In-situ Flow Information Telemetry (IFIT) is a new fashion data plane telemetry technique. Different from the active and passive OAM schemes, IFIT will not generate additional test traffic, but to insert the telemetry instruction into the user traffic, and measure the real user traffic.
1. IFIT Framework [EN]
Publication URL: https://datatracker.ietf.org/doc/html/draft-song-opsawg-ifit-framework
Efficient network operation increasingly relies on high-quality data-plane telemetry to provide the necessary visibility. Traditional Operation, Administration and Maintenance (OAM) methods, which include proactive and reactive techniques, running both active and passive modes, are no longer sufficient to meet the monitoring and measurement requirements. The complexity of today’s networks and service quality requirements demand new high-precision and real-time techniques.
We used to apply active OAM tools for data plane test. Like Ping, and TWAMP. They will generate test traffic and measure the delay, loss of the test traffic to simulate the user traffic. Now there is a trend to apply the IFIT techniques. They will not generate additional test traffic, but to insert the telemetry instruction into the user traffic, and measure the real user traffic. So there are many advantages:
- It can provide fine grained flow SLA monitoring. Active OAM can only provide the path level precision.
- It can measure the real user traffic. Not the simulation way.
- It can monitor very packet behavior in the network. So we can see the sequence of devices the packet visited along its path. The time the packet spent buffered in every switch. The set of rules the packet matched at every device along the way. The flows that the packet shared each queue with. And so IFIT can provide abundant data plane information to enable big data and AI.
2. IFIT E-Book
Publication URL [CN]: https://support.huawei.com/enterprise/zh/doc/EDOC1100195086
Publication URL [EN]: https://support.huawei.com/enterprise/en/doc/EDOC1100201704
This book focuses on the background of IFIT, reveals the reasons why IFIT is attracting attention, expounds the unique technical value of IFIT, and demonstrates the diverse application scenarios and wide development space of IFIT. This book also briefly introduces the implementation principles of IFIT, which will help you better understand the technical advantages of IFIT.
3. Reactive IFIT for IPv6 and SRv6 - MPLSSD&AINetWorld22
Publication URL: PDF - Reactive IFIT for IPv6 and SRv6
1. IFIT Data Plane
Alternate Marking Method
Publication URL: https://datatracker.ietf.org/doc/html/rfc9341
This document describes the Alternate-Marking technique to perform packet loss, delay, and jitter measurements on live traffic. This technology can be applied in various situations and for different protocols. According to the classification defined in RFC 7799, it could be considered Passive or Hybrid depending on the application. This document obsoletes RFC 8321.
Clustered Alternate-Marking Method
Publication URL: https://datatracker.ietf.org/doc/html/rfc9342
This document generalizes and expands the Alternate-Marking methodology to measure any kind of unicast flow whose packets can follow several different paths in the network; this can result in a multipoint-to-multipoint network. The network clustering approach is presented and, for this reason, the technique described here is called “Clustered Alternate Marking”. This document obsoletes RFC 8889.
IPv6 Application of the Alternate Marking Method
Publication URL: https://datatracker.ietf.org/doc/html/rfc9343
This document describes how the Alternate Marking Method can be used as the passive performance measurement tool in an IPv6 domain and reports implementation considerations. It proposes how to define a new Extension Header Option to encode alternate marking technique and both Hop-by-Hop Options Header and Destination Options Header are considered.
Segment Routing Header encapsulation for Alternate Marking Method
Publication URL: https://datatracker.ietf.org/doc/html/draft-fz-spring-srv6-alt-mark
This document describes how the Alternate Marking Method can be used as the passive performance measurement tool in an SRv6 network. It defines how Alternate Marking data fields are transported as part of the Segment Routing with IPv6 data plane (SRv6) header.
Encapsulation For MPLS Performance Measurement with Alternate Marking Method
Publication URL: https://datatracker.ietf.org/doc/html/draft-ietf-mpls-inband-pm-encapsulation
This document defines the encapsulation for MPLS performance measurement with alternate marking method, which performs flow-based packet loss, delay, and jitter measurements on live traffic.
Constrained Application Protocol (CoAP) Performance Measurement Option
Publication URL: https://datatracker.ietf.org/doc/draft-fz-core-coap-pm
This document specifies a method for the Performance Measurement of the Constrained Application Protocol (CoAP). A new CoAP option is defined in order to enable network telemetry both end-to-end and on-path.
Enhanced Alternate Marking Method
Publication URL: https://datatracker.ietf.org/doc/html/draft-zhou-ippm-enhanced-alternate-marking
This document defines data fields for the alternate marking with enough space. The main idea is that more information can be considered within the alternate marking field to facilitate the efficiency and ease the deployment. The definition aims to be general, even if for some protocols there can be dedicated solutions
Data Fields for In-situ OAM
Publication URL: https://datatracker.ietf.org/doc/html/rfc9197
In-situ Operations, Administration, and Maintenance (IOAM) records operational and telemetry information in the packet while the packet traverses a path between two points in the network. This document discusses the data fields and associated data types for in-situ OAM. In-situ OAM data fields can be encapsulated into a variety of protocols such as NSH, Segment Routing, Geneve, IPv6 (via extension header), or IPv4. In-situ OAM can be used to complement OAM mechanisms based on e.g. ICMP or other types of probe packets.
In-situ OAM Direct Exporting
Publication URL: https://datatracker.ietf.org/doc/html/rfc9326
IOAM allows telemetry data to be pushed into data packets while they traverse the network. This document introduces a new IOAM option type called the Direct Export (DEX) option, which is used as a trigger for IOAM data to be directly exported without being pushed into in-flight data packets.
In-situ OAM Flags
Publication URL: https://datatracker.ietf.org/doc/html/rfc9322
This document presents new flags in the IOAM Trace Option headers. Specifically, the document defines the Loopback and Active flags.
In-situ OAM IPv6 Options
Publication URL: https://datatracker.ietf.org/doc/html/draft-ietf-ippm-ioam-ipv6-options
This document outlines how IOAM data fields are encapsulated in IPv6.
Inband Flow Analyzer
Publication URL: https://datatracker.ietf.org/doc/html/draft-kumar-ippm-ifa
In-band Flow Analyzer (IFA) records flow specific information from an end station and/or switches across a network. This document discusses the method to collect data on a per hop basis across a network and perform localized or end to end analytics operations on the data. This document also describes a transport-agnostic header definition that may be used for tunneled and non-tunneled flows alike.
2. IFIT Control Plane
BGP SR Policy Extensions to Enable IFIT
Publication URL: https://datatracker.ietf.org/doc/html/draft-ietf-idr-sr-policy-ifit
Segment Routing (SR) policy is a set of candidate SR paths consisting of one or more segment lists and necessary path attributes. It enables instantiation of an ordered list of segments with a specific intent for traffic steering. In-situ Flow Information Telemetry (IFIT) provides a reference framework that supports network OAM applications to apply dataplane on-path telemetry techniques acquiring data about a packet on its forwarding path. This document defines extensions to BGP to distribute SR policies carrying IFIT information. So that IFIT behavior can be enabled automatically when the SR policy is applied.
PCEP SR Policy Extensions to Enable IFIT
Publication URL: https://datatracker.ietf.org/doc/html/draft-chen-pce-sr-policy-ifit
Segment Routing (SR) policy is a set of candidate SR paths consisting of one or more segment lists and necessary path attributes. It enables instantiation of an ordered list of segments with a specific intent for traffic steering. In-situ Flow Information Telemetry (IFIT) provides a reference framework that supports network OAM applications to apply dataplane on-path telemetry techniques acquiring data about a packet on its forwarding path. This document defines extensions to PCEP to distribute SR policies carrying IFIT information. So that IFIT behavior can be enabled automatically when the SR policy is applied.
In-situ Flow Information Telemetry (IFIT) Node Capability Advertisement
Publication URL: https://datatracker.ietf.org/doc/html/draft-wang-lsr-ifit-node-capability-advertisement
For advertising In-situ Flow Information Telemetry (IFIT) node capabilities within the entire routing domain, this document extends a new optional TLV to the OSPF RI Opaque LSA, a new optional sub-TLV to the IS-IS Router CAPABILITY TLV, and a new Node Attribute TLV that is encoded in the BGP-LS attribute with Node NLRIs to carry IFIT node capabilities information. Such advertisement allows entities (e.g. a centralized controller) to determine whether a particular IFIT functionality can be supported in a given network.
BGP Extension for Advertising In-situ Flow Information Telemetry (IFIT) Capabilities
Publication URL: https://datatracker.ietf.org/doc/html/draft-wang-idr-bgp-ifit-capabilities
This document defines extensions to BGP to advertise the In-situ Flow Information Telemetry (IFIT) capabilities. Within an IFIT domain, IFIT-capability advertisement from the tail node to the head node assists the head node to determine whether a particular IFIT Option type can be encapsulated in data packets. Such advertisement would be useful for mitigating the leakage threat and facilitating the deployment of IFIT measurements on a per-service and on-demand basis.
3. IFIT Management Plane
A YANG Data Model for In-Situ OAM
Publication URL: https://datatracker.ietf.org/doc/html/draft-ietf-ippm-ioam-yang
This document defines a YANG module for the IOAM function.
UDP based Publication Channel for Streaming Telemetry
Publication URL: https://datatracker.ietf.org/doc/html/draft-ietf-netconf-udp-notif
This document describes an UDP-based notification mechanism to collect data from networking devices. A shim header is proposed to facilitate the streaming of data directly from line cards to a collector. The objective is to rely on a lightweight approach to allow for higher frequency and better transit performance compared to already established notification mechanisms.
Subscription to Distributed Notifications
Publication URL: https://datatracker.ietf.org/doc/html/draft-ietf-netconf-distributed-notif
This document describes extensions to the YANG notifications subscription to allow metrics being published directly from processors on line cards to target receivers, while subscription is still maintained at the route processor in a distributed forwarding system.
Problem Statement and Requirement for Inband Flow Learning
Publication URL: https://datatracker.ietf.org/doc/html/draft-hwyh-ippm-ps-inband-flow-learning
This document addresses the challenges of inband flow identification which operators face in large scale deployment. Furthermore, it also proposes the requirements of supporting the IFIT inband flow learning mechanism.
4. Multicast IFIT
Multicast On-path Telemetry Solutions
Publication URL: https://datatracker.ietf.org/doc/html/draft-ietf-mboned-multicast-telemetry/
This document discusses the requirement of on-path telemetry for multicast traffic. The existing solutions are examined and their issues are identified. Solution modifications are proposed to allow the original multicast tree to be correctly reconstructed without unnecessary replication of telemetry information.
1. Reactive In-situ flow information Telemetry
Publication URL: https://portal.etsi.org/webapp/WorkProgram/Report_WorkItem.asp?WKI_ID=59544
The present document will describe the motivation, requirements, and challenges of using flow-oriented on-path telemetry techniques which provides relevant measurement or event reports to the AI-enabled network entities. The present document will outline a reference framework, named as “In-situ Flow Information Telemetry (IFIT)” and identify technical requirements, including: modes of flow-oriented on-path telemetry; IFIT-based reactive telemetry framework; and technical requirements, including intelligent flow and packet selection, intelligent data export, dynamic network probe, on-demand underlying technique selection.
1. Technical requirement of automatic In-situ Flow Information Telemetry (IFIT) for carrier network
2. Dataplane technical requirement of automatic In-situ Flow Information Telemetry (IFIT) for carrier network
1. IFIT: Intelligent Flow Information Telemetry
Publication URL: https://dl.acm.org/doi/pdf/10.1145/3342280.3342292
This is short paper accepted by the SIGCOMM2019 Posters and Demos session.
2. Discover IP new techniques: IFIT
Video URL: https://support.huawei.com/enterprise/en/doc/EDOC1100134313
1. Beijing Unicom and Huawei successfully complete the pilot of IFIT solution on the 5G transport network [EN]
Publication URL: https://www.techgenyz.com/2019/06/28/beijing-unicom-and-huawei-ifit-solution-on-the-5g-transport-network
2. Huawei’s IFIT Solution Wins Best of Show Award Special Prize at Interop Tokyo 2019 [EN]
Publication URL: https://www.capacitymedia.com/articles/3823905/huaweis-ifit-solution-wins-best-of-show-award-special-prize-at-interop-tokyo-2019
3. Huawei launches NetEngine 8000 series of routers [EN]
Publication URL: https://www.lightreading.com/huawei-launches-netengine-8000-series-of-routers/d/d-id/757743
4. Zain Selects Huawei to Build Middle East’s First Intelligent IP Network [EN]
Publication URL: https://telecomdrive.com/zain-selects-huawei-to-build-middle-easts-first-intelligent-ip-network/
5. China Mobile deploied IFIT for large scale on path telemetry in their mobile transport network in Zhejiang Taizhou [CN]
Publication URL: https://baijiahao.baidu.com/s?id=1700078379973126509
6. China Mobile Liaoning released “IFIT intelligent operation solution for transport network” together with Huawei [CN]
Publication URL: https://www.cnii.com.cn/tx/202202/t20220223_359760.html