Summary:	DAHLIN-00265: sf in-band signalling does not work with any version of DAHDI's dahdi_cfg
Reporter:	Don Froula (donf99)	Labels:
Date Opened:	2011-11-12 09:53:44.000-0600	Date Closed:	2012-04-06 18:10:27
Priority:	Major	Regression?
Status:	Closed/Complete	Components:	dahdi (the module)
Versions:	2.6.0	Frequency of Occurrence	Constant
Related Issues:	duplicates DAHLIN-00166 Support for single freq signaling does not appear to exist is duplicated by DAHLIN-00335 DAHDI SF signalling does not function as described in documentation
Environment:	astlinux-0.7.10, asterisk-1.4.42	Attachments:
Description:	Currently, I'm running Asterisk/Zaptel 1.2.1. The original set of patches I applied enabled proper operation of "sf" in-band signalling in Zaptel. This required compiling and installing the "ztcfg-dude" package, which properly sets up sf in-band signalling. The regular "ztcfg" command, used to start Zaptel, did not support any of the sf signalling variants mentioned in sample zaptel.conf file. With the move to dahdi from Zaptel, the ztfg-dude functionality appears to have been dropped completely. However, support for sf in-band signalling is still referenced in the sample "/etc/dahdi/system.conf" file (that took the place of zaptel's zaptel.conf). In dahdi, "dahdi_cfg" has replaced "ztcfg". It does not support sf signalling either. It appears there is no possible workaround in dahdi, due to the removal of "ztcfg-dude" functionality. Example "/etc/dahdi/system.conf": =================================================== ; Channel(s) are signalled using in-band single freq tone. ; Syntax as follows: ; channel; => sf <rxfreq>,<rxbw>,<rxflag>,<txfreq>,<txlevel>,<txflag> ; ; rxfreq is rx tone freq in Hz, rxbw is rx notch (and decode) ; bandwith in hz (typically 10.0), rxflag is either 'normal' or ; 'inverted', txfreq is tx tone freq in hz, txlevel is tx tone ; level in dbm, txflag is either 'normal' or 'inverted'. Set ; rxfreq or txfreq to 0.0 if that tone is not desired. ; =================================================== ... and in chan_dahdi.conf Example: =================================================== ; sf: SF (Inband Tone) Signalling ; sf_w: SF Wink ; sf_featd: SF Feature Group D (The fake, Adtran style, DTMF) ; sf_featdmf: SF Feature Group D (The real thing, MF (domestic, US)) ; sf_featb: SF Feature Group B (MF (domestic, US)) =================================================== See http://lists.digium.com/pipermail/asterisk-dev/2009-December/041277.html for a bug report concerning this. Using Astlinux, I attempted to get sf signalling working over TDMoE. This worked fine for E&M signalling, but "dahdi_cfg" refused to recognize sf signalling and it's arguments in "/etc/dahdi/system.conf". Has anyone found a workaround in dahdi for this? I realize in-band sf signalling is seldom used over T1/TDMoE, but I am surprised that support for it seems to have been dropped completely.
Comments:	By: Shaun Ruffell (sruffell) 2012-04-06 18:10:27.550-0500 Don, I looked at the ztcfg-dude source in zaptel and it doesn't compile cleanly, and I'm not sure about the license to the code for the notchfilter that is included. So, there seems to be a bit of work in order to forward port that to DAHDI. I'm going to close this for now since for it to move forward someone will probably need to step forward with a tested patch. Sorry.