Some lessons I learnt the hard way :

A GUI

If you installed a GUI, deinstall it. If you have the GUI config and installation in  a backup : remove it from the backup also. Then, print the GUI sources, and shred them. Really, do so. If you have a real problem, and a GUI, and no knowledge of Asterisk, you’re totally screwed.

The hardware

First, make sure Asterisk knows your hardware. dahdi_hardware should give some output. If it doesn’t, reinstall the kernel drivers, and make sure that the driver is loaded. I used the .src.rpm for building those, but the instructions at https://wiki.asterisk.org/wiki/display/AST/Building+and+Installing+DAHDI also work.

Load the kernel drivers : I needed to load wcb4xxp and dahdi.

Asterisk software

I installed Asterisk 10.6, using a homebrew RPM. No special reason for this version : It was the latest available.

Configurating Asterisk

First, I ran dahdi_genconf, that took care of configuring all 4 spans.
My chan_dahdi.conf looks like :

[trunkgroups]

[channels]
; Deprecated, don't use it
[lines]

echocancel = yes
echotraining = yes
signalling = bri_cpe
callerid = asreceived
context = bri-incoming
group = 1
channel = 1,2
channel = 4,5
dahdichan => 1,2,4,5

The SIP phones also need config. This is done in /etc/asterisk/sip.conf :

[jdioffice](!)
type=friend
context=sipphones
host=dynamic
nat=no
dtmfmode=auto
disallow=all
allow=ulaw
allow=g722
allow=g729
qualify=yes
language=nl

[00085D3XXXXX](jdioffice)
secret=mysecret

This gives us two asterisk contexts : sipphones, and bri-incoming. You need these to tell Asterisk what to when a call comes in or goes uit on a certain context.

I use a LUA based dialplan : I know how to code, and that gives me an extensions file that is a whole lot better to read then the ‘traditional’ Asterisk dialplan config.

Entrypoints are in a table :

extensions = {
  -- Incoming calls
  ["unauthenticated"] = {
    ["_."] = e_drop_call
  };

  ["sipphones"] = {
    ["_#NXX"] = e_hotdesk_login,
    ["_#000"] = e_hotdesk_logout,
    ["_0X."]  = e_outgoing_sip,
    ["_NXX"]  = e_internal_sip,
    ["112"]   = e_outgoing_emergency,
    ["911"]   = e_outgoing_emergency,
    ["_*."]   = e_dial_custnr,
    ["_**."]  = e_dial_employee
};

  ["bri-incoming"] = {
    ["_X."]   = e_incoming
  };

  ["default"] = {
    include = { "unauthenticated" }
  };
}

You can clearly see the context, and the resulting mapping. All names are actual lua functions, which take a context and extension as a result.

Next post : More on the dialplan, things I’ve run into, and the solutions, if available.

Now, people share a phone. Not something we want. The Siemens PBX is also as extensible and flexible as solid concrete. We had 2 options :

• Buy a new PBX from Siemens (Siemens phones only work on a Siemens PBX)
• Throw everything out, and start from scratch with a VOIP based solution.

After receiving the offer for the Siemens PBX, recovering from falling of my chair, and being resuscitated by one of my collegues, I decided to start from scratch with a VOIP solution. We soon ended up with :

• Asterisk as the software platform
• A Digium B41oP 4 port Euro ISDN card
• Aastra 6757i SIP phones

Hardware was quickly ordered. I’ve upgraded our old fileserver with extra memory, a new storage array (which needed replacement anyway), and the Digium card. The OS has been manually upgraded from CentOS5 to CentOS6, since installer totally screwed up the upgrade.

The’re no packages for CentOS 6, only for CentOS 5. I needed a shole bunch of non-standard libs :

• libss7
• libopenr2
• libpri
• dahdi

Downloaded, and packaged them. Asterisk was next : Version 10 wasn’t an option, since OpenPBX refuses to work with that. I ended up with 1.8.13.0, since that’s an LTS release. Welcome if you don’t want to restart you PBX every day or so.

I’m going to publish the SRPMS and i386 binaries in my RPM repo, no x86_64, sorry. If you want modifications to those RPM’s, contact be, and we’ll work something out.

Packages can be downloaded from my RPM repo

Later today I’ll upload my binutils and gdb packages.

Vim has a UltiSnips, but that has some preconditions : It need vim 7.3 with Python >= 2.6 compiled in. CentOS has neither of them. You can’t just upgrade Python on a CentOS machine, since lots of things (yum being one of them) depend on a specific version. So if you overwrite the default version, all hell will brake loose.

I’ve created packages for both Python and Vim (x86 and srpms), available at http://www.palsenberg.com/rpmrepo/

Happy VIMming !!!

• JIRA 4.4 en Fisheye 2.6.0-2.6.3 don’t get along when using trusted authentication. You get Seraph errors : Error handling trusted applications authentication attempt:BAD_SIGNATURE
• Make sure the user that is authenticating the application link (and managing the JIRA project) has read errors to Fisheye projects. Else you can’t link you repo to the JIRA project.

Make sure you have adequate backups before attempting to upgrade. Without them, it’s a one-way ticket of something goes wrong.

A nice addition is that it also allows macro’s to be embedded into that page. I’m going to use that to add some information of my own personal projects, like commit history.

• Error checking is practically absent. Bad input results in bad runtime behaviour instead of errors.
• Make sure that all input in conditions is handled; Input encountered in states without a matching rule results in the resulting code jumping to a (semi) random rule. Again, this doesn’t result in errors.
• RTFM about what regular expressions re2c supports. No error checking what so ever.
• Rules with wildcard conditions (<*> <regexp>) are first processed, above all other rules. A condition with a matching rules overrides the wildcard condition. This is important if you have a match-all condition [^], since that will precede the wildcard condition rule.

If you live up to the above undocumented things, re2c make writing lexers as easy as it gets.