Configuring Precision Time Protocol (PTP) on UniFi Enterprise AV Switches

UniFi Enterprise AV (EAV) switches support hardware-based Precision Time Protocol (PTP) synchronization for professional AV deployments using protocols such as AES67 networked audio and SMPTE ST 2110 broadcast video. PTP provides the precise clock synchronization required to keep audio and video streams aligned across the network.

For guidance on QoS, PTP traffic matching, and other AV network optimizations, see ProAV Traffic Optimization on UniFi Switches.

PTP Clock Modes

Each EAV switch can operate in one of three PTP clock modes:

• Grandmaster: Acts as the network’s timing source and synchronizes to an external GPS clock connected to the switch’s SMA port.
• Boundary: Synchronizes to the Grandmaster and actively distributes timing to downstream devices using its own clock.
• Transparent: Forwards PTP messages while correcting for the time they spend traversing the switch.

A PTP deployment requires one Grandmaster as its primary timing source. This can be a UniFi EAV switch or a compatible third-party Grandmaster.

The default mode is Transparent, which assumes another device provides the network’s timing source. If a Boundary switch cannot detect an external timing source, it can automatically assume the Grandmaster role through PTP election.

The current clock role is displayed under Timing & Synchronization in the switch’s Device Overview.

Choosing Boundary or Transparent

Use Boundary mode for switches that should actively distribute timing, typically at the core or distribution layer.

Use Transparent mode for switches that primarily forward timing, such as access-layer switches.

For smaller deployments, a single Grandmaster with remaining switches operating in Transparent mode is typically sufficient.

Connecting EAV Switches

When possible, interconnect EAV switches directly using their QSFP28 100 GbE uplinks. High-bandwidth applications such as SMPTE ST 2110 benefit from keeping PTP timing on the most direct, high-capacity path.

Non-PTP-aware switches can forward PTP traffic but cannot compensate for the time PTP messages spend traversing them. Timing error can therefore increase as additional non-PTP-aware switches are introduced into the path.

Configuring PTP Profiles

When an EAV switch operates as a Boundary or Grandmaster clock, select the profile appropriate for your deployment:

• AES67 for compatible professional audio deployments
• SMPTE 2059-2 for SMPTE ST 2110 broadcast video environments
• Custom when interoperability or deployment requirements differ from the predefined profiles

Use the same profile and timing parameters across the PTP domain.

PTP profiles configure:

• Sync Interval
• Delay-Request Interval
• Announce Interval
• Announce Timeout
• Domain

Use a Custom profile when integrating third-party PTP equipment that does not support the same predefined profiles or requires different timing parameters.

PTP Network Considerations

Keep the following in mind when designing your PTP deployment:

• PTP operates on the native VLAN.
• PTP does not support Link Aggregation (LAG).
• PTP is enabled on all switch ports by default.
• PTP can be disabled on ports connected to network segments that do not require timing.

Disabling PTP on unnecessary ports is optional, but can help keep the PTP domain scoped to the AV infrastructure that requires synchronization.