Broadband connections can be provided via two distinct technical methods. One method is through the television cable, called direct cable, and, the other is through POTS (Plain Old Telephone System) connections, called ADSL (Asymmetric Digital Subscriber Line). Both utilize frequency spectrum capability not normally available for the intended communication medium. In the case of direct cable, the frequency spectrum at the upper (in excess of 20 Mbps for downstream signals) and lower (in excess of 2 Mbps for upstream signals) end of the cable is available for data. This is in addition to the cable TV signals that may be transmitted.

The ADSL service furnished through the telephone system also uses frequency spectrum previously not used in the last 18,000 feet of the copper twisted pair POTS communication system. It not completely true that this frequency spectrum has not been used, in that, the TELCO had previously used it for home and business security dialing at a much cheaper cost than broadband would demand. The POTS phone line continues to function for telephone, fax, or analog data communication as before.

What does this have to do with broadband routers, you ask? Well, for starters, with home and small business connections having this much (1100 to 1500 Kbps) bandwidth, more than one computer may be setup to be on-line at the same time. The best way to accomplish this is to establish a network for the computers and to install a router to handle the connection. The class of routers for this task are called broadband DSL/Cable routers as noted above. Most of these routers have one or more, usually four, ports in a switch arrange to act as a smart hub in the network. One or more computers can be connected to the router through the switch ports. The router then acts to keep the connection with the broadband modem, DSL or cable.

Broadband service - DSL or Cable
A brief description of broadband service, DSL or cable, includes the ability to provide a direct connection to the  Internet. And, it goes without saying that either technique is much faster than analog dial-up  Internet access.  A physical connection general description of each broadband technique follows. Each router may have its own install quirks that must be attended to from the instructions provided by the vendor.

In the case of direct cable, a splitter is installed to tap the data signal off of the TV signal. The cable company provides their signal through a series of subnetworks within their cable infrastructure. These subnets each service about 250 to 400 customers. Each subnetwork provides adequate TV and data signals through the COAX cable to provide both TV and data. The data COAX is split and run within the home or business to a demark wall plug. A COAX jumper cable connects the demark cable with a broadband cable modem. The cable modem is then either connected directly to a NIC (Network Interface Card) within a single computer or to the uplink in a hub or switch in a network. This cable is provided by the modem vendor and is a CAT 5 cross-over RJ45 cable. This is the point that a broadband router comes into the picture. The cross-over cable is plugged into the router WAN (Wide Area Network) port. The computers are plugged into the router switch ports via RJ 45 CAT 5 jumper cables.

In the case of the DSL connection, the ADSL functions are turned on at the TELCO CO (Central Office). A regular POTS phone line is used as the carrier. There is a physical limit to this service. The user’s copper twisted phone line must be within 18,000 feet of the CO to maintain data signal strength. SW Bell actually requires that the service be within 17,500 feet. The TELCO can determine if a user is within the required copper distance during the phone call for service startup. As above, a DSL modem is attached to the demark line connection. The TELCO, SW Bell in San Antonio, provides line filters for the analog side of the phone line. Use the filters per their instructions. The DSL modem is then either connected directly to a NIC within a single computer or to the uplink in a hub or switch in a network. This cable is provided by the modem vendor and is a CAT 5 cross-over RJ45 cable. Again, at this point, a broadband router can be installed in the network matrix. The cross-over cable is plugged into the router WAN port. The computers are plugged into the router switch ports via RJ 45 CAT 5 jumper cables.

As can be seen, the physical connection of the broadband router into the network is fairly simple. The router becomes another node on the local network. It’s function is to know where to connect to in the next stage up stream from the network. Routers are specialized computers that send data along to it’s final destination by knowing who is at the other end of it’s connection between networks. Routers work between networks. Routers know where to send data by maintaining configuration tables of the connections inside and outside their network to other networks. The configuration table maintains the addresses of each node inside the network and the addresses of other networks that it is directly connected to. An example for our broadband router is that it knows the addresses of the hosts in it’s network by their IP addresses, and, the address of the next level up, either satx.rr.com, for Time Warner Roadrunner, or sbcglobal.net for SW Bell.

I need to make one point about these routers. Broadband routers are simple computers with a need for only limited knowledge about the inside and outside of the networks it services. The  Internet Domain Name Server routers in the backbone have massive address list configuration tables to keep track of. All routers work within the TCP/IP protocol standards. Routers have two separate, but related jobs. First, it makes user that data does not go where it should not go. This is crucial for keeping volumes of data from clogging the connections of bystanders. Second, the router makes sure that information does go to the proper destination address.

Broadband Router configuration
In general, nearly all of this class of routers are setup by using a browser to log-on the router Web page using an  Internet protocol address pre-set into the router. Most are set with one of the Class C non-routable IP address, 192.168.X.X, with a submask of 255.255.255.0. This allows up to 256 users on one transmittable IP address. The general settings that must be setup in the router Web page using one’s browser are as follows.

Most of these broadband routers have a quick setup page. In the Addtron ADR-200 router I am now testing, the quick setup asked for the WAN IP setup. There are three choices; Dynamic, Fixed, and PPPoE. Dynamic WAN means that the ISP will dynamically assign the IP connecting address. There are not enough IP addresses to cover all the users in a subnetwork by the ISPs. By dynamically assigning these IP addresses, the ISP can have many users in the system just like the analog dial-up providers do. It is also a security feature as well. Fixed WAN means that the ISP provides an  Internet routable IP address. PPPoE WAN means that the router will be connected to a VPN (Virtual Private Network) for secure communication. The only other entry in the quick setup is to assign the DOMAIN of the ISP so that the router knows where to send its data. This Addtron router is working through my Roadrunner connection at this time.

Most of these routers have advanced setup steps as well. The primary setup to be concerned with is the DHCP (Dynamic Host Configuration Protocol) built into the router. This function allows the user to setup the internal network as a TCP/IP addressing scheme. The usual DHCP addressing scheme installed in the router is a Class C IP addressing set, normally 192.168.1.1. With the DHCP function turned on, each computer NIC in the network can be set to receive it’s IP address dynamically. Windows 95/98/Me, Windows 2000, and Windows XP all are ready to receive the IP address dynamically. The router controls the IP addressing to each computer and handles the NAT (Network Address Translation) between it and the ISP IP address. NAT, by the way, is a basic line of defense against hackers. The 192.168.X.X IP addressing scheme is also non-routable to the outside world. DHCP functions in the router are setup via the router Web page setup scheme.

Broadband Routers on the market
This class of routers are shelf items at computer stores. They can be obtained from catalog vendors, local computer stores, and wholesalers. Their cost is from $59.00 to $300.00. Keep in mind that you get what you pay for. The lower end routers do not have as many functions as the upper end models. I recommend that one pay for the upper end models in order to gain the security from hackers.

Vendors include Linksys $93.00 to $159.00, Addtron Technology $98.00 to $120.00, Multitech $275.00 to $500.00, Sonicwall Tele2 $529.00 to $4,150.00, Zoom, SMC Networks $109.00 to $259.00, Farallon $109.00 to $264.00, Xsense $94.00 to $279.00, Netgear $259.00, Watchguard $359.00 to $1,999.00, Asante $145.00 to $329.00, Cisco $1,139.00 to $2,319.00, and Netopia $309.00 to $639.00. One’s pocketbook and sense of security should determine one’s router of choice.

I have installed Linksys, Addtron, and Multitech broadband routers. Each presented it’s own quirks in installation. None was hard to do. I personally like the Multitech line because I get good Customer Service help and a lifetime warranty. The Addtron router is a good shelf product and has a good warranty.

Conclusion
Broadband Internet connections provide each of us the ability to have high speed connections to the Internet. Adding a broadband router into the mix allows individuals and SOHO users the ability to setup and operate networks at home or in the small business. This class of routers is within the price range of individual and SOHO users. And, they are not hard to setup.