N4891A 400GBASE FEC-aware Receiver Test Solution

• FEC-aware physical layer test for PAM4-based modules and components
• Measurement of frame loss ratio in 400G Ethernet links using FEC by supplying one stressed lane, without stress on the other lanes
• Compliant with IEEE test specification for 400GAUI-8 and 400GBASE-LR8/-FR8/-SR8 interfaces
• Supports 26.5625 Gbaud PAM4 in PRBS or FEC (KP4) mode
• Powerful analysis tools

Accelerate the Deployment of Next Generation 400G Devices in Datacenters

Keysight’s N4891A is a flexible and complete Forward Error Correction (FEC) aware compliance testing solution for 400GE. It addresses a critical gap in the testing of 400GE class optical transceiver modules and associated host ASIC: monitoring the FEC performance during layer one compliance testing.

The solution provides unique insights into how component and system design tradeoffs are affected by FEC requirements and allow to predict the system margin under real conditions.

The N4891A solution combines the M8040A 64 Gbaud high performance BERT to generate the correct striped FEC test pattern on the single lane under test, along with a A400GE-QDD 400GE layer 1 BERT and KP4 FEC multiport test system to provide the proper aligned striped FEC traffic on the other seven lanes enabling to measure the FLR of the tested interface under stress conditions.

Combined with Keysight compliance test solutions such as the optical receiver stress test and the IEEE 802.3bs receiver test pre-compliance application, the 400GABASE FEC-aware solution provides fast, accurate and repeatable optical and electrical stress signal calibration to test interoperability requirements.

The 400GBASE FEC-aware receiver test solution addresses following applications:

• Design of 400GE systems and components
• 400GE interoperability test for IEEE 802.3bs/cd standards

Principle of FEC-aware layer 1 testing

FEC Codeword Stats page – FEC port stats with advance measurements such as Pre-FEC BER, Frame Loss Ratio.

The N4891A received honors in the Field Test Equipment category from Lightwave Innovation Reviews in 2020.

The N4891A was awarded Runners-up in the Testing category at Interop 2020 Tokyo.