Testing a video telephony system has a lot of aspects. One of the most important ones is the resulting video quality of the system. Problem is, there’s no easy way of doing that. Two approaches exist today for video quality testing: Testing against a known video reference Testing the video without any reference 1. Testing against a known video reference If we receive a video stream that is known in advance, we can
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By Tsahi Levent-Levi | March 17th, 2008 | Filed under Technology
Developing a videophone or any other telecommunication client? You should start thinking seriously about IMS. Today, there are two main standards used for multimedia communications over IP: SIP and H.323, where SIP is the standard which is being adopted by most vendors today - especially in the consumer market. As 3GPP, 3GPP2, TISPAN, Packet Cable and WiMAX have all selected IMS for their next generation networks, it goes without saying that a lot of vendors will start working on IMS
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By Tsahi Levent-Levi | March 6th, 2008 | Filed under Clients
I read a while ago an opinion stating that there is no need anymore for standards - people choose their proprietary way of communication by installing a given application on their desktop or mobile device - be it Skype or one of the other services out there. I disagree with this view. Proprietary solutions definitely have room in our world. If you take telecommunication, the first thing that comes to mind is Skype. They are based on a proprietary protocol,
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By Tsahi Levent-Levi | February 7th, 2008 | Filed under Standardization
It’s the beginning of 2008 and of course, people love to make predictions for the year ahead (if anything to guarantee a good laughter after all). Yours truly is not an exception - this post was thought to appear under the name of Crystal Ball 2008, and it was supposed to make a number of bold (how else) predictions regarding the future of the communication technologies for upcoming year. Thinking about it, isn’t it great to know what the future
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By Anatoli Levine | January 29th, 2008 | Filed under Technology
This is the second part of Interoperability in SIP and its relation to Art. You can read the first part here. SIP Interoperability workshop There were about 20 short but essential presentations at the 90 minutes workshop by the people representing different companies and organizations (yours truly represented IMTC and RADVISION). Overall message was rather unified. It is not all doom and gloom - there is basic interoperability in SIP. But all interoperability is extremely clustered - implementations usually work
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By Anatoli Levine | January 22nd, 2008 | Filed under Interoperability
SIP today is a standard-de-facto, “The Protocol” which runs our multimedia communication. I believe nobody would argue with this statement. All the vendors have their SIP based equipment in the field, so considering the level of maturity of the protocol (about 10+ years old) and more than 20 SipIt events -(SIPit IOT events) as well as numerous IOT events by other consortia and standard bodies, we can expect that majority of devices on the market are highly interoperable.
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By Anatoli Levine | January 15th, 2008 | Filed under Interoperability
We all had that joyful moment of downloading another application from the web. Some of us (well, probably a lot of us) are using Skype - a downloadable client for desktops. But what about mobile handsets? Can we have a downloadable client that truly works on a handset? In the past year, I’ve answered RFIs and RFQs of operators and handset vendors who were seeking to develop a VoIP client. The customers asked for a client that should support
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By Tsahi Levent-Levi | January 3rd, 2008 | Filed under Clients
