Oct 11 2008

My experience in Open Source Asterisk Platform

Category: AsteriskBipin Balakrishnan @ 11:00 pm

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The story begins an year ago.

I was doing my Fifth Semester MCA at SNGIST College, Cochin,India. There was a main project to be done as a part of the course during this semester.  We had just finished our mini project (which happens just before the main project) the previous semester.  As the mini project didnt go the way I anticipated, I was breaking my head for the subject of this main project.

So many questions came to my mind, like the platform, learning the technology to be used, how to make it successful, etc, as this was  important in deciding a career.  Moreover there was the pressure as i thought it is the final semester project which decides our future career.

At this point of time, I got a call from a friend of mine, who told me about an opening in Telephony domain in Torque Technology Solution (Now named as MObME) at Technopark, TVM,India. He was working as a web developer   in that company.  This struck me with the idea of doing a Telephony project.  My thought went this way, if I happen go get a chance to do my project work in this company along with the job, I could very well venture into a career in Telephony domain. Moreover I have done my degree in Electronics and had some experince in telephony domain, earned by doing  an academic project in EBAPX during the final semester. I decided to apply for that job.

Later I was interviewed and they found me fit for that position.  More over, they agreed that I may do my project work there. Thus, on April 2007, I became an employee of Torque.

Until that time, i haven’t heard anybody  doing a project in this domain in the academic project , So there were lots of questions in my mind when I started; whether it would be accepted by the college, what is the future with this technology, will I be able to make a career out of it,etc.

But there were my colleagues in Torque for help. They were really passionate about this technology even though they didnt work on it a lot. They were my inspiration.  I started learning it with the support of Mr Sanil and Mr Kenny jecob who were the co-founders of the company.They taught me how to dig in to a technology and what are the tips for it. I managed to do my academic main project on asterisk in a short period of time which gave me lot of confidence and energy to learn and try more.

I started my experiments with dial Plans, followed by AGI.  During that time Hutchison Kerala, India came up with a project for developing a customer care application called 55555 IVR.  I was given this assignment and the application was intended to enable the subscribers hear various offers available to them by calling a toll free number 55555.  This project was successfully completed  with in a short time.We used PRI connectivity provided by the service Provider to implement this.As it was simple branching, I used only dialplan.Moreover  i was not having  deep understanding of AGI at that time.

Along with that assignment, I also worked for developing a web application for making calls to the gsm network for hutchison Kerala,India with the support of Mr Sanil.  Meanwhile Hutchison was taken over by Vodafone in India. My next assignment was to make the normal 55555 to a best offer IVR.The best Offer IVR announces the best Offer to the Customers depending on the validity and talktime available as well as the static offers. Now it has changed to three layers , the first layer consists of the dynamic offers depending on the previous recharge, the second layer consists of the dynamic offers depending on validity and talktime and third layer consists of various static offers. This project was completed successfully and now vodafone Kerala is using the IVR application as well as the outbound call application developed in Asterisk Platform.  We uses both ss7 and PRI connectivity for implenting this.
I have also done other projects on making on VoIP calls, Call Conference,Making Software as well as Hard ware PBX using the Asterisk platform.

More coming in the next posts.

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Feb 12 2008

Zapata Configuration for PRI

Category: AsteriskBipin Balakrishnan @ 4:08 pm

The Zap channel module permits Asterisk to communicate with the Zaptel device driver, used to access Zaptel telephony interface cards. You configure Asterisk’s Zap channel module in the zapata.conf file.The file

is located in the path /etc/asterisk/zapata.conf.

You will need the Zaptel kernel module device driver installed. See:
Zaptel Installation

Almost all of the things described in zapata.conf can be put as the
default values.The rest to be configured is mentioned here.
A sample zapata configuration having double span E1 card

switchtype = euroisdn           //the type of switch using
signalling = pri_cpe              // signalling used
context=torque  // context in the extensions.conf
group = 2 //grouping the channels
channel => 1-15,17-31,32-46,48-62      //channels avilable

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Feb 12 2008

PRI Troubleshooting

Category: AsteriskBipin Balakrishnan @ 2:55 pm

When the PRI card was purchased from Digium, Digium has provided free
technical support for configuring the card.

The lights on the PRI card can be red, amber/green or green. When all is
well they are green.

If Asterisk aborts when you try to start it, there are several things you
can check:

The Linux modules for your Zapata cards have to be loaded in order for the
connections to work. You load the PRI driver, wct4xxp, before you load the
FXS/FXO driver, wctdm.

You also have to execute the program ztcfg to get things to work. If all is
well, when you run ztcfg it should not produce any output unless you
specify verbose output (”ztcfg -vv”). When you run ztcfg, the lights should
change to green, even if Asterisk has not been started.

Loading of the modules may or may not be done automatically by the system.

Digium says it is possible to construct a loop-back plug to test your
PRI card. You do this using an RJ45 plug, connecting pin one to pin four
and pin two to pin five. When the loop-back connector is connected to the
card, the light should turn green. Again, the modules have to be loaded
and possibly ztcfg has to have been run.

The B channels listed in zaptel.conf must agree with the channels listed in
/etc/asterisk/zapata.conf, otherwise Asterisk may abort when you try to
start it. Zapata channels are indexed starting at one rather than zero
(Zap/1, Zap/2, etc.)

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