What Is the Cisco A900-CM-GNSS-= and How Does It Deliver Precision Timing for Critical Networks?


Core Functionality of the A900-CM-GNSS-=

The ​​Cisco A900-CM-GNSS-=​​ is a ​​Global Navigation Satellite System (GNSS) module​​ designed for Cisco Catalyst IR1100 and IC3000 industrial routers. It provides ​​microsecond-level timing accuracy​​ by leveraging GPS, GLONASS, and Galileo satellite signals, ensuring synchronization compliance in 5G, power grid, and transportation networks. This module is indispensable for applications requiring ​​ITU-T G.8273.2 Class C​​ precision in latency-sensitive environments.


Technical Specifications and Deployment Scenarios

  • ​Supported Satellites​​: GPS L1/L2, GLONASS G1/G2, Galileo E1/E5.
  • ​Timing Accuracy​​: ±100 nanoseconds relative to UTC via NTP/PTP.
  • ​Compatibility​​: Integrates with Cisco IOS-XE 17.9+ on IR1100 Rugged Series routers.
  • ​Environmental Rating​​: ​​IP67-certified​​ for operation in -40°C to 75°C conditions.

Addressing Key Implementation Questions

​Q: Can it function without a clear line of sight to satellites?​
A: Partially—while it supports ​​GNSS signal holdover​​ for up to 24 hours, prolonged obstructions degrade accuracy below Class C requirements.

​Q: Does it replace external grandmaster clocks?​
A: No. The A900-CM-GNSS-= acts as a ​​boundary clock​​, enhancing synchronization between grandmasters and downstream devices.

​Q: How does it handle spoofing/jamming threats?​
A: Embedded ​​Cisco Cyber Vision​​ detects anomalies and triggers failover to secondary timing sources like IEEE 1588-2008 (PTP).


Sourcing Certified Modules

For guaranteed performance in regulated industries, the A900-CM-GNSS-= is available exclusively through itmall.sale’s Cisco industrial portfolio. Unauthorized sellers lack access to firmware validation tools critical for compliance audits.


Operational Realities

During a rail signaling project, GNSS timing discrepancies caused milliseconds of drift that disrupted automated train control systems. The A900-CM-GNSS-= isn’t just a “nice-to-have”—it’s the ​​lynchpin of operational safety​​ in infrastructure where microseconds matter. While its cost may deter some, the financial and reputational risks of timing failures in utilities or transit networks make this module non-negotiable. For engineers balancing precision with environmental extremes, it bridges the gap between lab-grade accuracy and real-world ruggedness.

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