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According to the 3COM white paper, all four pairs are used. Hybrids are used, like in a telephone, to allow simultaneous transmit and receive on each pair.

If you want a nice whitepaper/technical document on gigabit over copper/802.3ab you could do a lot worse than to check this out.

Yes, 3com makes one
3com Winmodem specs

3Com coerced a local PD into falsifying an affidavit for a search warrant of a business owned by the spouses of 3Com employees. 3Com is allowed to search the business and homes unsupervised and remove documents and materials without recording them! (as admitted by the cop "in charge" of the search)

After 2 miserably failed attempts to put the now former 3Com employees (and their spouses) in jail, a lawsuit is issued against 3Com and the local PD.

Its a very sad case and I hope these folks prevail against the huge greedy corporation. Its good reading if you can get a copy of the court documents. Its very sad that things like this go on all too often...

Besided the suggestions for the ISDN router, which are good suggestions I think some mention should be made for the external terminal adapter option. The two best IMO are the 3com impact and the zyxel omni.net plus.

This option is really appealing if you are used to POTS modems because they behave just like them. They hook up to your serial port and they have dial out commands just like modems. They work seemlessly with ppp and do not require that one get involved in any isdn4linux stuff. It isn't that the isdn4linux stuff is bad it is a little hard to work with if you don't live in europe. And the isdn4linux debate on it's regular inclusion in the linux kernel is still not completely resolved.

The reason I like both the 3com and the zyxel product is because they both have the capability to do 230kbps or more across the serial port. This is important if you want to use all 128kbps of ISDN. USB would make the whole serial port discussion a null issue but it is not quite ready in linux. The 3com impact does 230kbps and the zyxel does 460kbps. Don't let the zyxel fool you 460kbps is better then 230kbps but only marginally. Instead, let the zyxel price lure you. The zyxel is generally cheaper then 3com but has just as high customer satisfaction (I own a zyxel myself and am very happy with it).

This brings up an important point. Most serial ports have the 16550A UART which does a smashing good job of 115kbps. This is more then enough for 56K modems. But for ISDN even at 115kbps one will find that the best throughput is really only 95kbps due to overhead on the UART. And if one can make a 128kbps connection the throughput is even worse. So if you go the route I describe I suggest picking up a serial port board with a 16750 or 16950 UART. These UARTs are supported in linux kernel 2.2.x or newer. A good manufacturer is pacific commware. Their turboexpress 920 board is isa pnp which will require isapnptools and a little elbow grease. I need to stress that the newer UARTs are not supported in the older 2.0.x kernels.

And now the URLs:

• 3Com Impact IQ
• Zyxel Omninet plus
• Pacific Commware's Turbo Express 920
• Serial HOWTO
• ISA PnP tools
• Theodore Tso's serial port driver, not necessary with 2.2.x kernels.

I don't know how well Linux supports the various ISDN modems out there. I do know that I didn't want to find out.

Even in this day and age of ISDN maturity, it is still pretty darn complicated compared to POTS and a well-supported 56kbps modem.

Having said that, four months ago, I got ISDN to my home. The smartest move I made was getting a 3Com OfficeConnect ISDN LAN Modem.

The 3Com box has an ISDN input, four ethernet ports, two analog phone jacks (so you can use the ISDN for voice, too), a DHCP server and is configured using a web browser. And more!

The box plugged in, did a self-diagnostic and was ready to go. It took fewer than 15 minutes to configure it to dial my office and my ISP. The web interface is great.

It dials on demand. Since it interfaces with your Linux box over the net, there is nothing to configure (I assume you already have TCP/IP working). I've got two linux boxes and an NT box hooked into mine. If you are dialing into a 3Com system (or something compatible), it'll do hardware data compression and a few other nifty features (light traffic over the D channel (DNS, etc.) so as to connect time (ie: money) on the B channels).

The list price is just under $400 which may seem a bit high compared to a $250 ISDN modem. I assure you, however, it's the quickest, easiest and most reliable way to get ISDN up and working.

Disclaimer: I don't have anything to do with 3Com, I just really like this product.

InitZero

The 3Com 5610 for example, has been verified to work in Linux.

A HOWTO for mapping PCI modems to the /dev/modem port and a list of PCI non-winmodems can be found on the PCI modems and linux page.

I believe 3com's "Internet Gaming Modem" fits the bill.

Also, external modems are pretty decent, although the UART on your standard motherboard may not be able to make the most of a compressed 56K connection.

Why not mail 3com's linux drivers address, and thank them for all their hard work?

Here, I'll make it easy for you all. linux_drivers@3com.com.. I've already sent them mail thanking them for releasing the source under the GPL, and affirmed that they'll be part of my next purchasing list because of it.

This sort of positive advocacy is what Open Source really lacks; so, come on, click through and mail!

3COM has an x86 implementation of IEEE 802.11 called AirConnect

I guess this is interesting because it's Open Source, but nCipher has been making chips that do 300 RSAs/s. 3Com recently announced an Ethernet card with a built-in crypto processor that does 3DES and TCP segmentation/reassembly/checksumming. They claim that using IPsec and this card results in no network slowdown, so presumably it can encrypt and decrypt at 100Mbps.

It's quite clear from the document linked above that the lawsuit is being settled.

All vendor/consortium links I'm afraid...

• 3Com, "Gigabit Ethernet Comes of Age" http://www.3com.co m/technology/tech_net/white_papers/503003.html
• 3Com, "ATM LAN Emulation", http://www.3com.com/nsc/500617.html
• ATM Forum, http://www.atmforum.com
• Gigabit Ethernet Alliance, http://www.gigabit-ethernet.org
• Cisco ATM switching overview, http://www.cisco .com/univercd/cc/td/doc/cisintwk/ito_doc/55755.htm
• Cisco Introduction to Gigabit Ethernet, http://w ww.cisco.com/warp/public/cc/cisco/mkt/switch/gig/t ech/gigbt_tc.htm

All vendor/consortium links I'm afraid...

• 3Com, "Gigabit Ethernet Comes of Age" http://www.3com.co m/technology/tech_net/white_papers/503003.html
• 3Com, "ATM LAN Emulation", http://www.3com.com/nsc/500617.html
• ATM Forum, http://www.atmforum.com
• Gigabit Ethernet Alliance, http://www.gigabit-ethernet.org
• Cisco ATM switching overview, http://www.cisco .com/univercd/cc/td/doc/cisintwk/ito_doc/55755.htm
• Cisco Introduction to Gigabit Ethernet, http://w ww.cisco.com/warp/public/cc/cisco/mkt/switch/gig/t ech/gigbt_tc.htm

3Com don't exactly ignore Linux at the moment, but it will be nice if they confirm this story with a press release.

Also on that site is an interview with Martin Butler (a well-known UK Linux basher/FUD-flinger/agent of influence for M$) entitled Lambasting Linux. I've got to admit that I'm actually beginning to look forward to this guy's comments - he's continually predicting Bad Things for Linux and of all the things he's said over the last year, the exact opposite has happened. Keep up the good work, Butler! :-)

Dodger

I found it here if anyone's interested.