ISDN and the Internet

What does INS64 offer the Internet user?

Speed and bandwidth (64 kbps or 128 kbps). All digital data transfer. Quick connection setup. The reliability of an all-digital network.

Modem model

ISDN model

Do all ISPs in Japan provide dial-up ISDN?

Most do. Check to see if yours does before investing in ISDN. You may need to look for a new ISP. Services have probably changed since you subscribed with your ISP, and another ISP in your area may be offering a better deal. Ask your friends which ISP they use and what they think of the service. Always do your homework before signing up for a whole year.

Which ISPs offer ISDN and English Support?

Asahi Net, Global Online, and Twics to name just a few offer English support. Some other ISPs post maintenance and outage announcements in both Japanese and English. If you're looking for an ISP in your area, check out Slavek Gronski's Independent Guide to Internet Service Providers in Japan.

Will my ISP charge more for dial-up ISDN?

Some do, some don't. Check with your ISP. Typical ISDN speeds being offered by ISPs in Japan are: 38.4 kbps and 57.6 kbps (asynchronous) and 64 kbps and 128 kbps (synchronous). Synchronous is what you want. Some are offering 64 kbps at the same cost as analog, but are charging more for 128 kbps. A good ISP should offer 64 kbps synchronous ISDN at the same rate as analog. Kcom, for example, offer 33.3 kbps modem, 64 kbps, and 128 kbps connections all at the same cost.

What do I need to know from my ISP?

You need to know your ISP's dial-up number for ISDN in your area (It may well be the same as the analog number that you currently use.) When you contact your ISP, ask how many other ISDN customers they have, and what their total bandwidth is. You can check the bandwidth yourself using the ISP map in Internet Magazine.

Can I still use my modem to connect to my ISP?

Yes. Your modem can be connected to an analog port on the TA, as shown below. In this case, you'd use your ISP's analog access telephone number.

Modem via ISDN

Can ISDN be used with any computer platform?

External TAs and plug-in cards for use with Macintosh, PC-98, and IBM PC-compatible (DOS/V) computers are readily available. Apple PowerBooks and portable PCs can be used with an external TA or PCMCIA ISDN card.

Can I use my existing Internet software?

Yes. You can use the same software for e-mail, Web browsing, FTP, etc., regardless of how you connect to it.

Can I use Tele-Hodai with ISDN?

Yes. NTT have a Tele-Hodai service specifically for use with ISDN called INS Tele-Hodai. See Tele-Hodai charges.

How long does it take to connect to the Internet with ISDN?

Noticeably less time than with a modem, which may takes between 10 and 20 seconds. With ISDN, Internet connections are established in just a few seconds.

Can ISDN be used for anything other than the internet?

Yes. File transfer between computers. For example, transferring 100 MB page-layout files to your service center for output to film. When computers are connected directly, you can expect consistent transfer rates that far exceed those possible over the Internet. ISDN can also be used for international data transfers and videoconferencing.

What about remote networking?

Macintosh-ready TAs usually come with CCL (Connection Control Language) scripts for use with Apple's ARA (Apple Remote Access) software. Windows-ready TAs usually come with a configuration file for use with Windows RAS (Remote Access Server) networking.

How does a 128 kbps connection work?

To achieve a transfer rate of 128 kbps, the two 64 kbps B channels are multiplexed together. This is sometimes referred to as bonding.

Does 128 kbps cost more?

Yes. Because you are using both B channels you have to pay double to NTT.

Do many ISPs in Japan offer dial-up ISDN at 128 kbps?

Many do. Check with your ISP, or take a look at the ISP guide in Internet Magazine.

Is Web surfing with ISDN really that much faster than with a modem?

Yes. Web surfing with ISDN is fast, and the connection setup time is quick when compared to a modem. However, Internet performance is only as fast as the weakest link. In theory, a 64 kbps ISDN connection should be twice as fast as a 28.8 kbps modem, and nearly ten times faster than a 14.4 kbps modem. However, the speed at which data gets from a Web server to your computer is dependent on many things, so ISDN is no sure fix for Web surfing stress, but it is one less weak link in the chain. If your ISP is running over capacity, or the Web site you're accessing is busy, you'll still have to put up with the World Wide Wait, as the server sending your data responds to requests from other users, transfer rates vary--sometimes wildly.

What do the experts say?

In the October 1996 issue of Internet World magazine, the IW Labs conducted several "real world" tests to determine the overall performance of an ISDN Internet connection. Although the tests were performed in the united States they are still relevant to Net surfers in Japan. IW found that when surfing at 128 kbps, one 64 kbps B channel did most of the work, the other only coming into action when the first channel was saturated. Of course, even with only one channel doing most of the work you still have to pay double to NTT, and perhaps more to your ISP. A TA that supports BOD (Bandwidth On Demand) automatically uses the other channel only when necessary, thereby saving on your telephone bills. With one 64 kbps B channel in operation throughput averaged 38.4 kbps, or 60% of capacity, which is about the same as that of a 28.8 kbps modem. When the B channels were combined for 128 kbps, throughput averaged 50.6 kbps, or 44% of capacity, which is 25% down on the single-channel performance. IW concluded that ISDN was worth the extra cost and setup and a dramatic improvement would be noticed by those upgrading from 28.8 kbps modems. In another article about ISDN routers, IW Labs claimed that with a BOD (Bandwidth On Demand) TA and Multilink PPP software (i.e., 128 kbps), only one B channel is used for Web browsing and e-mail, but both B channels are used for FTP file downloads.

Having actually used BOD (Bandwidth On Demand) and 128 kbps I can confirm the findings of IW. Using the default BOD settings of my Aterm TA, I found that most of the time Web surfing did not benefit from 128 kbps. When 128 kbps kicked in during an FTP file download, e-mail file attachment download, or real video stream, however, throughput went up but so did my telephone bill!

What is BOD?

Bandwidth On Demand allows a TA to dynamically allocate B channels as and when needed. For example, when downloading a file off the Internet at 64 kbps (i.e., one B channel), the TA may activate the second B channel if throughput is, say, higher than 70% for more than 30 seconds, providing a combined bandwidth of 128 kbps. When the download is complete, or throughput drops under 20% for more than 20 seconds, the second B channel is deactivated and the connection reverts to 64 kbps. Note that bandwidth is not the same as speed, so although the connection jumps from 64 kbps to 128 kbps, Net performance won't necessarily be any quicker. It will, however, mean that you can use more Internet services simultaneously, for example, run several FTP downloads while streaming audio and video.

What about computer performance?

With a plug-in ISDN card, virtually all computers can be used at 64 kbps or 128 kbps. If you're connecting an external TA to your computer, however, you need to make sure that your computer's serial ports can handle the high speeds.

Macintosh

The serial ports on Macintosh computers using 68030 or 68040 microprocessors cannot handle data rates above 57.6 kbps. The only way to achieve a transfer rate of 64 kbps or 128 kbps on these Macs is with a plug-in card. You'll have to decide whether it's worth investing in an obsolete NuBus-type ISDN card that cannot be used with the newer Power Macs, which use the PCI bus system. Power Macs and 660AV and 840AV Geoport Quadras have a theoretical maximum serial port speed of 250 kbps, so these Macs should be useable with an external TA at the maximum ISDN speed of 128 kbps. However, it appears that even Power Mac serial ports max out at 115 kbps (something to do with AppleTalk using Modem port resources), making it impossible to achieve the 230 kbps port speed that TA manufacturers recommend for use with 128 kbps ISDN. In my own experiments with an 8500 Power Mac and Aterm IT55DSU, I found that the TA would not repsond to PPP commands when the port speed was set to 230 kbps, although it works okay at 115 kbps. I was unable to determine whether it was the serial port or TA which was at fault.

Having said that, I have witnessed a noticeable improvement Web surfing on a 68040 Mac with 64 kbps ISDN. IW Labs noted an average transfer rate of 38.4 kbps when Web surfing with ISDN, something a 57.6 kbps serial port should be able to handle.

Apparently, the maximum transfer rate for Power Mac serial ports is 115.2 kbps when AppleTalk is being used, and, because the Modem port shares resources with the Printer port and floppy disk drive, any activity on the Printer port or having a floppy disk inserted, limits Modem port throughput. I have tried disabling AppleTalk but was still unable to establish a port speed of 230 kbps.

MegaWolf produce a series of high-speed serial port cards for Power Macs.

Since the Modem port has a higher priority than the Printer port, always connect your TA to the Modem port.

I have no idea how accurate Free PPP's throughput monitor is, but I've observed speeds of 73,900 bps and 91,400 bps using INS64, an 8500 Power Mac, and NEC Aterm IT55DSU.

Tip: If your 68k Mac has an Ethernet networking card, or you have a Quadra with built-in Ethernet, even if you have the latest Power Mac, get yourself an ISDN router and eliminate serial-port performance bottlenecks for good.

Windows

For Windows PCs, serial port speed is determined by the UART (Universal Asynchronous Receiver Transmitter) chip. The 8250 and 16450 chips found in most 286 and 386 PCs max out at 57.6 or 115.2 kbps. So you will not achieve maximum throughput with one of these computers. High-speed ISDN connections require a 16550A UART, found in some 486 PCs and most Pentium PCs. This UART supports serial speeds of up to 921.6 kbps. If you're using Windows 95, you can easily check whether your computer has a 16550A UART as follows. Right-click the My Computer icon, and choose Properties. The System Properties window appears. Click the Device Manager tab, and then double-click Ports. Depending on which port you intend to connect to your TA, double-click either COM 1 or COM 2. The Communications Port Properties window appears. Click the Port Settings tab, and then click Advanced. If you have a 16550A UART, the "Use FIFO buffers" option will be checked. Plain 16550 (minus the letter A) UARTs do not support FIFO (First In, First Out), and are known to have several bugs. Avoid them. Also be aware that having a Pentium processor in your PC doesn't necessarily mean that its serial ports support these high-speeds. Serial port UARTs are often fitted on plug-in cards, and cheaper cards may not have the 16550A UART. Check before buying.

Windows 95 supports ISDN Internet connections at 64 kbps with external TAs. Software for 128 kbps is typically bundled with TAs designed for use with Windows 95. Microsoft make an ISDN Accelerator Pack for Windows 95, providing Plug and Play for plug-in ISDN cards, the ability to connect to another computer running Windows 95 using built-in Dial-up Networking features, and a version of the PPP software. You need this pack to access the Internet with a plug-in card, but not an external TA. Windows 98 supports 128 kbps Internet connections out of the box. Windows 3.1 requires software drivers and PPP software that supports high-speed Internet connections, and are typically bundled with a Windows 3.1-supporting TA. Windows NT version 3.5 or later has ISDN and PPP support built-in.

In my own experiments with a Pentium PC and Aterm IT55DSU, I found that the TA would not repsond to PPP commands when the port speed was set to 230 kbps, although it works okay at 115 kbps. I was unable to determine whether it was the serial port or TA which was at fault.

Tip: To eliminate serial-port performance bottlenecks, get yourself an ISDN router. See Routers.

Is it difficult to configure PPP software for use with ISDN?

Macintosh

If your PPP software is already configured for use with a 28.8 kbps modem, you only need to change the telephone number and modem init string parameters. Your ISP will provide the telephone number, and your TA's manual will explain the init string. There may be different init strings for 64 kbps and 128 kbps.

The following two screen shots show which parameters in FreePPP version 2.5 need to be changed for ISDN.

FreePPP phone number

FreePPP modem init string

If you are using the Apple PPP software and Modem control panel that come with Mac OS 8 or later, the installation software supplied with your TA will install an appropriate script file. Script files for pre-Mac OS 8 TAs may be available via manufacturers' Web sites.

Windows

If your PPP software is already configured for use with a 28.8 kbps modem, you only need to change the telephone number and install the driver supplied with your TA. This usually involves double-clicking the Modem Control Panel and adding a new type of modem (TA). There may be different drivers for 64 kbps and 128 kbps.

Why is a plug-in TA faster than an external TA?

Because computer serial ports tend to max out at around 115 kbps and are asynchronous, not synchronous, which means individual data bits are enclosed by additional start and stop bits and transferred at varying intervals. These extra bits can add a 10% overhead. So even with a 64 kbps or 128 kbps synchronous connection to your ISP, the connection between your TA and computer is still asynchronous. A card that plugs into your computer's internal data buses, however, takes the synchronous data right into the heart of your computer.

What ISDN plug-in cards are available?

For Macintosh computers, CSS produce the TimeLiner range of ISDN cards, which support Internet access at 64 kbps and 128 kbps. The TimeLiner 64 is available in three different bus versions--PCI, NuBus, and PDS--and supports virtually all Macs.

See the CSS Web site for a comprehensive list.

For Windows computers, NEC offer the Aterm IB55Pro for around ¥20,000 (PC/AT, PC98). It's a PCI card, supports both 64 kbps and 128 kbps Internet access, Plug and Play, and has one analog port. NEC also have the Surf-2-Surf-EZ ISA card. It has the same features as the IB55Pro, but no analog port. If you use Windows 95, look for an ISDN card that supports Plug and Play, so Windows 95 can automatically configure the card for you. Make sure you get a card that supports the type of bus used by your computer: ISA, EISA, or PCI.

How do I hookup a plug-in ISDN card?

In the United States, it is common to use just a plug-in ISDN card. In Japan, however, external TAs are more popular, and plug-in cards are used in conjunction with external TAs as shown below.

Plug-in card hookup

Unless you have an ISDN bus setup, the plug-in card connects to the S/T jack on the external TA (something else to consider when choosing a TA). Even if your TA supports only 64 kbps Internet access, you can still use a 128 kbps card.

How do I hookup a PCMCIA ISDN card?

PCMCIA ISDN cards can be connected to an ISDN bus after the DSU, or to the S/T jack on an external TA. If the TA supports only 64 kbps Internet access, you can still use a 128 kbps PCMCIA ISDN card.

PCMCIA card hookup

PCMCIA ISDN cards can also be used with NTT's ISDN public telephone boxes, which have a built-in DSU. Instructions are available in Japanese and English. Analog ports are also provided for use with regular modems.

Can I connect to NIFTY-Serve using ISDN?

Yes. NIFTY-Serve offers INS64 access in 33 locations throughout Japan through the HyperRoad64 connection points.

What do I need to connect a network of computers to the Internet via ISDN?

The simplest way to connect a network of computers to the Internet is via a dial-up ISDN router, which connects to your network using standard Ethernet, as shown below.

ISDN router network

Do dial-up ISDN routers have any other benefits?

Yes. Since the connection to your computer is via Ethernet, typically a 10 Mbps connection, serial-port performance issues are eliminated, valuable serial ports are free for other duties, and you can connect an entire network of computers to the Internet via a single dial-up connection.

What do I need to use an dial-up ISDN router?

An Ethernet network. Macintosh computers have always had networking built-in and newer models come with 10base-T ports as standard. PCs require plug-in Ethernet networking cards. ISDN routers typically have 10base-T Ethernet ports.

Do I need to use PPP software?

No. The dial-up router automatically connects to the Internet when a user on the network tries to access an Internet service, such as the Web or e-mail, and automatically disconnects after a specified time of inactivity.

Who makes dial-up ISDN routers?

Here's some blurb on the NTT MN128-SOHO dial-up ISDN Router that we use at the office.

The NTT MN128-SOHO ISDN Router (around ¥50,000) available with and without a DSU can be used as a regular TA connected to a computer's serial port, or as a router on an Ethernet network. AutoNAT (Network Address Translation + IP Masquerade) means that several computers can connect to the Internet simultaneously using a single dial up account and IP address. The included CD-ROM contains setup utilities for both Mac and Windows, a PDF version of the manual, Internet Explorer, Acrobat Reader, plus several other utilities. Quick setup involves entering the telephone number of your ISP, your user ID, and an IP address. Up and running in minutes! Not that you'll need a Japanese-capable Web browser in order to display the setup pages, which, by the way, are stored inside the MN128 as HTML pages. Apparently, you can also use Telnet to set it up.

The NTT MN128 range of ISDN routers contains several models to suit various applications.

Are there any software solutions for sharing a Net connection?

Yes. For Windows 95/98/NT, see Proxy Server Tools. For Macintosh, see the Vicom Internet Gateway.

What is OCN?

OCN (Open Computer Network) is NTT's Internet access network, providing dial-up Internet access for ¥2,300/month for up to 15 hours (¥1/minute thereafter), or a dedicated 128 kbps ISDN connection for only ¥38,000/month, including all usage charges. The latter service, called OCN Economy, is ideal for those looking to setup their own e-mail and Web servers, and is the cheapest dedicated Internet connection service in Japan.

Does anyone else offer dedicated 128 kbps services?

Yes. Japan Telecom offer ODN (Open Data Network) for ¥34,900/month, and DDI offer DION (DDI Integrated Open Network) for ¥32,900/month.

<--Previous TOC Home Next-->

Created: 16 May 1997. Modified: 26 October 1998.
Copyright (c) 1998 Paul Findon. All rights reserved.