Dell Precision R5400 Remote Access Device: Task-Based User Guide  - Page 16

PCoIP Technology User Guide (Vol I) 6 Bandwidth Considerations Bandwidth usage in PCoIP Systems varies depending on the use category and desired user experience. This section outlines some bandwidth configuration considerations. Bandwidth Usage PCoIP Systems have four general sources bandwidth usage: • Host to Portal imaging data - dominates bandwidth • HD Audio streams - typically significantly lower bandwidths • USB bridging - typically significantly lower bandwidth • System management - relatively negligible bandwidth Imaging Bandwidth As imaging dominates bandwidth usage, it is important to note these characteristics: • Only changing screen areas generate imaging related network traffic • Low resolution displays have fewer possible pixel changes resulting with less bandwidth usage than high resolution displays • Worst case: high resolution, high contrast, full screen moving image (e.g. video games & real-time 3D rendering) • Configurability to reduce bandwidth requirements vs. user experience • Long periods with no pixel changes result in low average network traffic Audio and USB Bandwidth HD audio and USB considerations: • Audio compression can be enabled to reduce bandwidth during congestion • USB data is not compressed • USB bulk data transfer (e.g. USB FLASH drive) is often in opposite direction (i.e. Portal → Host) to imaging (i.e. Host → Portal) and therefore is not additive © 2008 Teradici Corporation TER0806003 Issue 1 Bandwidth Priorities PCoIP System bandwidth priorities are: • USB and Audio are given priority • Imaging uses remaining available bandwidth Bandwidth Configuration Bandwidth webpage parameters: • Portal webpage defines Portal → Host • Host webpage defines Host → Portal • Bandwidth range: 3 to 220 Mbps Figure 13: Bandwidth Webpage The Bandwidth webpage has two fields: Device Bandwidth Limit • Limits maximum peak; only uses up to limit (or less during periods of network congestion) • '0' allows PCoIP Technology to adjust for congestion; no congestion, no limit • Recommended to set to link limit (minus 10% headroom) of network connected to Host and Portal Note: Device Bandwidth Limit is applied immediately after selecting Apply Device Bandwidth Target • Soft network limit during congestion • During congestion, device bandwidth rapidly reduced to target; then slowly • Allows for more even distribution of user bandwidth on congested trunks • Should understand network topology well before setting to non-zero value Note: Device Bandwidth Target is applied on next PCoIP Session after selecting Apply Page 16 of 25