A Guide to Ethernet Switch and PHY Chips

Thirteenth Edition

Published July 2017

Authors: Bob Wheeler and Loring Wirbel

Corporate License: $5,995

Evaluating and Comparing the Latest Ethernet Switches and PHY Chips

The Ethernet market is marked by technology transitions, which often result in large shifts in vendor share. Over the past several years, large data-center operators have increased the pace of technology innovation, creating markets for new speeds and new physical layers. These dynamics are behind the introduction of high-density 100G Ethernet switch chips, which also serve the new 25G and 50G Ethernet standards. The same operators also have a huge appetite for data-center interconnect (DCI) bandwidth, creating early demand for 400G Ethernet.

In Ethernet switches, Barefoot Networks, Broadcom, Cavium, Centec, Innovium, Marvell, and Mellanox are competing to win market share in data centers. These vendors are adding 100G Ethernet support along with new features for SDN and NFV. For data centers, most PHY development now focuses on 100GbE retimer chips using 25Gbps serdes technology, with 50Gbps PAM4 on the horizon.

The large size of the Ethernet switch and PHY market continues to keep it a competitive environment. "A Guide to Ethernet Switch and PHY Chips" breaks this market into three growth segments:

  • Data-center switch chips
  • 10GbE PHYs for copper (10GBase-T)
  • 100GbE gearbox PHYs and 25Gbps retimers

Unlike typical market research, this report provides technology analysis and head-to-head product comparisons. Which chips will win designs and why? How will these vendors be positioned as 100GbE ramps? Only The Linley Group’s unique technology analysis can provide this forward-looking view.

We Sort Out the Technology and the Key Vendors

“A Guide to Ethernet Switch and PHY Chips” begins with an extensive overview of this dynamic market. The report provides tutorials that help you decipher the myriad of acronyms and Ethernet standards. We explore the target markets and applications for Ethernet silicon, followed by an explanation of the common attributes of these products.

Following these introductory chapters, the report delivers a complete chapter on five leading switch vendors: Barefoot Networks, Broadcom, Cavium, Intel, and Marvell. Each vendor chapter includes company background information, full details of announced products, a discussion of the vendor’s roadmap where available, and our conclusions about the vendor and its products. Then, for each product segment, we include a chapter covering other vendors and a chapter comparing the products in the segment.

Product-segment chapters include coverage of switch chips and PHY chips. We cover switch chips from Centec, Innovium, and Mellanox. For the physical layer, we focus on 10Gbps Ethernet-over-copper chips and 100Gbps gearbox PHYs and retimers. Covered PHY vendors include Aquantia and Inphi. Finally, we offer our outlook for the leading vendors in each segment and for the overall market.

Make Informed Decisions

As the leading vendor of technology analysis for networking silicon, The Linley Group has the expertise to deliver a comprehensive look at the full range of chips designed for 10GbE/25GbE/100GbE applications. Principal analyst Bob Wheeler and Senior Analyst Loring Wirbel use their broad experience to deliver the deep technical analysis and strategic information you need to make informed business decisions.

Whether you are looking for the right Ethernet chip for your application or seeking to partner with or invest in a chip vendor, this report will cut your research time and save you money. Make the intelligent decision, order "A Guide to Ethernet Switch and PHY Chips" today.

This report is written for:

  • Engineers designing Ethernet switch products or systems that embed an Ethernet switch or PHY
  • Marketing and engineering staff at companies that sell related chips who need more information on Ethernet chips
  • Technology professionals who wish an introduction to Ethernet chips
  • Financial analysts who desire a detailed analysis and comparison of data-center Ethernet semiconductor companies and their chances of success

This market changes rapidly, don't be left behind!

Updates to the Thirteenth Edition of "A Guide to Ethernet Switch and PHY Chips" incorporate new announcements made since the release of the previous edition.

  • Coverage of Broadcom’s new Tomahawk II, Trident 3, and Jericho+ Ethernet switch chips
  • Coverage of Marvell’s Bobcat 3 25G Ethernet switch
  • Coverage of Barefoot Networks’ Tofino programmable switch
  • Coverage of Innovium’s 12.8Tbps Teralynx switch
  • Full-chapter coverage of Cavium’s Xpliant programmable switch
  • 2016 market size and vendor share for GbE switch chips, 10GbE switch chips, and 10GbE PHYs
  • Updated market forecasts for GbE through 100GbE switch chips as well as 10GbE and 100GbE PHYs, from 2016 - 2021
  • Product comparisons updated to include the latest chips

This report examines Ethernet switch chips and physical-layer (PHY) chips for data-center applications. We look at 10G Ethernet (10GbE), 25G Ethernet (25GbE), and 100G Ethernet (100GbE) switch chips. Some 100GbE products enable draft-standard 200G Ethernet and 400G Ethernet rates as well. We cover 10GBase-T (copper) PHYs as well as 100GbE gearbox PHYs and retimers. The newest 10GBase-T chips also handle the new 2.5Gbps and 5Gbps standards for twisted-pair cabling.

The market for Ethernet chips was once dominated by enterprise applications but now relies on cloud data centers for growth. In data centers, virtually every OEM and ODM system design uses ASSPs. Cisco’s ASIC-based Nexus products are the major exception, but even this line uses ASSPs in some models. The rising white-box movement also threatens to loosen OEMs’ hold and shift the market toward bare-metal systems built by ODMs. Hyperscale-data-center operators are driving the early ramp in 100G Ethernet switch chips, which enable 25G and 50G Ethernet for server access.

In 2016, however, 10GbE still dominated data-center switch shipments. We estimate combined 10GbE/40GbE switch- and PHY-chip revenue reached $1.4 billion in 2016, driven by fixed-configuration switches for top-of-rack (ToR) and leaf/spine use.

Although we refer to them as optical PHYs, 10Gbps serdes components also serve in SFP+ direct-attach cabling. Because new ASSP and ASIC designs integrate these serdes, we believe the market for standalone optical PHYs has peaked. By contrast, switch chips won’t integrate 10GBase-T PHYs in the foreseeable future. As a result, 10GBase-T PHY revenue grew nearly 60% in 2016. An emerging opportunity exists in 100GbE PHYs based on 25Gbps serdes technology. Owing to signal-integrity challenges, we expect an increasing portion of switch designs will require retimers between switch ASSPs/ASICs and optical modules.

The vendor landscape for data-center switch chips comprises one dominant supplier, several incumbents with limited share, and a number of new entrants vying for a piece of this fast-growing market. Technology discontinuities include new Ethernet data rates — 25Gbps, 50Gbps, 200Gbps, and 400Gbps — as well as software-defined networking (SDN). The latter trend has led to new programmable switch architectures that are more flexible than traditional fixed-pipeline designs.

Broadcom gained share in the 10GbE transition, and it controlled more than 90% of the market by revenue in 2016. The company’s Trident family dominates ASSP-based data-center switch designs for 10GbE. In 2015, Broadcom shipped its first Tomahawk switch for 100GbE designs, and it saw revenue ramp in 2016. Avago’s acquisition of Broadcom, which closed in February 2016, has had little impact on the Ethernet switch and PHY products. The company continues to invest in three different switch architectures serving the data center. One is Trident 3, an evolution of the venerable Trident family that adds programmability.

Marvell is Broadcom’s top competitor across the full Ethernet switching market, but it fell behind its archrival in the data-center segment. Following 2016 management changes, the company has refocused its Ethernet strategy, and it brought its first 25G/100G Ethernet switch (known as Bobcat 3) to production. Still, Marvell has yet to match the breadth of Broadcom’s data-center portfolio.

Among the new entrants is Cavium, which was the first vendor to begin production of a customer-programmable 100GbE switch chip. This product line came from its spin-in of Xpliant. Cavium is now sampling a second-generation design that competes more directly with Trident 3.

Barefoot Networks is another newcomer with a programmable 100GbE design. It stands out by supporting an open programming language called P4. The startup supplies a P4 compiler that customers can use to generate code for its Tofino switch chip.

Innovium is the latest startup to disclose a data-center switch chip. It was first to announce a chip that handles the new 200G and 400G Ethernet standards, but that chip had not yet sampled at press time.

InfiniBand leader Mellanox is a recent entrant in Ethernet switch chips and is shipping 100GbE products. The company has strong technology and an excellent record of product execution. It has primarily supplied system-level switch products, however, limiting its impact in the chip market.

Based in China, privately held Centec initially targeted Carrier Ethernet designs, but its newest products also address data-center designs. In 2016, it reached production with its first 10GbE switch chip, which includes 100GbE uplink ports.

Before 2015, Intel shipped conventional 10GbE/40GbE switch chips that competed with those from Broadcom and others. The company’s most recent product, however, is a unique chip that combines multiple host controllers with an Ethernet switch. The FM10000 (code-named Red Rock Canyon) works with Xeon server processors in network appliances.

In addition to switch chips, Broadcom and Marvell offer PHYs for 10GbE and 100GbE. PHY specialists that serve the data center include Inphi, which was first to market with a 100GbE gearbox chip developed in CMOS technology. Privately held Aquantia emerged as an early leader in 10GBase-T and pioneered the NBase-T specification, which later became the basis for the 2.5G/5G Ethernet standard.

List of Figures
List of Tables
About the Authors
About the Publisher
Executive Summary
1 Networks and Equipment
Evolution of Ethernet LANs
Cable Plants
Ethernet Clients
Data Centers
Carrier Networks
Ethernet Equipment
Desktop Switches
Data-Center Switches
Modular LAN Switches
2 Ethernet Technology
Network Layers and IEEE 802 Standards
Link Layers
Spanning Tree and VLANs
Data Center Bridging
Link Aggregation
Authentication and Security
Ethernet Physical Layers
Fast Ethernet
Gigabit Ethernet
10GbE Optical
40GbE and 100GbE
Backplane Ethernet Standards
Energy Efficient Ethernet
Physical-Layer Interfaces
Optical Modules
Related Protocols
VM Switching
QoS and DiffServ
IP Routing and Multicast
Equal Cost Multicast Routing Protocol (ECMP)
Fibre Channel Over Ethernet (FCoE)
Timing Synchronization
Network Management
Fabric and Host Interfaces
PCI Express
3 High-Speed Design Issues
Signal Integrity
Crosstalk and EMI
Channel Effects: ISI and Reflections
Impairments on Fiber
PCB and Connectors
Signal Conditioning
4 Ethernet Switch and PHY Chips
Switch Chips
Common Characteristics
System Design
Software Considerations
10Gbps Ethernet PHYs
Optical-Module Architecture
Optical-PHY Architecture and Common Characteristics
Copper-PHY Architecture and Common Characteristics
Interoperability and Compliance
40Gbps and 100Gbps Ethernet PHYs
5 Technology and Market Trends
Software-Defined Networks
Open vSwitch
Open Compute Project
Tunneling Protocols
Service Function Chaining and Network Service Headers
Emerging Ethernet Rates, PHYs, and MSAs
200G and 400G Ethernet
100GbE PHYs and MSAs
25G and 50G Ethernet
25GBase-T and 40GBase-T
2.5G and 5G Ethernet
Ethernet-Silicon Technology Trends
Data-Center Switch Chips
Optical-PHY Chips
10GBase-T PHY Chips
6 Market Outlook
Market Share
Market Forecast
ASSPs for Ethernet Switching
5G, 10G, and 100G Ethernet PHYs
7 Barefoot Networks
Company Background
Key Features and Performance
Design Details
8 Broadcom
Company Background
Switch-Chip Features
StrataXGS Switch Chips
StrataDNX Switch Chips
Switch-System Design
10Gbps Copper PHYs
100Gbps PHYs
Product Roadmap
9 Cavium
Company Background
Key Features and Performance
Design Details
Product Roadmap
10 Intel
Company Background
Key Features and Performance
Design Details
11 Marvell
Company Background
Switch-Chip Features
Switch-System Design
10Gbps Copper PHYs
100Gbps PHYs
12 Other Switch-Chip Vendors
Company Background
Key Features and Performance
Company Background
Key Features and Performance
Company Background
Key Features and Performance
13 Other PHY Vendors
Company Background
Key Features and Performance
Company Background
Key Features and Performance
14 Switch and PHY Comparisons
Comparing Data-Center Switch Chips
100GbE Hyperscale-Fabric Switch Chips
25GbE Top-of-Rack Switch Chips
Key Differentiators
Comparing 10-100Gbps PHYs
100GbE Gearbox and Retimer Chips
10GBase-T Copper PHYs
Key Differentiators
15 Conclusions
Vendor Outlook
New Entrants
Other Switch Vendors
Closing Thoughts
Appendix: Further Reading
Figure 1-1. Typical enterprise-LAN architecture.
Figure 1-2. Typical enterprise data-center components.
Figure 1-3. Generic network architecture.
Figure 2-1. IEEE 802.3 basic frame format.
Figure 2-2. Ethernet physical layer.
Figure 2-3. 10G Ethernet physical layer.
Figure 2-4. Layer model for 40G/100G Ethernet.
Figure 2-5. Modules and interfaces for 10Gbps applications.
Figure 2-6. 40GbE and 100GbE modules and interfaces.
Figure 3-1. Data transmission across connectors.
Figure 3-2. Data transmission using pre-emphasis.
Figure 3-3. Impulse response and equalization.
Figure 4-1. Architecture of a generic SFP+ optical module.
Figure 4-2. Block diagram of a 10Gbps serdes.
Figure 4-3. Block diagram of a generic 10GBase-T PHY.
Figure 4-4. Block diagram of a typical gearbox chip.
Figure 5-1. P4 abstract forwarding model.
Figure 5-2. Comparison of MicroQSFP, QSFP-DD, and CFP8 MSAs.
Figure 6-1. Worldwide revenue market share for 10GbE switch chips.
Figure 6-2. Worldwide revenue market share for 10Gbps optical-PHY chips.
Figure 6-3. Worldwide revenue market share for 10GBase-T PHY chips.
Figure 6-4. Forecast for Ethernet switch-ASSP revenue, 2016–2021.
Figure 6-5. Forecast for Ethernet PHY-ASSP revenue, 2016–2021.
Figure 7-1. Block diagram of Barefoot Pisa pipeline.
Figure 7-2. Block diagram of Barefoot Tofino-64 switch.
Figure 8-1. Block diagram of Broadcom 32x100GbE ToR switch.
Figure 9-1. Block diagram of Cavium CNX880xx switch.
Figure 10-1. Block diagram of Intel FM10000 switch.
Figure 10-2. Block diagram of quad-socket server using Intel FM10000.
Figure 11-1. Block diagram of Marvell 25GbE top-of-rack switch.
Figure 11-2. Marvell Prestera software stack.
Table 2-1. OSI reference model.
Table 2-2. Ethernet PHY standards.
Table 2-3. PCI Express revisions and characteristics.
Table 6-1. Worldwide revenue market share for 10GbE switch chips.
Table 6-2. Worldwide revenue market share for 10Gbps optical-PHY chips.
Table 6-3. Worldwide revenue market share for 10GBase-T PHY chips.
Table 6-4. Revenue forecast for Ethernet switch ASSPs by speed, 2016–2021.
Table 6-5. Revenue for Ethernet PHY ASSPs by speed/media, 2016–2021.
Table 7-1. Key parameters for Barefoot Tofino-64 switch.
Table 8-1. Key parameters for selected Broadcom data-center switch chips.
Table 8-2. Key parameters for selected Broadcom StrataDNX devices.
Table 8-3. Key parameters for selected Broadcom 10GBase-T transceivers.
Table 8-4. Key parameters for Broadcom 100Gbps transceiver chips.
Table 9-1. Key parameters for Cavium Xpliant switch products.
Table 10-1. Key parameters for selected Intel Ethernet switch chips.
Table 11-1. Key parameters for Marvell data-center switch products.
Table 11-2. Key parameters for Marvell 10GBase-T PHYs.
Table 11-3. Key parameters for Marvell 100Gbps transceiver chips.
Table 12-1. Key parameters for selected Centec Ethernet switch chips.
Table 12-2. Key parameters for Innovium Teralynx switch.
Table 12-3. Key parameters for Mellanox Spectrum and Spectrum-2 chips.
Table 13-1. Key parameters for second-generation Aquantia AQrate PHYs.
Table 13-2. Key parameters for Inphi 100Gbps PHYs.
Table 14-1. Comparison of 100GbE hyperscale-fabric switch chips.
Table 14-2. Comparison of 25GbE ToR switch chips.
Table 14-3. Comparison of 100Gbps gearbox chips with RS-FEC.
Table 14-4. Comparison of 100GbE retimers.
Table 14-5. Comparison of quad-port 10GBase-T PHY chips.

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