User guide

EDA System Services
1/1551-HSC 901 35/3 Uen C 2005-12-02
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Two End-users are shown in Figure 34 on page 44. The DSL configuration
is set for the total bandwidth of the entire customer services combined.
End-user 1 has four EDA Services, which gives a total bandwidth demand
of 13184 kbps downstream, and 1216 kbps upstream. The bandwidth for
each PVC is set individually, and the DSL bandwidth is set to the total
amount of all PVCs bandwidths together.
End-user 2 has one EDA service (single PVC) that contains two CoS flows:
high priority for video and low priority for data. The bandwidth needs for the
PVC is 12288 kbps downstream and 640 kbps upstream. It is not possible
to configure the bandwidth of each CoS flow individually.
The DSL bandwidth can also be set to less than the sum of the services
bandwidth. In this case, the bandwidth of the services will decrease
according to the priority of each service, when simultaneously used
services demand more than the available DSL bandwidth.
The control of the upstream bandwidth for each service should be done by
the CPE modem. The IP DSLAM supports Integrated Local Management
Interface (ILMI) for the configuration of the CPE modem. If the CPE modem
does not support ILMI, the IP DSLAM can force upstream policing. No
matter how the CPE modem is configured, the total upstream bandwidth
can never exceed the DSL upstream bandwidth.
The bandwidth of the EDA Services can be changed on the fly. In order to
be able to do that, the DSL bandwidth must be set to the highest requested
bandwidth. That means that there might be situations where the DSL
bandwidth is larger than the sum of all the PVCs bandwidths. If there is no
total control over the configuration of the CPE modem PVC upstream
bandwidth, it is possible to impose policing in the Ethernet layer in the IP
DSLAM. The policing can be imposed per PVC, CoS flow or both. Please
note that policing, unlike shaping, discards packets if the specified
bandwidth is exceeded even in short periods.