In the digital home, we have already seen the convergence of the wireless access point with the Ethernet router/firewall, and now both functions are merging with the broadband modem and voice-over-IP (VoIP) adapter to form the home gateway. This convergence trend is now occurring in small and medium-sized businesses (SMB) as well. The end result in a piece of equipment known as the “office in a box” or SMB gateway.

The SMB gateway is similar to the SOHO gateway but requires greater throughput. As this market emerges, processor vendors are deploying new products, in many cases with accompanying software, to support these office-in-a-box products. This situation creates an opportunity for OEMs and ODMs to target this growing market.

Office in a Box

A small office today needs an Internet connection, possibly through a legacy T1/E1 link, SHDSL, or other broadband service. This link typically connects to the LAN through a security box that implements a firewall and possibly VPN services (for secure remote access). The LAN may use a router with 4 to 24 ports. The wired LAN is often supplemented with wireless LAN (802.11) access points.

Small businesses are starting to adopt enterprise technologies such as VoIP and network attached storage (NAS). An IP PBX can replace the traditional PBX system, converting analog phone calls to VoIP calls that can be routed over the Internet. A NAS box is a storage server that allows one or more hard drives (typically in a RAID configuration) to be shared across the LAN by multiple PCs.

Although these technologies can reduce costs and enhance productivity, small businesses typically lack a dedicated IT person to install and maintain all this equipment. Configuring these devices to work together can be a nightmare, and if they are made by different vendors, getting comprehensive support is nearly impossible.

As in the digital home, combining multiple features into a single box can simplify installation and maintenance. Support requires a single phone call. Convergence can also reduce equipment cost and the space it requires. These advantages are driving the development of the office in a box.

Processors Target SMB

Convergence reduces hardware cost by allowing a single processor to handle multiple functions. In a SOHO gateway, an off-the-shelf RISC CPU can perform routing, security, and VoIP functions in software at ADSL speeds, assisted only by an on-chip encryption engine. SMB equipment, however, requires greater packet throughput, more VoIP ports, and additional security functions, such as intrusion detection. To meet these demands, vendors have deployed a variety of architectures.

For example, Freescale’s MPC8543 uses the same single-CPU approach as a SOHO processor, but it provides a powerful superscalar processor that operates at up to 1GHz. (The MPC8548 goes even faster.) The single-CPU approach simplifies software development and provides flexibility. But throughput is limited by the number of CPU cycles available, and adding voice or security functions will reduce number of the CPU cycles available for routing.

Mindspeed’s Comcerto 100 instead takes a dual-CPU approach. The second CPU typically handles voice functions, so implementing VoIP does not slow down other tasks. Both CPUs are standard ARM cores, so programming is still fairly easy.
Leveraging its network-processor architecture, LSI included a complete data-plane pipeline in its APP2200. This approach ensures high throughput even with small packets. Like the Comcerto device, the APP2200 includes a second CPU for VoIP, further offloading the CPU.

The LSI architecture is complex, adding cost. It also requires LSI to write all data-plane firmware in its proprietary instruction set. The abundance of processors, however, delivers excellent performance and is more power-efficient than a single CPU. Furthermore, throughput remains constant even when features such as security and VoIP are enabled.

OEM Opportunity

Using these processors, designing an SMB gateway can be as easy as adding an appropriate Ethernet switch chip for LAN connectivity; an 802.11 chip for WLAN; the required WAN chip (e.g., T1/E1, DSL, PON); and SLICs for the desired number of VoIP lines.

As in the SOHO market, processor vendors are developing complete reference designs and software packages for SMB. These packages often leverage Linux and other open-source software, such as Asterisk OpenPBX. Design firms such as Intoto also provide office-in-a-box solutions based on the leading processors. This level of support enables OEMs and ODMs to more easily develop SMB equipment.

Originally published in Nikkei Electronics Asia, December 2007

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