226Figure 69 IPv6 NetStream systemFlow agingIPv6 NetStream uses flow aging to enable the NDE to export IPv6 NetStream data to NetStream servers.IPv6 NetStream creates an IPv6 NetStream entry for each flow for storing the flow statistics in the cache.When the timer of the entry expires, the NDE does the following operations:• Exports the summarized data to NetStream servers in an IPv6 NetStream data export format.• Clears IPv6 NetStream entry information in the cache.For more information about flow aging types and configurations, see "Configuring IPv6 NetStream flowaging."IPv6 NetStream data exportTraditional data exportIPv6 NetStream collects and exports the statistics of each flow to NetStream servers.This method consumes a lot of bandwidth and CPU usage, and requires a large cache size. In addition,you do not need all of the data in most cases.Aggregation data exportAn IPv6 NetStream aggregation mode merges the flow statistics according to the aggregation criteria ofthe aggregation mode, and it sends the summarized data to NetStream servers. The IPv6 NetStreamaggregation data export uses less bandwidth than the traditional data export.Table 13 lists the available IPv6 NetStream aggregation modes. In each mode, the system mergesmultiple flows with the same values for all aggregation criteria into one aggregate flow. The systemrecords the statistics for the aggregate flow. These aggregation modes work independently and can takeeffect concurrently.
