CIFS: The Common Internet File System Protocol

Microsoft Corporation

July 1996
Updated April 30, 1997
(Revised links in Industry Support)

Overview

The Internet is rapidly opening up new ways of communicating for individuals and organizations alike. Until now, most Internet usage has been limited to simple one-way file transfers or read-only browsing. However, the demand for greater interactivity on the Internet is exploding. Now, there is the Common Internet File System (CIFS) protocol to support rich, collaborative applications over the Internet.

CIFS defines a standard remote file system access protocol for use over the Internet, enabling groups of users to work together and share documents across the Internet or within their corporate intranets. CIFS is an open, cross-platform technology based on the native file-sharing protocols built into Microsoft® Windows® and other popular PC operating systems, and supported on dozens of other platforms, including UNIX. With CIFS, millions of computer users can open and share remote files on the Internet without having to install new software or change the way they work.

See the sections below for more information on CIFS:

CIFS in a Nutshell
CIFS Benefits
Industry Support
CIFS Specification and Resources
Other CIFS and SMB Resources
Press Releases

CIFS in a Nutshell

CIFS enables collaboration on the Internet by defining a remote file access protocol that is compatible with how applications already share data on local disks and network file servers. CIFS incorporates the same high-performance, multi-user read-and-write operations, locking, and file-sharing semantics that are the backbone of today's sophisticated enterprise computer networks. CIFS runs over TCP/IP and uses the Internet's global Domain Naming Service (DNS) for scalability. CIFS is specifically optimized to support slow-speed dial-up connections common on the Internet.

With CIFS, existing applications and applications for the World Wide Web can easily share data over the Internet or intranet, regardless of computer or operating system platform. CIFS is an enhanced version of Microsoft's open, cross-platform Server Message Block (SMB) protocol, the native file-sharing protocol in the Windows 95, Windows NT®, and OS/2® operating systems and the standard way that millions of PC users share files across corporate intranets. CIFS is also widely available on UNIX, VMS, and other platforms.

Microsoft is making sure that CIFS technology is open, published, and widely available for all computer users. Microsoft has submitted the CIFS 1.0 protocol specification to the Internet Engineering Task Force (IETF) as an Internet-Draft document and is working with interested parties for CIFS to be published as an Informational RFC. CIFS (SMB) has been an Open Group (formerly X/Open) standard for PC and UNIX interoperability since 1992 (X/Open CAE Specification C209).

CIFS is not intended to replace HTTP or other standards for the World Wide Web. CIFS complements HTTP while providing more sophisticated file sharing and file transfer than older protocols such as FTP. CIFS is designed to enable all applications, not just Web browsers, to open and share files securely across the Internet.

CIFS Benefits

Industry Support

Industry leaders Data General, Digital Equipment Corporation, Intel Corporation, Intergraph, Network Appliance Inc., and SCO are working actively with Microsoft in support of the CIFS initiative. CIFS is already widely supported in commercial software products such as AT&T Advanced Server for UNIX, Digital's PATHWORKS, HP Advanced Server 9000, IBM Warp Connect, IBM LAN Server, Novell Enterprise Toolkit, and Unisys ClearPath HMP NX Server, among others. In addition, CIFS is the featured file-sharing and print-sharing protocol of Samba, a popular freeware network file system available for LINUX and many UNIX platforms. The companies listed below have CIFS products or interests.

(Please note that these links point to servers that are not under Microsoft's control. Please read Microsoft's official statement at http://www.microsoft.com/Misc/NonMS.htm regarding other servers.)

CIFS Specification and Resources

Other CIFS and SMB Resources

Press Releases