In-situ OAM provides real-time telemetry of individual data packets and flows. It is based on telemetry information which is embedded within live data packets. The IOAM WG intends to define data formats and associated procedures for in-situ OAM, including mechanisms for capturing path and path-traversal related information as well as procedures to employ, configure, trigger, and export the embedded telemetry information. 
 
The IOAM WG will define the following in-situ OAM components:
 
* Data-records for in-situ OAM to cover path-tracing and path verification information (node-ids, ingress/egress interfaces), timestamps, transit-delay, transit jitter, sequence numbers, application-defined metadata. In-situ OAM data-records are defined using an in-situ OAM namespace. It should be possible to control the information that gets recorded in data-records.
* Procedures to add, update, remove, retrieve and export data-records for in-situ OAM to live traffic and active probing.  In case of live traffic a classifier to select subset of live traffic for addition, update, removal and retrieval of in-situ OAM data-records. In case of active probing procedure to return the in-situ OAM data records to the source of the probe.
*  Scope of in-situ OAM operation. In-Situ OAM operations are defined for a specific operational domain. In-situ OAM data-records are added and removed at domain boundaries and updated by nodes within the in-situ OAM domain. Procedure to deal with various challenges in packet forwarding and error handling such as ECMP processing, path MTU and ICMP message handling when in-situ OAM is enabled in an in-situ OAM domain.
*  Data-records for in-situ OAM are to be defined in a way that makes them independent from the transport protocol used. Data-records for in-situ OAM will need to be embedded into transport protocols such as IPv4, IPv6, VXLAN-GPE, LISP, NSH, SRv6, Geneve.
* Procedures and data-records optimized for software dataplane and hardware dataplane implementations of in-situ OAM.
* In-situ OAM to support layering. If several transport protocols (e.g. in case of tunneling) are stacked on top of each other, in-situ OAM data-records could be present in every transport protocol layer.
* Management and control of role of nodes for in-situ OAM operation, dynamic control of in-situ OAM data collected in the data records, data export optimization.
 
The IOAM working group intends to work on and publish:
* Definition of the data-type formats used in in-situ OAM and namespaces for in-situ OAM.
* Definition of procedures that in-situ OAM enabled nodes will perform on data traffic that carries in-situ OAM information (e.g., introducing, removing, processing, modifying, and exporting the telemetry information from the associated data packets).
* Configuration and operational data models for controlling in-situ OAM data and operations.
In-situ OAM data records could be embedded into a variety of transports. The transports are expected to be defined in the respective working group(s) like NVO3, SFC, 6man, MPLS etc in consultation with the IOAM working group documents. IOAM WG exclusively focuses on mechanisms which piggyback OAM-related metadata onto en-route traffic for OAM purposes. Other ongoing OAM-related efforts in working groups(s) such as MPLS and IPPM that do not piggyback information onto the live user data traffic are out of scope of the IOAM WG.
 
Milestones
 
April 2018 - submit data format and associated procedures document to IESG.
March 2018 - WGLC for data format and associated procedures document.
April 2017 - working group adoption of data format and associated procedures document