Display Protocol FUD
By ThinGuy on Oct 02, 2007
The competition is clearly reading white papers from 1999 and picking low hanging fruit since “SLIM” was a name chosen while trademarks and patents were being completed for the Appliance Link Protocol (ALP). Would it be fair to compare the competitions thin client offerings or protocol support from 1999? We choose not to do so since it's highly unethical, not to mention embarrassing for them. Sun Ray has always had 24 bit color, CD quality audio, bi-directional audio and could play 30 Frames per second with ShowMeTV and MPEG-2 movies.
Comparing ALP to VNC on one hand is a compliment as both are protocols which is independent of any operating system, windowing system, and application. A key difference between the two approaches is the manner in which the display is updated. With the Sun Ray protocol, updates are transmitted from the server to the consoles as they occur in response to application activity. VNC, on the other hand, uses a client-demand approach. Depending on available bandwidth, the VNC viewer periodically requests the current state of the frame buffer. The server responds by transmitting all the pixels that have changed since the last request. This helps the system scale to various bandwidth levels, but has the drawback of larger demands on the server in the form of either maintaining complex state or calculating a large delta between frame buffer states.
Most people in the server based computing industry have used VNC and while most would agree it is an interesting technology that fills many needs, most will also agree that their experience with the VNC protocol is that even in low-latency, high-bandwidth environments VNC is sluggish at best and not a good solution for a thin client protocol. Thus the competitions comparison of ALP to VNC and calling them “somewhat similar” is done to invoke thoughts of sluggish performance, no device access, no multimedia features. Further complicated by a connection process of having launching the VNC server and then telling the VNC client which server instance and port number to connect to.