HP Velocity Technology Overview
Copyright © 2013 LiveQoS Incorporated All Rights Reserved Microsoft, Windows, and Windows Vista are U.S. registered trademarks of Microsoft Corporation. Confidential computer software. Valid license from HP required for possession, use or copying. Consistent with FAR 12.211 and 12.212, Commercial Computer Software, Computer Software Documentation, and Technical Data for Commercial Items are licensed to the U.S. Government under vendor's standard commercial license.
Contents Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 HP Velocity technology overview 4 Quality of Experience with HP Velocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Benefits of HP Velocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 HP Velocity components . . . . .
HP Velocity technology overview Quality of Experience with HP Velocity HP Velocity is a Quality of Service (QoS) software engine that improves the overall Quality of Experience (QoE) for real-time network applications. Real-time streaming applications delivered over data networks can be compromised by packet loss and transmission latency; this results in stop-and-go behavior, loss of interactivity, and an overall reduction in the throughput of an application.The experience dissatisfies application users.
NOTE: HP Velocity protects flows between HP thin clients and HP Velocity-enabled virtual desktops or terminal services servers. Benefits of HP Velocity Adaptive HP Velocity continuously monitors end-to-end network conditions network analysis for individual data flows, providing adaptive optimizations and data flow protection. Monitoring HP Velocity collects and reports an extensive set of statistics: • System Information: Operating system, network adapter, CPU, and memory usage.
HP Velocity components The HP Velocity solution consists of three key components (Figure 2), which form an integrated system dedicated to improving the overall QoE. Figure 2. HP Velocity components Network Profiler The Network Profiler profiles the network path between HP Velocity-enabled endpoints. It identifies the type of network connectivity (wired or wireless) and measures key network metrics (packet loss, latency, bandwidth constraints) independently for each flow.
3. LiveTCP: Optimizes TCP throughput over all networks and provides latency mitigation for RDP, RGS, and ICA protocols. HP Velocity improves the throughput of streaming and remote desktop applications by modifying TCP flow control mechanisms to perform better in highlatency environments. For more information, see “LiveTCP” on page 13. LiveQ Packet loss occurs when one or more data packets traversing a network do not reach their destination.
UDP QoE and packet loss UDP does not provide a recovery strategy for packet loss, and applications that use UDP are directly impacted by even small amounts of packet loss. UDP-based applications typically react to packet loss by slowing down or reducing bitrate.
Encoding modes The encoding mode determines the number of logical data segments that are generated based on the original packet. HP Velocity automatically adapts a flow’s encoding mode according to the configured TLR and to the flow’s current network conditions. Figure 4 demonstrates how HP Velocity selects the appropriate encoding mode based on measured network loss and TLR. In this case, HP Velocity changes encoding modes to keep the correct loss level below a TLR of 0.04%. Figure 4.
LiveWiFi WiFi is constrained for a number of technical reasons and, as a result, delivers a much lower network performance experience. High-end, consumer-grade WiFi access points (APs) advertise that they are capable of speeds of 300 to 450 Mbps. In reality, WiFi capacity is much lower than advertised (Figure 5): • Distance (signal strength): The further away a WiFi-enabled device is from the AP the lower the signal strength, which in turn lowers the effective available throughput.
• Management overhead: WiFi networks carry a significant amount of management overhead. APs advertise their presence and wireless clients must regularly probe the AP to notify it that they are still there. When there are a large number of WiFi devices present in a single location, the management overhead becomes excessive and the capacity of the WiFi network is reduced. • Acknowledgments: All WiFi packets must be acknowledged by the receiver to ensure successful delivery.
TCP on WiFi Standard TCP traffic acknowledgments interfere with the transmission of useful data on a WiFi network (Figure 6). With LiveWiFi enabled, HP Velocity modifies the rate of TCP acknowledgments to reduce protocol overhead and improve network performance. This can liberate up to 15% of additional usable WiFi bandwidth. Figure 6.
LiveTCP Real-world IP networks introduce both latency and packet loss to application flows. A primary cause of these issues is network congestion. TCP retransmits lost packets, providing applications with guaranteed, correctly sequenced packet delivery. TCP also has built-in algorithms to avoid excessive congestion of the network.
By improving on native TCP, LiveTCP accelerates the speed at which thin client protocols transmit data. For example, RDP, which is highly sensitive to latency, can benefit from LiveTCP by improving transmission speeds up to 10 times. RGS improvements are in the range of two to three times faster, whereas ICA is up to twice as fast with LiveTCP.
Summary HP Velocity's patented technology is available exclusively on HP thin clients. It provides a seamless, integrated QoE solution for both managed and unmanaged networks. This allows organizations to gain valuable insight into their thin client data flows, offload more expensive infrastructures (such as MPLS networks) to lower cost networks, and achieve maximum performance regardless of network conditions.
