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The iPhone In My Office

I’ve said many times that I would never buy and iPhone. Well, true to my word…I didn’t….yet one graces my desk anyway. A co-worker gave me his older 3G after he upgraded his family to a set of shiny new iPhone 4s. Call it an effort at recycling.

In truth I have no interest in the iPhone as a cell phone, but I look forward to having an iOS platform on which to try some of the more interesting apps that have been offered. With its built-in microphone the iPhone 3G is, for me, a better option than an iPod touch.

In just the day or two that I’ve been tinkering with the iPhone I’ve loaded the Media5 soft phone. Zeeek raved about it some time ago, and it’s G.722 capable which dovetails nicely with our Polycom & Gigaset phones.

While interoperability with our various existing phones seems ok for the purposes of out-of-house calling, I don’t get call media between the Media5 phone and other in-house extensions. There must be some NAT issue with the hand-off of the call from OnSIP to the other in-house phone as OnSIP doesn’t hold onto the media path.

This issue aside, my initial impressions have been good. The call quality is very good, easily on par with the Gigasets.

I made a couple of test calls to compare call quality using the built-in mic & speaker against the Bluetooth headset. While on a call to a wideband capable conference bridge I made a short recording of my voice.

I did this again once I paired the iPhone with my Plantronics Savi Go Bluetooth headset. The Savi Go is a wideband capable headset, so the question I sought to answer was whether the Bluetooth radio on the iPhone would permit wideband calls?

When displayed in a waveform editor the call using the built-in mic & speaker clearly shows energy well beyond the 3.4 KHz limit imposed by the PSTN.

Sadly, the call made using the Plantronics Savi Go headset does not show this same wideband energy distribution. As you can see in the above screen shot, the energy is clearly clipped at around 3.4 KHz. Apparently the Bluetooth radio on the iPhone does not permit wideband audio calls.

C’est la vie.

I look forward to learning something new about voice-over-Wifi using the iPhone. It’s been a while since I last gave that a try.

This Post Has 4 Comments
  1. Interesting regarding calling in-house extensions. Using sipdroid connected to Onsip, I am unable to call in house extensions as well. Meanwhile every out of network call has worked perfectly.

    1. Yet calls between my various Polycom and Gigaset phones work fine, in-house and externally. I’m sure that there’s an issue with handling of media and reinvites. If it gets to be a bother I may chase it with OnSIP and Media5.

  2. Hmm, I wonder if intra calls between these sip clients would work? If you get a chance, call hero@ the same domain as before. Should ring the sipdroid client.

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