SMB multichannel on Synology: a practical guide

SMB multichannel lets compatible clients and servers use several network connections within one logical SMB session. Instead of sending parallel file operations through a single TCP stream, endpoints can distribute traffic across multiple channels. On a supported Synology NAS, this can improve throughput for simultaneous access while preserving the normal shared-folder experience.

It is not a universal speed multiplier. A lone user reading one file may see little difference, while a busy design studio or small Melbourne office copying many files can benefit. The disk, file size, protocol, network adapter and workload all influence the result.

Both ends must support SMB multichannel, and support varies by Synology model, DSM release and client operating system. Windows 10 and 11 are common candidates, while Linux and macOS clients require a compatible Samba or native implementation. Ordinary Ethernet switches can carry the channels, provided the endpoints have suitable drivers and interfaces.

For Australian users, this should be a measured upgrade: keep SMB1 disabled, change only supported Synology systems, and compare real workloads before and after. That avoids trading security for speed or chasing a feature the hardware cannot use.

What SMB multichannel changes

Multichannel extends SMB3 by creating additional TCP connections for the same authenticated session. Read and write requests can travel in parallel, while applications continue to use a mapped drive or mounted share. Users do not need special multichannel storage software.

The improvement comes from concurrency rather than compression. Large sequential transfers may already fill one fast link, while smaller random operations often benefit more. Multichannel also does not combine physical cables into one larger connection; each channel remains constrained by the available bandwidth.

Why it matters in Australia

Australian home and small-business networks commonly combine NBN service with Wi-Fi routers. Workplaces in Sydney, Brisbane and Perth may mix gigabit Ethernet, Wi-Fi 6 and fixed-wireless access. Wired clients generally gain more than wireless ones because Wi-Fi contention can erase the advantage of parallel TCP streams.

Regional connectivity adds another constraint because fixed-wireless and copper services vary by suburb and provider. In an Adelaide office, compare a wired workstation with a Wi-Fi one before blaming the NAS. Multichannel cannot remove ISP latency, and a business on an unstable NBN connection may gain little until its uplink improves.

Enabling SMB multichannel on Synology

First update DSM and confirm that the exact NAS model lists SMB multichannel as supported. Back up the configuration. In DSM, open Control Panel, choose File Services, select SMB and enter the advanced service settings, then look for Enable SMB multichannel. Labels can differ slightly between DSM releases.

Set the maximum protocol to SMB3 and keep SMB1 disabled. Save the change, then reconnect or restart the client so it negotiates fresh channels. On Windows, use a current network-adapter driver; on Linux, verify the Samba version and negotiated transport. If the option is absent, check DSM release notes and model compatibility rather than forcing it.

Some Synology models received this feature later than others, and business equipment may follow different DSM maintenance schedules. A NAS designed for SMB2 or SMB3 is not automatically capable of multichannel. Record the model, DSM version and client versions so the test can be repeated or reversed.

Preparing clients and network hardware

Multichannel needs low latency and little packet loss. Use Cat6 or better cabling, update switch firmware and avoid daisy-chained home routers. Check the Synology NIC speed and whether the workstation has several usable addresses and adapters.

A managed switch is useful when VLAN segmentation or multiple physical interfaces are required, not because Ethernet switches understand SMB. For a small VLAN-separated office, compare network switch options for suitable port counts, VLAN support and Australian availability. SMB traffic remains regular TCP port 445.

Security and Australian compliance

Multichannel changes transport concurrency, not access controls. Keep SMB signing and encryption aligned with the organisation’s risk, use strong accounts, enable multi-factor authentication where available, and restrict NAS administration to authorised administrators. Patch DSM and client systems in line with Australian Cyber Security Centre guidance.

If the NAS holds personal information, the Privacy Act 1988 and Notifiable Data Breaches scheme may still apply; parallel channels do not reduce notification duties. Review shared-folder permissions, backups and activity logs. Home users can apply the same discipline, while small businesses should document access rights and the response to a lost device.

A practical Synology rollout checklist

Before changing DSM, complete this preparation list:

• Record the DSM version, protocols, multichannel setting and active shares.
• Test a representative client using its existing mapped drives and applications.
• Export the NAS configuration and confirm that a recent backup exists.

After saving the change, use this verification list:

• Reconnect the clients and confirm SMB3 negotiation with multiple channels.
• Repeat the same timed copy, comparing disk and network load.
• Restore the previous setting if stability or access regresses.

Documenting the change and moving forward

Keep a short record of the NAS model, firmware, cabling, client systems and measured results. When staff or contractors need a non-technical explanation, the slideshow and business-video tools at goneat.org can turn the rollout checklist into a visual onboarding guide.

Your next step is to export the current DSM configuration and schedule a 30-minute test window with one representative Synology workstation, recording the result beside its pre-change baseline.