ROUTER

By J.B. MilesSpecial to GCNA popular current misconception holds that network routers will soon be as rare as rotary telephones. Don't believe it.It's true that Gigabit Ethernet-class switches with Layer 3 routing modules are replacing high-end routers for handling traffic at the core of high-speed networks. But as the Internet becomes a more strategically important information pipeline for organizations inside and outside of government, the jobs of standalone IP access routers at the edges of departmental LANs will increase in importance.Routers work by directing data packets from one network to another according to various network protocols and network operating systems. Most new routers can also bridge LAN traffic over a WAN by keeping track of the logical addresses of workstations on another LAN and passing data packets directly on to them.The main challenge routers face is the inherent difficulty of efficiently managing multiple protocols. If overpowered by this task, routers themselves can become major network bottlenecks. But for groups of users on small branch office LANs that need to be connected to their main offices over various types of WAN connections using Internet protocols, the routers listed in this Buyers Guide are hard to beat for efficiency and cost-effectiveness.I scoured router manufacturers' Web sites for access routers based on IP/Internet Packet eXchange protocols that were designed primarily for use in remote, small branch offices. (Keep in mind that the routers featured here are generally part of much larger product families; I couldn't list them all, so contact the manufacturers or check out their Web sites for more information.)The simplest and most basic of these routers employ analog 56-Kbps telephone connections or the Integrated Services Digital Network basic'rate interface of two B-channel 64-Kbps lines for top uncompressed throughput speeds of 128 Kbps. Most of them employ a single 10Base'T Ethernet connection for up to 10 LAN users; others incorporate a small Ethernet hub of six or eight ports for several dozen or more users.Models such as Chase Research Inc.'s IOLink SOHO, Ericcson Datacom Inc.'s Congo Data and FlowPoint Corp.'s FlowPoint 128 can cost as little as $500 and represent a true bargain for network administrators seeking to connect a small branch office with a limited number of users to a central office site.The multiprotocol routers listed perform at slightly higher levels of functionality than basic IP, ISDN or basic telephone service models, but are also designed primarily for connecting small branch office LANs to central sites. In addition to using standard telephone or ISDN access lines, many of them also provide leased-line 56- and 64-Kbps, dedicated T1, fractional T1, X.25 or frame relay connections.The units often feature optional access modules for combining variuos types of connections. Such a module adds several hundred dollars to the cost of a base unit, but it can be well worth the expense if you need dedicated access.ADC Kentrox's Pacesetter Pro, Develcon Electronics Ltd.'s Orbiter 5100 and Eastern Research Inc.'s SpanNet 2500 Series fall into this category and are also generally capable of handling a wider range of interior and exterior routing protocols than their lower-end relatives. Base prices for this class of router can be as low as $1,295; additional models for various WAN access options generally cost $500 to $1,000.A new category of products dubbed multiservice routers is beginning to emerge. The products in this category are capable of adding analog voice, fax and voice over IP to basic data services. Cisco Systems Inc.'s 1720/1750 Modular Access Router Series, IBM's 2210 Nways Multiprotocol Routers, Motorola's Vanguard 6435/6455 Series and Xyplex Networks' EdgeGuardian Integrated VPN/WAN Access Router are good examples.Multiservice routers are flexible and scalable, providing modules for servicing all or most of the standard WAN access technologies ranging from ISDN to T1, as well as providing support for most IP/IPX-related routing and network protocols. They generally come in a variety of models that bundle options for enhanced security, including encryption, firewalls, advanced network management features and virtual private network support.As mentioned, they usually offer voice over IP support along with connections for several analog lines for standard voice and fax transmissions.Most provide options for two or more autosensing 10/100-Mbps Ethernet ports, integrated 56-Kbps channel service units or T1 data service unit/channel service units, automatic ISDN backup and more. The bare-bones cost of such units can be as low as $1,295 or slightly more, but expect to pay $4,000 or more for a model featuring all the options you want. Nevertheless, that can be a bargain for a powerful standalone device powered by a RISC processor that can provide dozens of users with instant high-speed Internet access for less than $100 per user.How do you pick a router from the large selection available? You can start by checking the following features to see if the access router you have in mind will meet your performance requirements: Anytime you move data from one device to another, especially from LAN to LAN over a public WAN or VPN, security concerns are inherent. Even at the low end, IP access routers should include user authentication measures such as support for the Password Authentication Protocol and the Challenge Handshake Authentication Protocol. Remote access dial-in user service is another user authentication tool.Software- or hardware-based firewall protection, such as Cisco's optional IOS Firewall, guards LANs against outside attack by filtering out illegitimate data packets, as well as offering other features, such as Java blocking, denial-of-service detection and prevention, audit trail and real-time alerts.For mission-critical applications, consider a router with a built-in or optional 64-bit key IP Security Data Encryption Standard module or a triple DES module with a 168-bit key.When moving traffic across a VPN, look for support for tunneling standards such as IPSec, Generic Routing Encapsulation, and Layer 2 Forwarding and Layer 2 Tunneling and protocols. Cisco and other makers of modular access routers generally provide these as options with their families of products designed for remote users, branch offices or large departments. QOS controls let routers provide high levels of traffic availability and predictability. This can translate into determining which users or applications have access to how much bandwidth, with priority going to mission-critical applications.High-end multiservice routers such as Cisco's 1720/1750 series provide such services as committed access rate, whereby traffic types are classified and specific allowable bandwidth is allotted for each type.Policy routing also classifies and prioritizes traffic by IP precedence but doesn't set allowed bandwidth, as does CAR.Weighted fair queuing provides consistent response time by scheduling low-bandwidth traffic to the front of the queue to reduce response time. Generic traffic shaping controls and smooths outbound WAN traffic to a specified bandwidth.The Resource Reservation Protocol reserves guaranteed bandwidth for specified applications from one end of the WAN to the other. Most of the routers listed in the accompanying table support Simple Network Management Protocol and Telnet protocols that allow them to be managed from central consoles elsewhere on the network.If vendor-specific management software such as Cisco's CiscoView or Cabletron Systems Inc.'s clearVISN is included, it usually is an SNMP version optimized for its own product.Cost-cutting measures. IP/IPX protocol Spoofing and Network Address Translation/Protocol Translation help manage the costs associated with using access routers over WANs.Protocol spoofing saves money for users by getting dial-up ISDN lines to shut down when inactivity is detected, thereby reducing online costs.NAT/NATP protocols help reduce Internet charges by allowing users to map multiple local IP addresses to a single IP address provided by an Internet service provider.The Dynamic Host Configuration Protocol saves money by allowing configuration of devices to be handled by a central server. The need to install a DHCP server on a separate PC on the network is eliminated, thus reducing LAN installation and maintenance costs. With compression technology such as Stac LZS, the data transfer rate passed through the router can increase by up to 600 percent, reducing online costs. There are a couple of factors to consider here, the first of which is the router's ability to handle the various existing WAN technologies such as leased lines, frame relay, ISDN, Switched Multimegabit Data Service and others.Second is the router's ability to handle various IP routing protocols such as the Routing Information Protocol and RIP2, ARP Address Resolution Protocol, the Proxy, the Internet Control Messaging Protocol and others. Finally, you may want the flexibility of adding voice and fax services to your high-speed data routing.Obviously, if your needs are simple, keep it simple with an inexpensive, straightforward router.But if you need more, a high-end modular unit will be the answer. Routers used to be a bear to install, often demanding that users write their own lines of code to make them operate properly.Most of today's models, particularly at this end of the service scale, come with Microsoft Windows installation wizards that make it possible even for nonprofessionals to install them in minutes.XXXSPLITXXX-XXXSPLITXXX-