Dealer Focus: ISDN Routers

The time seems to be well and truly past when ISDN stood for it still doesn?t network. Instead, it is becoming a flexible way of linking people who work from home or in small offices with a larger network. We test 10 routers which can easily connect a local network or home PC to a larger company network or the internet.

Until recently, there were only two ways of linking an office or home system to a network: a modem or a permanent leased line. Practically and technically, a leased line is best because it provides a permanent link. But it is very expensive and the line cannot easily be moved.

The modem is at the other extreme. The software and hardware is tried, tested, inexpensive and available from almost anywhere. But the bandwidth is limited and not that stable.

A network connection using an ISDN line occupies the middle ground: it combines both the bandwidth and stability of a rented line with the flexibility of a modem connection.

What is ISDN?

An ISDN connection chiefly consists of three digital channels: a D-channel, which carries control messages, and two B-channels, which carry the data traffic and which each have a bandwidth of 64Kbits.

For normal applications, the D-channel and one B-channel can be used to carry a normal telephone conversation or to make a 64Kbit connection to another network. Because the connection is digital, as opposed to analogue, no time is wasted in setting up the connection, so ISDN is ideal for dial-on-demand applications.

The bandwidths of both B-channels can be combined, a function that router manufacturers call bandwidth-on-demand.

Data traffic via ISDN

This test is made on a selection from the standalone ISDN router market. ISDN adaptors, modems and cards were left out of the test to keep it simple.

There are three main markets for ISDN routers:

First, organisations that need to link one network with another. Insurance companies, for example, frequently use ISDN to link small offices and agencies to a central system.

Second, those companies that are installing intranets in their offices to allow access to an ISDN link.

Third, and perhaps most significant, is the SoHo market.

The networks that use a router to communicate with the outside world may be very small ? possibly just a standalone PC. Indeed, there is now a trend towards employees taking work home and accessing the company network remotely.

But there is a downside. Switching from an analogue line to ISDN means dumping any existing analogue equipment, which will not work on the new ISDN line. But it is worth noting that increasing amounts of ISDN kit have analogue sockets so that telephones, answering machines and fax machines can be plugged in.

A number of units in the test have one or two analogue ports to the router to allow old equipment to be connected.

Corporate Choice

Taking into account matters such as speed, ease of configuration, functionality, documentation and price, a number of the routers tested are likely candidates for our Corporate Choice. It was a very difficult decision.

Eventually, however, the Ciscopro 765 came out on top, mainly because of its low price. But the 3Com Officeconnect, the Ascend Pipeline 75 and the Bintec Bianca also deserve a special mention.

Absent friends

The 10 routers tested represent a cross-section of the market. Some manufacturers, including Farralon and Shiva, did not reply to our request for test routers, and Gandalf fell out of the race because the software did not arrive in time.

Test results

All the routers tested obtained a throughput of between 6.5Kbps and 7.2Kbps, making good use of the single ISDN channel.

The Case Matchbox and Bintec Bianca were the fastest routers. But their performance has to be put into perspective.

The tests were carried out on one specific setup, while hundreds of variants are possible ? routing setups with several channels, with IPX instead of IP, bridging, compressed traffic and so on. Furthermore, the results shown by each of the routers under test are not that different from each other.

In short, it would not be a good idea to select the best router on the basis of these figures alone. The tests show the capacities of the various routers and allow potentially inferior ones to be identified. As far as technical considerations go, however, there is no bad router in the group.

Testing, testing...

Testing ISDN routers is no easy task. In principle, you need to have two routers ? the one that is being tested and one to dial it up. Behind each router there is a complete network with its own IP or IPX structure. This means it is important to check that there is a real connection between the two networks and that the network packages are being sent through as they should be.

There is a lot of work to be done to test all the capabilities of the routers. As a result, our tests have been confined to one complete test setup ? one that looks like a typical IP routing environment, such as a large Wan, or a public network, such as the internet.

So come up to the lab...

On the basis of the existing network and telephone structure of our laboratory, we have set up a completely enclosed test environment which makes it possible to simulate real-life ISDN routing.

At one end is the router to be tested, connected via a UTP cable, on a small 10Base-T IP network with one customer PC in it. This corresponds to a SoHo network. This router is linked up to our ISDN telephone switchboard, which is connected to the other network without the need to dial out.

The dialling-in router is constructed from ordinary PC hardware, a passive ISDN card and Linux as a control system. It is used to dial in to all the other routers in order to eliminate any advantage a router might gain by dialling in on another of the same make. The configuration of the dialling-in router also provides complete control of the software and hardware, which helps with troubleshooting.

Behind this second router is the actual lab network, a small 10Base-T IP network with seven servers and customers, on which a variety of operating systems and software is running.

In real life, this part of the test setup could be likened to a larger company network or a larger Wan with several interconnected networks. IP traffic is routed back and forth between these two networks. Only standard IP routing without bridging, compression or filtering of other options is used. The data is sent via one ISDN channel by HDLC with a synchronous PPP connection. Identification and routing is negotiated with PAP.

After the configuration has been set up and tried out, we set up a connection and test the bandwidth of the ISDN link between the two routers. In theory, this is 8Kb a second (64Kbits), but routing always brings some overheads with it.

Actual bandwidth can be established by sending a few small IP packages of a certain size to a machine at the other end of the line and determining how long it takes for them to come back.

For the first test, 20 small packages of 512 bytes were sent over the line and the average time measured for them to come back. This allows the bandwidth for sending small IP packages to be calculated.

The same is done with 20 packages of 1,024Kb to calculate the available bandwidth for large IP packages.

Test Results

Bintec Bianca Brick XS

Germany, where the Bintec Bianca Brick hails from, was quick to make the switch to digital telephone systems and as a result it produces a vast number of interesting ISDN products.

The Brick XS is a serious rival to the other routers in the test. Once given the required IP address, the machine can be configured entirely within the desktop internetworking management environment (Dime). Dime, a graphical interface, is clearly worth the money and makes the router easy to configure.

The machine supports a wide range of connections and can bridge Appletalk, Netbios and SNA protocols. What is more, it has two analogue telephone connections that are compatible with the telephony applications programmer interface (Tapi). Tapi is used, among others, by Microsoft, offering plenty of potential for the future.

Most valuable is the router?s support for Remote Capi ? the Brick XS is the only router tested to support this option. Remote Capi makes it possible for the users to telephone or fax from the router to the outside world via ISDN channels. Small local networks can also use the Brick XS as a fax server.

The Brick XS is not only a good router ? it came out of as one of the fastest tested. It is also one of the new telecoms appliances which uses ISDN to integrate all telephone, data and fax applications in one machine. In a few years maybe everyone will have a router like it at home.

ADC Kentrox Pacesetter Pro

The ADC Kentrox Pacesetter Pro could compete for the prize as least noticeable router. Inside its small box you would expect to find a modem rather than a complete router. Yet it is a fully fledged router, which supports all the predictable routing options and protocols. The Pacesetter Pro even has a few extra interesting capabilities.

It has to be configured using a serial terminal or Telnet, when the IP address is established. The interface isn?t friendly, but fortunately the router works with a number of example configurations. These provide a template for users to enter the necessary data and these, when combined with the clear sketches and instructions in the manual, mean it should not be too hard to get the router running. But the manual is limited, so users may not fully understand what they have done.

There are two categories of example configurations: enterprise and internet. The Pacesetter Pro is particularly concerned with its internet functionality. If you dial in with the Pacesetter on a personal ISDN account with one IP address, the router will use a special IP translating protocol to ensure that each machine is connected to the internet. IP translation is also possible for a limited range of IP addresses.

The SoHo variant of the Pacesetter has a built-in four-port radio mains hub. Two analogue connections and software provide call-forwarding, call-waiting and conferencing capabilities. These features and the router?s low cost make it attractive to SoHo market.

3Com Officeconnect 520s

The Officeconnect is a nice-looking appliance. It is richly endowed with the necessary connections and proper functional indicator lights, but there is no on/off switch. The router can be stacked with 3Com hubs and fastened together with the usual small clips.

Configuration was a simple matter. It took less than 15 minutes to unpack the router and make the first connection. As far as functionality is concerned, the Officeconnect has all the usual routing functions: IPX and IP routing and bridging, support for the usual protocols and filtering. All that is missing is network address translation. Moreover, an analogue line can be connected to the router, enabling the use of an analogue telephone or fax machine. There are a few weak points. Some people will find it annoying that the configuration can only take place via a terminal or Telnet connection. The software is very clear and well-organised, but some users might prefer Windows software to configure and manage the router.

Simple installation, acceptable functionality, the analogue connection and a competitive price make the Officeconnect ideal for the small office.

Since the test, 3Com has confirmed that it will be bringing out a new model for SoHo users, which will enable internet access using an ordinary ISDN internet account to four workstations via IPX.

Case Matchbox

The Case Matchbox seems to be mainly intended to link small offices to large networks. It is the only router in the test which is supplied with a built-in eight-port hub. Local network PCs simply have to be plugged in and you can get straight down to work with it.

Configuration is achieved in a clear, no-nonsense way using a serial cable or a Telnet session, and all the options are simply leafed through. There is a wide selection of options for keeping track of the traffic over the router, as well as a remarkable number of connections.

The manual mentions Windows 95 and NT versions of an external configuration program, but this was not supplied with the router. The Matchbox also still appears to be in the process of being tested, because the word ?preliminary? appears in the instructions.

The routing software is reasonable and offers numerous options, although there?s nothing here that is really new. What is notable is the fact that a great many frame relay capabilities are supplied, so this type of router came out at the top end of the test.

If we are talking about speed, the Case Matchbox is again right near the top. In the test setup, it repeatedly came in second place, which gives some idea of its capabilities.

Ascend Pipeline 75

Ascend?s Pipeline 75 has won its place in the router market: this is an excellent, very complete ISDN router.

It has two analogue connectors in a wide array of connections, and under the bonnet there is excellent IP and IPX filtering, IPX spoofing, Stac LZ compression, call-back plus dial and bandwidth-on-demand. In short, it has got everything.

Its biggest disadvantage is the way in which it is configured, which is achieved using a serial cable or Telnet. As experienced Ascend users may also confirm, the interface has been botched, prompting much cursing in the labs for the first half-hour. According to an Ascend product manager, the company has identified this problem and is trying to eliminate it by launching a Java configuration program which should make it possible to configure the router using a Web browser.

The manual provided is excellent and information can be found very quickly.

Ascend has a whole range of Pipeline routers, from the Pipeline 25 to the Pipeline 75, each with its own specific capabilities, connections and target group. The routers are also competitively priced, and we think that they will attract a great many users.

Ciscopro 1003 and 765

Cisco is still the make of router. The company?s presence at the high end of the market is such that for many people the name Cisco is synonymous with router. For most network professionals, too, Cisco still means a guarantee of quality. But often this sort of quality carries a high price.

The company is now aiming to dominate the lower end of the market with two series of ISDN routers in its Ciscopro family. The 750/760 series is aimed at the SoHo market, and the 1000 series is intended for heavy duty tasks, such as connecting one Lan to another.

The Cisco 765 is not really a proper Cisco machine ? it came into the range following the takeover of Combinet. The equipment does not run the internetworking operating system (IOS) used by other Cisco routers, although the company is in the process of porting the required functions from IOS to the 760 series.

None of this means the 765 is a bad router: it has all the capabilities that can be expected of a good SoHo router. The configuration can be achieved graphically using Ciscopro Connect ? a useful program with two specific modes: an easy configuration and an advanced configuration, which allows some tinkering with the settings.

The command line interface can be used instead of the graphical software, which is where the simple small configuration cards for the various routers are really useful, allowing the router to be set up speedily. A complete manual is supplied on CD in HTML format.

The 1003 with IOS 2.21 is a real Cisco. It can be configured using Ciscoview ? which is not supplied with the router ? or the command line prompt. This will not prove hard for anyone with experience of routers and Unix, but is daunting for beginners. What is remarkable is that the configuration of this router is stored on a small PCMCIA memory card which is pressed into the machine, at the back.

The company is also bringing a Web-based technology, Clickstart to the market. Clickstart can be used to configure Ciscopro 1003 and 1004 routers, as well as to monitor other Cisco routers. In addition, to link up with Novell networks, Cisco also supplies Ciscopro Internet Junction as an option. This package allows a kind of IPX-to-IP gateway to be run on a server, eliminating the need to request extra IP addresses. As IP doesn?t have to be run as well as IPX, it also reduces the load on the network. The package with the whole Cisco 1000 family.

The two Cisco routers are excellent products. They deliver quality and functionality all the way.

Livingstone Portmaster

Livingstone has always had a reputation for being a sort of poor man?s router. But this perception is wrong, because the company offers a series of excellent, state-of-the-art routers.

The Portmaster ISDN Officerouter is a real chameleon: it comes in a form to connect up to analogue modems, as a line driver or for the obligatory ISDN-BRIs.

After gaining access with a serial cable and a modem program, the router can be fully configured with the PMconsole package, which runs under MS or X Windows and allows the Portmaster to be manipulated using a real GUI interface. System managers can also keep an eye on their routers with this package. Of course, SNMP is always an alternative, but PMconsole gives more direct information.

The Portmaster is a satisfactory router which has everything that is needed. It is let down only in terms of compression, providing only the usual Von Jacobson method.

Motorola Vanguard 311

The smallest member of the Vanguard family, the 311 has considerable capabilities, but is really intended for communicating with other Motorola routers. It can also be used as a PPP and internet router.

All the configuration software for the 311 is supplied on CD. The software comprises three programs: terminal emulation, a software loader for sending software updates through to the router; and a configuration loader for sending existing configurations to the router. The CD also contains a number of ready-made configurations that can be sent direct to the router. All of which meant that the 311 was configured in a matter of minutes for the test setup. As well as sample configurations for PPP customer and server routers, some frame relay setups are also provided.

When connected to other Motorola routers, the 311 can use the company?s proprietary compression, achieving a ratio of up to 8:1. Although excellent, this doesn?t work with other routers. Perhaps the 311 is aiming a little too high by going for the SoHo market, but it is ideal for linking to a Wan via ISDN.

Bay Networks Clam

The Clam is the smallest router on test. It looks like a shell with a small light on top. Only three cables can be connected so it is easily put together. The interface is almost a replica of the 3Com router ? research reveals that Xygologics and 3Com once bought their software from the same company.

In the meantime, this software has been altered and Bay asserts that it has built in strong personal functionality. In this way, the routing of the Clam must be made as dynamic as possible. So a great deal of emphasis is laid on sending routing information via RIP and PG packing.

The Clam is the first model in a whole line of routers. The series also contains the heavier Marlin model and slots in at the bottom end of the market with the heavier Annex series. The Clam is also available with an extra analogue port.

A number of limited, but clear manuals are supplied with the Clam. When we tested out the appliance, we expected that this router would be intended as a cheap option, but in reality its price is too high for this.