheckUpDown robot) identifies a URL resource whose actual media type 1) does not
agree with the media type specified on the request or 2) is incompatible with the current data for the resource or 3) is incompatible with the HTTP method specified on the request.Detecting exactly what is causing this problem can be difficult, because there a number of possible reasons. Often the request involves transfer of data from the client to the Web server (e.g. a file upload via the PUT method), in which case you need to confirm with your ISP which media types are acceptable for upload.
501- Not implemented: Your Web server does not understand or does not support the HTTP method it finds in the HTTP data stream sent to it by the client (e.g. a Web browser or our CheckUpDown robot).
502- Bad Gateway: A server (not necessarily a Web server) is acting as a gateway or proxy to fulfill the request by the client (e.g. your Web browser or our CheckUpDown robot) to access the requested URL. This server received an invalid response from an upstream server it accessed to fulfill the request.This usually does not mean that the upstream server is down (no response to the gateway/proxy), but rather that the upstream server and the gateway/proxy do not agree on the protocol for exchanging data. Given that Internet protocols are quite clear, it often means that one or both machines have been incorrectly or incompletely programmed.
503- Service Unavailable: Your Web server is currently unable to handle the HTTP request due to a temporary overloading or maintenance of the server. The implication is that this is a temporary condition which will be alleviated after some delay. Some servers in this state may also simply refuse the socket connection, in which case a different error may be generated because the socket creation timed out.
504- Gateway Timeout: A server (not necessarily a Web server) is acting as a gateway or proxy to fulfil the request by the client (e.g. your Web browser or our CheckUpDown robot) to access the requested URL. This server did not receive a timely response from an upstream server it accessed to deal with your HTTP request.This usually means that the upstream server is down (no response to the gateway/proxy rather than that the upstream server and the gateway/proxy do not agree on the protocol for exchanging data.
505- HTTP Version Not Supported: Your Web server does not support, or refuses to support, the HTTP protocol version specified by the client
(e.g. your Web browser or our CheckUpDown robot) in the HTTP request data stream sent to the server.The HTTP protocol has various versions identified as major.minor e.g. version 0.9, 1.0 or 1.1. Your server is indicating that it is unable or unwilling to complete the request using the major version provided by the client - other than with this error message.Assuming that your request identifies a valid major.minor version number (the request is not fundamentally corrupt), then this error should mostly only occur if you are trying to use version 1.0 or 1.1, but your
|
|
|
|
|
|
Why Skills Hosting...
Our experience hosting and providing web services for more than 6 years makes us the top choice for reliable and experienced hosting!
|
|
|
|
|
