[Freeswitch-users] T1 RBS Support Revisited

Robert Dyck rob.dyck at telus.net
Fri Aug 22 08:40:30 PDT 2008


I messed up. The E lead receives signalling whereas the M lead is used to send 
to the far end.

On Friday 22 August 2008, Dennis D Hock wrote:
> Rob I believe you have the grasp of RBS.  It has nothing to do with MF or
> the type of signaling per se but rather the encoding of the signaling as
> you have described it here.
>
> Dennis Hock
>
> -----freeswitch-users-bounces at lists.freeswitch.org wrote: -----
>
>
> To: freeswitch-users at lists.freeswitch.org
> From: Robert Dyck <rob.dyck at telus.net>
> Sent by: freeswitch-users-bounces at lists.freeswitch.org
> Date: 08/21/2008 11:08PM
> Subject: Re: [Freeswitch-users] T1 RBS Support Revisited
>
> If RBS means robbed bit signalling then it is transmitted in the media bit
> stream but as the name implies it is not used for media. If I remember
> correctly the LSB from every sixth frame is robbed leaving 7 bits and 1
> faked which would probably be correct about 50% of the time. RBS introduces
> a small amount of distortion. The channel bank will use the state of the
> signalling bit to set the M lead (on or offhook ) of the appropriate
> channel. The E lead sets the signalling bit for the other direction. Think
> Ear and Mouth.
>
> MF of course is encoded into the bit stream the same as any other audio
> source. To avoid RBS, on/offhook can be transmitted using SF ( 2600 HZ ) in
> band. You would want to disable RBS in that case. Compatible equipment is
> required obviously.
>
> On Thursday 21 August 2008, Brian West wrote:
> > Isn't RBS more than just MF?  Unless I'm forgetting something you rob
> > a bit.
> >
> > /b
> >
> > On Aug 21, 2008, at 7:44 PM, John Wehle wrote:
> > >> Is there support in FreeSWITCH for MF?
> > >
> > > To answer my own question ...
> > >
> > > Perhaps I can add a ZAP_COMMAND_SEND_MF case to zap_channel_command
> > > patterned after ZAP_COMMAND_SEND_DTMF and just use teletone_set_tone
> > > to set the proper frequencies???
> > >
> > > -- John
> > > -----------------------------------------------------------------------
> > >--
> > >
> > > |   Feith Systems  |   Voice: 1-215-646-8000  |  Email:
> > >
> > > john at feith.com  |
> > >
> > > |    John Wehle    |     Fax: 1-215-540-5495
> > >
> > > -----------------------------------------------------------------------
> > >--
> > >
> > >
> > > _______________________________________________
> > > Freeswitch-users mailing list
> > > Freeswitch-users at lists.freeswitch.org
> > > http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> > > UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-user
> > >s http://www.freeswitch.org
> >
> > Brian West
> > sip:brian at freeswitch.org
> >
> >
> >
> >
> > _______________________________________________
> > Freeswitch-users mailing list
> > Freeswitch-users at lists.freeswitch.org
> > http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> > UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> > http://www.freeswitch.org
>
> _______________________________________________
> Freeswitch-users mailing list
> Freeswitch-users at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org






More information about the FreeSWITCH-users mailing list