Load Switching
Table
Figure B-1 Hub autoswitching menu
•Auto Switching - This is a Vipersat Feature which is enabled in the CDM Features Menu. If Auto Switching is not enabled, Load Switching will be ignored.
•Load Switching - This is a type of Automatic Switching that is based on the amount of traffic at a remote. If this mode is not set, then no remote will be switched based on load.
•STDMA Slot Capacity - This is a threshold value. When the amount of outbound traffic at a remote exceeds this percentage of the current STDMA slot capacity, a load switch is initiated. It is important to understand that in most STDMA modes, the amount of bandwidth allocated to a remote varies with need and thus from cycle to cycle. Thus the amount of traffic that constitutes X% will also vary from cycle to cycle. Furthermore, since the D2 allocation algorithm tends to provide no more bandwidth than is needed, remotes operating in this mode will normally appear to be near 100% capacity whenever they are passing real traffic. Thus, in this mode, if the threshold is set too low, switches will occur unnecessarily.
•STDMA Switch Delay- This is a built in latency that forces a remote to maintain an average load over some number of seconds after reaching a switch condition before the switch is actually initiated. This prevents switches due to momentary
•Percent Allocation - This is an excess amount of bandwidth that is allocated beyond the current traffic rate when the switch to SCPC is made. For example, if the current average traffic at the time of the switch is 60K, and the Percent Allocation is 10%, then the allocation will be for 60K + 6K = 66K. (Furthermore, the hub always allocates bandwidth in 16K blocks so 66K rounded up will actually be 80K.)
Appendix B - Automatic Switching |
