Wed, 11 Jul 2018 21:15:59 +0000 (UTC) Stuart Henderson <s...@spacehopper.org> > On 2018-07-11, Tom Smyth <tom.sm...@wirelessconnect.eu> wrote: > > Hello all, > > > > this is an odd one but I have a client that needs to > > migrate some legacy services > > Is there support for ISDN type interfaces in OpenBSD ? > > > > man / apropos shows nothing > > > > or is there a package that would add ISDN support > > (although I didnt see a package containing isdn or ISDN > > in packages) > > is ISDN support available under a different name by any chance > > > > Thanks > > > > Tom Smyth > > > > > > ISDN covers various things, data/voice, and various types of line > (BRI = 2 64k data/voice "B" channels plus one signalling "D" channel .. > PRI = up to 30 B channels over an E1/T1 circuit).
Hi Tom, Mandatory reference material to restore retro knowledge where applicable. Integrated Services Digital Network (elements) https://en.wikipedia.org/wiki/Isdn#ISDN_elements BRI (2B+D) https://en.wikipedia.org/wiki/Basic_Rate_Interface PRI (30B+2D) https://en.wikipedia.org/wiki/Primary_Rate_Interface > Would need more information about what the "legacy services" are before > it's possible to make any kind of suggestion (but apart from some data > services on BRI which might work with an async TA, it's not really going > to involve OpenBSD in directly terminating the ISDN). There are both external and internal modems for BRI ISDN, with similar to the analogue (ISDN is digital) modem caveats. External modems use HAYES, https://en.wikipedia.org/wiki/Hayes_command_set#The_basic_Hayes_command_set command set (AT commands) and can do bonding at ISDN level so you get the 128 kbps as advertised when using both B channels. I've successfully did a number of deployments using Zyxel external modems which could be bought in stores as CPE (Client Premises Equipment) just as the other modems but at a considerably higher cost. The nice part of the ISDN setup were that you could pick up the phone and the modem would go single channel auto as the D line for signalling handles these, and you can get a micro ISDN PBX setup with the 2 lines for up to 8 phone lines of the "cheapest" models.. There are also internal cards, Fritz! AVM is one notable brand of devices AVM (BRI ISDN PCI cards) https://en.wikipedia.org/wiki/AVM_GmbH#Products both hardware and software based sets (the soft WOULDN'T work) which were possible to get to work yet very unreliable. As for the PRI ISDN, I have done only a couple of deployments for considerably high costs (300 EU/mo) local fees + activation (2x) and it is terminated by the TELCO as E1 line 2048 kbps most typically as HDSL2E1 termination for PBX E1/PRI interfaces so this provided 30 incoming and outgoing concurrent digital phone lines. You'll probably never have the chance to use PRI these days as faster and newer less complicated (and expensive) subscriber lines do the last mile. The time frame this got obsoleted is 2005 here in the SE EU with the mass avail of inexpensive ADSL broadband for the general population all towns. The most looked after feature was the synchronous data line rates for BRI and the almost instantaneous dial (digital signalling) connection set up, which I was typically configuring as dial-on-demand (at the gateway PC).. In Germany (where I worked at the time) ISDN lines were also used as ADSL due to the reliable and fast operation (digital lines) and similar costs. As a closing line (pun intended) the ISDN is considered obsolete in 2018. Kind regards, Anton Lazarov
