Dell Precision R5400 Remote Access Device: Task-Based User Guide  - Page 19

PCoIP Technology User Guide (Vol I) Addressing Fairness One issue in network usage is fairness, or the fair sharing of the network resources. Without control, some users may end up getting a larger share of network bandwidth than other users. The administrator can improve fairness by configuring Device Target Bandwidth, e.g. through the Administrative Interface. Target Bandwidth Example This section outlines a simplified example of configuring Device Bandwidth Target to improve fairness. The following parameters are considered: • Four users sharing a 100 Mbps link • All users constantly active using graphically intensive applications (approx. 60% of display changing) • Device Bandwidth Limit set to 0 Mbps (i.e. PCoIP Technology adjusts bandwidth usage depending on congestion to allow users to take advantage of unused bandwidth when available) • Bandwidth measured over 60min at 5sec intervals • Device Bandwidth Target settings: No (0 Mbps, 20 Mbps, 25 Mbps and 30 Mbps No Device Bandwidth Target The figure below shows 4 users sharing a 100 Mbps link. Each user has the following bandwidth configuration: • Device Bandwidth Limit: 0 Mbps • Device Bandwidth Target: 0 Mbps Figure 15: No Device Bandwidth Target From the figure above, we can see: • Many dips below 17 Mbps • Grossly "unfair" at times as some users always 'stuck' with lower bandwidths © 2008 Teradici Corporation TER0806003 Issue 1 20 Mbps Device Bandwidth Target Now each user has the following bandwidth configuration: • Device Bandwidth Limit: 0 Mbps • Device Bandwidth Target: 20 Mbps Figure 16: 20 Mbps Device Bandwidth Target In the figure above, we now see • Clamps at 20 Mbps • No one more than 20% of the time below "fair" usage 25 Mbps Device Bandwidth Target The bandwidth parameters are now updated so each user has the following bandwidth configuration: • Device Bandwidth Limit: 0 Mbps • Device Bandwidth Target: 25 Mbps Figure 17: 25 Mbps Device Bandwidth Target With Device Bandwidth Target set to 25 Mbps, we see: • 25 Mbps per connection is the network capacity (100 Mbps / 4 users) • Congestion management keeps bandwidth tight around 25 Mbps • Some dips down to 19 Mbps Page 19 of 25