sFlow aka sampled flow was first introduced in 1991 by HP. According to an article published by Opservices, sFlow greatly helps IT teams and network administrators to overcome monitoring-related problems so that existing problems become easier to overcome. What exactly is sFlow? What are its advantages and limitations? Find out more by continuing to read this article.

Simply put, sFlow is a simplification of the NetFlow protocol (NetFlow protocol). According to an article published by Iptrc, the concept behind sFlow is random packet sampling to determine broader network traffic trends. The sFlow system consists of several devices that perform random packet sampling and counter sampling based on time. After the sFlow sample packet and counter data are recovered, they are then sent to the sFlow collector as an sFlow datagram. Unlike NetFlow, sFlow can collect traffic from OSI layers 2 to 7 because it is not limited to IP traffic monitoring.

sFlow is divided into 2 components, namely:

The sFlow agent is an internal function in a switch/router that collects information from outgoing packets and forwards samples.

The sFlow collector is a function designed to analyze information delivered by the sFlow agent.

Limitations of sFlow

  1. Accuracy
    For sFlow, accuracy is not a problem if using a high sample rate. Conversely, if the user fails to ensure the sample rate is high enough, it will provide unreliable and inaccurate sample data. For this reason, you must ensure the sample rate is high enough to get accurate readings.
  2. Limited Packet Detail Analysis
    Unlike NetFlow, in using the sFlow sampling rate, it does not provide packet-level details of the protocol. With this, you can only see random packets from the entire packet sent. This allows you to find general trends but it leaves a large gap in your visibility. This gap is certainly not ideal for performing deeper analysis.
  3. Devices Must Be sFlow Compatible
    Make sure your entire network infrastructure supports the sFlow protocol before using sFlow as part of your monitoring strategy. Why? Because if the number of devices that support sFlow is limited, it will dilute your results even further than the initial sampling technique.
  4. Limited Threat Identification
    Every time sFlow performs random sampling, there are a ton of packets that are not visible to the user. This is bad for threat identification because it means you have to recognize malicious packets in the sample. This can reduce your chances of diagnosing an attack and can leave the network vulnerable to outside attackers.

Advantages of the sFlow Protocol

  1. Network Troubleshooting
    Constantly, problems that occur in traffic are seen in abnormal traffic patterns. With sFlow, these patterns can be made visible in detail for rapid identification, diagnosis, and correction.
  2. Controlling Traffic Congestion
    sFlow can be used when monitoring traffic flow continuously across all ports to immediately highlight congested links and identify the source of this traffic. Not only that, sFlow also provides the information needed to build effective controls.
  3. Security and Audit Trail Analysis
    sFlow data can be used to account and charge for network usage by clients. They can also be used to present clients with a breakdown of their total traffic, highlighting the most consuming users and applications. This information gives customers confidence in the accuracy of rates and provides better cost control.
  4. Route Profiles
    sFlow can be used to profile more active routes and verify the specific flows carried by these routes. This is because sFlow contains the information that is forwarded. Understanding routes and flows allows for route optimization, improving connectivity and performance.
  5. Accounting and Billing
    Detailed network usage is needed to collect accurate rates for network services and to recover costs from value-added services. sFlow data can be used to account and charge for network usage by clients. They can also be used to present clients with a breakdown of their total traffic, highlighting the most consuming users and applications. This information gives customers confidence in the accuracy of rates and provides better cost control.

References:

https://www.itprc.com/sflow-vs-netflow/#What_is_sFlow

https://www.opservices.com/o-que-e-o-protocolo-sflow-e-equais-suas-vantagens/