CIFS (Common Internet File System)
CIFS is an Internet file-sharing system developed by Microsoft in 1996 as a replacement for other Internet file protocols such as FTP (File Transfer Protocol). CIFS goes beyond FTP’s simple file transfer facilities by providing a sophisticated and relatively secure file-sharing environment that can be used for collaborative applications over the Internet.
CIFS is an extension of Microsoft’s existing SMB (Server Message Block), Microsoft’s open, cross-platform file-sharing protocol is available in the Windows 95, Windows 98, Windows NT/Windows 2000, and OS/2 operating systems. SMB runs on other platforms as well, including Linux. CIFS allows users to share documents over the Internet in the same way they share documents when running peer networking services on their internal SMB networks.
Here are important features of CIFS:
- CIFS uses the same multiuser open, close, read, and write operations, as well as file-sharing semantics that are used on most enterprise networks.
- File and record locking prevents multiple users from overwriting the work that another person is doing on a file or record.
- CIFS runs over TCP/IP and uses the Internet’s global DNS (Domain Naming Service).
- CIFS support fault tolerance and can automatically restore connections and reopen files that were open prior to interruption.
- CIFS is “tuned” to provide optimal performance over dial-up links.
- Users refer to remote file systems with an easy to use file naming scheme.
- CIFS is also widely available on UNIX, VMS, and other platforms.
CIFS complements standard Web protocols such as HTTP (Hypertext Transfer Protocol) by providing a more sophisticated file-sharing protocol. Users do not need to rely solely on their Web browsers to access Internet information because with CIFS, most existing applications can access that data directly by using the standard Open and Save dialog boxes that users are already familiar with.
The security features in CIFS include support both for anonymous transfers and for secure, authenticated access to named files. File and directory security policies are easy to administer and use the same paradigm as share-level and user-level security policies in Windows environments. Most major operating system and application developers support CIFS.
CIFS competes with Sun Microsystems’ Web NFS, a distributed file system that Sun is integrating directly into Web browsers and other clients. Netscape Navigator includes embedded Web NFS. A paper at the Network Appliance Web site listed on the related entries page compares NFS and CIFS.
CIFS is important to NAS (network attached storage). The Storage Networking Industry Association (SNIA) formed a working group in January 2000 to develop NAS concepts and how CIFS will work with NAS.