Hughes HX System, System Overview

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Chapter 5 • Bandwidth management
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in the allocated bandwidth. The decrease amount is
dictated by step-size.
•
Session activity timeout – The period of IP inactivity after
which the session will be disconnected and the bandwidth
freed for use by other satellite routers.
CIR
In this bandwidth assignment service, satellite routers are
allocated bandwidth based on the following parameters:
•
Minimum CIR rate – The amount of bandwidth that will be
immediately allocated to a satellite router at the initiation of a
data session. This minimum CIR is low jitter, as the
bandwidth is assigned to the satellite router until the CIR
session terminates. Minimum CIR bandwidth is prioritized
after configured CBR bandwidth. Termination of the CIR
session is based on idle period.
•
Guaranteed CIR rate – The amount of bandwidth to be
allocated to a satellite modem when the satellite modem’s
bandwidth utilization exceeds the configured threshold
percentage of the minimum CIR value. When this occurs,
bandwidth allocation to the satellite modem is increased to
the configured guaranteed value.
Guaranteed CIR value is available only in the inbound
direction.
•
Maximum CIR rate – The maximum amount of bandwidth
to be allocated to a satellite router when the advertised
backlog exceeds the configured guaranteed.
Note: The idle timeout feature can be disabled in order to
configure nailed-up bandwidth assignment.
Figure 7: CBR services