H3C Technologies H3C MSR 50 - Manual (Page 103)

Configuring NetStream
Overview
Conventional ways to collect traffic statistics, like SNMP and port mirroring, cannot provide precise
network management because of inflexible statistical methods or the high cost of required dedicated
servers. This calls for a new technology to collect traffic statistics.
NetStream provides statistics about network traffic flows, and it can be deployed on access, distribution,
and core layers.
NetStream implements the following features:
• Accounting and billing—NetStream provides fine-gained data about network usage based on
resources such as lines, bandwidth, and time periods. The ISPs can use the data for billing based
on the time period, bandwidth usage, application usage, and QoS. Enterprise customers can use
this information for department chargeback or for cost allocation.
• Network planning—NetStream data provides key information, such as the AS traffic information,
for optimizing the network design and planning. This helps maximize the network performance and
reliability while minimizing the network operation cost.
• Network monitoring—Configured on the Internet interface, NetStream allows for monitoring traffic
and bandwidth utilization in real time. Based on this information, administrators can understand
how the network is used and where the bottleneck is, so they can better plan for the resource
allocation.
• User monitoring and analysis—NetStream data provides detailed information about network
applications and resources. This information helps network administrators efficiently plan and
allocate network resources, which helps ensure network security.
NetStream basic concepts
Flow
NetStream is an accounting technology that provides statistics on a per-flow basis. An IPv4 flow is
defined by the following 7-tuple elements: destination address, source IP address, destination port
number, source port number, protocol number, ToS, and inbound or outbound interface. The 7-tuple
elements define a unique flow.
NetStream operation
A typical NetStream system comprises the following parts:
• NetStream data exporter (NDE)—The NDE analyzes traffic flows that pass through it, collects
necessary data from the target flows, and exports the data to the NSC. Before exporting data, the
NDE might perform processes on the data, such as aggregation. A device with NetStream
configured acts as an NDE.
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