Not long ago I wrote about a start-up with a broadband-bonding technology that lets enterprises cobble together multiple high-speed wired Internet connections to boost network speed and reliability. Now the company, Mushroom Networks, has added support for cellular wireless access, which can come in handy in the event a company loses its primary wired broadband connections.

Broadband bonding is a method of combining dissimilar broadband access technologies to form a single, virtual pipe. Connecting the links provides greater redundancy; if one of the bonded links fails, the bonding appliance can spread the traffic across the remaining links without interruptions. It can be an appealing technology for businesses that aren’t getting the bandwidth they need from say, a single T-1, but can’t afford to upgrade to a DS3 or partial DS3 pipe.

Mushroom Networks made its debut earlier this year with Truffle, an appliance that lets users create a virtual broadband pipe with download speeds up to 65Mbps and as many as six bonded Internet access links, including T1, DSL, cable, and satellite links. A key feature of the Truffle appliance is its do-it-yourself approach: Users can combine their available connection resources without having to coordinate with their ISPs or make changes to the local network.

The Ethernet-based Truffle appliance gets installed between the broadband modems and the local network at the customer’s premises. Optional routing and firewall features are available, and the device supports Internet services including port-forwarding, static IP, dynamic IP, DHCP and Dynamic DNS. There’s no equipment or software required at the ISP premises.

Privately held Mushroom Networks, which is based in San Diego, says its technology is suited for small and midsize businesses, large enterprises, multi-tenant buildings and broadband service providers.

What’s new from the company is the addition of cellular wireless broadband access support to the Truffle Broadband Bonding Network Appliance (BBNA).

Mushroom Networks added a PCMCIA port to its standard Truffle device. With it, cellular data cards supporting EV-DO, HSPA, EDGE or GPRS can be configured as an independent WAN connection that enterprises can choose to be always on, or used only for failover. In the always-on mode, the wireless data card is broadband-bonded with other high-speed services managed by the Truffle device, the vendor says. In the case of failover-only mode, Truffle will automatically switch to wireless data card services when all other wired broadband connections have failed.

Ann Bednarz is associate news editor at Network World.