Up to this point in the short history of IT, there have really only been two protocols that have been the workhorses for delivering the end user experience:
- ICA (Citrix) - The Independent Computing Architecture was developed by Citrix back in the 90s when they decided to take Windows NT and allow it to manage multiple users remotely accessing it at the same time to run applications - it was called Winview but soon became WinFrame (based on Windows NT 3.51) when the company signed a source code license in 1995. The idea was simple - make the operating system do what it did on a central machine then deliver the interface to the end user on the other end of a network or COM connection. ICA was the protocol that did this heavy lifting and was awesome in the way it conserved bandwidth by only transmitting updated window changes upstream, while end user mouse and keyboard input. Additionally, it supported 128 bit encryption but allowed for and open access model, because the end user's only requirement was that he or she run the Citrix client. on a PC or a purpose built thin client.
- RDP (Microsoft) - As Citrix started gaining awesome traction with the WinFrame product, Microsoft decided it was too much fun for one company to have when Windows NT 4.0 went live in the late 90s, and pulled the source code licensing agreement back and introduce Windows NT 4.0 Terminal Services Edition that allowed multiuser access by their own protocol known and RDP (Remote Desktop Protocol). Besides the act of being a typical "dirty pool" trick for Microsoft, the protocol was also not as robust as ICA - it used "screen scraping" to deal with output changes which required a larger amount of bandwidth and did not have as many channels broken down within the protocol that allowed for more advanced refinement like animation acceleration to improve the end users' experiences. But, for many people, this was "good enough" since there weren't ICA dollar cost premiums associated with the system. Additionally, over time RDP became better accepted because bandwidth amounts increased and things were also improved under the protocol's hood.
Starting with VMWare View 4.0 (formerly VDI), IT managers now have the ability to use a new contending protocol to enhance the end user experience called PCoIP. While it was originally developed by a company called Teradici, VMWare has, I assumed, OEMed it as the preferred desktop delivery protocol for the best end user experience possible.
Why is it primed to deliver the best experience possible? Because rather than breakdown the end user's session into compressed window bitmaps or screen scrapes,PCoIP instead chooses to work with the session at the PIXEL level...a feat that only until now could have been possible because of the exponential growth and distribution ofhigher bandwidth networks. But that's OK - ICA and RDP are staying in their separate camps, so PCoIP has a chance to grow in its adoption.
Plus, PCoIP also offers a feature that has generally been a fickle one with RDP and ICA -Transparent USB Bridging...an absolute MUST HAVE for anybody needing to make the remote access workstation/PC concept as close to the real thing as possible. End users need to access their flash drives and webcams, right :-)?
Old dogs can learn new tricks and in the case of PCoIP, more IT folks should consider adopting the centralized model...you'll be happy you did!