Router SoC 101

Do you ever wonder what goes on inside a router? In this article, we take a close look at the SoCs inside of them, which help us manage and maintain our connected lives.


What, exactly, does a router do? And how does it do it? Although the answer to the first question can be relatively simple—a router routes data packets along networks—all of the complexity lies in "how."

Routers come in many shapes and sizes: a room full of rack-mounted, dedicated systems for enterprise clouds; off-the-shelf commercial boxes from manufacturers like Linksys or D-Link; and DIY solutions the size of a deck of cards, built on hobbyist platforms like Raspberry Pi.

Leaving aside the overall meta architecture of packet exchange, the core hardware of a modern commercial router (aimed at the small business and home networking markets) distinguishes it from enterprise or application-specific solutions. Specifically, such a router emphasizes convenience. Single devices act as a DSL modem, router, wireless access point, media server and connection to the smart kitchen sink. Also, the processor and connectivity are geared toward a completely different profile (high-bandwidth use for gaming and streaming, along with simultaneous connections from multiple devices, including smartphones and fridges) than enterprise-oriented platforms.

This article focuses on the hardware that runs modern consumer routers. And in today's routers, SoC (system on a chip) solutions are universal—all of the hardware we cover comes in the form of integrated SoCs. These multi-function systems comprise a variety of configurations with different capabilities, making it more difficult to dig into their respective architectures; but they simplify the router design process. There are far fewer devices to consider when a single board comes with everything built onto it.

That doesn't mean completely integrated systems are the only off-the-shelf setups worth considering, though. Even in the world of SoCs, factors like cost, power consumption and OEM requirements do create a world of chimeric SoC solutions, with multiple high-power radios or transceivers pressed in to service a higher-level processor/memory board, or an xDSL modem connected to one of the ports of a more general-purpose processor. Solutions with discrete RAM or flash memory modules and transceivers with separate radio chips do exist, but they are few and far between. And so we focus on the two classes of SoCs that are most often seen in the wild: processor/all-in-one chips and transceivers.

Rendered image of a D-Link Wireless AC750 Dual Band Gigabit router. Source: D-LinkRendered image of a D-Link Wireless AC750 Dual Band Gigabit router. Source: D-Link

A Note On Software/Firmware

Commercial routers overwhelmingly favor Linux as an operating system, and often employ a customized version. A lightweight Web server is almost always installed as well for user-controlled device configuration.

Another OS, VxWorks, is used only in enterprise-class systems, but it merits a mention if only because it is used on the Mars Reconnaissance Orbiter, and I would buy a commercial router running VxWorks regardless of how unwieldy the final system becomes.

Finally, an open, Linux-based standard, OpenWrt, is being embraced by more OEMs, even though it was previously mostly used by prosumer hobbyists.

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Router SoC Functional Components

In a router SoC, packetized data arrives through input ports, is directed using a network of connections called the Switching Fabric (which can be thought of as wires connecting each component to every other), and leaves through output ports.

Router Conceptual ArchitectureRouter Conceptual Architecture

The router SoC keeps, in memory, a look-up table of addresses associated with each packet, and the processor uses various rule sets to determine the best path for sending data. It also listens in to keep tabs on network traffic, updating its "available" and/or "best" path for packets based on load levels.

The SoC's on-board memory maintains routing tables, consisting of network and host addresses. To determine the best path for delivering a packet to its destination, the routing table includes all known network addresses, instructions for connecting to other networks, possible paths between routers and a measure of distance between nodes or network addresses known in the form of cost functions. This on-board memory usually takes the form of flash  or EEPROM. The size of the memory chip is less important than its speed.

By their nature, routers do not communicate directly with end devices like laptop or desktop computers, but with their network adapters. Each NIC has a network address—Ethernet switches, adapters, Wi-Fi transceivers and radios are all NICs.

Rendered image of a D-Link AC750 Mainboard, Source: D-LinkRendered image of a D-Link AC750 Mainboard, Source: D-Link

Additional hardware can provide dedicated support to the main CPU. A cryptographic chip can offload encryption and hashing functions from the main processor. A dedicated load balancer can jump in to optimize different types of data streams—streaming video versus regular Web page browsing, for example. USB, SATA and other types of capabilities on routers are also added in the form of interface cards, often integrated right into the main processor board.

The architecture gets more complex when you consider that many routers also provide an xDSL, cable or cellular data modem. In this case, the router's interface card is the component that mediates data between the modem and switching fabric.

A modem modulates and demodulates digital signals into analog and vice versa, to be sent out over the "line"—cable or xDSL. However, we will not cover cellular modems in this article; those require architecture and protocol different from xDSL or cable modems.

Processors And Transceivers

The Processor

Any host processor can, theoretically, act as a networking processor, but the hardware in commercial routers is optimized to handle very specific networking tasks. These include key look-up (database look-up using a key), computation, data bit-field manipulation, queue management, pattern matching and control processing. A GPU, for example, would yield less-than-optimal results as the brains of a router (though the reverse problem, gaming on a networking processor, would run up against fundamental limits pretty quickly).

Before HD (or 4K) streaming video, multiple devices communicating over the same home network or intensive network gaming, wasting a multi-core processor on routing tasks was unheard of, even in the prosumer segment. Clearly, this has changed. Processor performance, especially on older routers, can bottleneck the bandwidth of ISPs serving gigabit-class Internet.

Beyond cores and clock rates, CPU specifications can quickly become mind-numbing. But in the networking world, they can generally be split into their instruction set architectures (ISAs): ARM and MIPS.

Of course, there are other architectures other than ARM and MIPS used in networking devices. These are usually dedicated co-processors like DSPs, cryptographic processors, media accelerators and so on.


ARM Cortex-A refers to a series of microprocessors designed by ARM Holdings PLC. The company doesn't manufacture the hardware, but instead licenses its designs. The suffix "A" stands for "applications," hinting that the A series is meant for general-purpose use. There are also "M" (for microcontroller) and "R" (for real-time) families.

The implementations most commonly found in modern networking devices are the older Cortex-A9 or Cortex-A5 chips. Both are based on the 32-bit ARMv7 architecture.

ARM Cortex-A9 Architecture, Source: ARMARM Cortex-A9 Architecture, Source: ARM

The Cortex-A9 was introduced in 2007. It features L1 instruction and data caches that can be configured independently to 16, 32 or 64KB; up to 8MB of L2 cache and clock rates as high as 2GHz. Cortex-A9 processors are included in many current SoCs, including the Apple A5 and A5X; Broadcom BCM11311; Nvidia Tegra 2, 3 and 4i; and even Sony's PlayStation Vita.

The Cortex-A5 hit the market in 2009 as a less powerful alternative to the A9 for low-end and mid-range consumer devices. It's available with between one and four cores, and includes from 4KB to 64KB of L1 instruction/data cache. It is used on many transceiver SoCs.


The MIPS architecture (short for microprocessor without interlocked pipeline stages) was introduced in 1981 by John L. Hennessy of Stanford University. It is currently developed by MIPS Technologies, which has been part of the UK-based Imagination Technologies group since 2013. MIPS uses a reduced instruction set computer (RISC) architecture, enabling specialized chips with low power consumption that are widely used in embedded systems for routers. There are two instruction set versions currently in use: the 32-bit MIPS32 and 64-bit MIPS64. Both were introduced in 1999.

MIPS32 is used in various microarchitecture families—namely, 4K/E, 24K/E, 34K, 74K, 1004K, 1074K/f, microAptiv, interAptiv and proAptiv. The latter three are the most current, introduced in 2012.

2MIPS 1004K Architecture, Source: Imagination Technologies2MIPS 1004K Architecture, Source: Imagination Technologies

The microAptiv, interAptiv and proAptiv microarchitectures typically come with 32x 32-bit general-purpose registers (up to 64x are allowed). The architecture allows for up to 8MB L2 cache, and current implementations operate at frequencies as high as 1.5GHz. MIPS32 is meant to be upward-compatible with MIPS64, which means its features are supposed to be a subset of what MIPS64 offers. Both utilize fixed-length commands in a three-operand format and a load/store data model, catering to high-level programming languages.

Chips based on MIP32 include Broadcom's BMIPS3000, BMIPS4000 and BMIPS 5000; BCM53001 and BCM1255; Ingenic Semiconductor XBurst 1; and Baikal Electronics P5600. Chips using the 64-bit MIP64 architecture include Broadcom's BCM1125H and BCM1255; the Cavium octa-core processors CN30xx, CN31xx, CN36xx and CN38xx; Octeon Plus: CN5xxx, Octeon II: CN6xxx, and Octeon III: CN7xxx; Ingenic Semiconductor XBurst 2, NEC VR4305 and VR4310.


A transceiver is a device that combines a data transmitter and receiver in a single package. Most commercial routers have transceivers with integrated radio/antenna systems, and most often, a small controller or dedicated chip on the board handles radio functions. While "transceivers" are most commonly associated with radio frequency (RF) signals, they have analogs in other transmission standards, though few (if any) of these analogs will be seen in a commercial router for home/small-business use. The Ethernet versions of transceivers are MAUs (medium attachment units), while fiber and 10GbE have their own set of acronyms (GBIC, XAUI, etc.) to describe transceiver devices.

Silex SX-PCEAC 3x3 PCIe Mini WiFi Transceiver Module based on the Qualcomm Atheros QCA9880 Chipset, Source: Silex.Silex SX-PCEAC 3x3 PCIe Mini WiFi Transceiver Module based on the Qualcomm Atheros QCA9880 Chipset, Source: Silex.

Although the trend toward complete SoC solutions continues unabated, many new devices tend to take the transceiver plus processor card approach. Ensuring backward compatibility with older 802.11b/g/n networks—and avoiding a complete redesign with a router refresh, where new functionality can be thrown in just by adding another card—is a big factor. It should also be noted that many packages called "SoCs" omit the actual transmission-receipt function, instead providing a PCI/PCIe slot for the router manufacturer to fill with a network card.



The landscape of networking device manufacturers has changed drastically within the past five years. The big names—Ralink, Ubicom, Atheros—are gone, absorbed by bigger companies. The ground is now held by two giants: Broadcom and Qualcomm. A relative newcomer to the field, MediaTek, is holding its own through the strength of acquisitions. Smaller manufacturers like Marvell and Quantenna have also introduced SoCs used in many mid- and high-end routers, while the networking division of RealTek supplies D-Link and Huawei with chips.

D-Link DI-524 Mainboard, Image by Niels HeidenreichD-Link DI-524 Mainboard, Image by Niels Heidenreich

In 2015, there were some new technologies that affected the giant-dominated line-up, including 5G Wi-Fi Wave 2, 4x4 and 8x8 MU-MIMO. All of the players have exciting offerings, and some of the smaller companies (Quantenna, specifically, with its 10G SoCs) had a lead on Broadcom and Qualcomm at CES 2015.

Chipset Vendors: Broadcom

Broadcom is the wireless and broadband component manufacturing industry's leader. Its undisputed strength lies in its transceivers and radios, which are even used in conjunction with competing router SoCs.

Broadcom Router SoCs

Introduced in 2013, the StrataGX BCM5862X series is part of Broadcom’s Northstar Plus family, featuring single- or dual-core ARM Cortex-A9 processors at 1.2GHz. They connect to two transceivers via PCIe, and are designed for 5G Wi-Fi in combination with capable transceivers. With two SATA 6Gb/s interfaces, a cryptographic accelerator and fast memory, the BCM5862X series is intended for storage appliances.

Broadcom BCM5862X SoC, Source: BroadcomBroadcom BCM5862X SoC, Source: Broadcom

The BCM5301x and BCM470X lines brought 802.11ac-specific support to the Broadcom portfolio in 2012. The 5301x is the enterprise/small business version of the 470x series suitable for residential routers and gateways, and both are manufactured on a 40nm processes. The 4709/AO/CO chips succeeded the popular 4708 series; the AO model was released in 2013, followed by a base model in 2014. The newest member of the family, the BCM4709CO, came out in 2015 (and is also listed as the BCM47094).

Broadcom's latest and greatest for "affordable and mid-tier" residential/small-business routers, the BCM47189 and the BCM53573, were introduced in January 2015 at CES. They are (probably) meant to be paired with the BCM4366 5G Wi-Fi 4x4 MU-MIMO transceiver (radio) chip. Broadcom also announced its enterprise- and cloud-oriented SoCs from the same family, the 43465/43525 and the 47452.

Model NumberYearProcessor Specs Wireless SpecsAdditional CapabilitiesUsed In
BCM5862X Series2013Dual-core 1.2GHz ARM Cortex-A92xPCIe slots
5G Wi-Fi ready
Designed for 2xBCM43460 transceivers
Programmable packet accelerator that offloads tasks from the main CPU cores, with local memory.
Support up to DDR3-1600 memory (16-bit for the 58622 and 58623, 32-bit for 58625).
Twin 2.5G SATA 6Gb/s interfaces
Crypto accelerator
Unknown as of yet
2015Dual-core 1.4GHz ARM Corex-A93xPCIe slots for Tri-Band (Xstream)
Designed for 3xBCM4366 4x4 radios
Network hardware acceleration, Layer 2 switch and flow control
Integrated 5 port 10/100/1000 BASE-TX Ethernet transceivers
USB 3.0, offering >100MB/s data rates
RGMII expander ports
Asus RT-AC3100, RT-AC5300, RT-AC88U
Netgear R8500
D-Link DIR-885L
2015“High Performance” ARM CPUSimultaneous dual-band 2x2/1+1 5G Wi-FiRGMII to enable GbE
iPA and ePA support
Unknown as of yet
BCM631382015Dual-core 1GHz ARM Cortex-A9None InherentIntegrated ADSL/VDSL/Vectoring DSL modem + home-gateway
Data rates “in excess of” 1 Gb/s with a 106MHz spectrum
Actiontec R3000
Netgear D7000
BCM63182013333MHz Single-core BMIPS3300Wi-Fi-capable4x Ethernet, 1x USB 2.0 portsHuawei HG532d
TP-Link Archer D7 v1.x
TP-Link Archer D9 v1.x
TP-Link TD-W8960N v5.x
2012MIPS 400MHzIntegrated 802.11n radio
BCM63268 designed to pair with BCM2057 radio
BCM63168 designed to pair with BCM4360 transceiver (5G WiFi)
BCM63168 has VoIP support
GbE switch core
3x FE PHY, 1x GE PHY
Crypto accelerator
D-Link DSL-6740B rev C2
Comtrend VR-3031u
Huawei HG658
Netgear D6400
Various Others
BCM47062011MIPS 74Kc 600MHzDual PCIe Slots
Designed to pair with BCM4331 transceiver (802.11n 3x3)
Integrated GbE, Integrated 512KB Fast Net RAM
USB 2.0
Asus RT-AC66U
D-Link DIR-865L
Linksys EA6500
Netgear R6300
Netgear WNDR4500
Western Digital My Net AC Bridge
Various Others

An ADSL router SoC, the BCM6318 is designed for integration with entry-level networking devices, providing an all-in-one solution for turnkey router development.

Another integrated modem/router solution with an external wireless NIC, the BCM63268, is one of the most widely used chips for xDSL platforms. It is designed to work in conjunction with the BCM2057 radio. The 63168 provides VoIP support (multi-channel HD voice) and is designed for use with the BCM4360 5G Wi-Fi transceiver.

The BCM4706 sits right at the edge of obsolescence, but a number of popular, low-end routers from 2012 and 2013 use this chipset. Its dual PCIe interfaces are designed to pair with a BCM4331 802.11n 3x3 Wi-Fi transceiver, and it operates both in selectable and simultaneous dual-band configurations.

Broadcom Transceivers

The BCM4352, BCM4360, BCM43526 and BCM43516 were a family of Gigabit 5G chips introduced in 2012 meant for the consumer market. They differ mostly in nominal speeds; the BCM4360 is the fastest, at 1.3 Gb/s via three streams, the BCM4352 and BCM43526 offer two streams at 867 Mb/s and the BCM43516 comes in last, providing 433 Mb/s. The BCM43526 comes with USB instead of a PCIe interface and targets set-top boxes and televisions. The BCM4360 is widely used in wireless routers like Asus' RT-AC56S and RT-AC56U; D-Link's DIR-860L; Linksys' EA6200, EA6300 and EA6350; and Netgear's D6200, EX6200 and R6200, among others.

Netgear R8500, featuring BCM4366 radios, Source: NetgearNetgear R8500, featuring BCM4366 radios, Source: Netgear

The BCM43131 is a Wi-Fi chipset from 2013 with PCIe interface and support for Wi-Fi standards 802.11b, 802.11g and 802.11n. Equipped with a BCM2057 radio chip, it is used in wireless routers from Tenda, namely the D152, W150D v6 and W311E.

An earlier incarnation of this chipset, the BCM43217 (2012) is equipped with the BCM2055 radio, and supports b/g/n. It was used in wireless routers from a number of vendors, including Asus' RT-AC56S and –U; Belkin's F9K1113 and 1118; Linksys' EA6200, EA6300, EA6350 and EA6400; and Netgear's DGN2200, R6200 and R6250.

Introduced in 2014 as a 3x3 MIMO 802.11ac chip for routers, the BCM43602 is equipped with a 320MHz single-core processor and comes with a PCIe interface. Broadcom rates its peak performance at 900 Mb/s. The chip has been used in multiple routers, including Asus' RT-AC3200; the Linksys EA9200; Netgear's D7000 and R8000; and the TP-Link Archer C3200.

Announced in January 2015 as Broadcom's then-fastest 4x4 MU-MIMO chip, the BCM4366 is a 5G radio unit meant to be used in high-end consumer devices. The BCM4366 comes with an 800MHz Cortex-A7 processor. Its Wi-Fi speed is a nominal 5.4 Gb/s (in theory, since, in practice, most consumer devices are unable to saturate it). More important is the MU-MIMO capability, allowing the BCM4366 to handle up to eight clients simultaneously. The radio spans 160MHz, which, unfortunately, also means that only two such networks fit in the 5GHz band without overlap.

Chipset Vendors: Qualcomm

Atheros absorbed Airgo Networks in 2006, making it a heavyweight in the wireless domain. Qualcomm, originally not a player in the commercial networking field, announced a takeover of Atheros in 2011, and Atheros became a subsidiary named Qualcomm Atheros. Qualcomm Atheros went on to acquire Ubicom for its SoC IP in 2012, and Wilocity in 2014 for its 802.11ad expertise. Another interesting Qualcomm Atheros acquisition from September 2011—Bigfoot Networks, a manufacturer of networking solutions for gaming applications—struck out on its own as Rivet Networks. Its SoCs and NICs are marketed under Killer Networking's name, and show up in high-performance gaming motherboards.

Qualcomm Router SoCs

The IPQ40X8/X9 is Qualcomm's latest Wave 2 MU-MIMO SoC. Because it was introduced in October 2015, information on this chipset is still scarce. But we do have some of its specifications.

The A/IPQ806X chipset family is designed to enable "smart-home" platforms, and it borrows from the MSM8974's mobile pedigree to do it. The 2012 APQ8064 used the same Snapdragon S4 processor as the MSM8974 and had a 3G/4G modem, whereas the IPQ8064/62 looks more like a traditional router platform but with a plethora of slots and ports, as well as SDIO support.

Model NumberYearProcessor Specs Wireless SpecsAdditional CapabilitiesUsed In
IPQ40X8/X92015Quad-core 1.4GHz ARM Cortex-A9Twin 2x2 integrated radios (1.73 Gb/s max PHY rate)USB 3.0, PCIe, SD/eMMC ports/slots
LTE support
Unknown as of yet
A/IPQ806X  FAMILY2014ARMv7 Compatible
2x Krait 300 1.4GHz/1GHz
3x PCIe Ports
SATA 6Gb/s, 2x USB 3.0 + HSIC, xGMII, DDR3, SDIO,
Crypto accelerator (AES/3DES/SHA)
NAND support
ASRock G10
Compex AP148
Linksys E8350 and EA8500
Netgear D7800, R7500, R7500v2
TP-Link Archer C2600 v1.x
QC401X, QCA4531X2015MIPS 24Kc 650MHzBuilt-in Wi-Fi (802.11n, 2x2 MIMO for the QCA4531)Up to 128MB DDR2/DDR1 RAM, up to 16MB NOR flash
USB 2.0 host, UART, JTAG, PCIe
AllJoyn framework (Qualcomm proprietary)
12 GPIO lanes, up to 5 (4+1) FE Ethernet Ports
Unknown as of yet
QCA95XX Family2013/2014MIPS 74Kc 750MHz (Slower in earlier models)Built-in Wi-Fi (802.11a/b/g/n, 3x3 MIMO)PCIe host, USB 2.0 host,
Integrated FE switch
Belkin F9K1115 v2
Buffalo WZR-450HP2D
D-Link DGL-5500
Linksys EA4500 v3
Netgear WNR2500
TP-Link Archer C5 v1.x
Netgear WNDR4300v2
TP-Link Archer C7 v1.x

We wouldn't normally include the QC401X and QCA4531 chipsets, since they're targeted at low-power devices for IoT networks, but their newness merits a mention. Qualcomm’s newest WiSoCs, the low-end RTOS-driven QCA401X family and the QCA4531 SoC that runs OpenWrt Linux, support the AllJoyn IoT standard running off a 650MHz, MIPS 24Kc-based processor.

A very popular chipset family, the QCA95xx was introduced in 2013 and was refreshed in 2014. It's found in routers from pretty much every vendor.

Qualcomm Transceivers

The QCA9880 is a 3x3 dual-band radio chip introduced in 2013. It's meant to be paired with the QCA9558 SoC, providing up to 1.7 Gb/s. It is used in various routers, including Cisco's DPC3941; D-Link's DIR-859, DIR-862L and DIR-863; Linksys' E8350; Netgear's C6300 and R7500; and TP-Link Archer's C5, C7, D7, TGR1900 and TL-WDR7500.

The QCA9882 is a 2x2 dual-band radio chip introduced in 2013; its the QCA9880's "little brother," despite its higher model number, and it complements the QCA9880 for home networking. The QCA9890 and QCA9892 are their counterparts for enterprise solutions. The QCA9882 is rated for up to 1.3 Gb/s and is used in various routers, including Asus' RT-AC55U and RT-AC55UHP; D-Link's DAP-2660 and DGL-5500; and Netgear's D6200, JR6100, R6000 and R6100.

In the same family, the QCA9890 and the QCA9892 were also introduced in 2013 as 2x2 and 3x3 dual-band radio chips. They both provide up to 1.3 Gb/s utilizing the 802.11ac standard. The difference between them lies in their number of streams. QCA9890 is the "bigger" of the two, complementing chips for enterprise solutions featuring three streams. The QCA9890 only offers two streams. The QCA9890 has been used in AirTight Networks C-75 and -E, as well as Gateworks Ventana GW3056.

The QCA9860 and the QCA9862 are stand-alone combo chips that complement the above families of radio chips introduced in 2013. The bigger of the couple is the QCA9860, offering three streams, whereas the smaller one, the QCA9862, only offers two. Both reach up to 1.3 Gb/s. Unlike the QCA9880/82 and QCA9890/92, which are meant to be paired with an SoC solution, the QCA9860 and QCA9862 are stand-alone SoCs.

Chipset Vendors: MediaTek

Taiwanese chipset manufacturer MediaTek started out in the optical drive and home entertainment segments, then moved to dominate the smartphone and mobile chipset markets. In 2011, the company bought Wi-Fi chipset manufacturer Ralink, whose chips could be found in every router vendor's devices, marking its entry into the networking chipset space. Ralink itself had previously purchased its major competitor TrendChip in 2010, acquiring ADSL SoC expertise.

MediaTek Router SoCs

MediaTek's integrated SoC offering, the MT7623A/N, was announced in Q2 2015, with optimizations for audio/video streaming. With a storage accelerator and the OpenWrt standard, this chip has the flexibility to enable very capable NAS setups as well.

Intended for IoT gateways and media routers, the MT7683 was announced in Q3 2015, and it differs from the MT7623A/N systems in some key areas—noticeably, the introduction of a Mali 450 GPU. This allows the 7683 to display the status of connected IoT devices on a monitor or TV. IoT control is provided by the MT7687 SoC, MediaTek's first ARM Cortex-M4-based IoT Wi-Fi solution.

The MT7683/23 chips support a number of content streams over cable, Bluetooth and BLE for wearable devices. NFC is enabled for quick setup. Wi-Fi is delivered via the powerful 802.11ac Wave 2 MTC7615 transceiver, announced in Q1 2015.

A power-efficient IoT SoC, the MT7687, was announced in Q2 2015. With a maximum power output of 21 dBm, this chip works as a stand-alone IoT gateway or with the MT7683 as a powerful smart-home solution.

Model NumberYearProcessor Specs Wireless SpecsAdditional CapabilitiesUsed In
MT7623A/N, MT7683, MT76872015Quad-core 1.3GHz ARM Cortex-AEmbedded 1x1 802.11n dual-band Wi-Fi + Bluetooth
Integrated MT6625L Radio
32b LPDDR2/DDR3/L up to 2GB
USB 3.0(2), USB 2.0 OTG
PCIe 2.0 Host(3)
Audio interface: SPDIF, I2S(32b, 384Kb), PCM
HW storage accelerator (Samba> 100MB/s)
2 Gb/s IPv4/6 routing, NAT, NAPT+HQoS, Packet Sampling
HW Crypto Engine ~400-500 Mb/s IPSec throughput
Unknown as of yet
MT7621 A/N/S2015200MHz ARM Cortex M4F1x1 802.11 b/g/n embedded, IoTIntegrated security engine
Open SDK
Unknown as of yet
MT7621 A/S/N2014Dual-core MIPS1004Kc 880MHz (Single core on the S/N variants)3x PCIe Hosts
802.11ac Wi-Fi with transceivers MT7612E+MT7603E (AC1200 config) or 2xMT7615(AC2600 config)
16b DDR2/3 up to 256/512MB
HW storage accelerator
HW Crypto Engine
Buffalo AirStation WSR-1166DHP
D-Link DIR-860L rev B1
Linksys RE6500
Asus RT-N56U B1
Netgear WNDR3700v5
MT7620 A/N2013MIPS 24KEc 580MHzIntegrated 2x2:2 802.11 b/g/nSupport external PA/LNA
16b SDR/DDR1/DDR2 up to 256MB
USB 2.0 Host/Device
Asus DSL-N16U
Buffalo WHR-300HP2
D-Link DIR-810L rev B1
Linksys EA6100
Netgear R6050
TP-Link Archer C20i
Camera - Belkin F7D7602 v2
Repeater  bridge - Linksys RE2000 v2
3G mobile router - NetComm 4GM3W-01
MT7628 A/K/N2015MIPS24KEc 575/580MHz2T2R 802.11n 2.4GHzSupport external PA/LNA
5p FE SW or 1p IoT mode
16-bit DDR1/DDR2 up to 256MB
MT7628A: full functions with external DRAM
MT7628K: embedded 8MB DRAM and L-shape 2L PCB
MT7628N: same as MT7628A, w/o PCIe, w/o IoT mode
Asus RT-AC1200
MT7510/MT75112014/2015MIPS 34Kc 750MHz1x PCIe HostFour-port Fast Ethernet Switch
1x GbE
TRGMII and RGMI interface for external LAN devices
PCM for VoIP
Smart Packet Accelerator
Asus DSL-N17U
Asus DSL-AC68U
Asus DSL-N16
Asus DSL-N17U B1

MediaTek's most popular offerings are MIPS-based SoCs. The MT7621 A/N/S powers everything from mid-tier routers to access points. Another comprehensive low- to mid-range SoC, the MT7620, is also used in a variety of networking applications, and is extremely popular across all market segments. The MT7628 family is an update to the popular 7620.

An integrated xDSL (VDSL2/ADSL2+ IAD) and router solution, the MT751x series, is designed for a flexible networking system design, also containing a little bit of everything. Interestingly, these chips adopt a twin-CPU solution consisting of a 32-bit MIPS CPU and an xDSL Discrete Multi-Tone (DMT) engine.

Although Ralink was absorbed by MediaTek, its last few chips were showing up in routers as late as 2013. And the sheer number of devices powered by Ralink silicon means you can't quite forget about the company's SoCs. The 6855 was the last Ralink chip to show up for FCC approval in 2013. Both the 6856 and the 6855 were powered by the dual-core MIPS 34KEc 700 processor. The RT63XXX family of xDSL router SoCs were still being used for new devices as late as 2014 by a loyal TP-Link (in one case, married to a MediaTek transceiver; TP-Link's TD-W8951ND v6 was powered by Ralink's RT63365E and MediaTek's MT7601E).

Smaller Chipset Manufactures

Marvell Technology Group creates SoCs for networking devices, often pairing them with Broadcom transceivers. Chips in Marvell's Armada 38x family are equipped with ARMv7 Cortex-A9 dual-core processors (with the 88F6810 chip, Armada 380, being an exception). They feature GbE, DDR3/3L/4, PCIe 2.0 links and a host of other features that make Marvell competitive. We're not seeing many devices with the company's hardware, though. Armada XP (MV78XXX) chips, with up to a quad-core ARM v7 PJ4 processors, seem to share the same fate.

A new addition to Marvell's Avastar SoC family was announced in Q1 2015, targeted at enterprise APs, hotspots and residential multi-stream (video or gaming) applications. An earlier iteration, the 88W8864, supported up to 1.3 Gb/s and 4x4 MIMO. It was used in the Linksys WRT1200AC and WRT1900AC wireless routers.

Linksys WRT1900ACS Router featuring the Marvell Armada 385 SoCLinksys WRT1900ACS Router featuring the Marvell Armada 385 SoC

We're calling it a "smaller" manufacturer, but in reality, Realtek is one of the largest chip makers in the world. But the company's networking segment peaked with its 10/100 Ethernet controllers. Its wireless offering haven't enjoyed the same level of market penetration. So it's not the most popular chip on the block, but it does deserve a mention: the 2013 ADSL2+ modem/router from RealTek, based on its Lextra LX processor (a 32-bit implementation of the MIPS architecture) held its own for a while. It was used in D-Link's DSL-2740E, Huawei's WS319 and other routers.

WRT1900 ACS Router Block Diagram Featuring the Marvell Armada 385 SoC, Source: LinksysWRT1900 ACS Router Block Diagram Featuring the Marvell Armada 385 SoC, Source: Linksys

Quantenna specializes in wireless SoC transceivers. Its R&D focused on high-end 802.11ac and 802.11n devices. Competing neck and neck with the giants of the industry, Quantenna introduced a number of new devices in 2015, all on the cutting edge. It was first to launch a 4x4 MU-MIMO 802.11ac chipset, and has demonstrated a 10G system. The QSR2000 Wave 2 is a transceiver designed for high-speed Wi-Fi routers. It is marketed as an integrated chipset for 802.11an/ac or 802.11b/g/n Wave 2 applications, dual-band switchable, with 4x4 MU-MIMO four spatial streams. It has 80MHz channels (for the 5GHz band), PCIe 2.0 connectivity and a peak PHY of 1700 Mb/s.

The QSR10G family of chipsets supports 10Gb speeds. There are four variants, ranging from the "U"—a top-tier 12-stream, dual-band device with a peak PHY rate of 10 Gb/s—down to the "5" variant, with eight-stream 5GHz single-band operation with a peak PHY rate of 8.6 Gb/s.

The Future Of Router SoCs

Just as in-home HD video and game streaming drove the innovations behind MU-MIMO and Wave 2 wireless, IoT and smart-home initiatives are poised to drive capabilities in the next generation of routers. Expect to see more and more devices capable of handling low-power, low-data rate, always-on clients in addition to existing high-end capabilities. Qualcomm is already making forays into this area, and Broadcom will not be far behind. Intel is also collaborating with cellular modem manufacturers and has a grand IoT vision, so expect to see new players in the field.

Another series of innovations will target mobile routers—those with integrated cellular modems. With the number of travelers carrying two or more computing devices (laptops, smartphones, tablets, smartwatches), the demand for small, integrated wireless router/cellular modem combination devices is expected to rise. MediaTek has a solid lead here, with its dominance of the cellular modem/device market, but expect to see solutions pairing MediaTek, Quantenna and Broadcom modems with other router SoCs, whereas Qualcomm will probably provide fully integrated solutions out of the box. We even expect to see Western Digital add more high-end devices to its current mobile line-up.

Another paradigm change is the use of the OpenWrt OS, as more manufacturers embrace its standards and compatibility. Also expect to see greater emphasis on security, in parallel with hardware features designed to support "smart router" functions (i.e., remote administration via smartphone or Web apps, which at the moment, is a feature solely up to individual router manufacturers to implement).

On the negative side, the 2.4 and 5GHz bands used for Wi-Fi are becoming more crowded. Interference from multiple devices on these bands, especially in public and enterprise Wi-Fi spaces, means interference and higher error rates, all of which serve to slow down individual connections regardless of actual hardware capabilities. As this is somewhat of a physics-imposed limitation, expect to see active workarounds that include the shunting of smart-home-appliance and IoT connections to other transmission bands.

The 802.11ah extension to the 802.11 Wi-Fi standard allows the use of sub-1GHz bands for Wi-Fi communications, and will be up for approval in its entirety in March 2016. A sub-component to the “ah” extension, the “HaLow” standard operates on the 900MHz band and was recently approved by the Wi-Fi Alliance. It allows for low-power and high-obstacle-penetration operations.

The next iteration of conventional 2.4GHz and 5GHz Wi-Fi is expected to be the 802.11ax standard, still in early stages of development, but which promises 10 Gb/s speeds. Finally, expect further work on all the other iterations of 802.11 standards that utilize bands other than the 2.4GHz and 5GHz, specifically 802.11af that uses the unused TV bands (UHF/VHF white-space spectrum) between 54 and 790MHz.

Follow Gene Fabron @fabrongene. Follow us on Facebook, Google+, RSS, Twitter and YouTube

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Gene Fabron is a Contributing Writer for Tom's Hardware. Follow her on TwitterFollow us on FacebookGoogle+RSSTwitter and YouTube.

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  • letapragas
    Awesome job!
  • zodiacfml
    Intel do use one of their chips for a similar device.
  • QuangT
    Nice article, is there any more on how tech works? Like cpu and gpu?
  • bwhiten
    Uhhhh...Those first pictures are not "schematics". They are CAD renderings of the box and main board at best, but definitely not schematics.
  • EdJulio
    Uhhhh...Those first pictures are not "schematics". They are CAD renderings of the box and main board at best, but definitely not schematics.

    Thanks, bwhiten. Updated the caption...
  • bit_user
    Nice article!

    Small, irrelevant fact: MIPS was once owned by SGI and used in their servers and workstations. They even used a MIPS CPU in the N64, which they designed for Nintendo. In fact, that was largely the outcome of a previous (if not the first) wave of VR hype. But, I digress...

    Also, most people consider ARM to be RISC. Or, at least as much as anything is, these days. Indeed, the name once stood for Advanced RISC Machines.

    But I didn't know what MIPS originally stood for, so thanks for that. I wonder whether or how long that remained true of their architectures.
  • EdJulio
    Anonymous said:
    Nice article!

    Small, irrelevant fact: MIPS was once owned by SGI and used in their servers and workstations. They even used a MIPS CPU in the N64, which they designed for Nintendo. In fact, that was largely the outcome of a previous (if not the first) wave of VR hype. But, I digress...

    Also, most people consider ARM to be RISC. Or, at least as much as anything is, these days.

    Thanks! I'll share this with Gene! Cheers!!!
  • bit_user
    Anonymous said:
    Thanks! I'll share this with Gene! Cheers!!!
    Thanks, but I did say it was irrelevant. It really has no bearing on the routers using these chips.
  • GeneFabron
    Nice article, is there any more on how tech works? Like cpu and gpu?

    Hi QuangT, we have a Wireless Routers 101,4456.html and a PSUs 101,4193.html article, and there will be more coming soon!
  • Gabriel_1965
    Question: I've seen a router with 72 cores would that be made to be a 72 core pic and I could use the cores for multi ore computing?
  • Gabriel_1965
    Question: I've seen a router with 72 cores would that be made to be a 72 core pic and I could use the cores for multi ore computing?

    Sorry can it be used as pc for multi core computing?
  • DavidC1
    Indeed, the name once stood for Advanced RISC Machines.

    The A actually stands for ACORN. It's Acorn RISC Machines.
  • DavidC1
    Actually, you are right. It used to be called Acorn, but now its Advanced. Not that it makes a difference to anyone...
  • GeneFabron
    Question: I've seen a router with 72 cores would that be made to be a 72 core pic and I could use the cores for multi ore computing?

    Networking chips are generally very specialized - they handle certain tasks like I/O and data transport/filtering really, really well. Physics simulations...not so much. So it would really depend on what kind of calculations you were carrying out, how well you can parallelize the operations, and the base architecture you were implementing. If you could *translate* your model problem into something that can be expressed as network I/O data transfer (I can think of a couple of very specialized machine learning algorithms whose math can be expressed this way), then you could take advantage of this kind of system. Either way, I expect you'd have to do the math and all coding from scratch. Or you could brute-force it by (heavily) modifying pre-existing code for Beowulf clusters and the like...

    In most cases, you will get much, much better cost:efficiency ratios with a more traditional setup, or an actual cluster.

    If this is the TILE-Gx72 Processor you are talking can support up to 1Tb of interesting problem.

    tl;dr yes, you can do anything, but it may not be the most efficient, most cost-effective, or "best" method based on the type of computational problem you are trying to solve.
  • bit_user
    Anonymous said:
    Indeed, the name once stood for Advanced RISC Machines.

    The A actually stands for ACORN. It's Acorn RISC Machines.
    No, but it once did. I worded my statement, carefully.

    when the company was incorporated in 1990, the acronym was changed to "Advanced RISC Machines", in light of the company's name "Advanced RISC Machines Ltd." At the time of the IPO in 1998, the company name was changed to "ARM Holdings"