Comtech EF Data SLM-5650A Vipersat - Manual (Page 99)

Appendix B - Automatic Switching B-1
A
P P E N D I X
A
UTOMATIC
S
WITCHING
General
Automatic switching is a feature of the VMS that allows dynamically changing
the network configuration in response to changes in either traffic type network
traffic loads (Load switching) or Type of Service (ToS) detecting stamped pack-
ets with Diffserv values.
The following material applies to the Vipersat SLM-5650A. For purposes of
simplicity, these units shall be referred to as modem/routers.
The basic signal topology in a Vipersat network is TDM (Time Division Multi-
plex) outbound and Vipersat’s proprietary STDMA (Selected Time Division
Multiple Access) inbound. The STDMA slots can have their duration and band-
width allotments varied, tailoring bandwidth allocation to meet the bursty traffic
load of a typical data network.
When required, a network is switched from STDMA to SCPC. SCPC band-
width is allocated from a bandwidth pool by the VMS to meet QoS or other
requirements for the duration of a connection. When the SCPC connection is no
longer required, the bandwidth is returned to the pool for use by another client.
This basic structure gives the VMS-controlled network its flexible, automated
network utilization and optimization capability.
The VMS has the intelligence to interpret the constantly changing statistics
gathered by the Vipersat modem/routers and uses this data to issue commands
back to these intelligent modem/routers, effectively managing the Vipersat
network operation in real time, and optimizing each user’s bandwidth usage to