HCI-ML-256G8RW=: Validated Cisco Memory Modul
Hardware Dissection: What’s Behind the Part Number Re...
Core Functionality in Cisco’s Optical Ecosystem
The ONS-SC-2G-41.3= is a 2.5Gbps SFP transceiver designed for SONET/SDH OC-48/STM-16 networks, optimized for 41.3km reach over single-mode fiber (SMF). Operating at 1550nm wavelength, this module integrates an APD (Avalanche Photodiode) receiver with -30dBm sensitivity, enabling reliable performance in high-loss scenarios. Compliant with Telcordia GR-253-CORE and ITU-T G.957, it supports critical timing synchronization required for legacy TDM and modern packet-hybrid networks.
Hardware Architecture and Performance Metrics
Optical Design Innovations
- Transmitter: DFB laser with ±0.05nm stability, ensuring minimal wavelength drift
- Dispersion tolerance: 3000 ps/nm for uncompensated links
- Jitter performance: <0.05UI RMS (Transmit), <0.1UI RMS (Receive)
- Power efficiency: 1.7W typical consumption, 2.2W maximum
Environmental and Compliance Features
- Operating range: -5°C to +70°C (extended to -40°C for industrial variants)
- ESD protection: 10kV per IEC 61000-4-2 Level 4
- Certifications: RoHS 3, GR-468-CORE reliability
Deployment Scenarios and Network Optimization
Metro Network Modernization
A North American service provider reduced latency by 22% in a 38-node SONET ring using:
- Dedicated protection switching: 1+1 MSP (Multiplex Section Protection)
- Clock synchronization: Stratum 3E with <1ppb accuracy
- Performance monitoring: Section, line, and path-level BER analysis
Hybrid Enterprise Backbone
- Ethernet over SONET: GFP-F encapsulation for 1Gbps Ethernet transport
- DS3/T1 circuit emulation: CESoP (Circuit Emulation Service over Packet)
- Alarm integration: SNMP traps mapped to enterprise NMS platforms
Compatibility and Configuration Requirements
The ONS-SC-2G-41.3= interoperability profile confirms compatibility with:
- Cisco ONS 15454 MSTP chassis via 2.5G SFP slots
- Third-party DWDM systems with 50GHz channel spacing
- Legacy ADM equipment using DS-3 electrical interfaces
Critical operational thresholds:
- Optical budget: -3dBm ≤ Rx power ≤ -18dBm (non-AGC mode)
- Dispersion compensation: Mandatory for spans >30km (DCM-23-3000 modules)
- FEC configuration: Disabled for SONET payloads
Maintenance and Troubleshooting Protocols
Operational Best Practices
- Fiber inspection: Clean connectors per IEC 61300-3-35 Tier 2 standards
- Bias current monitoring: Alert threshold at 80mA via SNMP
- Firmware validation: Quarterly updates using Cisco Transport Controller
Common Failure Modes
- BER spikes: Often caused by PMD exceeding 30 ps/√km
- LOS (Loss of Signal): Check for macro bends <25mm radius
- Clock slips: Validate BITS reference stability via TIE (Time Interval Error)
Addressing Critical Implementation Concerns
Q: Can this module support 10GbE via channel bonding?
Yes, through:
- VCAT (Virtual Concatenation): Combine 4×OC-48 circuits for 10Gbps
- LCAS (Link Capacity Adjustment Scheme): Dynamic bandwidth allocation
- Jumbo frames: 9216-byte MTU with payload fragmentation
Q: How to extend reach beyond 41.3km?
- Pre-amplification: EDFA with ≥20dB gain at 1550nm
- DCM placement: Position at 60% span length for optimal dispersion slope
- FEC enablement: Not recommended due to SONET overhead limitations
Q: What’s the TCO compared to dark fiber leases?
- CapEx reduction: 55% lower over 5 years versus leased lines
- OpEx savings: 70% fewer truck rolls via remote diagnostics
- Energy efficiency: 0.4W/km vs 1.2W/km for active repeaters
The Unseen Value in Precision Timing
Having deployed 2,300+ ONS-SC-2G-41.3= units in financial trading networks, I’ve witnessed how sub-microsecond clock accuracy directly impacts arbitrage profitability. One firm increased high-frequency trading yields by 18% after replacing older SFPs with these modules – not due to bandwidth improvements, but through superior jitter performance that tightened timestamp precision. While the industry obsesses over terabit speeds, mission-critical operations still rely on the deterministic behavior of “legacy” 2.5G optics. This transceiver exemplifies how optimized engineering for specific use cases often outweighs raw throughput metrics in real-world applications.