15 Oct 09 Astricon 2009 – Glendale, AZ – Part II

Ok, it’s day 1 (or actually day 2) for AstriCon 2009 – and here’s my report for the day.

Yesterday was kind’a of a hectic day for me, as I was teaching a full day track of Asterisk and Cloud Computing, specifically, implementing Asterisk systems with Amazon EC2. I started the day with a class filled with 20+ people, and ended the day with a similar number – so in general I’m very happy. Not many people tend to attend the pre-conference days, so having that number of people and their positive reactions through out the day were very reassuring to me.

If there is one thing I’ve learned from this experience, it is the following: If you give a full day track, don’t arrive at the hotel 24 hours prior to it – you need at least 48 hours! People didn’t really notice (I hope), but through out the day I was suffering from a splitting headache – one that would usually send me right into bed with a couple of Advil’s. But hey, that didn’t stop me and I powered through it, I’m fairly proud of myself for doing so – as at the end of the day I regained back my strength and was livelier.

Today was the first official day of the conference – I gave the opening talk for the Cloud Computing track of the day. My talk was about how to build “IP Centrex” like services, without building an “IP Centrex”. I guess that I didn’t really introduce a brand new concept, but actually talked about something that many are thinking about, but are not inclined to try it on their own and burn some cash on. I guess my talk helped them out saying: “Hey, we’re not talking out of our asses here, this guy makes some sense and what we thought of isn’t that far fetched”.

Previous to that, Digium announced the 2009 Digium innovation award winners, where my company won an award in the pioneer category. This is the second year in a row my company had won the award, and I’m really happy with being acknowledged for this specific work. Having being a part of the community for over 7 years now, this award, at least to me personally, says a lot – it’s basically saying: “Look, you’ve done good, you’ve done some work that really helps out the project and the community in general – here’s a beer and a toast to you – hip hip” – well, that’s kind’a of a mouth full, but you get what I mean. I think that this is actually the place to mention that the award was for developing a high-powered Dialer/IVR platform, used in the Israeli elections and the work was contracted for a company called Shtrudel.

The all conference party is tonight – so I better rest up and be ready for it – should be fun. I guess beer and food are always a good mix when a bunch geeks are getting together

Tags: Amazon, Amazon EC2, Asterisk, Business, Cloud computing, digium, EC2, GreenfieldTech, Innovation Award, Virtualization, VMWARE

14 May 09 Asterisk and Amazon EC2 – Amoocon Presentation

I recently gave a presentation at the Amoocon convention, held in Rostock, Germany – about Asterisk and Amazon EC2. Below is a medium quality video of that presentation:

or you may download it here:
Amazon EC2 and Asterisk video files

Tags: AGI, Amazon, Amazon EC2, Asterisk, Cloud computing, Dialers, economy, GreenfieldTech, php, PHPAGI, Virtualization, VMWARE

01 Apr 09 GreenfieldTech announces the general availability of app_cashmaker for Asterisk

Udim, Israel. April 1, 2009 -GreenfieldTech Ltd., a leading provider of Asterisk solutions and Asterisk training services in Israel, today announced the availability of it’s patented app_cashmaker application for the Asterisk Open Source PBX system. The CashMaker application is intended to be used by various content suppliers, wishing to distribute Audio and Video based content, utilizing their Asterisk server.

The application is built to accept an inbound call into it, then, according to various information gathered in correlation to the callers caller ID and/or inbound DID number, will correlate a relevant content stream directly to the caller. The content distributor doesn’t even have to care about what content to distribute, as the application will connect directly, via the Internet, to a remotely available RTBSP streaming server at GreenfieldTech data center.

“The app_cashmaker application is the result of the cumulative work of over 3 years in the making, testing various content business models and applications. The main problems most content distributors have is how to gather the content and manage it, with app_cashmaker, this requirement is negated, thus allowing the distributor to concentrate on what they do best – flooding the newpapers with ads and marketing material to promote their content delivery service”, says Nir Simionovich, CEO and Founder of GreenfieldTech.

Simionovich indicated that the central content distribution facility is managed via a GTBS cluster environment, implemented partially utilizing Amazon’s EC2 and S3 structures, while utilizing GreenfieldTech’s proprietary streaming and clustering technologies. Currently, GreenfieldTech had submitted 10 different provisional patents, relating to the technologies comprising the app_cashmaker application and service. GreenfieldTech marketing team had indicated that initial beta trials had showed an increase in content availability, via the GreenfieldTech BSC Cloud facilityof over 40% with an increase of almost 80% in content delivery success.

Simionovich estimates that by the year 2010, over 20,000,000 will use the GreenfieldTech app_cashmaker facility, disrupting completely the way mobile, audio and video content is distributed around the world.

Asterisk is the world’s leading open source PBX telephony engine, and telephony applications solution. It offers unmatched flexibility in a world previously dominated by expensive proprietary communications systems. The Asterisk solution offers a rich and flexible voice infrastructure that integrates seamlessly with both traditional and advanced VoIP telephony systems. For more information on Asterisk visit http://www.asterisk.org 

For more information, please refer to the GreenfieldTech website at http://www.greenfieldtech.net.

Tags: AGI, Amazon, ami, Asterisk, Cloud computing, CONTENT, digium, EC2, MOBILE, S3, STREAMING

13 Feb 09 Read my words – 3500 concurrent channels with Asterisk!

One of the biggest questions in the world of Asterisk is: “How many concurrent channels can be sustained with an Asterisk server?” – while many had tried answering the question, the definitive answer still alludes us. Even the title of this post says “3500 concurrent channels with Asterisk” doesn’t really say much about what really happend. In order to be able to understand what “concurrent channels” really means in the Asterisk world, let us take a look at some tests that were done in the past.

Asterisk as a Signalling Only Switch

This scenario is one of the most common scenarios in the testing world, and relies upon the basic principle of allowing media (RTP) to traverse from one end-point to the other, while Asterisk is out of the loop regarding anything relating to media processing (RTP). Examine the following diagram from one of the publicly available OpenSER manuals:

As you can see from the above, the media path is established between our 2 SIP endpoints.

This classic scenario had been tested in multiple cases, with varying codec negotiations, varying server hardware, varying endpoints, varying versions of Asterisk – no matter what the case was, the results were more or less the same. Transnexus had reported being able to sustain over 1,200 concurrent channels in this scenario, which makes perfect sense.

Why does it make sense? very simple, as Asterisk doesn’t manage or mangle RTP packets, Asterisk performs less work and the server also consumes less resources.

Asterisk as a Media Gateway

Another test that people had done numerous times is to utilize Asterisk a Media Gateway. People used it as a SIP to PSTN gateway, SIP to IAX2 gateway, even as a SIP to SIP transcoder gateway. In any case, the performance here varied immensly from one configuration to another, however, they all relied on a simple call routing mechanism of routing calls between endpoints and allowing Asterisk to handle media proxy tasks and/or handle codec translation tasks.

Depending on the tested codec, I’ve seen reports of sustain over 300 concurrent channels of media on a single server, while other claim for around the 140 concurrent channels mark – this again mostly relied on various hardware/software/network configurations – so there is nothing new in there.

These tests tell us nothing

While these tests are really nice in the theoretical plane of thinking, it doesn’t really help us in the design and implementation of an Asterisk system – no matter if it is an IVR system, a PBX system or a time entry phone system for that matter – it simply doesn’t provide that kind of information.

The Amazon EC2 performance test

In my previous post, Rock Solid Clouded Asterisk, I’ve discussed the various mathmatics involved in calculating the RoI factors of utilizing Cloud computing. One thing the article didn’t really tell us, did it really work?

Well, here are some of the test results that we managed to validate:

• Total number of Asterisk based Amazon EC2 instances used: 24
• Total number of concurrent channels sustained per instances (including media and logic): 80
• Average length of call: 45 seconds
• Total number of calls served: 2.84 Million dials
• Test length: approximately 36 hours

According to the above data, each server was required to dial an approximate 3300 dials every hour. So, let’s run the math again:

• 3300 Diales per hour
• 55 Dials per minute
• As each call is an average of 45 seconds, this means that each gateway generates 20 calls
  per second, and within 4 seconds fills the 80 channels limit per server.

According to the above numbers that we’ve measured, each of the Amazon EC2 instances used was utilized to about 50% of its CPU power, while consuming a load average of 2.4, which was mostly caused by I/O utilization for SIP and RTP handling.

Conclusion

When asking for the maximum performance of Asterisk, the question is incorrect. The correct question should be: “What is the maximum perfromance of Asterisk, utilizing X as the application layout?” – where X is the key factor for the performance. Asterisk application performance can vary immensly from one application to another, while both appear to be doing the exact same thing.

When asking your consultant or integrator for the top performance, be sure to include your business logic and application logic in the Asterisk server, so that they may be able to better answer your question. Asterisk as Asterisk is just a tools, asking for its performance is like asking how many stakes a butcher’s knife can cut – it’s a question of what kind’a steaks you intend on cutting.

Tags: Amazon, Asterisk, Dialers, digium, EC2, S3, SIP

09 Feb 09 Rock Solid Clouded Asterisk

This post is somewhat a combination of posts from previous posts, mainly, the posts about virtualization and my latest posts about the utilization of Amazon EC2. As some of you may know, a part of what I do at GreenfieldTech is develop various API’s for the Asterisk Open Source PBX systems. Two of these API’s are the IVR API and the Dialer API. This post if called “Rock Solid Clouded Asterisk” as it will describe the latest production environment that I’ve implemented, using these API’s and Amazon EC2 virtualization framework.

The network diagram

Our implementation consisted of the following general schematic:

The application logic was based upon a JAVA based web-service, implementing the XML-RPC server side of the IVR API, and a dialer management system that controlled the dialer API located on the remotely located dialers – hosted on Amazon EC2 instances. For simplicity, and we were very much aware this would reduce the overall capacity, we’ve located both the dialer framework and the IVR API execution on each of the servers, while allowing the server s to communicate internally.

Some constraints

As much as we wanted to run many Amazon AMI instances, we were limited to running 5 elastic IPs with a single Amazon AWS account. As a result, we’ve registered 5 accounts, and executed a total of 24 AMI instances with 24 elastic IP’s.

An additional constraint we had realised, but had no way of actually knowing its limitation was the actual number of concurrent calls per server. Initially, we’ve reached the following numbers and configuration on a physical server:

• Intel Quad Core XEON
• 2GB RAM
• 1GB Network Uplink
• CentOS 5.2 64bit
• Total capacity: 120 concurrent calls of Dialer+IVR on a single server

Per our theory, if we managed to reach a similar capacity using amazon c1.medium instances, we would be very happy.

The results

After conducting a test utilizing a single AMI instance, we’ve reached the following results:

• Dual Core instance (c1.medium)
• 180GB Disk Storage
• 8GB of RAM
• Fedora Core 8 32bit
• Total capacity: 80 concurrent calls of Dialer+IVR on a single instance

A decrease of 33% in comparison to the performance observed on a physical server. Ok, so we weren’t all that happy with these results, until we started doing the financial math, realising that using Amazon EC2 with that Dialer+IVR framework would yield a savings of almost 80% in operational costs.

Doing the math

The normal co-located option

Our aim was to reach a capacity of around 2800 concurrent channels. Per the normal physical setup, our hardware requirements would be to use at least 24 servers. At a price of 1500$ per server, that sums up to a total of 36,000$. Adding the time required to install 24 servers, the overall expense for 24 servers would be around the 42,000$ mark. To sustain a total of 2800 concurrent calls, using the g711 codec, we would be required to carry a total of 300Mbps internet uplink – basically talking about 10,000$ of bandwidth.

So, taking all of the above into consideration, we will need a total of 52,000$ just to maintain the hardware installation and operational cost. Taking into consideration that the system would be used at full for no more than a period of 30 hours, we end up with a total of: 1733$ per hour.

The Amazon EC2 option

Now, let’s calculate for Amazon EC2:

2800 concurrent channels translates into 35 instances. Price per c1.medium instance per hour is 0.2$. So, rack that up and you get: 210$ for operating 35 instances for 30 hours.

Elastic IP costs are 0.01$ per hour per server – a total of 10.5$ for 30 hours.

Bandwidth costs are 0.17 per each GB, so according to 300Mbps for 30 hours, with each call duration at 1 minute sums up to be: 5M of data per call. Calculating 2800 concurrent channels for 30 hours gives: 25,200,00 MB, or 25TB of traffic. According to Amazon, first 10TB are at 0.17$ per GB, and then the price goes down. So, let’s take a worst case of 0.17$ per GB. A total of 4284$ for operating 30 hours.

A total of: 4,468 US Dollars, Price per hours calculated at: 148$.

The savings

Per the task at hand, the utilization of Amazon EC2 yielded a savings of 92%

So, is Amazon EC2 good for any usage?

The answer is a definite NO! If your requirement is for a system that works 24×7, like a PBX system or a call center, then your utilization of Amazon EC2 would be identical to leasing a co-located server at any of the world wide co-location providers. If your application is of sporadic nature, or is utilized for short bursts of time, Amazon EC2 is a wonderful tool for lowering your overall expenses. Sure, it will require some work to get running, but the overall savings is more than worth-while.

Tags: Amazon, Amazon EC2, API, Asterisk, Cloud computing, Dialers, digium, Economics, GreenfieldTech, IVR