12 Feb 10 Beyond the dialtone – PBX user experience revisited

When most of us think about PBX systems, we usually associate these with cumbersome usage, confusing dialing codes and in most cases – a PBX system is automatically associated with the annoying task of transferring a call from one handset to another. Lately, I’ve been thinking deeply about how people use PBX systems, is this really the only way to use a PBX system? is there something else to the mix? can we really enrich one of the oldest operational paradigms in the world? – and for that matter, can the public be re-educated to assimilate a new breed of PBX systems or services?

As to answering the question of re-educating the public, I guess I’ll have to leave that question to the head shrinks. As to answering the latter, enriching the PBX experience is both achievable and advisable. When I say enriching, I mainly talk about your ability to bring to the IP phone functionality usually not associated with it. Imagine to have the ability to receive a stock exchange RSS feed to your phones idle screen, notice that you stock is either rising or falling, and by the flick of a button – either sell or buy. We’ve all come accustomed to IP phones that look like the one of the right. A whole bunch of buttons, that in most cases have no direct use when our phone is utilized using a single account. However, these buttons can be externally re-assigned and re-programmed to achieve greater functionality – surpassing the normal behavior of just making phone calls.

The technology involved exists on almost every high-end IP phone on the market (well, at least those made by SNOM, Aastra, Cisco and Polycom – most of the Chinese makers don’t have this) – it’s called a Mini Browsers. Mini Browsers are exactly what they are called, these are simplified versions of your typical Internet browser. Some vendors had produced their own XML based Mini browser markup language (SNOM, Cisco, Aastra) while others had decided to provide a sub-set of XHTML (Polycom). The variations between the vendors are at the neck deep of the problems of using Mini Browsers, and that is that the formats are considerably different. Sure, SNOM had more or less adopted Cisco’s general structure, however, it still varies.

Through the utilization of this technology, it is possible to create phone based browser applications, that seem native to the phone user, as the general interface resembles the native phone interface. It is now the developers job to make the web interface displayed to the user as seamless and as native as possible, keeping in mind that the developer must remain agnostic to the information retrieval layer. Most companies leave their phone systems and these tasks to their system administrators and infrastructure team, however, this task is far beyond their capabilities and skill set. Creating an agnostic IP phone minibrowser dislplay layer, capable of utilizing multiple vendors and models, is a question of content management and content rendering, very must similar to the content transcoding problem that is common to the mobile content world – in other words, a sys-admin will create an ad-hoc solution, a programmer will create a proper, well structured, well designed solution that carry the enterprise beyond its initial needs and requirements.

A short example of how these interfaces work can be found here – on my company blog.

Tags: Aastra Technologies, Asterisk, Cisco, Cisco Systems, digium, Fonality, FreePBX, freeswitch, Markup language, Nortel, Polycom, sangoma, SIP, TrixBox, User interface, VoIP, XHTML, XML

02 Feb 09 So long SigValue – Hello Asterisk + EC2!

As some of you may know, I’ll be attending the ITExpo in Miami Beach, Florida. The subject I’ll be lecturing about is “Virtualizing Asterisk”. However, I have to be honest, I really need to change the subject to be called “Asterisk in the Cloud“.

Ever since the introduction of Amazon EC2, people had been trying to get Asterisk to run properly inside an EC2 instance. While installing a vanilla Asterisk on any of the Fedora/RedHat variant instances in EC2 isn’t much of a hassle, getting the funky stuff to work is a little more tricky.

One of these tricky bits (which I hadn’t yet found a solution for) is the issue of supplying a timer for Asterisk’s MeetMe application. In the old days (prior to Asterisk 1.6), Asterisk required the utilization of a virtual timer driver, provided by Zaptel in the past and now the DAHDI framework. The problem is, that while you are fully capable of compiling and installing DAHDI on an Amazon EC2 instance – the problem starts once you want to use it.

A few words about Amazon EC2

For those not familiar with Amazon EC2, its general infrastructure is based upon the XEN virtualization project. XEN is a para-virtualization framework, meaning that is performs some of the work utilizing the underlying Operating System kernel and some of the work performed with a special Kernel in the virtualized Operating System instance. This poses an interesting issue with every type of application that relies on hardware resources and their emulation.

To learn more about the XEN project, go to http://www.xen.org.

So, where’s the big deal?

So, if you can compile your code and run it in an instance, as long as you have the kernel headers and kernel source packages – you should be just fine – right? WRONG!

Amazon EC2 deploys its own Kernel binary image upon bootstrap, causing what ever compilation you may have done to the Kernel to go away (unless you’re creating a machine from real scratch). Another issue is a version skew between the installed Operating System kernel modules, the actual kernel and the installed compiler. For example, the instance that I was using had the XEN capable kernel compiled with gcc version 4.0.X, while the installed operating system was gcc version 4.1.X – so, no matter what I did to compile my kernel modules or binary kernel, I would always end up in a situation where loading the newly compiled kernel modules will generate an error.

Did I manage to solve it? – NOT YET. I’m still working on it, and I have to admit, that considering the fact that I have over 10 years of Linux experience and had compiled kernels from scratch many times, this one has gotten me a little baffled – I guess I’ll just need a few more nights and a case of Red-Bull to crack this one open.

So, what can we do with EC2?

In my view, EC2 + Asterisk is the ultimate IN/NGN services environment – and I have proof of that. A recent lab test that I did with one of my customers showed a viable commercial alternative to Sigvalue when using Asterisk and EC2 structures. The main reason for our belief in using EC2 was the following graph:

What we’ve noticed was that while our IN/NGN system was generating traffic, it’s general usage showed peak usage for a period of 2.5 hours, with a gradial increase and decrease over a period of almost 10 hours. Immediately that led us to a question: “Can we use Amazon EC2 to provide an automatd scaling facility for the IN/NGN system, allowing the system to reduce its size as required?”

To do this, we’ve devised the following IN/NGN system:

Our softswitch would have a static definition of routing calls to all our Asterisk servers, including our EC2 instances which had static Elastic IP numbers assigned to these. The EC2 Controller server was incharge of initiating the EC2 instances at the pre-defined times, mainly, 30 minutes prior to the projected increase in traffic. Once the controller reaches its due timer, it will automatically launch the EC2 instances required to sustain the inbound traffic.

For our tests, we’ve initiated 5 AMI instances, using the EC2 c1.medium instance. This instance basically includes 2 cores of an AMD opteron, about 8GB of RAM and about 160GB of Hard drive – more than enough. Initially, we’ve started spreading the load evenly across the servers, reaching about 80 concurrent channels per instance, and all was working just fine. We managed to reach a point where we were able to sustain a total of about 110 concurrent channels per instance, including the media handling – which is not too bad, considering that we are running inside a XEN instance. The one thing that made the entire environment extremely light weight is the GTx Suite of APIs for Asterisk. Thanks to the GTx Suite of APIs, scalability is fairly simple, as all application-layer logic is controlled from a central business logic engine, serving the Asterisk servers via an XML-RPC based web service. Thanks to Amazon, practically infinite, bandwidth allocation – the connections from the Asterisk servers to the US based central business logic was set at a whopping 25mSec, thus, there was no visible delay to the end user.

It is clear that the utilization of Asterisk and EC2 operational constructs can allow a carrier to establish their own IN/NGN environment. However, how these are designed, implemented and operated are at the hands of the carrier – and not a specific vendor. If the carriers around the world will take to this approach, time will tell. As a recent survey stated that 18% of the US PBX market is currently dominated by Open Source solution, having Digium dominate 85% of these 18% (~15%), I’m confident that we will see this combination of solutions in the near future.

Tags: Amazon, Asterisk, Broadsoft, digium, EC2, Nortel, Personeta, S3, SigValue, Sylantro, Virtualization

11 May 08 Psyched and ecstatic at the same time – Asterisk Bootcamp Israel

OK, I’m fairly psyched out at this point, actually, I would say that I’m ecstatic. The first ever Asterisk Bootcamp training will be taking place on the 25th of May, in Ramat-Gan, and I’m the trainer

If you are not from Israel, you may regard this as: “What’s so special? Asterisk bootcamps are all over the place!” – but for me this is something really special. In 2002 I began a journey into the world of Asterisk, starting to develop various applications and voice systems based upon this wonderful piece of software. As time progressed, my interest in Asterisk grew, and thus, also my interest in the adaptation of Asterisk to Tier-1 telecom infrastructures.

In 2006 I’ve finalized my first Tier-1 Asterisk application, an International Operator Assisted Dialing platform. If you are from the telecom business, you are most probably familiar with the Nortel TOPS platform. The platform that I’ve developed replaced a Nortel TOPS system, that was installed at Bezeq International in Israel. This was the first ever Asterisk installation as a critical Tier-1 carrier service, within a Tier-1 carrier. Just to give you an idea of the big ho-ha, in Israel, this platform is a regulatory issue – no system, no license – no license, company go bye bye!

A year ago I left Atelis, the company that I help found and manage – a Digium channel and reseller in Israel and the UK. I’m now a freelance consultant/developer, focusing mainly on the integration of Asterisk in various applications and business structures. This training session, to me, is somewhat of a climactic event – as it bring my 5 years of Asterisk experience, into a situation where I can share this experience and know-how with a select group of people – who all share the same goal: they want to learn Asterisk to the fullest.

Training will begin on the 25th of May, and I will try to post each day of the bootcamp, telling you my thoughts, feelings and news from the bootcamp – I’ll even throw in some pictures to match

Tags: Asterisk, Bootcamp, Nortel, open source, TOPS, Training, VoIP