Tech: VDI Remoting Protocols Turned Inside Out

During Microsoft’s educational event Teched Europe in Berlin beginning this month, Bernard Tritsch, CTO of Immidio presented a session called: RDP, RemoteFX, ICA/HDX, EOP and PCoIP – VDI Remoting Protocols Turned Inside Out. The session presents the outcome of unbiased testing of different remoting protocols in LAN and WAN situations. These testings and findings were performed together with Shawn Bass an independant consultant, who is very active in the server based computing community.

The session starts with explaining the desktop composition, which consists of different ways to present graphics and multimedia, namely GDI, DirectX, PDF, OpenGL, Windows Presentation Foundation, Flash, Silverlight, videos and animations, and what makes up the desktop remoting architecture.


Rendering and client side versus host side rendering are discussed and the most popular remoting protocols are presented:

  • Microsoft RDP and Microsoft RDP 7.1 with RemoteFX (formerly known as Calista)
  • Citrix ICA and HDX for XenApp and XenDesktop (formerly known as PortICA)
  • Quest EOP (Experience Optimized Protocol, RDP+)
  • VMware/Teradici PCoIP (PC over IP)
  • Ericom Blaze (RDP+)
  • Red Hat RHEV SPICE (Simple Protocol for Independent Computing Environments, through acquisition of Qumranet)
  • HP RGS (Remote Graphics Solution)
  • Oracle/Sun ALP (Appliance Link Protocol, Sun Ray)
  • Oracle/Sun/Tarantella AIP (Adaptive Internet Protocol)

After that a protocol comparison is made differencing between protocols with and without hardware acceleration. The comparison details the different presentation methods versus the tested remoting protocols in a LAN and WAN situation.



  • Remoting protocols play a significant role for different Virtual Desktop products and solutions
  • Critical network factors:
    • Bandwidth – the protocols take all they get, 2 MBit/s required for good UX
    • Latency – at 50ms things start getting tough (sometimes even at 20ms)
    • Packet loss – should stay under 1%
  • The new concepts require additional hardware (GPUs for the masses)
    • Microsoft RDP 7.1 with RemoteFX on the LAN (partner enhancements for WAN)
    • Citrix HDX 3D on both LAN and WAN
    • Teradici PCoIP on the LAN