Comtech EF Data CIM-550 Installation And Operation Manual page 164

CiM-550 IP Enabled Satellite Modem
CLI and Telnet Interface
Menu Options/Fields
Max Bandwidth
Priority
Entry Description
packets for a route because of a lack in carrier
bandwidth. The Min Bandwidth is entered in multiples
of 8 Kbps.
# The Max bandwidth field establishes a hard maximum
traffic rate that can be processed by the CiM before it
starts to silently discard traffic. A value of 0 for this field
implies that no maximum limit is assigned to a route.
This value is entered in multiples of 8 Kbps.
# Priority allows the user to specify a specific route to be
prioritized as either Priority 1 or Priority 2. Priority 1
was intended to be used when the route is servicing
traffic that requires as much latency and jitter
suppression as possible, for example RTP (voice)
traffic. All other traffic should be given Priority 2, to
ensure that mission critical traffic using Priority 1 will
have no performance degradation. Default value for
Prioity is 1.
NOTES on QoS and QoS Prioritization:
On input of Min B/W per route, please ensure SUM of
Min B/Ws do not exceed total modem Transmit
bandwidth. This is not automatically checked by CLI.
When a Min B/W is specified for any Priority 1 or
Priority 2 Route, All Priority 1 Max B/Ws are
automatically calculated and filled in based on the
following explanation:
The CLI sums all routes' Min B/W (MINSUM) and then
calculates Excess Bandwidth = Total Modem Tx
Bandwidth - MINSUM
The Excess Bandwidth is then equally distributed
across the number of Priority 1 streams. That means
the Max B/W per Priority 1 stream is automatically filled
in as that specific route's MIN plus the divided up
Excess Bandwidth.
This is done for two reasons:
If a Priority 1 route does not have a Max B/W limit, it
will take all excess bandwidth, starving any Priority 2
from its guaranteed MIN B/W. This ensures Priority 2
MIN B/W settings are honored.
To calculate for the administrator -- given all configured
Min B/Ws, total bandwidth of modem, and equally
distributed excess bandwidth across all Priority 1
routes -- what the Max B/W would be for each Priority 1
specific route.
Please note that when no MINs are specified the MAXs
are left at zero, meaning QoS is handled on a pure
priority basis.
Max/Min B/W settings are given in 1024 blocks. To
calculate the actual B/W setting simply multiple the
number shown by 1024. Alternatively note, that Tx
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