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?

Hardware-based IP phone
Image via Wikipedia

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.

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Digium TE205P vs. OpenVox D210P

If there is one thing I like doing is testing hardware, specifically, testing new hardware that is related to Asterisk. I was more than pleased when OpenVox had approached me, asking to review one of their products – specifically after I once announced that I really dislike cheap clone cards. So, I got OpenVox’s D210P card, which is a fairly similar clone to the TE205/TE210 of Digium, and I decided to take a it for a test drive.

So, first off, lets take a look at Digium’s TE205 card:

Digium TE205P Card

Digium TE205P Card

The card is based upon two specific chips, the Xilinx Spartan FPGA and an Inifineon based Quad E1/T1/J1 framer chip. Technically speaking, the entire brain of the outfit is located in the Xilinx FPGA (naturally), which on the TE205P now enables remote firmware upgrades and some additional features. Digium had been using Xilinx based boards for over 8 years now, and they’ve been doing the job more than well.

Now, let’s take a look at the OpenVox clone board:

OpenVox D210 Card

OpenVox D210 Card

OpenVox utilizes the same Inifineon framer chip (well, it’s a clone after all), while utilizing the Lattice Mico8 FPGA chip. Now, from a technological point of view, I couldn’t really find much differences between the Mico8 and the Spartan, beside a minor differences here and there – but these are not important. So, I proceeded to testing the card with Asterisk. So, the nice thing about this clone is that it doesn’t require patches to the stock version of DAHDI, which in my book means that OpenVox are aiming at being a real-clone, not some would be patched version of a clone – so that’s good. Installation was fairly similar to that of the Digium TE205P card, so I couldn’t really find specifics in there to prefer one over the latter. So, I started testing the card in various situations: Normal telephony, 3G based transmission (64kbps bearer capability),  dropped calls during high loads and checking CPU/Load spikes during high usage.

The Test Scenario and Comparison

All of the above tests were conducted according to the following scenario:

Testing Lab Server

Testing Lab Server

In general, I’ve connected 3 different IP phones to the testing server: A Polycom 650, a SNOM 370 and a Grandstream GXP2000. All IP phones include the latest firmwares and updates and were all working flawlessly with another similar setup, so I assumed they were all bug and issue free for the testing lab. The main reason I’m using 64Bit CentOS is simply due to the fact that all my servers are 64Bit capable (mainly E5410 and E5405).

Test 1: Normal Telephony

Well, in general, the card does exactly what it should – provides a connection to an E1 circuit (we only have E1 circuits in Israel). I’ve conducted normal telephony functions from all the above mentioned phones. In general, I’ve conduct from each phone a total of 40 calls, and repeated the test once for the Digium TE205P card and once for the OpenVox D210P card. The results were fairly similar with a slight advantage for Digium. In general, the OpenVox card had slipped about 4% of the calls, mainly to an IRQ miss that occurred for some reason. With the Digium card, the IRQ misses were not exhibited, allowing for all 120 calls to traverse normally.

Conclusion: In a normal office telephony scenario, the D210P is a fair choice – however, not my preference for a Call Center or a service provider.

Test 2: 3G based transmission (64kbps bearer capability)

I’ve been playing around with IVVR and Asterisk, mainly using the Fontventa H264 packages for Asterisk (that’s why I used 1.4 branch). With this test, the D210P provided less then medium results, specifically when trying to stream large 3gpp based video streams, while the TE205P had showed no specific issue with the transmission. Main issues exhibited were related to choppy video streams, causing jumps in the stream. The Digium card was fully capable of stream the video without a hitch. Now, I won’t hold this again OpenVox, as this usage is fairly advanced and is required by a very small portion of the market, but I believe they still have some work to do there. As they are using the same framer as Digium, I would deduce that their firmware is either an older import from Digium (reverse engineer) or some other firmware related issue.

Conclusion: Not a pick for 3G transmission with Asterisk.

Test 3: Dropped calls during high loads

No matter what test I did, with OpenVox I’ve always received a dropped call ratio of around 3-4% – when at high loads that went up to around 7%. When I mean high loads, I mean generating 30 outbound calls from Asterisk to one circuit, then receiving them on the second port (yes, a back-loop). I’ve conducted 100 runs of this test, at various speeds. It would appear that when generating calls with a 100ms interval between one initiation to another on the circuit, the OpenVox will drop a call here and there – at sporadic intervals. This may be actually related to the IRQ misses exhibited in Test 1.

Conclusion: If you have high load anticipated – OpenVox is not the choice for you.

Test 4: CPU Load/Spikes

It is a well known fact that all card that are used with Asterisk introduce load spikes of a sporadic nature. In the past, the masters of low spikes were Sangoma, however, with the introduction of Digium’s VoiceBus, that balance had tipped and Digium took the upper hand. In order to evaluate the spikes, I’ve monitor the machines’ load while having 30 calls traverse from one port to the other. The calls were playing back a static file of 5 minutes, and after disconnecting the calls would generate and additional one and continue from there. Both cards exhibited slight spikes when multiple calls either originate or disconnect, however, the CPU spikes that the OpenVox card had exhibited were about 40% higher than the ones exhibited by Digium and there were more spikes than with Digium.

Conclusion: If your system isn’t as beefy as mine, and you need full capacity – OpenVox isn’t the choice for you

Overall Operational Conclusion

The OpenVox card promises to be a low-cost alternative to the Digium card, and it surely delivers. Over all, if you have an office PBX system or a low scale IVR environment, the OpenVox alternative can be evaluated, although it’s not my personal favorite. Sure, in many cases I can say: “OpenVox would do the job” – but hey, I would always rather go with the original and not the clone. I believe that OpenVox are far ahead of its clone competitors (Atcom, Yeastar, Varion, PhonicEQ, etc), simply because it does a better job at building and designing a better card – however, they still have some way to go in order to be completely in-lined with Digium and Sangoma.

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I’m not rude, I’m eccentric

Polycom, Inc.
Image via Wikipedia

Today I got the chance to speak at a Polycom half-day convention, mainly to speak about Asterisk and HDvoice. Now, putting aside the part about HDvoice (I’m getting a post about that on its own), I gotten to the point where I believe that I’m currently perceived as being an eccentric.

So, why am I eccentric? very simple, I’ve reached a point where I can say things that may be perceived as rude – and write it off an being an eccentric quirk.

I’ve talked about Asterisk ability to support Video, while the current Polycom VVX1500 video phone isn’t yet supported at its fullest. One of the people in the crowd mentioned some sleezy,al-cheapo, SIP Video phone (to be more exact, he’s the local distributor) – and I claimed that I don’t count that phone as a comparison to Polycom or other VoIP Video phones, simply because in my view it’s not a worth while comparison. Comm’on, let’s be realistic, can you compare a Polycom VVX1500 (an HDvoice Video phone) with some shitty sub-VGA SIP Video phone from China? the mere comparison is simply insulting for Polycom.

Shortly after negating that phone, the person stood up and left the room. At the break, a friend said to me that I shouldn’t have said that, in order to come out the bigger man. Common, the guy is surely making a joke of himself. I commented: “I’ve said what I said, I stand by my opinion – besides, you know I’m eccentric – eccentric people say eccentric things” – he agreed that I’m eccentric, after all, you can’t be an Open Source evangelist without being an eccentric – now can you?

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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 :-)

Astricon 2009 – Glendale, AZ – Part I

Well, as some of you know, I’ll be speaking at this week’s AstriCon convention, being held in Glendale, AZ. I guess that in normal days I wouldn’t be starting to write about it prior to the actual convention, however, this time I decided to write about it earlier. I guess the title of this post can be changed to: Tosche Mark Spencer.

In order to understand what I’m talking about, we need to take a trip down memory lane, to be more exact – 2.5 years back memory lane.

Date: January 2007, Location: Tel-Aviv, Israel. Mark Spencer along side with Schuyler Deerman of Digium are on their way for their first time visit to Israel. Both of them are flying to Israel together after spending their Christmas holidays in the Middle East, mainly Egypt. Back at that time, I used to work for a company called Atelis – we were the Digium Israeli distributor. To make a long story short, Mark and Schuyler got held up at the airport for almost 4 hours, by Israeli security. The only thing that helped was for me to call my brother in-law, back then at the NY Israeli consulate, to try and find out what happend to both of them. Aparently, they were held up for questioning – without notifying anybody on the outside – who were waiting for them – what is going on.

Fast forward…

Date: October 2009, Location: Philadelphia, USA. I’m being held for a seconday inspection and the immigration control at the US border. The funny thing is, this is not my first trip to the US this year – I was here last February. The immigration officer looks at me and decideds that I’m a candidate for an illegal worker for some reason. Maybe the fact that I came in on an e-Ticket and didn’t have my itenirary printed throw him off, maybe the fact that I looked somewhat young to him, or maybe the fact that I’m continuing to Phoenix flagged me – I don’t know, in any case,
I’m now being held in secondary inspection, while I have only 50 minutes to get to my connecting flight – talk about turning up the heat. So, here I am, infront of this immigration officer, who I had to admit does his best to be polite and correct about the way he does his job. I gotta hand it to these guys, I guess they come across some of the worst scums in the world, and yet, they are able to sustain a professional and polite manner at all times – brava. Any way, he starts questioning me about my travel to the US, who paid for it, where am I going, where do I work, etc, etc. So, I
start explaining to him what AstriCon is, giving the guy the 5 minute “Asterisk is” introduction, and for some reason, it doesn’t really cut it with him. So, I decide to pull out the ultimate weapon – The Internet. I ask him if he’s able to logon to www.astricon.net and see that my picture is on the website. He looks the site up and indeed my picture is on there. The guy is now convinced that I’m here to lecture and nothing more – thank god. I get my passport back, pick up my stuff and run like the wind to my connecting flight – getting to it right before they close the boarding doors.

So, although I didn’t get the same 4th degree Mark/Schuyler did, I understand what they must have felt like in there. I guess it could have been worse, another guy that was in there with me got deported back to where he came in from (don’t know where that was) – not a very pleasent scenario.

Points for travelers

  1. You’re coming to the USA, have your itenirary printed and ready
  2. Have you flight invoices printed and hotel reservations printed – it may be required
  3. If you are staying with friends, not at a hotel – state that when asked, don’t hide it.
  4. If you had memorized your answers, these guys will pick up on it really easy – they know their job.
  5. If you are lecturing in a convention or tradeshow, make sure you can point the officer to an online mention of your talk – this helps smooth things faster.

Tomorrow’s update – AstriCon Cloud Computing class