[asterisk-bugs] [Asterisk 0015175]: [patch] v.110 dialin support for ISDN channels

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
====================================================================== 
https://issues.asterisk.org/view.php?id=15175 
====================================================================== 
Reported By:                dwmw2
Assigned To:                
====================================================================== 
Project:                    Asterisk
Issue ID:                   15175
Category:                   Applications/NewFeature
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     new
Asterisk Version:           SVN 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
====================================================================== 
Date Submitted:             2009-05-22 03:04 CDT
Last Modified:              2009-05-26 04:02 CDT
====================================================================== 
Summary:                    [patch] v.110 dialin support for ISDN channels
Description: 
Many years ago I wrote app_v110.c for use with mISDN channels. It was
included in the Beronet app_bundle which I thought they were going to
submit after chan_mISDN was merged:
http://www.asteriskguru.com/archives/asterisk-dev-re-chanmisdn-in-asterisk-beta-2-vt60496.html#170458

Someone's now made it work with Zap channels too, and is asking why it
didn't get merged.

I'll attach my original code for reference and state that I have a
disclaimer on file. Hopefully I can let the person who ported it to Zap
take care of submitting an up to date version which is tested with current
Asterisk code.
====================================================================== 

---------------------------------------------------------------------- 
 (0105381) dwmw2 (reporter) - 2009-05-26 04:02
 https://issues.asterisk.org/view.php?id=15175#c105381 
---------------------------------------------------------------------- 
I have a vague recollection that when I first wrote app_v110, I was having
to flip the bits too. I think they come in from the hardware "backwards",
which is actually the way we want them for app_v110. And chan_mISDN was
reversing them to be "correct". I think that it was the
'MISDN_DIGITAL_TRANS' variable we set before accepting the call which
disables the bit-flipping.

This is probably all different now that chan_mISDN is deprecated by
chan_lcr.
I don't know whether app_v110 is still working with LCR. (I did make a new
box to take over from my ancient Asterisk installation, but got sidetracked
after realising that chan_misdn no longer exists and I have to set up LCR
to run in parallel with Asterisk.)

I optimised the bit manipulation routines to cope with
'backward-bit-endian' data; there will be more efficient ways to handle
normal data than just bit-flipping all input and output from the existing
code. 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2009-05-26 04:02 dwmw2          Note Added: 0105381                          
======================================================================