ISP Japan FAQ : ISDN Appendix

ISP FAQ Top Page ISDN Appendix

F Let's ISDN: If you can't get ADSL, FTTH Optical fiber or CATV Cable in your area, then NTT plus provider charges for unlimited 24-hr. 64K "F Let's ISDN", formerly called "IP connection service", are about the same: NTT charges ¥2,900/mo., and the ISP charges a fixed sum – as low as ¥200/mo. for NTT-East Plala, ¥300/mo. for Alpha, ¥ 450/mo. for Asahi-Net, ¥800/mo. for NTT-ME WakWak, but typically ¥2,000/mo. unlimited (typically permits dial-up or mobile phone access from other areas as well as unlimited hours). You are given the phone no. of a local NTT server & can log on to, i.e. switch between, different providers if you wish, (NTT-East has convenient free (optional) FLet's Manager dialer software for Windows-J & Mac, for this purpose), but can still use dial-up ISDN as before. In July & August, service was expanded by NTT-East & NTT-West to cover major cities from Hokkaido to Kagoshima, and again by East Japan from Jan. thru' Mar. (mainly in Kanagawa, Chiba, Tochigi). You can check if your area is supported by NTT-East ( check Tel. no. ) or NTT-West Not necessarily static IP except for ODN's "Always" service. Providers...

English-language resources include Paul Findon's ISDN-J FAQ, [in Tokyo, Bricks will handle ISDN application procedures for you]. Dr. Jeffrey Race's Thai ISDN FAQ.

Why is ISDN better than an analog line? Read the pioneering ISDN-J FAQ.
Shorter connection setup time. Connecting can take 20-40 sec. with a modem, but just a few seconds with ISDN.
Faster data throughput. It might seem that a 56K asynchronous analog modem would provide similar throughput to a single 64K synchronous ISDN channel. In practice, however, 64K ISDN is about two or three times as fast as an analog modem (maybe providers restrict modem throughput to 33.6 Kbps?)
Two independent channels (e.g. for data and phone) on your existing phone line. ISDN BRI (Basic Rate Interface) uses your existing phone line to provide two 64 Kbps B-channels that can operate simultaneously, so you can use phone or fax on one channel while you are surfing the Internet on the other channel.
Cheaper than two analog lines, and costs little to switch from analog to ISDN. The base rental for your two ISDN channels (NTT's INS64) is about the same as paying for 1.5 analog lines. If you do the setup, it can cost as little as ¥2,800 (plus TA, another ¥20,000 or so, see below) and take under two weeks for NTT to switch an analog line to ISDN.
Different telephone numbers for phone and fax, without an extra line. i-Number service gives an extra number for (Yen) ¥300/month – e.g. for a fax – (or two for ¥400) but you can't use them simultaneously. An extra no. that can be used simultaneously costs ¥900/mo. You can have three nos. corresponding to the three analog ports on most ISDN TAs. Some TAs can be cascaded to expand the number of ports.

Can I still fax from my fax modem? (Will I still need it?) You can connect your fax modem to an analog port on the ISDN TA. Alternatively, you can use a fax service like efax; or Net2Fax (bundled with the Net2Phone software) (the software is like a "fax printer" driver, and the fax is sent via a Net2Fax gateway to a fax machine).

What hardware do I need for ISDN? Most ISDN TAs (Terminal Adapters) include built-in DSU which terminates the ISDN line at the customer site; the TA provides DA (digital-analog) & AD conversion for analog telephone, fax or modem, & 64K synchronous to RS-232C serial asynchronous or USB data connection. Major suppliers: NEC, NTT-ME. More...

TA hardware. Basic TAs like NEC IT60L/D or IT21L have two data ports (one USB, one RS-232C), which can't be used simultaneously, and two analog ports. If the TA supports three analog ports (or multiple "child" PHS mobile phone connections), your TA may have intercom/PBX functions to transfer phone calls between ports and set up conference calls; most TAs can be daisy chained to give more analog ports (or PHS nos). High-end TAs like the NEC ITX80/D come with two USB data ports and allow Windows NetBEUI file-sharing / printer-sharing networking between them (Ethernet cards not required). Such TAs support multilink or BOD (see below); some even permit simultaneous connections to two providers. Multi-port TAs have router functions to support Internet connection sharing (ICS): 2 or 3 users – connected to USB/RS-232C, PHS or other wireless LAN cards – sharing an Internet connection (and mapping public IP address to multiple private) by NAT/PAT Network/Port Address Translation with DHCP automatic IP address (and gateway address) assignment. Combination TA–router–(four-port, 10 Mbps) Ethernet hubs are also available, e.g. NEC's IR450 or NTT's MN128 SOHO series. NEC's IWX70 is a combination TA and 64K PHS (voice/data) base station. Some TA/routers, like the Melco ("Buffalo") WLAR-128G and Yamaha NetVolante RTA54i/RT60w are also compatible with ADSL/CATV. Note: ISDN Multilink (2-channel, 128K data) and BOD (Bandwidth On Demand: autoswitch from 64K (one channel) to 128K (two) when channel usage is near capacity, and automatic fall back) are not supported by many ISPs. Battery backup (so you can use the TA if power ever fails) is another option in some TAs – however, your phone may not work without power.

Do all ISDN TAs work with PCs and Macs? Old PC and Macs? FLet's ISDN? NEC and maybe NTT generally provide software and cables for both PC and Mac. Check whether your PC or Mac has USB or just RS-232C serial communications port for the data connection. Most TAs support both. Old PCs and Macs have just RS-232C. TAs behave like modems; if you get a TA with RS-232C serial port, and know the 64K synchronous (provider) to asynchronous (computer) AT command string (it's AT$N1=1 for most Japanese TAs, see GOL for list) then you can use a TA with an old 68040 Mac: though throughput may be a bit less than is possible, it is considerably faster than with a modem. For a Windows PC with RS-232C serial port, all you need is the TA INF file (search for *.INF, maybe MDMNIT.INF for an NEC TA, on the disk supplied with the TA). For F Let's ISDN, check that your TA/router is on the approved list; Mac users may need to use FreePPP. Likewise, for certain DSL modems/ISDN TAs there may not be USB driver support for Macs or Win2000, etc. For a Windows PC, all you should need to do is to point Windows to the location of the serial communications port INF file (as mentioned above) or USB INF (and associated VXD/SYS) driver files on the disk supplied with the TA/modem.

Is English software available for my ISDN TA? For a Mac, there may be a script file (corresponding to the modem INF file in Windows) plus a USB (driver) extension, and English Mac users get Japanese Language Kit (optional install) with Mac OS9. Software to configure the analog ports, and software to update the TA firmware in flash ROM, is Japanese only. For NEC TAs, it is also possible to configure the analog ports (e.g. assign different phone numbers to different ports) by dialing commands from a telephone – but manuals are in Japanese. NEC BigLobe setup service. NEC help number is 0120-361-138, NTT is 0120-109-217 – but be prepared for a long wait. While some ISPs supply Japanese "easy setup" programs, you can set up your PPP dialler and TCP/IP settings manually.

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