Background Intelligent Transfer Service (BITS) is a component of modern Microsoft Windows operating systems that facilitates prioritized, throttled, and asynchronous transfer of files between machines using idle network bandwidth. It is most commonly used by recent versions of Windows Update, Windows Server Update Services, and Systems Management Server to deliver software updates to clients, and is also used by Microsoft's instant messaging products to transfer files. Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... Windows Update version 5 through Netscape Browser 8. ... Screenshot of a Windows Software Update Services administration console Windows Server Update Services (WSUS) provides a software update service for Microsoft Windows operating systems and other software. ... Microsoft Systems Management Server (SMS) [1] is a product for managing large groups of Microsoft-based computer systems. ... Software Update is a software tool by Apple Computer that install the latest version of Apple software on computers running Mac OS X (there was also a Software update tool for classic Mac OS). ... Microsoft Corporation, (NASDAQ: MSFT, HKSE: 4338) is a multinational computer technology corporation with global annual revenue of US$44. ...

Technology

BITS uses unused bandwidth to transfer data. Normally, BITS transfers data in the background, i.e., BITS will only transfer data whenever there is bandwidth which is not being used by other applications, for example, when applications use 80% of the available bandwidth, BITS will use only the remaining 20%. BITS constantly monitors network traffic for any increase or decrease in network traffic and accordingly throttles its own transfers to ensure that other foreground applications (such as a web browser) get the bandwidth they need. BITS also supports resuming transfers in case of disruptions. This article or section does not cite its references or sources. ... Bandwidth throttling is a method of ensuring a bandwidth intensive device, such as a server, will limit (throttle) the number of requests it will respond to within a specified period of time. ... An example of a web browser (Internet Explorer), displaying the English Wikipedia main page. ...

BITS version 1.0 supports only downloads. From version 1.5, BITS supports both downloads and uploads. Uploads require the IIS web server, with BITS server extension. Microsoft Internet Information Services (IIS; sometimes, erroneously called Server or System) is a set of Internet-based services for servers using Microsoft Windows. ...

Transfers

BITS transfers files, on behalf of requesting applications, asynchronously, i.e., once an application requests the BITS service for a transfer, it will be free to do any other job, or even terminate. The transfer will continue in the background, as long as the network connection is there. Even when a user is not logged on, BITS continues the data transfer.

BITS suspends any ongoing transfer when the network connection is lost, or the operating system is shut down. It resumes the transfer, from when it left off, when the computer is turned on later and the network connection is restored. BITS supports transfers over both HTTP and HTTPS. HTTP (for HyperText Transfer Protocol) is the primary method used to convey information on the World Wide Web. ... https is a URI scheme used to indicate a secure HTTP connection. ...

Jobs

BITS uses a queue to manage file transfers. A BITS session has to be started from an application by creating a Job. A job is a container, which has one or more files to transfer. A newly created job doesn't have any file, files must be added to it specifying both the source and destination URIs. While a download job can have any number of files, upload jobs can have only one. Properties can be set for individual files. Jobs inherit the security context of the application which created it. Uri may refer to: geography: Canton of Uri is a canton (region) of Switzerland. ...

BITS provides API access to control a job. A job can be programmatically started, stopped, paused, resumed, and queried for status. Before starting a job, a priority has to be set for it, to specify when the job is processed, relative to other jobs in the transfer queue. By default, all jobs are of Normal priority, which can be optionally set to High or Low. A High priority job runs in foreground, and competes for network resources with other applications. Background transfers are optimized by BITS, which increases and decreases (or throttles) the rate of transfer based on the amount of idle network bandwidth that is available. If a network application begins to consume more bandwidth, BITS decreases its transfer rate to preserve the user's interactive experience. A application programming interface (API) is the interface that a computer system, library or application provides in order to allow requests for services to be made of it by other computer programs, and/or to allow data to be exchanged between them. ...

Scheduling

BITS schedules each job to receive only a finite time slice, for which only that job is allowed to transfer, before it is temporarily paused to give another job a chance to transfer. Higher priority jobs get a higher chunk of time slice. Round-robin scheduling to process jobs in the same priority, and prevent a large transfer job from blocking smaller jobs. Look up scheduling in Wiktionary, the free dictionary. ... Pre-emption as used with respect to operating systems means the ability of the operating system to preempt or stop a currently scheduled task in favour of a higher priority task. ... Round-robin is one of the simplest scheduling algorithms for processes in an operating system, which assigns time slices to each process in equal portions and in order, handling all processes as having the same priority. ...

When a job is newly created, it is automatically suspended (or paused). It has to be explicitly resumed to be activated. Resuming moves the job to queued state. When it is its turn to transfer data, it first connects to the remote server and then starts transferring. After the time slice expires, the transfer is temporarily paused and the job is moved to queued state. When it gets another time slice, it has to connect again before it can transfer. When the job is complete, BITS transfers ownership of the job to the application that created it.

BITS includes built-in mechanism for error handling and attempt recovery. Errors can be either fatal or transient, either moves a job to its respective state. A transient error is a temporary error that resolves itself after some time. For a transient error, BITS waits for sometime and then retries. For fatal errors, transfers the control of the job to its creating application, with as much information regarding the error as it can provide.

Version history

• Version 1.0 (October 2001)
  • Initial release. Included with Windows XP RTM.
• Version 1.2 (July 2002)
  • Included with Windows XP Service Pack 1 and Windows 2000 Service Pack 3. BITS' inclusion with Windows 2000 brought Automatic Updates capabilities into the core of that operating system.
  • No other external changes were made.
• Version 1.5 (September 2003)
  • Included with Windows Server 2003 and made available as a separate download for Windows 2000 and Windows XP.
  • Added upload and upload-reply capability, command-line execution for events, explicit credentials, and support for Windows 2000.
• Version 2.0 (August 2004)
  • Included with Windows XP Service Pack 2 and Windows Server 2003 Service Pack 1, and made available as a separate download for Windows 2000 Service Packs 3 and 4, and prior releases of Windows XP and Server 2003.
  • Added support for performing concurrent foreground downloads, using Server Message Block paths for remote names, downloading portions of a file, changing the prefix or complete name of a remote name, and limiting client bandwidth usage.
  • BITS 2.0 is a minimum requirement for Windows Software Update Services.
• Version 2.5
  • Adds support for certificate-based client authentication for secure HTTP transports and custom HTTP headers.
  • Support for IPv6
  • Microsoft's BITS documentation suggests that this version will be available for download for Windows 2000, Windows XP, and Windows Server 2003.
• Version 3.0 (November 2006)
  • Adds peer caching allows users to download content from peers and also serve content to peers, receive notification when a file is downloaded, access the temporary file while the download is in progress, and control HTTP redirects. BITS 3.0 also uses Internet Gateway Device counters to more accurately calculate available bandwidth.
  • Adds Group policies to control peer caching and limit download times, number of jobs and files download. BITS 3.0 also writes diagnostic and troubleshooting events to the system log which can be viewed in Event Viewer.
  • Included with Windows Vista, and is scheduled for inclusion with Windows Server "Longhorn". BITS 2.5 capabilities are also included in Windows Vista and Windows Server "Longhorn".

Windows XP is a line of proprietary operating systems developed by Microsoft for use on general-purpose computer systems, including home and business desktops, notebook computers, and media centers. ... Windows 2000 (also referred to as Win2K) is a preemptible, interruptible, graphical and business-oriented operating system that was designed to work with either uniprocessor or symmetric multi-processor 32-bit Intel x86 computers. ... Windows Server 2003 is a server operating system produced by Microsoft. ... Server Message Block (SMB) is an application-level network protocol mainly applied to shared access to files, printers, serial ports, and miscellaneous communications between nodes on a network. ... Screenshot of a Windows Software Update Services administration console Windows Server Update Services (WSUS) provides a software update service for Microsoft Windows operating systems and other software. ... Internet Protocol version 6 (IPv6) is a network layer protocol for packet-switched internetworks. ... Universal Plug and Play (UPnP) comes with a solution for Network Address Translation (NAT) traversal. ... Local Group Policy Editor in Windows XP Media Center Edition Group policy is part of Microsofts IntelliMirror technology which aims to reduce the overall cost of supporting users of Windows. ... Event Viewer in Windows XP. Event Viewer in Windows Vista December CTP 5270. ... Windows Vista is a line of graphical operating systems used on personal computers, including home and business desktops, notebook computers, Tablet PCs, and media centers. ... Windows Server Longhorn is the codename for the next server operating system from Microsoft. ...

List of non-Microsoft applications that use BITS

• SharpBITS : A free download manager GUI for BITS
• WinBITS : Another free download manager GUI for BITS
• BITS Download Manager : Yet another free download manager GUI for BITS

• Novell ZENworks Desktop Management: A systems management software that can use BITS to deliver application files to workstations.^{[citation needed]}

GUI can refer to the following: GUI is short for graphical user interface, a term used to describe a type of interface in computing. ... GUI can refer to the following: GUI is short for graphical user interface, a term used to describe a type of interface in computing. ... GUI can refer to the following: GUI is short for graphical user interface, a term used to describe a type of interface in computing. ... Novell ZENworks is a software product suite developed and maintained by Novell, Inc. ... Systems management refers to enterprise-wide administration of distributed computer systems. ...

See also

• List of Microsoft Windows components
• Protocols for file transfer

The following is a list of Microsoft Windows components. ... A protocol for file transfer or file transfer protocol is a convention or standard that controls or enables the transfer of files between two computing endpoints. ...

External links

• Background Intelligent Transfer Service in Windows Server 2003
• BITS version history