voip

22 Articles

Vocera B1000A Teardown

June 5, 2011 by 17 Comments

vocera_teardown

[Gray] over at Geek Chique had a bit of an eBay mishap and was suddenly the proud owner of 16 Vocera B1000A badges. If you are not familiar, these badges are small, lightweight communications devices similar to the famous Star Trek communicator, which allow users to talk to other individuals via VOIP. He was working on getting the remaining badges up and running by reimplementing the server software, and figured that since one of the badges he purchased was not working, he might as well take it apart.

It took him awhile to get the well-made badges apart, requiring a rotary tool and some elbow grease to get the job done. Inside, he found that the device was split into two circuit boards, one being the “WiFi” board, and the other the “CPU” board. The WiFi board uses a Prism WiFi chipset, which was incredibly common at the time of construction. The CPU board sports small SRAM and flash chips as you would expect, with a Texas Instruments 5490A DSP running the show.

While it remains to be seen if tearing the device down helps [Gray] to get things up and running again, it never hurts to take a closer look to see what you are working with.

Hacking Analog Phones For VOIP

April 23, 2011 by 30 Comments

analog_phone

[Tyler] has been using Google Voice extensively for some time now, but he hasn’t quite found a microphone/speaker setup he is happy with. He tried a headset, but that just didn’t do it for him.

While browsing around at his local thrift store, he came across an old Model 500 rotary phone for just a few dollars and decided it just might do the trick. Once disassembled, he mapped out the circuitry and got busy wiring up the handset to a pair of 3.5 mm stereo plugs – one each for the earpiece and microphone.

Once everything was reassembled, he hooked it up to his computer and gave it a spin – success!

While he is happy with how the phone works at the moment, he already has plans for improving it. He is currently looking for a way to use the handset hook to disconnect calls as well as a way to implement the rotary dial for number entry. We think that hacking a Bluetooth headset would easily take care of the first part, as well as eliminate the need for any sort of wired interface to his PC. It would also make it dead simple to use with any other Bluetooth-enabled device such as a cell phone.

We’re pretty sure he is open to implementation suggestions, so let us know what you think.

Hackit: Why We Don’t Need Phone Numbers

September 4, 2009 by 72 Comments

do_we_need_phone_numbers

[digg=http://digg.com/software/Why_we_don_t_need_phone_numbers]We’re starting to think that phone numbers are deprecated; it may be time to integrate how we connect telephones with the new digital millennium. To get a firm grasp on this topic it is important to take a look at the reason we started using phone numbers, why we still use them, and the why’s and how’s of transitioning to a new system.

Continue reading “Hackit: Why We Don’t Need Phone Numbers” →

Vonage On IPhone

August 27, 2009 by 6 Comments

vPhone2

Vonage has promised to release an official iPhone app to compete with other providers such as Skype, and it is currently working its way through Apple’s well documented approval process. Unfortunately, this app would most likely come with an initial cost and/or subscription fee, though a way has been figured out to retrieve Vonage’s SIP authentication information, which would allow use of the Vonage network over other iPhone SIP Clients such as Fring. This solution does still contain the Wi-Fi only clause, but we have ways of making you talk, iPhone. This could also possibly be used on other platforms with SIP clients such as Android or WinMo.

Customers Make VoIP Calls On American Airlines Flights

August 26, 2008 by 13 Comments


Less than a week after American Airlines introduced in-flight internet, hackers have already figured out how to use the system to make VoIP calls in a few easy steps with Phweet, a Twitter application. While the network blocks most VoIP services, Phweet can connect two people using a Flash app. Aircell, the company responsible for the system, is aware of the oversight, but it remains to be seen whether this little loophole will be fixed in a timely manner. Meanwhile, we encourage those of you who do fly on American Airlines to avoid making those phone calls; your neighbor would probably appreciate it.

[via Digg]

Eavesdropping Encrypted Compressed Voice

June 19, 2008 by 1 Comment


A team from Johns Hopkins University has discovered a way to eavesdrop on encrypted voice streams. Voice data like the kind used by Skype for its VoIP service sends encrypted packets of varying sizes for different sounds. The team learned that by simply measureing the size of the packets, they could determine what was being said with a high rate of accuracy. VoIP providers often use a variable bit rate to use bandwidth more efficiently, but it is this compression that makes audio streams vulnerable to eavesdropping.

The team’s software is still in its early stages of development, yet incapable of parsing entire conversations. It is capable, though, of finding pre-determined keywords and inferring common phrases bases on the words it detects. It also has a higher rate of accuracy in identifying long complicated words than short ones. The team’s goal was not to eavesdrop, but to expose the vulnerability; team member [Charles Wright] notes, “we hope we have caught this threat before it becomes too serious.”

[via Schneier on Security]
[photo: altemark]

Wiretapping And How To Avoid It

June 19, 2008 by 8 Comments


No matter who you suspect is plotting your doom, you’ll need need to know the way wiretapping works in order to learn their plans and shield yourself from their surveillance. Luckily, ITSecurity has posted a comprehensive
article about wiretapping, including information on how to wiretap and how to find out if someone is wiretapping you.

One of the more intriguing methods of wiretapping the articles discusses is a service by a company called FlexiSPY. It works by covertly installing a program onto the target’s cellphone. Once installed, the spying party can listen to anything going on in the room the target is in by calling the phone. It won’t ring, vibrate, or give any indication that it is transmitting audio data.

Some of the more hack-oriented methods involve tapping into a landline, using special software to record VoIP calls, or buying a wiretapping kit. Of course, countermeasures, are also discussed, but some of the links they provide are a little more informative on the topic of defense against wiretapping.