Inside KWGR614

KWGR614 is powered by the same RTL8651B processor used in the high performance Netgear Rangemax WPNT834 Access Point. Besides the RTL86151B SoC at 200 MHz, KWGR614 also sports the RTL8185L/RTL8225 WiFi chipset supporting WPA2-PSK and a generous 4 MB Flash/16MB of SDRAM enough to run many additional applications.


RTL8651B is an "Advanced Home Gateway Controller" from Realtek. The SoC is targeted towards high performance home gateways and wireless routers. A highly capable and integrated multi-layer switch provides significant performance advantages for common NAT and Firewall tasks. The switch also provides L2/L3/L4 switching acceleration for traffic to/from the external wireless chipsets connected via the PCI bus.

Inside KWGR614The RTL8650B/RTL8651B integrates the following key components and technologies:

  • 6-port layer 2/3/4 switch MAC, 5 Fast Ethernet transceivers, and an MII interface
  • Hardware Access Control List (ACL) for firewall applications
  • A Lexra Lx5280 32-bit RISC CPU with a 4K I-Cache, a 4K D-Cache, an 8K I-MEM, and a 4K D-MEM
  • A powerful protocol engine to support auto L3/L4 checksum check and re-generation, auto VLAN tagging, and auto PPPoE encapsulation
  • Rich set of peripherals for value-added services: two UART ports, a USB 1.1 host controller, a PCM interface, and 22 GPIOs


RTL8185L 802.11a/b/g Wireless LAN Controller and RTL8225 802.11b/g transceiver is integrated on board. The 8185L has fairly up-to-date support for WPA2 and other Wireless security protocols.

The 200MHz Lexra Lx5280 32 bit RISC processor offloads most of the fast path network tasks like switching, NAT, Firewall and routing to the integrated multilayer switch. The hardware accelerated wire-speed switching, routing and NAT performance for most of the common L2,L3 and L4 traffic leaves much of the CPU bandwidth free for new applications. In KWGR614 the RISC CPU is used primarily for providing the Web based UI, few of firewall/NAT/ALG session handling, processing of WiFi traffic and security protocols, and a few ALGs when active. The processor should have enough bandwidth left for writing additional applications - that too without compromising the network performance.

The firmware is based on the Linux Kernel 2.4.26 in an uCLinux distribution. 

  • The source code is based on uCLinux distribution but the kernel is based on the usual Linux 2.4.26 with support for the MMU.
  • The Linux Netfilter/Iptables is replaced by the binary only ROME drivers which provides an interface to the hardware accelerator for NAT/Firewall/routing.
  • A binary only 8185L WiFi Access Point driver is included. It may be a good idea to back port the open source 8185L driver available here.
  • The use of the binary drivers makes it imperative that only the given linux kernel 2.4.26 could be used. Any other patches possibly need to be back ported into this distribution.

It would be nice to have some OpenWRT versions running on this platform - but there is not much of a progress at that front. There is no third party frimware available at this point but don't get disheartened. Overall the platform and firmware SDK is fairly complete and once you dig deeper you will find many readily included goodies like VPN, QoS etc. These features are not enabled in the KWGR614 official firmware - but isn't the open source router is all about having your own customized version? 

Additional Information

RTL8651B supports the following features but haven't checked out but it seems most of the peripherals other than one UART for debug serial console are possibly not accessible in the KWGR PCB.

  • System Processor
    • LX5280 32-bit RISC CPU, clock rates up to 200MHz
    • Embedded 4K I-Cache, 4K D-Cache, 8K I-MEM, 4K D-MEM
  • Integrated Switch
    • 6-port integrated MAC switch with 5-port physical layer and transceiver for 10Base-T and 100Base-TX
    • Automatic MDI/MDX crossover on all ports
    • Supports sixth Port 5, MAC interface with 3 configurations to connect to external MAC or PHY
      • PHY mode MII (also known as Reverse MII) for router application
      • PHY mode SNI (also known as GPSI or 7 wires) for router application
      • MAC mode MII for HomePNA or other PHY application
  • L2 Capabilities
    • 1024-entry 4-way hash look-up table and 16-entry CAM
    • Supports source and destination MAC address filtering
    • Supports 8 active VLANs with 4096 VID number spaces to distinguish IP interfaces
    • Supports port-based and packet-tagged VLANs
    • Supports VLAN-based spanning tree forwarding
    • Non-blocking wire-speed reception and transmission and non-head-of-line-blocking forwarding
    • Complies with IEEE 802.3, 802.3u, 802.1D, and 802.1Q
    • Flexible full-duplex 802.3x flow control and optional half-duplex backpressure flow control
  • L3 Capabilities
    • Supports 8-entry IPv4 hardware routing table and longest-prefix-matching table lookup
    • Supports hardware ARP table for host IP addresses
  • L4 Capabilities
    • Supports hardware-switched Network Address Port Translation (NAPT) for TCP, UDP, and ICMP protocols
    • Supports hardware-switched 1-1 Network Address Translation (NAT) for IP protocol
    • Supports hardware-switched server ports (virtual servers)
    • Supports Application Level Gateway (ALG) tables for packets that should be further processed by software
  • QoS Support
    • Supports 2-level QoS based on port, VLAN tag, TCP/IP TOS/DS, L2/L3 table entry, and firewall rule
    • Supports policy-based QoS
  • PPPoE Support
    • Supports configurable automatic PPPoE encapsulation and decapsulation
    • Up to 8 PPPoE sessions
  • Firewall Capabilities
    • Supports 128 hardware Access Control List (ACL) rules for packet filtering
    • Supports both ingress and egress filtering
    • Supports field filtering for Ethernet, PPPoE, IP, TCP, UDP, ICMP, and IGMP protocols
    • Supports Stateful Packet inspection (SPI) firewall
    • Supports whole packet inspection function to scan contents of incoming packets
    • Supports policy-based routing function
    • Supports policy-based QoS function
    • Supports policy-based mirroring function
  • Peripherals
    • USB v1.1 host controller
    • 33MHz PCI v2.2 host interface for glueless connection of up to two devices
    • Two 16C550-compatible UARTs
    • 22 GPIOs

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