Asterisk disk full

Just after my last class today I though I'd copy the asterisk box from the presenter machine to my backup drive. I was shocked to see a 44GB file! Obviously there was some logging problem bloating the hard disk, but it was not asterisk's log files under var/asterisk but instead core files found in tmp.
These core files are effectively memory dump files created by CentOS when Asterisk mibehaves and crashes. I had 43 GB worth of dump files already. The problem is, that simple errors in your sip.conf can cause Asterisk to crash and restart and subsequently crash, going on until your HDD is full of dump files.
I found a easy post on how to control the core dumps here:
http://aplawrence.com/Linux/limit_core_files.html

But that only combats half the problem. The main part was why was asterisk is crashing so often. the answer lied in my case in the qualify=yes entries in my sip.config. If the Lync Mediation server does not expect to respond to the gateway (topology not published yet, Mediation Service not restarted) or is not online at all then the qualify will fail. Worse even, it will crash my Asterisk 1.6 box causing those dumps to quickly fill up the HDD (50MB per dump). So setting qualify=no has helped me keep my asterisk box more stable between my demonstrations.

Using 2talk SIP Provider with Lync

yesterday I posted about using Asterisk with Lync. Today I will share my configuration files for getting 2Talk up and running with the latest version of Asterisk 1.6:
Effectively there are two configuration files you need to worry about. The sip and the extensions files.
The sip.conf file specifies the different sip trunks and authentication mechanisms. The extensions.conf is your dialplan, which can be the trickiest to get working. Below are my versions (passwords removed)

sip.conf:

[general]
registerattempts=0
registertimeout=20
allowoverlap=no ; Disable overlap dialing support. (Default is yes)
udpbindaddr=0.0.0.0 ; IP address to bind UDP listen socket to (0.0.0.0 binds to all)
bindport=5060
bindaddr=0.0.0.0
tcpenable=yes ; Enable server for incoming TCP connections (default is no)
tcpbindaddr=0.0.0.0 ; IP address for TCP server to bind to (0.0.0.0 binds to all interfaces)
srvlookup=yes ; Enable DNS SRV lookups on outbound calls
notifyhold = yes

;register 2Talk number to receive incoming calls (replace placeholders with values, remove brackets)
register => :@2talk.co.nz/

[1001] ; A locally attached SIP extension (in my case an X-Lite client)
type=friend
callerid=1001
canreinvite=no
dtmfmode=rfc2833
mailbox=1001
disallow=all
allow=ulaw
transport=udp
secret=password
host=dynamic
context=default



[2talk]
type=friend
username=
fromuser=
secret=
host=2talk.co.nz
context=from-2talk ; going to use this in extensions.conf
dtmfmode=rfc2833
disallow=all
allow=ilbc
allow=gsm
allow=alaw
allow=ulaw
;allow=g729 ; only if you have licenses to use it
nat=yes
canreinvite=no
insecure=invite,port ; use insecure=very in earlier versions of Asterisk such as v1.2


[Lync_Trunk] ; Our Lync trunk
type=friend
port=5068 ; This is the default Lync Server TCP listening port
host= ; This should be the IP address of your Lync Mediation Server
dtmfmode=rfc2833
context=from-lync
qualify=yes
transport=tcp,udp

extensions.conf

[general]

static=yes
writeprotect=no

[globals]

[default]
;calls to a 4 digit extension starting with one are routed directly via SIP to local phones
exten => _1XXX,1,Dial(SIP/${EXTEN},20)
exten => _1XXX,2,hangup()

; outbound calls (outside of your own PBX) (only used for internal phones, not calls originating from Lync)
exten => _0.,1,Dial(SIP/${EXTEN:1}@2talk)
exten => _0.,2,hangup()

;calls coming in locally going to a 4 digit number starting with 2 are redirected over the Lync trunk
exten => _2XXX,1,Dial(SIP/Lync_Trunk/${EXTEN},20)
exten => _2XXX,2,hangup()

[from-lync]
;dialling other extensions starting with 1 followed by three digits are sent locally
exten=>_1XXX,1,Dial(SIP/${EXTEN},20)
exten=>_1XXX,n,hangup()

;send other calls to 2talk for Asterisk (no prefix here as Lync will probably have its own dialplan)
exten => _.,1,Dial(SIP/${EXTEN}@2talk)
exten => _.,2,hangup()


[from-2talk]
;send incoming calls on your 2talk number to a Lync Extension
exten => _X.,1,Dial(SIP/Lync_Trunk/2001)


That's it folks! Try using the two configurations with your 2talk SIP provider, add your own number, secret and Lync IP address and start making and receiving calls over Lync.

Using Asteriks with Lync 2010

Next week I am teaching how to install and configure Lync using the material provided in the course10533 from Microsoft. Although the course has some great stuff, it misses out on the really juicy bits. Setting up a PSTN connection for example.
I simply could not resist setting it up for myself. After some digging I found this GREAT! Post by Adam:
http://imaucblog.com/archive/2010/10/09/step-by-step-microsoft-lync-2010-asterisk-and-skype-installationintegration-guide/

But then I need to get my Virtual machines connected to the internet! Now ICS has proven to be rather icky. And Bridging really mucks things up. So in the end only a good ol Routing Service would do the trick.
John Paul has a nice article on how to configure Hyper-V to route traffic to your wireless adapter:
http://sqlblog.com/blogs/john_paul_cook/archive/2008/03/23/using-wireless-with-hyper-v.aspx

WARNING! Skip the first quarter of the screenshots where he shows bridging. don't wanna do that. jump down to where he starts talking about RRAS

Once I had routing set up and could connect to the net using the private ip-ranges I wanted, I was ready to install Asterisk using Adam's instructions.

Some tips for getting it all running:
No need to buy Skype Plugin if you wanna use sip. I used 2talk and am happy with the results. For the detailled config for 2talk try this page:
http://blog.2talk.co.nz/asterisk.html

IK found a mix between the settings from Adam and the ones from 2talk worked best.

WARNING! A typo or bad rule can send your Asterisk server into an endless crash loop. To fix that, copy the 2talk configurations back into the files and start over again.

Some helping commands I used along the way on the Linux box:
ifconfig (set a new IP address)
route (add a default route to connect to Gateway)
ping (test ip connectivity)
nslookup (test dns server connectivity)
ifconfig and route take effect immediately on the linux box. The changes made via the network setup program only come to life on the next reboot (which took about 5-10 minutes each time)
 
asterisk -r (connect to asterisk console)
  reload (reload all configs)
  diaplan reload (reload only the dialplan)
  sip show peers (see what routes are setup and working)

And as I hate using the command line editor, downlad a browser/editor for Windows ASAP, such as WinSCP: http://winscp.net/eng/download.php
You will need that editor to edit the /etc/asterisk/sip.conf and /etc/asterisk/extensions.conf files

Whenever you make a change to sip.conf or extensions.conf make sure to run the reload command in asterisk again.
Also, staying logged in to Asterisk will show what is going on and is useful when debugging conversation attempts.
Finally, try getting it working step by step.
1) connect X-Lite to SIP provider via Asterisk
2) connect X-Lite to Lync
3) connect Lync to X-Lite
4) connect Lync to SIP provider
Step 1 should be your priority. Once that works the rest falls into place.


Happy configuring. Having it all working is an exhilerating feeling. you'll know what I mean once you have made your first Lync phone call to a real land line.

Hierarchies inspired by Tube Maps

One of the probably most famous and useful navigation resource is the London Underground map. It is truly a masterpiece of navigational aid and has hardly changed since its inception. When reviewing the different possible ways to map out a navigation I came across Patrick Walsh's post : http://www.boxesandarrows.com/view/a-map-based-approach

There he describes a process of using Visio to create a tube map like representation of an intranet. A sample could look as such:

Using interconnections, call-outs and differently coloured lines it now becomes easier to show the different paths a user could take through the system, how the navigation nodes relate to each other and where cross linking is used to help navigation.

Also it should become easier to add lots more links onto a page while keeping it printable and overviewable.

Donna Maurer (http://www.maadmob.net/donna/blog/archives/000639.html) has already found the benefits of adding actualt data to a visio diagram, which makes updating th diagrams with new titles or descriptions a breeze. As datasource you can use either a excel file, Access database or even a SharePoint list!

A few tips for when you are working your way through connecting data to your shapes:
1) call the field which contains the url to the page Url. That way visio will automatically link the whole shape. You can rename a field in Visio, no need to fix the source.
2) create custom representations for your data using the Data Graphics button on the Visio 2010 ribbon.
3) create four different options, one for title above, one for below and one for each side. Changing one option will change all instances of that option. Thus, you will need to create four separate ones.

I'll be handing out samples of the visio I used to create a map at my IA course in Wellington which you can use straight away to build your own metro sitemaps!

Introduction to SharePoint Information Architecture

It is my pleasure to announce the newest course offering by Equinox in Wellington:
http://www.equinox.co.nz/training/Pages/CourseDescriptions/sharepoint-information-architecture-introduction.aspx
I've teamed up with Equinox to deliver three SharePoint Information Architecture courses in Wellington. A one day introduction which covers the basics of IA as well as the basics of SharePoint. A two day course which then goes into the depths of creating taxonomies and hierarchies in SharePoint which can withstand the test of time. Finishing off with an advanced course which covers records management, governance, scalability and other advanced concepts over another two days.
I've been spending many hours online and in libraries prepping the contents of the introduction course and while I will be demystifing some SharePoint myths during the course I also am looking forward to the interactive sessions with the students. IA simply is not something you can learn by listening to speeches or watching viedos. It really only sinks in when you do it for real, so expect some fun and enlightening hands on session to drive home the concepts learnt!

We'll be running the course on June 22nd. Places are limited; so make sure you book your place soon to avoid disappointment!
http://www.equinox.co.nz/training/Pages/CourseDescriptions/sharepoint-information-architecture-introduction.aspx

Expired Virtual Machines for 10232

Thank God, Microsoft Learning is fixing the date issue on the 10232 virtual machines. Looks like this time they didn't get away with "it is not broken, it is by design". So if you are planning on teaching Advanced SharePoint Development techniques any time soon, then make sure to get your hands on the newest images. They should be online within the next week or so.
Btw, 10232 is full of theory and "best practice" concepts. Great for solution architects, team leads and senior developers. Not really the stuff junior SharePoint developers are keen on. They just want to get their hands dirty coding WebParts.
Also, encourage the client to send their newbie SharePoint developers onto 10174 first before visiting any of the advanced courses. Although it is an admin focussed course it covers all the essentials which a developer needs to know about.

MCT Tips and Tricks for 10232

Fellow MCTs,
I am posting this for the benefit of those MCTs who have not figured out that there is a whole wiki page at http://borntolearn.mslearn.net on this course once you log in with your MCT LiveID account.

10232 was built with a trial key for SharePoint that has a fixed expiry date. You must turn the clock back to August 2010 (tested using 10th and 11th/08) to teach this course. Thanks go to Chris Barker for being the first to post a solution to this problem at the MCT forum. The key to getting the course to run is to set the clock of the host back before importing the VM and starting it up. This is due to the host setting the bios date of the vm on initial bootup. So changing the time after the fact in the vm does not help as the SharePoint key has invalidated itself by then.
BUT...
When setting the clock back to a date before the host was built you might have troubles getting any vm to start with a certificate failure. This is due to a certificate HyperV uses when initialising the VM. To solve the problem you need to delete the self-signed cert and reboot the machine. That will force Hyper-V to recreate the cert at the older date and the VMs will start. To do this follow these steps:
1) open MMC and add the Certifcates Snap-in
2) Select the service account option
3) Pick the HyperV Virtual Machine Manager service
4) drill down into the own Certificate folder (first folder)
5) delete the self signed cert with the machine name
6) reboot

Last Tips for a smooth running course:
Configure the machine to use an internal network so you can remote into the box from the host. That will make copy and paste much easier and also allows you to put fiddler on the machines. (my students loved seeing fiddler in action and could not stop fiddling with it)
Change the Integration settings for the vm to not synch the time. That will stop the host from updating the time in the VM. This does not work on initial boot, as the initial time and date on first start of the vm will always be set based on the current host regardless of that setting. But it should prevent the machine to take on a new date while it is running.
Then make a Snapshot!!!
Should the student have changed the time on the host during the course and the time did synch due to some fluke, you can easily revert back to the snapshot which has the correct time settings and a functioning SharePoint instance.

Happy teaching!