Juniper G10 CMTS, Hardware Manual

Page: 79 / 210

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System Architecture Overview
Data Path Processing
63
Upstream Data Path
Following is a description of the flow of a packet through the upstream data path of a DOCSIS
Module:
1. If you have configured and applied a subscriber management or IEEE 802.1 input filter,
a packet received on a cable interface of a DOCSIS Module is evaluated based on the
filter configuration and is either dropped or passed.
2. If the packet is not dropped by an input filter, it is classified to an ingress unit and either
bridged (Layer 2) or forwarded (Layer 3), depending on the configuration of the ingress
unit, to the egress unit.
3. If you have configured and applied a subscriber management or IEEE 802.1 output filter,
the packet is evaluated based on the filter configuration and is either dropped or passed.
4. If the packet is not dropped by the output filter, it is sent to QoS processing, where it is
ordered and scheduled based on its QoS parameters and the traffic scheduling policy
you have configured. If you have configured a congestion management policy, the
packet might be dropped, depending on its projected queue traversal latency.
5. The packet is transmitted to either the NSI or the HFC network on the physical interface
associated with the egress unit.