SMB Multichannel

[TMroy]

What is SMB Multichannel?
SMB (Server Message Block) multichannel is a feature in the SMB protocol that enables the simultaneous use of multiple network connections to enhance file transfer performance and reliability between a client and a server. SMB is a network file-sharing protocol commonly used in Windows environments for accessing files, printers, and other shared resources.

SMB multichannel works by utilizing multiple network paths between the client and server to distribute the load and improve data throughput. This feature is particularly beneficial in scenarios where high-speed, fault-tolerant connections are available.

Key features and aspects of SMB multichannel include:

1. Improved Performance: By using multiple network connections, SMB multichannel can increase the overall bandwidth available for file transfers. This is especially useful for large file transfers or situations where a high volume of data needs to be exchanged.

2. Redundancy and Reliability: In addition to performance benefits, SMB multichannel can provide redundancy. If one network connection fails, the protocol can automatically route traffic through the remaining active connections, reducing the likelihood of data transfer interruptions.

3. Automatic Discovery: SMB multichannel supports automatic discovery of available network paths. The client and server can negotiate and establish multiple connections based on the network capabilities without requiring manual configuration.

4. Compatibility: SMB multichannel is designed to be compatible with a variety of network configurations, including scenarios where the client and server have multiple network interfaces or are connected to different subnets.

Implementing SMB multichannel requires support from both the client and server sides. Many modern operating systems, including Windows Server and Windows client versions, support SMB multichannel. It's important to note that for SMB multichannel to be effective, the network infrastructure must also support the aggregation of multiple connections.

In summary, SMB multichannel is a feature that enhances the performance and reliability of file transfers by leveraging multiple network connections between SMB clients and servers.

How do I enable SMB Multichannel?
To enable SMB Multichannel, in TOS 6, it only takes a few simple steps. First, go to the "TOS > Control Panel > Network Services > File Services > SMB > Advanced" settings option. Then, check the "Enable SMB Multichannel" option in the advanced settings. This will enable the SMB Multichannel feature smoothly.

However, please note that implementing the SMB Multichannel feature requires certain network requirements. The same number of multi-port connections need to be established between your TNAS device and server or client. Only when this condition is met can you fully enjoy the convenience and performance improvements brought by SMB Multichannel. SMB Multichannel cannot function when only one port connection is available.

[MrVanz]

Hi TMRoy!

Is SMB Multichannel an alternative to Static Aggregation? How can I implement it? Have to connect both 2.5 GbE ports to switch ports?

I'm a newbie in this topics (SMBM and LAG).

Thanks
Mauro

[Gremlin]

From what I have read, SMB Multichannel must be supported on both server (nas in this case) and client (pc, for example) and both devices must have multiple LAN ports (ie two or more) on the same network.

Obviously SMB multichannel only applies to SMB transfers. LAG on the other hand is is applicable to all data passing from switch (or router) to NAS (in this case). You can have a bonded (LAG) setup on the NAS end, even if the switch/router does not directly support LAG. There are different methods for implementing LAG/Bond. I have one set up (2x1Gbe) between a NAS and switches in my "server room". I use 2 separate switches for that to provide redundancy. I have another between the "server room" and the main internet connection switch (2x1Gbe). The terminating switches in this case are similar models and I use a supported link protocol there. I have a third between second NAS and the main internet switch configured purely as a redundant backup link via a powerline connection. It is all about bandwidth. (not speed) Allows more connections at a greater speed than would be otherwise available with a single Gbe connection. (But, it is important to note, the max speed of any connection is still 1Gbe. in this case as all my adaptors are 1Gbe).

[MrVanz]

From what I have read, SMB Multichannel must be supported on both server (nas in this case) and client (pc, for example) and both devices must have multiple LAN ports (ie two or more) on the same network.
Obviously SMB multichannel only applies to SMB transfers. LAG on the other hand is is applicable to all data passing from switch (or router) to NAS (in this case). You can have a bonded (LAG) setup on the NAS end, even if the switch/router does not directly support LAG. There are different methods for implementing LAG/Bond. I have one set up (2x1Gbe) between a NAS and switches in my "server room". I use 2 separate switches for that to provide redundancy. I have another between the "server room" and the main internet connection switch (2x1Gbe). The terminating switches in this case are similar models and I use a supported link protocol there. I have a third between second NAS and the main internet switch configured purely as a redundant backup link via a powerline connection. It is all about bandwidth. (not speed) Allows more connections at a greater speed than would be otherwise available with a single Gbe connection. (But, it is important to note, the max speed of any connection is still 1Gbe. in this case as all my adaptors are 1Gbe).

Thank you very much for your reply dear Gremlin.
I have two switches Tenda TEM2010F, they have 8 ports and last two (7-8) are dedicated to NAS Static Aggregation. What I've read online this don't permit LACP and bidirectional communication between NAS and switch: so I have to connect with Ethernet cables the two 2.5 ports in the NAS to the 7-8 ports in the switch, and then my MacBook Air M1 to one of ports in the switch? Then configure on NAS the Static LAG or the SMB Multichannel? I've read that in MacOS SMB multichannel is active by default. Am I right?
Excuse me for my many questions but I see that you aren't a newbie as me, and TM support isn't as rapid as you in answering (I've send also email to their support).
Mauro

[Gremlin]

To use SMBM, your MacBook would need to have at least two active internet connections to the switch, which I don't think can be done (easily? I don't know Mac). It may well be 'active by default', (as is windows), but only with the multiple connections.

I don't know the Tenda switches, but I gather the model you have is unmanaged so it cannot be configured specifically (other than provided by default). Seems like you either configure the NAS to run as 'self adapting load balance' and do not enable NAS dedicated mode on switch, or you do not configure nas and use the dedicated mode on switch. Matter of test and confirm

I think if you institute a LAG that effectively becomes 1 channel, so you won't see any multichannel smb connection anyway. Can't say for sure as I have no use for it myself (as I only have single channel machines).

{I would probably take issue with the manual I saw which states 'the transmission speed is doubled to 5G'. That's either 2.5G bi-directional or 5G BANDWIDTH. It is ambiguous and misleading imo}

[Lau6311]

Able to use the SMBM smoothly for higher speed files transfer is a joy.

Hardware:
Windows PC with 2x2.5GBe ethernet connections (one is a usb-ethernet adapter)
TP-link 8 ports unmanaged 1GBe switch (using for 8 years)
F2-223 with 2x2.5GBe ethernet connections to switch

Setup is nearly plug and play, very simple with TOS 6.

With 2x1GBe SMBM connections, able to observe no less than 250MBps files transfer speed, for a 2 bays NAS with Singles setup, is good.
Decided not to spend $85 on a new 2.5GBE switch for reason of 2 bays NAS that does not provide much higher speed feature.
Surely, TOS 7 in the future, my Terra NAS will continue to serve well for high-speed files transfer.