J-Flow Is Juniper Networks’ proprietary protocol for monitoring and collecting IP flows (a flow simply being a series of IP packets moving from a source to destination, across a particular port, thereby sharing characteristics like source/destination IP addresses and ports, protocols and QoS policies).
Much like Cisco’s NetFlow, J-Flow is an IP sampler technology. It samples each input IP stream, or flow. Packets are sampled as they come into a router/switch interface. A new flow is logged if the packet contains unique information pertaining to one of these values: source/destination address, source/destination port, protocols used and so on. Subsequent packets with the same information are updated to the flow.
Packets with parameters differing from the flow are recorded as a new flow, and the previous flow is terminated. The flow data is then sent to a flow collector as UDP packets. The flow collector collects and analyzes the data, and provides pertinent information regarding bandwidth consumption, traffic identification and historical trend analysis.
WhatsUp Gold is traffic monitoring software that collects, monitors and analyzes flow data from a variety of protocols, including J-Flow. Flow Monitor leverages raw J-Flow data from Juniper devices on your network, to create business-impacting reports.
With Flow Monitor you can:
Flow Monitor monitors application performance (say, identifying unauthorized YouTube usage), user traffic (identify users hogging excessive bandwidth) and QoS policy verification. Additionally, by using WhatsUp Gold’s comprehensive reporting features, Flow Monitor produces pertinent reports, including Top Applications, Top Conversations, Top Senders and so on, to offer real-time as well as historical accounts of usage. Thresholds can be configured to track traffic volume, failed connections, unauthorized port usage etc., and real-time alerts can be set up to proactively troubleshoot and resolve performance bottlenecks and security issues.