ISDN drivers for AVM B1 and Fritz cards

Today I read a few postings in the Yellowtab forum which reminded about my project to write an ISDN driver for BeOS.

For those who can read german, the complete thread is here. In a nutshell, Bernd Korz, CEO of Yellowtab, is publically saying they have been geschädigt und verarscht genug (been harmed and spoofed enough) by AVM, and that there won't be support for AVM products in Zeta for at least the next 20 years. AVM is the manufactorer of ISDN and DSL hardware.

It was in 2001, Yellowtab was just founded, Be Incorporated was still in business and busy developing BONE (BeOS new network stack), and there was no Zeta yet. BeOS R5 was still using net_server, but I was on the BONE beta program, and had access to both. Be Inc had released a beta driver for AVM B1 cards (which didn't work for me), but it was rumored that they had no permission to use the sourcecode from Marco Borm on which it was based on. At that time Marco Borm made his sourccode public, and Be Inc never ever updated their driver.

After I talked with Bernd Korz about it, I decided to try again writing a ISDN driver for BeOS. AVM provided four ISDN cards for development to Yellowtab, two active B1 cards, and two passive Fritz cards. I got one of each. My intention was to get the simple active B1 card working first. Useful documentation for the B1 card was made available, too.

The project progressed pretty fast, and after a few weeks, the card specific driver was finished. Dialing a provider's telephone number worked, and PPP frames were transmitted into both directions. I was pretty happy.

Unfortunately, net_server did crash pretty easily when dealing with PPP frames received from ISDN, and a handshake never worked. Obviously, the net_server PPP stack didn't support the synchronous PPP as used with ISDN, while it did support asynchronous PPP as used with modems.

Because of the ongoing BONE beta programm, I tried to interface the ISDN driver with the new BONE network stack. There a huge bug emerged. BONE was using 100% CPU at a very high priority when reading from the emulated serial port that the driver provided. The same problem did not happen with net_server, but it made further development pretty impossible.

To cut a long story short, it was impossible to get any support from Be Inc. that would allow to solve the problem. Development was stalled. Trying again with net_server seemed to be a bad idea, because it was meant to be replaced by BONE. Shortly after that, Be Inc went out of business, and any further development wouldn't have been useful for me. In fact, now that Yellowtab is selling Zeta, I don't even have ISDN anymore, as I'm using DSL.

When development was cancelled, I passed all sourcecode to Yellowtab, hoping they could one day continue it. Now that they are developing Zeta, and seem to have all the sourcecode for the OS, I think it should be pretty simple for them to get the AVM B1 driver that I wrote to work with Zeta's network stack, which is BONE. But the comments made by Bernd Korz in the Yellowtab forum show a completely different direction.

I think Bernd Korz is acting very childish here, and not like a business person. I can truly understand why AVM doesn't like cooperating with Yellowtab anymore. In 2001, AVM gave cards to Yellowtab, but without return. A stable BeOS AVM B1 driver never got published.
I don't know what happened recently between Yellowtab and AVM. But a company's CEO who gives negative statements like this in a public forum isn't someone you can deal with and do business.

Beeing the single developer who, closely cooperating with Yellowtab and supported by AVM, tried to help bring ISDN support to BeOS in 2001, I'm very sad about this outcome.

I really regret having been involved with Yellowtab in this case, because AVM has probably blacklisted my name by now, due to the fact that Yellowtab doesn't behave in a businesslike manner.