The new device is an 8×56-Gbps PAM-4 to 16×25-Gbps NRZ forward and reverse gearbox, designed to enable high-performance switches with PAM-4 I/Os to connect to the large existing ecosystem of switches and plug-in modules with NRZ interface. The device can also be configured as an 8×56-Gbps PAM-4 retimer to extend high-speed copper and optical links in modern networks.
As data centers transition to higher speed server uplinks to support the increasing demand for data bandwidth, maintaining optical interconnects between servers and top-of-rack switches would minimize cabling costs and save capital expenditures (CAPEX) spending for bandwidth upgrade by allowing continued use of 100G QSFP28 optical modules.
With the availability of new switch ASICs and ASSPs such as the Tomahawk 3 from Broadcom, the BCM81724 provides a bridge connecting the high-bandwidth 400G PAM-4 interface of the switch to the NRZ interface on existing 100G QSFP28 optical modules.
Switch Processor Chips
Further, given the general availability of copper-based NRZ modules supporting 100 Gbps in existing systems, it would be essential to have a reverse gearbox that enables “next generation” switches to connect to these modules. The BCM81724 is Broadcom’s 4th generation gearbox that extends the capabilities of modern high-performance switches, optimized for high-density switching and routing in hyperscale data center and cloud networks.
“With the introduction of switches such as the Tomahawk 3 with 56G I/Os that are critical to meeting the rapidly increasing bandwidth needs in today’s cloud computing and hyper-scale data center environments, the BCM81724 is essential to interface these next generation high-density switches to the existing 100G optical module ecosystem,” said Lorenzo Longo, senior vice president and general manager of the Physical Layer Products Division at Broadcom. “Built with proven PAM-4 SerDes that are foundational to Broadcom’s state-of-the-art switch processor chips, both merchant silicon and ASICs, our 16nm PAM-4 Reverse Gearbox provides the most robust and essential bridge for the end-to-end solutions driving faster time to market for our customers and expanding bandwidth capacity of next generation networks.”
Broadcom BCM81724 Product Highlights Include:
- 8×56-Gbps PAM-4 to 16×25-Gbps NRZ Reverse Gearbox
- Retimer Mode Supporting 8×56-Gbps to 8×56-Gbps PAM-4
- Key Functionalities
- Forward/Reverse Gearbox
- Forward/Reverse Gearbox with FEC
- FEC Termination & Regeneration Modes
- Protocols Supported
- 3bj/802.3bs/802.3cd/25G_50G Consortium
- 50G/100G/200G Standard RS FECs
- High-performance Receive Equalization: ~30dB channel loss
- PRBS Data Generator & Checker
- Eye Monitoring Support
- Low Power 16nm CMOS Design
- 19mm x 19mm FCBGA, 0.8 mm pitch