[asterisk-ss7] libss7: Status update (ANSI works!!!!!)

[Matthew Fredrickson]

Hey all, long time no see, but I just wanted to give a status update on 
what is going on with libss7.  Last week I was able to commit my alarm 
detection code (in case you get an alarm on your spans that have 
signalling channels). It should restart the link when it comes out of 
alarm fine.  I think I need to get some more testing in though, since I 
mostly just wrote the code and did very rudimentary testing on it.  I 
also just added today support in zapata.conf for national_spare and 
international_spare networkindicator options in case your link uses the 
spare network  indicator values (someone on the list today had a 
problem with that).

On an entirely different note, I got an ANSI style link working this 
week!!!!  I didn't ask permission to see if they minded being 
mentioned, so I won't mention any names for now, however it was a night 
to remember.  It was over a 56kbps link channel, using an older switch. 
  It went surprisingly easier than I thought it would.  MTP2 was already 
working well, MTP3 only had slight modifications, and ISUP had the most 
changes.   Other than the fact that I'd never seen a 56kbps link 
before.  Basically, the difference was that they don't use the top bit 
in a DS0 timeslot for HDLC code.  So if you want to try out libss7 on 
your ANSI link, this is how you do it:

Disclaimer: You have to be using either a TE2xxp or TE4xxp for this to 
work, since I used the hardware hdlc features of the framer of that 
card to do the 56kbps link.

Get current zaptel-trunk, libss7, and asterisk-ss7 from svn (You may 
also have to get libpri, I haven't checked if chan_zap compiles cleanly 
without libpri installed)
Build them, and install them.

If you are using 56kbps links, when you load the wct4xxp.ko module, you 
have to pass it the parameter hardhdlcmode=0x7f and instead of using 
"dchan" in zaptel.conf for your signalling channel, you need to use 
"hardhdlc" on that channel.

In zapata.conf, setup your link following the pattern in the sample 
zapata.conf that comes with asterisk-ss7 and set your ss7type=ansi.  
That should pretty much be it.  All the rest of the configuration is 
the same.

As always, if you have any more questions, comments, requests, or 
anything else that matter, let me know.  I'd love to get feedback.

Matthew Fredrickson