Calnex Sentry Rack Mount Network Synchronization Monitor

Rack mount synchronization monitor for continuous remote monitoring of PTP, NTP and clock signals at Ethernet rates from 100M to 100G.

PTP (1588) – Main Channels: Layer 2 Multicast and Layer 3 (UDP/IPv4, UDP/IPv6) Multicast/Unicast
NTP – Main Channels: Layer 3 (UDP/IPv4/IPv6) Multicast/Unicast
PTP (1588) – Virtual Channels: Layer 3 (UDP/IPv4, UDP/IPv6) Unicast
NTP – Virtual Channels: Layer 3 (UDP/IPv4, UDP/IPv6) Unicast

Datasheet

Overview

Calnex Sentry is a rack mount network synchronization monitor for verifying phase, time and frequency synchronization across a whole network. It is designed for large network infrastructure environments such as data centers, where it provides independent, continuous verification that synchronization accuracy is being maintained, and helps identify performance trends before they become issues.

Sentry can be configured with up to two Ethernet measurement channels at rates from 100M to 100G and up to two clock modules for signals such as 1 PPS. One PTP or NTP stream is fully analyzed on each physical channel, with results viewable over VNC. With the multiple measurement option, 2wayTE can be measured on up to 32 additional unicast PTP or NTP streams, giving a total of up to 34 monitored streams. Sentry can act as a pseudo T-TSC to measure upstream network synchronization or as a network monitor measuring live network PDV and TE.

Remote operation and data analysis

The instrument is controlled remotely through Virtual Network Computing (VNC), which gives access to the onboard analytics and graphing, or through an API that automates setup and measurement downloads for integration into network management systems. Measurements run continuously and can be downloaded at short intervals or stored on the instrument for up to 24 hours. Downloaded data can be analyzed in the Calnex Analysis Tool (CAT) and the PTP Field Verifier (PFV), and archived as evidence of compliance with service level agreements or regulations such as MIFID II.

Reference and reliability

Sentry contains a Rubidium reference oscillator and a GNSS receiver; the Rb clock can be disciplined to GNSS or an external 1 PPS source and provides holdover for several hours if GNSS is lost. A hardware watchdog resets the instrument and restarts measurements if it freezes, and redundant hot-swappable power supplies allow one power circuit to be de-energized without interrupting monitoring. Power supply status can be read through the API.

Key Features

Verify phase, time and frequency synchronization
PTP accuracy verification and monitoring
Remotely monitor and diagnose synchronization issues on Ethernet and clock signals
Two Ethernet ports from 100M to 100G with IPv4 and IPv6
Monitor up to 34 PTP or NTP streams
Up to 5 clock inputs from 0.5 Hz to 200 MHz
Internal high-stability Rubidium oscillator disciplined to GNSS or external 1PPS
±75 ns constant TE measurement accuracy with reference to GNSS
Relative time error between clock inputs rTE ≤ 5 ns
Setup and data download over API; direct operation over VNC
Fixed duration or continuous measurements, all measurements simultaneous
Measurement data stored on the instrument for up to 24 hours
Measurements include TE, TIE, MTIE, TDEV, 2wayTE, dynamic TE, PDV, FPP and frequency error
Pass/fail against ITU-T masks and standards-based or vendor-specific limits
Detailed measurement report in PDF format
Onboard PTP packet capture and decode of Signaling, Sync, Del-Req, Del-Resp and Announce messages
Hardware watchdog with automatic reboot and measurement restart
Redundant hot-swappable power supplies
Full analysis in Calnex Analysis Tool (CAT) and PTP Field Verifier (PFV)

Specifications

Ethernet

PTP (1588) – Main Channels	Layer 2 Multicast and Layer 3 (UDP/IPv4, UDP/IPv6) Multicast/Unicast
NTP – Main Channels	Layer 3 (UDP/IPv4/IPv6) Multicast/Unicast
PTP (1588) – Virtual Channels Option 621	Layer 3 (UDP/IPv4, UDP/IPv6) Unicast
NTP – Virtual Channels Option 621	Layer 3 (UDP/IPv4, UDP/IPv6) Unicast
Measurement Channels	Maximum of 2 Channels Each channel can be configured with multiple line rates; only one line rate per channel is active for a measurement
Connectors	RJ45 for 100/1000 Base-T; SFP/SFP+ for 100M/1G/10G Optical; QSFP28 for 100G Optical; SFP28 for 25G Optical QSFP28 to SFP28 adapter supplied with 25G option. Optical transceivers not supplied.
Accuracy	PTP/NTP constant TE measurement accuracy with reference to GNSS ±75 ns Web page states ±75ns absolute accuracy to UTC; datasheet specifies reference to GNSS
Packet Rate	128 packets/sec if only main two channels are used decreasing to 1 packet/sec if two Main and 32 Virtual Channels are active
Virtual Channels Option 621	2wayTE can be measured on a total of 32 additional PTP or NTP streams Requires Option 621; Virtual Channels must be Unicast and differentiated by IP address
Data Capture and Visualization	Measured data is be downloaded over API in CSV format for further analysis Virtual Channel time error data is also saved by Sentry for download to the Calnex Analysis Tool (CAT)
Data available over API – Main PTP/NTP Channel	TIE, 2wayTE, Path delay, fwdPDV, revPDV, ESMC
Data available over API – Virtual channels	2wayTE, Path delay, fwdPDV, revPDV

Onboard Analysis and VNC Display

Masks / Test Limits	Masks or test limits can be applied to TE, 2wayTE, pktSelected 2wayTE, 2wayTEL, 2wayTEH, TIE, MTIE, and TDEV graphs
PRC/SSU/SEC Masks	Masks for G.811/G.812/G.813-clocks (ETSI 300 462-3)
Network Masks	According to G.823/G.824/G.8261/G.8261.1/G.8271.1/G.8271.2
Display Modes	TE, 2wayTE, pktSelected 2wayTE, TIE, MTIE, TDEV, Path Delay, PDV, 2wayTEL, 2wayTEH, Distribution of PDV Selected PDV, Floor Packet Percentage, Maximum Average Frequency Error
Number of Graphs	Up to 6 graphs of the same type can be over-laid on screen. Color coded.
Masks on Screen	Up to 6 MTIE and TDEV masks according to selected test mode Pass/Fail result available for each mask

Clock Module

Pre-defined Signal/Clock Types Option 610	1 pps (PTP Subordinate recovered clock); 8 kHz (frame clock); 64 kHz/64 kb/s (E0/DS0); 1.544 MHz/1.544 Mb/s (T1/DS1 clock/data); 2.048 MHz/2.048 Mb/s (E1 clock/data); 5 MHz/10 MHz (frequency reference); 25 MHz/125 MHz/156.25 MHz (SyncE clock rate); 34 Mb/s (E3), 45 Mb/s (DS3); 155.52 MHz/155 Mb/s (STM-1/STS-3 clock/data)
User-defined Clock Types Option 610	From 0.5 Hz to 200 MHz in 0.5 Hz steps Symmetrical, unipolar clock signals
Number of Ports Option 610	2 per module
Connector Option 610	BNC
Impedance Option 610	75 Ω, VSWR <2:1 or 1 MΩ
Voltage Range Option 610	±5.00 V
Sensitivity Option 610	min input voltage 60 mVpp Signal Check voltages are for indication only
Signal Type Option 610	Symmetrical pulse (clock signal); Unsymmetrical repetitive pulse (clock signal); HDB3-coded data (data signal); AMI B8ZS, B3ZS (data signal)
Frequency Measurement Option 610	TIE accuracy 1 ns
1 pps Accuracy Option 610	Constant TE measurement accuracy with reference to GNSS ±75 ns
Relative Time Error	rTE ≤ 5ns Accuracy with which Sentry measures the phase difference between any two clock inputs; web page states ±5ns relative time accuracy between any clock and PTP inputs

Internal Rb Clock

Reference Clock	Built-in Rubidium reference
Output Frequency Accuracy	1 x 10-9 7 mins to warmup
Ageing (1 day)	<1 x 10-12
Ageing (1 year)	<5 x 10-10

GNSS

Built-in GNSS Module	12 channels, TRAIM GNSS receiver, high sensitivity. GPS, GLONAS, Beidou, Galileo.
Time Accuracy	±15 ns at 1σ after 24 hours lock
Frequency Accuracy	2 x 10 - 12 averaged over 24 hours
GNSS Disciplining Modes	Always disciplining, always in holdover, disciplining only between measurements Requires 6 hours disciplining if disconnected from GNSS for <1 week; 12 hours if >1 week. Requires 1 hour disciplining if using Cs quality 1 pps (from any state).

External References

External 1 pps Timing Input – Voltage Range	0 V to 0.8 V (Low), 2 V to 3.3 V (High) into 50 Ω
External 1 pps Timing Input – Required Accuracy	±100 ns to UTC
GNSS Antenna Input	type N connector
GNSS DC-feed	+5 V on center pin to active GNSS antenna

Reference Output

Reference Frequency	10 MHz sine-wave
Output Levels	1 Vrms in 50 Ω
Impedance	Approx. 50 Ω
1 pps Output Source	Internal Rubidium oscillator
1 pps Output Logic Levels	TTL levels in 50 Ω

Interfaces and Storage

USB Host Port Connector	Std USB type A
USB Maximum Supply Current	400 mA
USB Version	2.0
Ethernet Communication Port	RJ45, 10/100/1000 Base-T
Ethernet Protocol	HTTP, HTTPS, DHCP or fixed IP (IPv4 or IPv6), FTP, VNC
Data Storage	Internal: Up to 32G; External: USB memory stick

Environmental

Operating Temperature	0°C to 40°C
Storage	Temperature from 0 to 50°C and humidity up to 90% non-condensing
Safety	EN61010:2010 +A1:2019
EMC	EN61326-1:2021

Power

Line Voltage	100 to 240 Vac ± 10%, 50 to 60 Hz ± 3 Hz
Instrument Power Consumption	<100 W Instrument will operate on one power supply but it is recommended that both are used

Mechanical

Dimensions	3U cabinet designed for 19” rack. Depth 17.3” (439 mm)
Weight	8.4 kg (max.)

Specifications are taken from the manufacturer's documentation. See the datasheet for complete and current values.

Applications

Data center synchronization monitoring
Telecom network synchronization monitoring
Detection of rogue time sources
Comparison of time domains in trading venues
Remote measurement of unicast boundary clocks
O-RAN DU rTE validation
5G network synchronization
MIFID II timing compliance verification
SLA evidence for timing provided to tenants

Included

Calnex Analysis Tool (CAT)
PTP Field Verifier Tool (PFV)
User manual on USB
Line power cord
1-year warranty and support

Options & Accessories

Option	Description
610	Clock module 1PPS/E1/T1 — Any clock from 0.5 Hz up to 200 MHz with 0.5 Hz step (maximum two per instrument)
615	100M/1G packet port (PTP/NTP) — Can order maximum of 2 x Opt. 615 (maximum two – Opt. 615 and/or Opt. 616 per instrument)
616	100M/1G/10G packet port (PTP/NTP) — Can order maximum of 2 x Opt. 616 (maximum two – Opt. 615 and/or 616 per instrument)
618	100G Interface — Ordered at same time as Sentry mainframe or SW upgrade enabling second 100G port
622	25G Interface — Ordered at same time as Sentry mainframe or SW upgrade enabling second 25G port; QSFP28 to SFP28 adapter supplied
620	PTP and NTP PDV measurement software — One license per instrument
621	32 additional virtual NTP/PTP measurements
812	One year extension of product warranty
813	Two years extension of product warranty