ND SatCom SKYWAN IDU 7000, Manual

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40 Network Design and Engineering Guide 2010-10-26
General Carrier Design
Essential SkyWAN
®
Satellite Link Layer Features
Scenario 4
Both IDU1 and IDU2 are configured for stream mode Stream within Guaranteed Through-
put . The traffic mix (see figure 2-23) consists of:
- A real-time IP based PC application with a bidirectional bandwidth requirement of 128
kbps between these two stations.
- Additionally 2 parallel voice calls served by Sky WAN
®
FAD real-time service should be ac-
tive between the stations.
Figure 2-23 Throughput Scenario 4
Effect
Beside the real-time services application, which consumes 5 streaming slots, for each station
one additional slot is available for other real-time services. This would allow 2 parallel voice
calls. After that the private bandwidth pools for both stations are exhausted. Any additional
streaming slot request from these stations would be rejected by the master, even if there are
still available slots in the common streaming pool. Other stations could use this capacity for
real-time services but IDU1 and IDU2 are limited to their private pools concerning real-time
bandwidth. Additional non real-time services however might still be possible for these stations
if there are unrequested slots in the common streaming or dynamic bandwidth pools.
For the specified real-time applications (PC appli 2 voice calls) both stations will always
have access to the required bandwidth. There is no risk for them to have their real-time services
blocked due to insufficient available streaming slots.
Note, that a reduced flexibility concerning the allocation of stream slots is engineered:
-
IDU1 and IDU2 can never allocate real-time bandwidth beyond their specified guaranteed
throughput.
- All other stations can never allocate real-time bandwidth beyond the specified common
streaming pool.