Common Internet File System (CIFS)

CIFS - a key file sharing protocol because of its broad feature range - includes enhancements suited for Internet authoring and file sharing. CIFS is typically used in workstation and server OSs and was a native file-sharing protocol in Windows 2000. CIFS is also used in embedded and appliance systems. Recent storage products, like Storage Area Network (SAN) and Network Access Server (NAS), are based on CIFS.

Supported CIFS protocol features include:

• File access: Supports basic file operations like open, close, read, write and seek.
• File and record locking: Supports unlocked file access and features like file and record locking.
• Safe caching, read-ahead and write-behind: Facilitates caching, read-ahead and write-behind for safe files and even facilitates these operations for unlocked safe files.
• File change notification: When file or directory contents are modified, the server is notified.
• Protocol version negotiation: CIFS has many versions and sub-versions, known as dialects, which are negotiated by network systems.
• Extended attributes: Supports the addition of non-file system attributes, like author name, content and description.
• Distributed replicated virtual volumes: Supports file system subtrees with multiple volumes and servers. Files and directories may be moved to different servers without changing names. Subtrees may be replicated for fault tolerance and load sharing.
• Batched requests: Facilitates multiple request batching as single messages to reduce round trip latencies. Messages are classified into connection establishment messages, namespace and file manipulation messages, printer messages and miscellaneous messages.