Re: Std. Serial ports beyond 115K?

[Jens B. Jorgensen]

Yeah Kevin, you can get standalone boxes which do ether-isdn and will dial/bandwidth on demand, etc. However, these nice little jobs will run you at least $300. A waste suitable only for buying hardware with other people's money. I *have* used one (the Ascend Pipeline 50) and loved it at a previous job. Now, I too am actually in the market for a higher-speed ISDN configuration. So here's the deal. Modern 16550A serial ports don't do more than 115.2kbps even though theoretically the 16550A can go up to 460.8kbps (the chip uses an input signal which is divided to come up with the reference signal driving the bit rate, and these chips don't have a driver signal which is high enough). There are boards on the market that use a Startech 16650 which not only have driving signals high enough to supply 460.8k but these chips also include a larger (32-byte, IIRC) fifo to help out as well. A quick lookup on shopper.com finds a single port 9-pin ISA 16650 adapter mfgr Lava available for $21.97 ($2.35 shipping, reportedly) from CDworld. Actually, the last time I looked the cheapest board I could find was a BOCA and it cost $50. I may just buy one of these. One last note though, you'll want the 2.2.X kernel because although the older driver in 2.1.34 supports the 16650 it disabled the FIFO in one direction (I can send send you more info about this if you're interested, I had a little email with Mr. Xu who wrote the driver). Finally, as for myself I'm sick eia-232 performance and would *really* like to get a USB TA. Unfortunately the USB support for Linux is still in its infancy. Kevin Traas wrote:  My big thing is that I want/need Dial- & Bandwidth-on-Demand support - very big requirements.   I don't think these little ISDN routers provide the level of control that I want.  (If you know different, please let me know.) Later,Kevin  -----Original Message----- From: Dimitri Patakidis <[EMAIL PROTECTED]> To: Kevin Traas <[EMAIL PROTECTED]> Cc: debian-user@lists.debian.org <debian-user@lists.debian.org> Date: Tuesday, February 23, 1999 8:17 PM Subject: Re: Std. Serial ports beyond 115K?  Hi there Kevin :) The best way to get the most bang for your ISDN buck is to use an ISDN router. ISDN IN ---> ETHERNET OUT No RS-232 translation in between. Now if I could find someone to sell my external BitSurfer, I would probably go with that :) Dimitri       At 07:34 PM 02/23/1999 -0800, you wrote: >>>> <?fontfamily><?param Comic Sans MS>I want to connect an external ISDN to my system using the MB's standard serial ports. However, everything's telling me I can only push 115K through these serial ports - far less than the theoretical max of an ISDN TA that does V.42bis. <?/fontfamily> <?fontfamily><?param Comic Sans MS>Any comments/suggestions on "overclocking" ;-) built-in serial ports to 230 (or 460) Kbps? <?/fontfamily> <?fontfamily><?param Comic Sans MS>Note: I realize that HS serial ports/boards are available, but I don't want to shell out the money if I don't have to.... Note2: If you can recommend a good external ISDN TA (North America) or an internal that supports DialD, I'd love to hear from you. <?/fontfamily> <?fontfamily><?param Comic Sans MS>Thanks, Kevin <?/fontfamily> Attachment Converted: "c:\PACDIAL\MIRC\dimitri\attach\Kevin Traas1.vcf"   <<<<     -- Jens B. Jorgensen [EMAIL PROTECTED]