Signal Delay Compensation Example 1

Time-Stamping and Time Synchronization

Platform
Intel® PAC
Napatech SmartNIC
Content Type
User Guide

In this section

This section contains the delay compensation calculations for the system configuration in SmartNIC Daisy Chain.

Assumptions

These assumptions are made for the system configuration:

  • SmartNIC #1: NT20E3-2-PTP
  • SmartNIC #2: NT20E3-2-PTP
  • SmartNIC #3: NT20E3-2-PTP
  • Cable lengths for all cables: 0.2 m

Signal delay for SmartNIC #2

The signal delay for SmartNIC #2 consists of these contributions:

  • TS_Out_Delay (SmartNIC #1, NT20E3-2-PTP)
  • Cable_Delay (0.2 m)
  • TS_In_Delay (SmartNIC #2, NT20E3-2-PTP)

Total signal delay in ns: 8 + 0.2 × 5 + 6 = 15

ntservice.ini code line: TimeSyncTimeOffset = 15

Signal delay for SmartNIC #3

The signal delay for SmartNIC #3 consists of these contributions:

  • TS_Out_Delay (SmartNIC #1, NT20E3-2-PTP)
  • Cable_Delay (0.2 m)
  • Daisy_Chain_Delay (SmartNIC #2, NT20E3-2-PTP)
  • Cable_Delay (0.2 m)
  • TS_In_Delay (SmartNIC #3, NT20E3-2-PTP)

Total signal delay in ns: 8 + 0.2 × 5 + 14 + 0.2 × 5 + 6 = 30

ntservice.ini code line: TimeSyncTimeOffset = 30