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NE40E V800R010C00 Configuration Guide - System Monitor 01

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Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).


IP Flow Performance Monitor (FPM) is a Huawei-proprietary feature that measures packet loss rate and delay of end-to-end service packets transmitted on an IP network. This feature is easy to deploy and provides an accurate assessment of network performance.


As IP services are more widely used, fault diagnosis and end-to-end service quality analysis are becoming an increasingly pressing concern for carriers. However, absence of effective measures prolongs fault diagnosis and increases the workload. IP FPM is developed to help carriers collect statistics and monitor end-to-end network performance.

Basic Concepts

The IP Flow Performance Monitor (FPM) model describes how service flows are measured to obtain the packet loss rate and delay. The IP FPM model is composed of three objects: target flows, a transit network, and the statistical system. The statistical system is further classified into the Target Logical Port (TLP), Data Collecting Point (DCP), and Measurement Control Point (MCP). Figure 2-1 shows the IP FPM model.
Figure 2-1  IP FPM model

  • Target flow

    Target flows must be pre-defined.

    One or more fields in IP headers can be specified to identify target flows. The field can be the source IP address or prefix, destination IP address or prefix, protocol type, source port number, destination port number, or type of service (ToS). The more fields specified, the more accurately flows can be identified. Specifying as many fields as possible is recommended to maximize measurement accuracy.

  • Transit network

    The transit network only bears target flows. The target flows are not generated or terminated on the transit network. The transit network can be a Layer 2 (L2), Layer 3 (L3), or L2+L3 hybrid network. Each node on the transit network must be reachable at the network layer.

  • TLP

    TLPs are interfaces on the edge nodes of the transit network. TLPs perform the following actions:
    • Compile statistics on the packet loss rate and delay.
    • Generate statistics, such as the number of packets sent and received, traffic bandwidth, and timestamp.

    An In-Point-TLP collects statistics about service flows it receives. An Out-Point-TLP collects statistics about service flows it sends.

  • DCP

    DCPs are edge nodes on the transit network. DCPs perform the following actions:
    • Manage and control TLPs.
    • Collect statistics generated by TLPs.
    • Report the statistics to an MCP.
  • MCP

    MCPs can be any nodes on the transit network. MCPs perform the following actions:
    • Collect statistics reported by DCPs.
    • Summarize and calculate the statistics.
    • Report measurement results to user terminals or the network management system (NMS).

Measurement flags, also called identification flags, identifies whether a specific packet is used to measure packet loss or delay. A specific bit in the IPv4 packet header can be specified as a measurement flag for packet loss or delay measurement.


Currently, the IP FPM Measurement flags cannot use the same Bit with Qos flags.


IP Flow Performance Monitor (FPM) measures multipoint-to-multipoint (MP2MP) service flows to obtain the packet loss rate and delay. In statistical terms, the statistical objects are the service flows, and statistical calculations determine the packet loss rate and delay of the service flows traveling across the transit network. Service flow statistical analysis is performed on the ingress and egress of the transit network. On the IP/MPLS network shown in Figure 2-2, the number of packets entering the network in the ingress direction on R(n) is PI(n), and the number of packets leaving the network in the egress direction on HUAWEI(n) is PE(n).

Figure 2-2  IP FPM statistics collection

The difference between the number of packets entering the network and the number of packets leaving the network within a specified period is the packet loss.
  • The number of packets entering the network is the sum of all packets moving in the ingress direction: PI = PI(1) + PI(2) + PI(3)
  • The number of packets leaving the network is the sum of all packets moving in the egress direction: PE = PE(1) + PE(2) + PE(3)

The difference between the time a service flow enters the network and the time the service flow leaves the network within a specified period is the delay.


IP FPM brings the following benefits to carriers:
  • Allows carriers to use the network management system (NMS) to monitor the network running status to determine whether the network quality complies with the service level agreement (SLA).

  • Allows carriers to promptly adjust services based on measurement results to ensure proper transmission of voice and data services, improving user experience.


The following examples describe how to configure packet loss measurement and two-way delay measurement in end-to-end proactive performance statistics and how to configure packet loss measurement and one-way delay measurement in hop-by-hop on-demand performance statistics.

IP FPM has the following limitations:
  • IP FPM does not support statistics collection on multicast and broadcast streams.
  • IP FPM supports statistics collection on only IPv4 packets and not IPv6 packets.
  • For the packets fragmented within a measurement domain, IP FPM supports statistics collection only on the first fragments. This may lead to byte loss or incorrect byte loss rate.
  • If the interface where the TLP resides is an inter-board trunk interface, a measurement flag is added to delay packets in polling mode in the upstream direction. That is, delay measurement is enabled on all the boards where the trunk interface resides one by one to ensure that a measurement flag is added to one packet each time. If there are N boards where the trunk interface resides and the measurement period is Interval, a delay measurement result is generated after a period of N x Interval at least.
  • If switching from a 1588 clock to an NTP clock occurs during IP FPM, the collected statistics are incorrect.
  • If a configuration change (such as a TLP or flow configuration change) occurs during IP FPM, the collected statistics are incorrect.
  • If a master/slave switchover occurs on a device during IP FPM, the data generated during the switchover does not take effect.
  • During 1588 clock synchronization, IP FPM delay statistics are incorrect.
  • A statistical instance supports at most two InPoint nodes.
  • For multipoint delay statistics collection, the packets that do not support ingress are copied. The statistics cannot be viewed, and no statistics result is available.
  • During traffic switching in master/slave RSG scenarios, there is a low probability that the delay statistics collected within the first period are incorrect.
  • Multipoint delay statistics collection is supported only after all the devices deployed with IP FPM (including MCP and DCP) are upgraded. Otherwise, only single-point delay statistics collection is supported.

IP FPM supports LPUF-50/LPUF-50-L/LPUI-21-L/LPUI-51-L/LPUF-51/LPUF-51-B/LPUI-51/LPUI-51-B/LPUI-51-S/LPUS-51/LPUF-101/LPUF-101-B/LPUI-101/LPUI-101-B/LPUS-101/LPUF-51-E/LPUI-51-E/LPUI-51-CM/LPUF-120/LPUF-120-B/LPUF-120-E/LPUI-102-E/LPUI-120/LPUI-120-B/LPUI-120-L/LPUI-52-E/LPUI-120-E/LPUI-120-CM/LPUF-240/LPUF-240-B/LPUF-240-E/LPUI-240/LPUI-240-B/LPUI-240-CM/LPUI-240-L/LPUF-480/LPUF-480-B/LPUI-480/LPUI-480-B/LPUI-480-L/LPUF-480-E/LPUI-480-CM/LPUI-200/LPUI-200-L/LPUF-200/LPUF-200-B/LPUI-1T/LPUI-1T-B/LPUI-1T-L/LPUI-1T-CM/LPUI-2T/LPUI-2T-B/LPUI-2T-CM service boards.

In P2MP (MP being two points) and MP2P (MP being two points) delay measurement scenarios, all devices in the delay measurement area must support P2MP delay measurement. Otherwise, delay measurement fails.

Updated: 2018-07-12

Document ID: EDOC1100028538

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