SMB Multichannel

The Server Message Block (SMB) Multichannel feature enables file servers to use multiple network connections simultaneously.

The SMB Multichannel feature facilitates aggregation of network bandwidth and fault tolerance when multiple paths are available between the SMB 3.x client and the SMB 3.x server. This capability enables server applications to fully utilize the available network bandwidth and makes them resilient to network failures.

SMB Multichannel channel provides the following capabilities:

Higher throughput

The file server can simultaneously transmit more data by using multiple connections for high-speed or multiple network adapters.

Network fault tolerance

When clients simultaneously use multiple network connections, the clients can continue without interruption despite losing a network connection.

Automatic configuration

SMB Multichannel automatically discovers multiple available network paths and dynamically adds connections as necessary.

In SMB Multichannel feature, the client negotiates SMB3 protocol and multichannel capability with the SMB server. The client then looks for available interfaces, and the SMB server provides the interface list (RSS, network speed) through the SMB File System Control (FSCTL) operation. The SMB client transparently chooses an appropriate setup and uses multiple channels based on the client workload, Network Interface Card (NIC) number, speed, and properties.