VoIP – Page 27 – Graves On SOHO Technology

HDVoice: A Visual Analogy

September 16, 2011
Michael Graves
Wideband

HDV IP550 Here’s something of a challenge; find a visual way to represent the information density of HDVoice vs a narrowband PSTN call…and try to make it something the everyone can relate to. This is part of my recent attempt at such a display.

The human voice can create sound energy in the range of 80 Hz to 14 KHz. In contrast, the PSTN conveys a much more limited pass-band, typically 300 Hz – 3.4 KHz. That means that the PSTN fails to convey more than 70% of the potential energy in a voice.

Telecom Factoid: This was state-of-the-art when the standard for “Toll Quality” telephony was defined

September 12, 2011
Michael Graves
networking, VoIP

Yes, sir. That little beauty to the right was the current state-of-the-art in 1937. That's when what we call "toll quality" calling was supposedly set down as a standard. In fact, I find it hard to believe that the entire…

Magic Jack Plus Finally Shipping

September 5, 2011
Michael Graves
VoIP, Wideband

magic-jack-plus-300 After being announced to much fanfare at CES 2011 it seems that MagicJack Vocaltec is finally shipping their new MagicJack Plus. The MagicJack Plus device still has a USB plug permitting its use with a computer. However, it also has a network jack allowing it to function as a freestanding FXS device, not unlike a traditional ATA.

This dual-mode operation offers greater flexibility in the face of competition from the like of NetTalk, whose “Duo” interface device doesn’t require the use of a computer. It also answers the wishes of people who have been hacking thin clients to provide a low-cost, low-power platform to host their Magic Jack service*.

The New York Times’ Gadgetwise makes mention of Magic Jack Plus in a piece that is largely focused on Skype’s new home phone line interface device. Over at the Unofficial Magic Jack Support forum users have reported the MJ+ devices started to arrive mid-August.

HDVoice: On The Cheap & Analog RJ-11 Style

HDVoice RJ-11 Wall Plate A short while back I addressed the question of how DECT & CAT-iq may foster the broad deployment of HDVoice. At that time I described one possible scenario where carriers would deploy customer premises equipment (CPE) with an on-board cordless base station. Although a frontrunner, and the basis of Comcast’s (decidedly non-HD) HomePoint service, this is not the only approach afoot. There’s another possibility arising that involves conveying HDVoice over a plain old analog RJ-11 connection.

At first glance HDVoice and analog lines would certainly seem to be mutually exclusive. The common wisdom is that wideband telephony requires the use of an all-IP call path. This is in fact a generalization, and not absolutely true.

Firstly, it has long been possible to pass wideband audio, in the form of G.722 encoded media, over the PSTN by way of ISDN connections. Also known as BRI interfaces, an ISDN connection supports up to two 64 kbps channels (bearer channels) and one D channel for the purposes of call setup & teardown signaling. High-quality voice using G.722 was one of the selling points of ISDN in the 1980s.

IT Expo West & CloudComm Summit 4

ITEXPO-Logo Let me be blunt, at present I’m just on the periphery of the telecom space. I’m still a user, specifically a home office user. Not being directly involved in the telecom industry I don’t get the opportunity to take part if many of the major industry events. However, when TMC decided to hold IT Expo West 2011 in Austin, TX it proved just too good an opportunity to pass up.

Austin is essentially right in my back yard. “Just over yonder” in local terms. OK, it’s really a two-and-a-half hour drive, but that’s still close compared to its usual location in Los Angeles. When TMC offered a deeply discounted uber-early-bird registration back in February I took the plunge and bought a show pass.

The Gigaset C610A: Dialing By SIP URI

August 22, 2011
Michael Graves
Gigaset, VoIP, Wideband

We’ve had the Gigaset C610A in the house for quite some time. It’s long been on my list of devices for review. However, it’s difficult to find the time to commit to such tasks when the current model of Gigaset is so much like one of the prior models. There’s just no getting around the fact that the C61H handset is very like the C59H, which we’ve had for over two years.

That said, the C610A does offer a few niceties that were suggested to the company when they launched the line in the US back in 2009. Earlier today a new thread in the DSL Reports VoIP Forum prompted me to take just a little time to explore dialing by SIP URI on the C61H handset.