Keysight and Credo Collaborate to Deliver PAM-4-to-NRZ Signal Conversion Technology

Estimated reading time: 2 minutes

Keysight Technologies, Inc., a leading technology company that helps enterprises, service providers and governments accelerate innovation to connect and secure the world, announced the first, cost-effective 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.

Data center operators have widely deployed mature 100GE NRZ-based technologies. However, higher speeds, such as 400GE, create a new mixed signaling, mixed FEC, multi-rate environment. This new environment produces unique challenges relating to the integration of PAM-4-based 400GE and 100GE-capable switch ports with existing 100GE NRZ signaling-based switch port technology.

The combined Keysight and Credo 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.”

The combined solution features the Credo HiWire AEC which allows flexibility in configuration of network rack equipment. Data center operators can install 400GE-capable ports and connect them when and where needed to legacy 100GE NRZ ports. Testing performed with the Ixia AresONE 400GE combined with the Credo HiWire SERDES speed shift and PAM4-to-NRZ conversion technology is completed at a fraction of the cost of the equivalent configuration using optical transceiver technology. Keysight and Credo are members of the HiWire Consortium, a non-profit organization dedicated to accelerating the adoption of AECs in applications such as this.

“Keysight’s Ixia AresONE 400GE test solution with 4x100GE per port fan-out has the scale and performance to meet the verification needs of multi-terabit Distributed Disaggregated Chassis networks,” said Jeff Twombly, Vice President of Business Development at Credo. “It is great to see them leverage our HiWire AEC interconnect solution to deliver this industry-leading and innovative data center solution.”