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Law Technology News (Volume 6, Issue 7, p. 31, col. 1)
July 1999
SO/HO Routers: What Exactly Are They?
by Wayne Spivak
SOHO ROUTERS sounds like an avant garde workshop tool. But they can be the answer to your Small Office-Home Office (SO/HO) Internet connectivity problems.
SO/HO routers are a new hybrid piece of hardware. They serve multiple duties in the small office/home office local area network (LAN.) First and foremost, they are routers. A router is part of a communications network that receives transmissions (information) and forwards those transmissions to their destinations, using the shortest route available.
In a network, that runs TCP/IP (Transmission Control Protocol/ Internet Protocol), a router is the gateway between the 'home' network and the foreign network.
Second, they are hubs. Hubs are devices that connect two or more network devices so they can communicate. A 10 Base T network requires hubs to connect each computer, so they all can communicate. The router is also connected to the hub, and senses when data needs to leave the 'home' network and travel to a foreign network.
Third, they also provide networking services, such as NAT, (Network Address Translation) - an effective firewall technology. They also act as DHCP (Dynamic Host Core Protocol), a way in which dynamic IP addresses are assigned to network devices. This is an effective way of assigning unique numbers to a device, without keeping explicit records.
Network Address Translation works as an internal IP address lookup table. Each network device on the internal network has a unique, but un-usable IP address. The address only works on the internal network. It will not work on the Internet, because the address ranged used is part of a special reserved IP class. This class of IP addresses only will not successfully hop from one router to the next It is for the exclusive use of private networks.
The NAT server takes each request from the internal LAN and sends them to the Internet with a single valid IP address that is assigned by the ISP each time the SOHO Router logs onto the ISP's network. When the response from the Internet is returned to the Router, the NAT server knows which network device on the network sent the original message, and sends the reply.
It is extremely difficult or nearly impossible to "hack" a network using NAT. Other elements increase the level of difficulty a hacker would have to compromise the network. Many or most of these SOHO Routers have these elements. This is why NAT is so popular.
Last, they have a built-in modem, which automatically dials your Internet Service Provider and connects your office to the Internet, on demand. These modems are almost exclusively ISDN (Integrated Services Digital Network). Many of the SOHO Routers permit additional telephone devices to be connected to the modem, increasing the usefulness of the ISDN phone lines (such as fax machines).
These new routers have been made so that in just less than 15 minutes almost anyone can have them configured and ready to use. The routers have built in Web-enabled menu systems and wizards that guide even the most novice computer user through the steps needed to configure the ISDN modem, the ISP phone numbers and user account, and the rest of the internal network.
For the hearty user, they permit the end-user/consultant to modify many of the parameters, which will make the router and internal network function more closely to the specific needs of the LAN to which it is attached. Again, many of these functions can be changed by Web-enabled menus, and some units require command line interfaces or Telnet sessions to access text based menus. Either way, experienced users should not find it difficult to configure this breed of router.
So, for the Small Office-Home Office, the purchase of a SO/HO Router can eliminate the need of purchasing several pieces of hardware (ISDN modem, hub, router) and permit the smaller office access to the Internet. For larger offices, a SO/HO Router can be used in conjunction with other hubs to provide access to the Internet. However, depending on the size of the office, there may be other router-type equipment better suited to the task.
Until DSL (Digital Subscribe Lines) become widely available, this is probably the best way to connect a Small Office/Home Office to the Internet.
Wayne Spivak is president of Bellmore, N.Y.'s SBA*Consulting.