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The Virtual Softphone

The thin client is not a new idea but it is gaining traction for many reasons. Wyse, HP and Sun have had thin client products for years. However, these have rarely been applied to VoIP.

The thin client reminds me of the days of the mainframe. The user has a display and keyboard with some (minimal) local processing and an Ethernet connection to the server. The server offers service to multiple users by sharing its resources, processor, disk storage, network connections and other peripherals. There are many advantages to the thin client:

* Lower hardware cost * Far lower energy to power the desktop and cool it (40+% less) * Greater security because there is no local storage and the data cannot be stolen as happens with a laptop * Better management and control * Better backup * Higher availability * Extended hardware life

Microsoft is promoting the Windows Virtual PC. The Windows 7 release is a virtualization program for Windows operating systems. The newest release, Windows Virtual PC, is available only for Windows 7 hosts. Virtual PC virtualizes a standard PC and its associated hardware. Supported Windows operating systems can run inside Virtual PC.

So why hasn't the thin client become a mechanism for VoIP? The answer is poor media support (media = sound, video, picture).

NEC has published a paper "Virtual PC Center (VPCC): The Benefits of Virtual PC with Telephony". The NEC solution has been to move media processing to the edge, in the thin client. The NEC enhanced thin clients, the US 100 and US110, have this edge media processing. The US110/110 devices work with an LCD display and remote (over Ethernet) server. The servers are only used for the call setup. Once the call has been established, the voice path over the IP network is a direct connection from thin client terminal (US110/110) to thin terminal. The NEC thin client includes the codecs for voice so the server does not perform the voice encoding.

The server is no longer involved in the call. Therefore the loading on the server will not have any affect on the voice quality transmission. Running other data applications simultaneously on the server will not interfere with the voice quality as can happen when VoIP is operating on a desktop/laptop PC.

The advantages of the thin client resident media solution are:

* High voice quality because the server is not used for encoding * Low bandwidth consumption * 100% portability of the phone extension to any virtual PC thin client

This is the first announcement I have seen for thin client resident media processing. I do not expect it to be the last announcement for thin client supported media processing. Look at the other thin client vendors for their announcements.

If you already are using thin clients, check with your vendor to see if your thin clients can be upgraded with media processors. The virtual softphone is another competitor that will slow the use of IP phones.