Comtech EF Data CDM-570/L Vipersat Parameter Editor - Manual (Page 50)

Vipersat
2-34 CDM-570/L, CDD-56X Parameter Editor User Guide
The Entry Channel mode is designed to accommodate the needs of remotes that
will not be continuously connected to the network, but which have the need to
be able to make an on-demand connection when required, such as in a mobile
remote.
Note: In ECM mode, the switch occurs as soon as the Hub receives an STDMA
ACK even though there may not be traffic at that time.
Fixed
In the Fixed mode, all remotes have the same slot size regardless of the type of
traffic or load.
No calculations are made to actively change slot size when operating in this
mode.
GIR (Guaranteed Information Rate)
In the GIR mode, the initial computed slot size value is the same as the
Dynamic Cycle mode except there is no maximum limit. After all remotes have
been assigned slots, the burst map is checked to see if the total cycle length
exceeds one second. If not, then all requirements are satisfied and the burst map
is complete. However, if the cycle is greater than one second, then the slots are
adjusted proportionally so that all remotes receive at least their guaranteed rate,
plus whatever excess is still available.
When the one second restriction is exceeded, remotes without a specified GIR
are reduced to the global minimum slot size and the remaining bandwidth is
distributed to remotes that have been assigned a GIR value. Remotes assigned a
GIR bandwidth allocation are given available excess bandwidth when needed.
Note: GIR allocations are restricted so that assigned GIR totals cannot exceed
the available bandwidth to insure proper bandwidth allocation when the
network is overloaded. Attempts to enter a GIR which would result in a
spin time of more than one second will error out.
The bandwidth allocation method selected will determine which of the associ-
ated parameters are available and applicable for that allocation method.
Depending on the capability of the CDM-570/570L and its function in the
network, some of the following parameters may be grayed out and unavailable.
Group ID
Active for both Hub and Remote modems.
The STDMA group ID number defines a group of equipment which will
respond to the output of a single STDMA burst controller. This group is
NOTE
NOTE