VCL-2103 - NTP Sub-Master Clock


Valiant’s VCL-2103, SUB-MASTER CLOCK is a high performance, “intermediate” time synchronization source which may be referenced to multiple Primary GPS Reference (Master) Clock(s) using NTP protocol to provide "Time-of-Day" synchronization to client-side NTP/SNTP Slave devices in the network. Applications of Valiant’s NTP Sub-Master Clock include all such installations where network segregation is considered to be essential to isolate sections of the network that are considered to be less secure that require added cyber-security.

Data Sheet

Valiant’s NTP Sub-Master Clock emulates the “CLOCK-IN-THE-MIDDLE” which installs between a secure (client) network(s) and an un-secured (public) network to allow the client-side terminals to securely synchronize to the public NTP servers with comprehensive network security. The NTP Sub-Master Clock incorporates a firewall that assistes in securing the “Client Network” from hostile attacks and intrusions that can originate from an un-secured, or less-secure sections of the network.


The VCL-2103 Sub-Master Clock mediates between the Primary GPS Reference (Master) Clocks and the Slave NTP/ SNTP devices, such as Time-of-Day Display Clocks in a LAN, to effectively isolate the GPS Primary Reference Clock Source from the NTP / SNTP Slave devices and provide NTP / SNTP time-of-day synchronization with better than 0.5 millisecond accuracy.

The VCL-2103 Sub-Master Clock is a highly accurate time-source that is equipped with an internal OCXO (with aggregate aging of less than 50us /day) that can accurately synchronize its “Salve” Terminals with an un-matched, better than 0.02 seconds / year hold-over accuracy in the event of loss synchronization with all “Primary Reference Time Sources”.

The VCL-2103 Sub-Master Clock provides two distinctly separate Ethernet Interfaces, each of which is assigned its own IP address which allows the VCL-2103 Sub-Master Clock to synchronize with the Primary GPS Reference (Master) Clock and to also provide time synchronization to multiple Slave NTP / SNTP devices in a LAN network. Multiple VCL-2103 Sub-Master Clock Units can be installed in a network to synchronize with the Primary GPS Reference (Master) Clocks to provide 1+1 or n+1 source redundancy in a NTP/SNTP time synchronization network. The VCL-2103 Sub-Master Clock automatically negotiates with and select the best available “Primary Reference Time Source” (i.e. the clock with the highest Stratum Level Time Source with minimum Jitter) to ensure that the “Client-Side NTP Terminals” are synchronized to the most accurate and most reliable “Primary Time Source” to provide 99.9999% time source reliability and availability.

Applications include:

  • Campuses and large Corporate Networks
  • Metro and Railway Stations and Airports
  • Large Power Plants
  • Military bases


  • NTP/SNTP Date and Time Synchronization
  • 1 x 10/100/1000BaseT Ethernet NTP Client for master-side synchronization
  • 4 x 10/100BaseT Ethernet NTP/SNTP Master client-side synchronization
  • High-Performance NTP Server
  • Capable of driving up to 1000, VCL-W-KLOX, NTP/SNTP Slave display devices
  • Remote Management over TCP-IP Network
  • Dual, 1+1 Redundant 90VAC-240VAC, 50-60Hz; or 24VDC / 48VDC power supply options.


NTP Sub-Master Clock for Network Isolation & Cyber Security

Data Sheet

Data Sheet