Channel hopping

Introduction

Internet communications technologies are evolving rapidly and, within a couple of years, modems – the longest standing means of Net connection – will be eclipsed by broadband communications. In the meantime, it’s getting more difficult to choose a Net connection method for domestic or work use. Here, we take a look at the hardware options available and at which one is right for which job. Given the rapid pace of change for this technology, the life span of any particular model cannot be copper-bottomed. We can, though, give you the estimated longevity of each technology – and the hardware you need to use it. First, if you’re not already hooked-up to the Internet, you’re in a tiny minority where Macworld’s readership is concerned. Last year, 83 per cent of our readers were hooked into the Net – a figure that is now almost certainly into the 90s. Being connected isn’t the big deal it once was. For instance, any iMac takes care of connectivity issues straight off. If your machine doesn’t have a built-in modem, you’ll have to buy some hardware. G3 Power Macs either have a built-in modem or at least a slot for one. There is, though, nothing stopping you from buying an external modem or a terminal adaptor. Older machines that use serial ports rather than USB still offer plenty of choice on the modem front, but ISDN terminal adaptors are less abundant. If you want to run ISDN on an older machine you’ll need to use an ISDN card – a more expensive option that might just be enough to encourage you to buy a new Mac instead. Analogue or digital?
Your main choice is whether to go analogue (modems) or digital (ISDN). Digital is the better option – but how much better relative to cost? In theory, the fastest analogue connection is 56Kbps. The reality is that this is, at best, 50Kbps. Often, 56Kbps is more like 33.6Kbps, depending upon your line and service provider. When compared to dual-channel ISDN, offering 128Kbps, it’s easy to see why ISDN is so appealing. There is a catch, though: cost. Even with the newly affordable BT Home Highway options, ISDN is still prohibitively expensive if you have anything less than a sizable budget: line rental is twice as expensive and, of course, dual channels means double the phone bill. Also, it’s likely that you’ll only use one of the two ISDN channels, and at a speed of 64Kbps. For the dough, this is hardly a vast improvement on 56Kbps. Other ISDN bonuses, though, do include faster dialling – allowing almost instant connections – and faster upload times. Unlike V.90, connection speed is the same in both directions, so uploading files to servers is as quick as downloading. The 56Kbps technologies fall down here, only offering 33.6Kbps upload speeds. The V.90 protocol works by using the digital telephone connection that is used by ISPs (Internet Service Providers). The signal that comes to you from the ISP is digital all the way to your street corner and is then turned into an analogue signal. This allows for the higher speed downloads, but the signal from your modem to the ISP is not as fast. To be totally digital, you need to use ISDN. Emerging options
Unlike hard disks and processors, a decade of rapidly increasing speeds has, for modems, reached its end. ISDN seems to be the natural progression: it’s faster and now freely available, albeit at a great cost. But ISDN itself is a mature technology, even though it’s only recently become more affordable for consumers. The rub, is that speeding up ISDN is merely a matter adding more channels which, in turn, demands a greater cash outlay. Each channel adds a 64Kbps data-stream, but at the cost of another telephone call. For consumers, it doesn’t make sense to spend extra cash to get more bandwidth beyond 128K – unless there are additional benefits, such as an continuous connection. Such benefits are on the way, but are slow in arriving, especially if you live outside a big city. Where extra channels make sense is with peer-to-peer file transfer. In time, they will also be used for Internet access. Another available technology is cable modems, but only in specific areas and through specific cable companies – and it works only with specific computers. If you have the opportunity to sign-up for a cable modem service, do so. Even though the service doesn’t have a guaranteed bandwidth, it’s an always-on service, so even if it runs slowly, you don’t have big telephone bills to worry about. In theory, it can run at speeds up to 36Mbps – in practice it runs at a fraction of this. But its high bandwidth means this is still extremely fast when compared to ISDN or modems. And what about ADSL (Asymmetric Digital Subscriber Line), which has been welcomed and pooh-poohed in equal measure? Its detractors claim the service will be available only to those living within half-a-mile of a BT exchange. They also claim it will be expensive – as much as £200 per month. BT is remaining tight-lipped about the exact service that will be offered and at what cost, so both these predictions could prove well-founded. The pro-ADSL lobby say that, while availability may indeed be limited, the distance is a two-mile radius of a BT exchange. This means that most big cities will have pretty good coverage. Outside these areas, coverage will remain, at best, patchy, and at worst non-existent. Cost is still an issue paramount to the success of ADSL. The lowest estimate I have come across is £60 per month – £40 of which is the price the ISP has to pay BT for the line. To become a mass-connection technology, ADSL cannot be more expensive than this. The service that will eventually be offered will be a chunky 512Kbps download capability and 256Kbps upload. This is upwards of four times the speed of dual-channel ISDN, eight times the speed of single-channel ISDN and more than ten times the speed of a conventional V.90 modem. Market forces are increasingly at work with BT’s ADSL service. Its biggest threat comes from cable access to the Internet. Although cable connectivity opportunities are limited, coverage is growing. Cable & Wireless offer a cable service for data “sometime next year”, and could pose a real threat to ADSL. Rumour has it that ADSL will be available first in areas that already have cable. This makes sense from a business perspective, as BT is likely to want to target areas most threatened by cable. This will have the effect of reinforcing the emergence of distinctive have and have-not areas when it comes to always-on options. File transfer
Before the Internet became the humming network it is today, ISDN was used to transfer sizable files from one site to another. In fact, it’s still the best way to move important files around the country, because it means the user does not have to rely on the temperamental bandwidth offered by the Internet. To use ISDN in this way, you need more than just a simple ISDN terminal adaptor: you require an ISDN card and special site-transfer software. This software is sold with the card, although compatibility is a problem. Here, a couple of years ago there were two main contenders: Hermstedt and 4-Sight (now known as Wam!Net). 4-Sight had the bulk of the market using its ISDN Manager software. Then German giant Hermstedt – already well established in Germany – brought out Grand Central Pro as a competitor title for 4-Sight. A compatibility war raged for a while, as Hermstedt made its product compatible with ISDN Manager, and as 4-Sight regularly updated ISDN Manager, which had the effect of undermining its compatibility. Since then, the industry has seen major changes. 4-Sight was bought out by Wam!Net and it, in turn, teamed up with Hermstedt. Wam!Net then brought a different business model to ISDN communications, offering a secure private network, which simplified and complicated file-transfer in almost equal measure. In the meantime, Hermstedt continues to develop its Grand Central Pro software, adding features such as on-the-fly compression, and greater compatibility with other file transfer protocols. Wam!Net still supplies solutions for normal peer-to-peer file transfers, using Transmission Manager – the new name for ISDN Manager. However, the main direction of the company is towards managed and tracked file-transfers, using its ISDN network. The service works through a charge being levied per megabyte for file transfers, in place of having a telephone bill to pay. Responsibility for its tracking and safe arrival has been shouldered by Wam!Net. For the less technophobic, Hermstedt continues to offer its Grand Central Pro software with its Leo ISDN cards. The Hermstedt cards have built-in hardware compression that is used by Grand Central to squeeze extra performance out of ISDN lines. This was originally 40 per cent faster than without compression, but new versions have advanced the technology and now file transfers of more than 900Kbps are possible over a standard 128Kbps line. This is highly dependant on the file that is being transferred. For example, a QuarkXPress document containing TIFFs is tricky to compress, because TIFFs can often be compressed already. Trying to compress already compressed components slow down the file-transfer the process. Now, Grand Central Pro skips the components that are already compressed, making it faster. ISDN is still the method of choice for important document transfer, and the print trade relies on it heavily. Although the alternatives discussed here will become available in time, they are not likely to replaced ISDN any time soon. If you need fast, reliable transfer of big files, then ISDN is what you need. Choosing your weapon
If you’re the owner of a pre-USB Mac, your options with modems and terminal adaptors are becoming limited. The serial port on older Macs is not ideal for ISDN, so a card is the better – but very expensive – option. It’s worth considering a USB card, and either a USB modem or terminal adaptor. You can pick up a Keyspan USB card from AM Micro (01392 426 473). This will add to the price of your modem or terminal adaptor, but will make sure that it remains compatible when you upgrade your Mac. If you have an even older NuBus Mac, a serial device is your only option. iMac owners already have an internal modem as standard, meaning there’s no point in getting another modem. ISDN, though, would improve connection speed. Blue G3 and the new G4 Macs have a slot for an internal modem. This can be filled either as a built-to-order option, or with a Global Village internal modem. Alternatively, external USB modems or USB terminal adaptors will do the trick. If you’re on the move with a PowerBook, you can get an ISDN PC card from Hermstedt, called Marco. The Marco card offers dual-channel ISDN access to the Internet and basic file-transfer software for £350. For an additional £299, you can upgrade the software to Grand Central Pro and use its advanced features. As both modem and ISDN technology are moderately mature technologies, there’s little difference in speed between competing models. The fluctuating speeds, achieved while connected to the Internet are more a symptom of your service provider and the server that you’re connected to. For example, connecting to the Internet at 128Kbps with dual-channel ISDN will not guarantee that things will be faster. You can be sure that speeds of less than 128Kbps are not the fault of your terminal adaptor. The best way to choose a device is by looking at the software. Many modems and terminal adaptors are designed primarily for Windows machines, with Mac-compatibility being something of an afterthought. The cross-platform models may be cheaper, but the software is unlikely to be as feature-rich. It’s difficult telling what kind of throughput you’re getting from your ISP and, consequently, hard to discriminate between one ISP and another. The WebShuttle, though, provides a way of monitoring such performance through the WebShuttle control panel. Apart from offering excellent control when turning the second channel on and off, it gives a real-time display of bandwidth use. This means you can tell how often you’re maxing-out on bandwidth, and whether it’s worth turning on the second channel. If you want your Mac to make the choice for you, set the parameters for automatic channel assignment. For example, you can set it so that, if the first channel is saturated for more than 15 seconds, the second one will kick-in. Then, once you have downloaded the file and the transfer speed drops, it will hang-up the second line. It’s best to set a minimum time of, say, five minutes, before closing the channel which gives you the minimum call-charge. Otherwise, you’ll connect twice in five minutes. The Billion USB ISDN TA 128 is a PC product with a basic Mac driver. The box promises all kinds of extras – including Answerphone, telephony, fax and file transfer software. Unfortunately, all it offers are Mac drivers, and these support only single-channel dial-up. Essentially, Macintosh users get a raw deal compared with the Windows mob. The ZyXel .net faired slightly better, but is still missing major PC functionality. But at least it has drivers capable of using both ISDN channels. The problem with this, is that you must choose between a single- or dual-channel connection before connecting. You’re unable to change your mind in mid-surf, which is frustrating. The WebShuttle is the only terminal adaptor that supports this via its bundled software. It does it this so elegantly, it puts the others to shame. With its drivers and even additional fax software, the Zoom ISDN MX/S performed fairly well. But, again, there is a problem. Even though last year, the Zoom won a Macworld Editors’ Choice award, the Macintosh world has moved on and USB has taken over. The MX/S is a serial device and, therefore, incompatible with any of the recent Mac range. This is a shame, because Zoom has spent more time than most of the ISDN manufacturers in getting the software right. However, nobody comes close to the Hermstedt WebShuttle, which is a Mac product through and through. The modems we examined are all USB devices, with the exception of the Global Village internal modem. The internal modem has all the functionality of the external modem, but hides inside your Power Mac G3. The design of the Power Mac G3 makes it installing it simplicity itself, although absolute beginners may find it a little scary. All you need is confidence and everything fits together very simply. If you’re still worried by the thought of opening your machine, there’s an external USB option. The shape will be familiar to those who remember the Teleport series, although the colour is now translucent white. All power is supplied by USB, so if you have more than a couple of USB devices you may need a powered USB-hub. The software for both models will be familiar to those who used previous Global Village modems. It’s simple to use and designed for the Mac, which is always a sign of good modem software. The other USB modems we looked at – the MultiTech MultiModem and the Zoom 56K USB – were also well supported by software. Both included the excellent Fax STF, simple and powerful fax software.
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