Keysight and Credo collaborate on PAM-4-to-NRZ

Keysight Technologies introduced a test solution that enables data center operators to leverage 400 Gigabit Ethernet (GE) capable test ports to link with and test legacy 100GE network equipment.

The new test solution is comprised of Keysight’s Ixia AresONE 400GE High Performance Layer 1 through 3 test system based on Pulse Amplitude Modulation level-4 (PAM4) signaling interconnected to legacy 100GE non-return-to-zero (NRZ) networking equipment ports using Credo’s HiWire Active Electrical Cable (AEC) technology. This collaboration provides speed-shifting of the signaling rates and forward error correction (FEC) conversion.

The companies said their combined test solution bridges the signaling gap between incompatible PAM4- and NRZ-encoded signaling. It removes potential compromises in testing configurations to improve overall performance validation and quality. The AEC cable technology performs the necessary conversions to allow a PAM4-encoded port to interoperate with an NRZ-encoded port. The solution provides support for testing four ports of 100GE NRZ from a single port of 400GE QSFP-DD PAM4 in 4x100GE speed mode.

“Data center operators are faced with a complex environment and need to leverage their existing investments for the future,” said Ram Periakaruppan, vice president, product development, Keysight’s Network Applications & Security group. “The Ixia AresONE 400GE test system supports Credo’s interconnect technology in high density 100GE test beds, enabling data center operators to accelerate validation of 100GE NRZ devices and network infrastructure while leveraging 400GE-capable PAM-4 ports to support demand in the future.”