[Asterisk-Dev] Announcing chan_ss7, a GPL'ed SS7 channel driver

[Kristian Nielsen]

Over the last few months, Sifira A/S has been implementing an SS7
channel driver for Asterisk, called chan_ss7. The channel driver works
with Digium E1 cards. The licence for the channel driver is GPL.

We are now ready to release the first public version of the code. The
purpose of this release is mainly to let people know what we are doing,
and to allow other developers with an interest in an Open Source SS7
driver to join forces with us.

I would encourage anyone interested in this, who has the necessary SS7
and Asterisk skills and access to SS7 equipment, to try the code and to
send us a note about their interest. The source may be downloaded from

    http://www.sifira.com/chan-ss7/

To compile it, a recent CVS HEAD version of Asterisk is needed. Success
or problems can be reported to

    chan-ss7 at sifira.dk

The current state of the code supports voice curcuits on one or more E1
links with a single timeslot 16 signalling link. Incoming and outgoing
calls are working. There's a good framework in place for handling the
MTP2/3 and ISUP layers. It should be fairly simple to add any missing
stuff to this, bit by bit, as the need arises.

Our plan is to extend chan_ulv to support a cluster mode, where two
Asterisk boxes running chan_ulv shares a single SS7 point code, with one
link on each box making a redundant link set. The two instances of
chan_ulv will then do heartbeat monitoring of each other, so that if one
box goes down the other can do automatic MTP3 failover and block the
dead voice curcuits on the ISUP level, thus eliminating single point of
failure for the system. However, none of this cluster mode has been
implemented yet.

 - Kristian.

-- 
Kristian Nielsen   kn at sifira.dk
Development Manager, Sifira A/S