Posts categorized "Podcasts"

The other story about the recording of the Telecom Junkies podcast: Interview with a VoIP Hacker - a.k.a. why my voice levels are so different

imageWhy does my voice change in audio quality about half-way through the new Telecom Junkies podcast?  Here's the story.

A few minutes ago I posted to both the Voice of VoIPSA weblog and also the Blue Box podcast site a note about the new Telecom Junkies podcast that features an interview with Robert Moore, one of the two people involved with the large VoIP fraud cast last year.  About mid-way through my connection dies and you hear Jason saying "Oh, we lost Dan!" and then I'm back, but with a much softer voice.

Since it says something about telephony - and since I'm also interested in relaying lessons for podcasting - here's what happened.

In the hotel I was staying at in Florida, I was getting pretty poor connections using my AT&T GSM phone (the replacement Blackberry had not yet arrived).  I'd noticed that when calling people from my room, even if I went out onto the balcony, calls would still drop out sometimes - even when I was sitting still.  Now I don't know if this was because I was on the 20th floor (room 2048, what a great geek number!) or because I was at just a particular angle for the GSM towers or what.  The phone seemed to indicate that I had great connection strength.  All I knew was that connections were dropping. 

Needless to say, I was a bit concerned going into the Telecom Junkies podcast recording.  Jason Huffman records his shows by having everyone call into a hosted conference service.  When the recording is done, he gets an email with a WAV file, slaps on the musical intro/outro, potentially does some minimal editing and posts the show to their website.  As Blue Box listeners know, I'm always looking to get the best audio quality possible so I was a bit concerned.

Given that cell phone coverage was problematic, I decided to try using a softphone over the hotel Internet.  Unfortunately, I am on a trial system for Mitel's softphone (using the latest development versions) and I had received the notice that I need to upgrade to a new trial load to keep using it - and hadn't yet downloaded the new version.  So I thought I'd use Skype instead.  However, I also had the dilemma (for either softphone) that because of space considerations I had left my nice new USB headset at home.  Given that I've had reasonable success with Skype's new 3.5 and no headset, I figured I would give it a try anyway.

So I actually first called into the conf bridge using Skype/SkypeOut and spoke with Jason briefly to ask about the sound quality.  He said I sounded a bit quiet and rough (keep in mind that I'm talking to the mic on my Dell laptop), so I called back in on my cell phone.  However, I didn't disconnect the Skype connection, but instead muted the microphone and plugged in a set of headphones so I didn't hear it.

Mid-way through the call, my cell-phone connection did die.  What I did next was put the PC headphones on and un-mute the Skype microphone... ta da... I was back in the conf call, albeit at a lower volume level.  So when you listen to the recording, the first part is via cell phone (and includes an audio cut-out or two) and the second part is via Skype without a headset microphone.

I thought there were a couple of interesting points here:

  1. I have got to find a really small headset that I can carry with me when traveling.
  2. VoIP can beat cell phones in availability (not that any of us in North America will even remotely dispute this!)
  3. It's good to have backups when doing interviews remotely.
  4. It never even occurred to me to use the hotel landline!

Let's think about that last point for a minute.  I had, sitting right there on my desk next to my computer, a perfectly functional phone tied into the hotel's PBX.  And yet, it never even remotely occurred to me to use it!  In fact, outside of calling within a hotel I can't think of the last time that I've actually ever used a hotel phone for an external call.  It's been probably... years!  I guess I've gotten too used to the typically-extortionist rates charged by hotels for phone usage that I just don't even consider it.  (Well, and every other time my cell phone has worked well!)

In any event... that's the story behind the story...  :-)

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Blue Box Podcast #56 posted, beginning a series of VoIP security tutorials

I posted Blue Box Podcast #56 tonight and with it Jonathan and I are beginning a series of mini-tutorials on subjects related to VoIP security.  In this show, we talked about voice encryption. In the next show (already recorded) we will talk about signaling encryption.  The idea is to cover some basic ground so that people not familiar with the area can have a basic understanding.

Just glad to get that one up - tomorrow I'm going to work on #57 to see if I can get it online for Wednesday.  We're trying hard to get back on a weekly schedule.  (#56 was intended to go up last week.)

Blue Box Podcast #50 finally hits the feed...

Fans of Blue Box have to be aware that I'm a wee bit behind in posting episodes... so I was delighted to finally get Blue Box #50 uploaded yesterday.  I still need to finish putting the show notes up there, but at least the show is out so that people can listen to it.  Given that we recorded it January 17th, it has already aged a bit.  Tonight or tomorrow I'm hoping to get #51 up... and then #52 has already been recorded as well... I'd like to get caught up before going out to ETel where I'm undoubtedly going to get more recordings for special editions.

Blue Box Podcast #48 out with our predictions for 2007, VoIP security news, etc. - and the frustrating audio issues in post-production

Earlier this week I uploaded Blue Box Podcast #48, where Jonathan and I go beyond just talking about the news to also review the "top VoIP security news stories of 2006" and also get into our predictions for 2007. My prediction #1 will be fairly obvious for anyone who has listened to the show for a while. We also cover the typical range of VoIP security stories, talk about OpenID for caller authentication and many more things.

This was a bit frustrating of a show to post-produce. Post-production is always a somewhat lengthy process, anyway, because I want the enhanced audio that you get from a wideband codec, which means that we use Skype. However, Skype creates its own challenges with voice that will simply fade away or get garbled. It's fairly routine that we have to disconnect and reconnect a time or two within the space of the hour in which we are recording the show. (That's actually apparent in this show where Jonathan's voice is at a lower level and then suddenly is much louder. After the reconnect, he wound up with more volume.) If I could get the audio quality in a softphone without the fade outs, I'd probably drop my post-production time by a good bit.

However, this week I couldn't blame Skype. I record the show in Audacity and it appears that because I had been previously editing a file located over on a USB hard drive, Audacity started writing its files for the new episode over on that hard drive. As anyone using Audacity will know, it writes a huge number of files to disk. Basically many, many little files with small pieces of audio in them. What seems to have happened is that periodically parts of the audio didn't get written. Or the files got destroyed. Or who knows what. Perhaps I had too many other apps running on the older computer I'm using for recording and Audacity couldn't keep up with what was being sent to it. Perhaps there was too much latency going to the USB hard drive. I don't know, but the end result was that there were gaps in the audio that got worse as the show went on. Just missing pieces of audio.

Unfortunately, I discovered it after the holidays were already underway and I couldn't really reconnect with Jonathan to rerecord. And also unfortunately, I wasn't running a backup record as I have in the past.

Given that my goal is high-quality audio production, this was a rather disappointing turn of events, but in the end I did put it out there with a big caveat in the show notes.

We just recorded show #49 today and I made sure to have nothing else running on the PC, to be writing to the main hard drive and to have a backup recorder. Hopefully I'll not experience the issue again.

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Blue Box Podcast #47 is now live... VoIP security hype, governments blocking Skype, SANS and VoIP training, more...

Blue Box Podcast #47 is now available for download. In this show, Jonathan and I talk about some of the recent articles and reports hyping VoIP security, recent comments from SANS about the need for better VoIP security training, moves by the Indian government to block Skype and other VoIP services and much, much more. Tons of listener comments in this show... probably the most we've ever had. See the show notes for all the links and info.

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Ken Camp: "I've been Blueboxed"

(Originally posted at

Finally getting caught up on content recorded for Blue Box, I finished up on Monday night the interview I did with Ken Camp out at Internet Telephony in San Diego and posted the interview today. Ken responded with his post: "I've been Blueboxed", which gave me a laugh because I don't think I've ever seen the show name used as a verb before!


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