Study Plan  2110 Topo  Return to Master Diagram

Module 02: Timing & PTP

"Timing is everything" in ST 2110 systems. Precise synchronization is achieved through Precision Time Protocol (PTP) as defined in SMPTE ST 2059-2 and ST 2110-10.

This module covers the essential steps to properly configure and verify PTP timing — the foundation that keeps video, audio, and data streams perfectly aligned across your entire IP fabric.

Without accurate PTP lock, even perfect network handshake, MTU, and IP addressing will still result in lip-sync errors, frame drops, unstable switching, and unreliable multi-source production.

Set PTP Domain Set the same PTP Domain on all devices in your ST 2110 timing island (recommended value is 127 per SMPTE ST 2059-2).

Devices where this action must be performed:
• PTP Grandmaster Clocks (Telestream SPG9000, Meinberg M1000, Tektronix SPG8000A, Riedel, Evertz, Artel, etc.) — set via web GUI or management software.
• All Endpoints (cameras, video servers, playout systems, audio consoles, IP gateways — AJA, Matrox, Lawo, Embrionix, Blackmagic, Riedel, etc.) — via device web GUI under PTP / Timing settings.
• Network Switches acting as Boundary Clocks (Arista, Cisco Nexus, NVIDIA/Mellanox, NETGEAR M4350, etc.) — CLI or web GUI.
• NMOS Controllers / Orchestrators (Imagine Magellan, Grass Valley Orbit, Arista MCS, etc.) — via their web UI or config files.

In every device’s PTP configuration screen (or CLI), set **PTP Domain Number** to the identical value (most facilities use **127**).

Important: Every device in the same ST 2110 system must use the exact same domain. Different domains isolate separate timing systems (e.g., one for video, one for audio-only).
PTP Grandmaster GUI / Device Web UI / Switch CLI Ensures every device in the ST 2110 network is synchronized to the same timing reference. A domain mismatch prevents devices from locking to the Grandmaster, causing lip-sync errors, frame drops, and unstable flows.
Set PTP Multicast Mode & Verify Status "Locked" 1. Set PTP to Multicast Mode
ST 2110 systems almost always use Multicast (or Hybrid) for PTP messages so every device can efficiently receive timing packets.

Devices where this must be done:
• PTP Grandmaster Clocks — set to Multicast announce/sync mode.
• All Endpoints (cameras, gateways, servers, consoles, NICs) — set PTP transport to Multicast.
• Network Switches (Boundary Clocks) — enable Multicast PTP on the media VLAN.
• NMOS controllers — configure multicast for PTP discovery.

In each device’s PTP settings (web GUI or CLI), select Multicast (or Hybrid if available).

2. Verify PTP Status = "Locked"
After configuration, confirm on every device that it reports:
• PTP Status: Locked / Slave
• Offset from Master: < 1 µs (ideally < 100 ns)
• Grandmaster ID matches your chosen Grandmaster

Check via device web GUI, switch CLI (show ptp), or tools like EBU LIST, Wireshark, or vendor diagnostics.
Device Web GUI / Switch CLI / Grandmaster UI Multicast  ensures reliable delivery of PTP  timing packets to all devices without unicast scaling issues. Verifying "Locked" status confirms the device is synchronized to the Grandmaster  - critical for frame-accurate switching, lip-sync, and stable ST 2110 streams.
PTP Math
UPDATED
04/08/26
V260408-1.0