asterisk users - Jul 2011 - Redirecting call from one E1 to another?

I'd be grateful if anyone here could comment knowledgeably on an idea
that I have had, as to whether it should be possible or not.

Consider two Asterisk boxes, each with one or more E1s on EuroISDN.
Each box has a different telephone number that hunts across all its
E1 channels. In addition there is another number that hunts across
all the channels on all the boxes.

A call comes in to one of the boxes and is answered. After some
interaction with the caller, the box decides that the call needs
to be handled by the other box.

I don't want just to relay the call through to the second box using
IAX or SIP or an additional PSTN channel. What I would like to do is
to redirect the call in the PSTN so that it ends up connected only to
the second box. That is why each box would have its own telephone
number as well as the global access number for all boxes.

Obviously, as well as the ability to redirect the call transparently
to a channel on the second box, I also need the second box to be able
to identify that this call is redirected, and not a fresh call from
outside. Presumably I sould use CLI in some way, and/or perhaps
USERUSERINFO.

Is the above possible using ISDN? If not, would it be possible using
SS7? Is SS7 support still active in Asterisk?

Any insight would be appreciated!

Cheers
Tony

-- 
Tony Mountifield
Work: tony at softins.co.uk - http://www.softins.co.uk
Play: tony at mountifield.org - http://tony.mountifield.org

Tony Mountifield wrote:
> I don't want just to relay the call through to the second box using
> IAX or SIP or an additional PSTN channel. What I would like to do is
> to redirect the call in the PSTN so that it ends up connected only to
> the second box.
If I recall correctly, it's only possible if the provider has a DMS-100

http://www.voip-info.org/wiki/view/RDNIS

Doug

-- 

Ben Franklin quote:

"Those who would give up Essential Liberty to purchase a little Temporary
Safety, deserve neither Liberty nor Safety."

In article <296076780.5348.1310743930593.JavaMail.root at zimbra>,
Richard Mudgett <rmudgett at digium.com> wrote:
> > I would suggest Two B-Channel Transfer (TBCT), transferring to a
> > unique
> > number (received as DNIS by the other server) that would identify the
> > call
> > as transferred from the first server and, perhaps, the reason for the
> > transfer.
> > 
> > It looks like TBCT may not have been implemented in Asterisk for
> > EuroISDN.
> > 
> It is implemented in EuroISDN(ETSI).
> You need Asterisk 1.8 and libpri 1.4.12 to take advantage of the feature.
Thanks. I had just a moment ago found the ETSI spec and then the libpri
file rose_etsi_ect.c, so I was almost there!

Does Asterisk implement actioning an ECT from the remote end (so as to
test with back-to-back Asterisks), or just support generating an ECT?

Cheers
Tony
-- 
Tony Mountifield
Work: tony at softins.co.uk - http://www.softins.co.uk
Play: tony at mountifield.org - http://tony.mountifield.org

> In article <296076780.5348.1310743930593.JavaMail.root at zimbra>,
> Richard Mudgett <rmudgett at digium.com> wrote:
> > > I would suggest Two B-Channel Transfer (TBCT), transferring to a
> > > unique
> > > number (received as DNIS by the other server) that would identify
> > > the
> > > call
> > > as transferred from the first server and, perhaps, the reason for
> > > the
> > > transfer.
> > >
> > > It looks like TBCT may not have been implemented in Asterisk for
> > > EuroISDN.
> > >
> > It is implemented in EuroISDN(ETSI).
> > You need Asterisk 1.8 and libpri 1.4.12 to take advantage of the
> > feature.
> 
> Thanks. I had just a moment ago found the ETSI spec and then the
> libpri
> file rose_etsi_ect.c, so I was almost there!
> 
> Does Asterisk implement actioning an ECT from the remote end (so as to
> test with back-to-back Asterisks), or just support generating an ECT?
> 
Yes, it does both ends.  ETSI is the only switchtype that libpri implements
initiating ECT and accepting ECT.  Asterisk can initiate ECT to eliminate
a tromboned call if the call is natively bridged and chan_dahdi.conf
transfer=yes is configured.

Richard