Support of Network
Observation Timestamping in YANG NotificationsSwisscomBinzring 17Zurich8045Switzerlandthomas.graf@swisscom.comHuaweibenoit.claise@huawei.comINSA-LyonLyonFrancealex.huang-feng@insa-lyon.frThis document extends the YANG Notification header with the YANG
objects observation timestamping, both for the "push-update" and
"push-change-update" notifications.To correlate network data among different Network Telemetry planes as
described in Section 3.1 of or among different
YANG push subscription types defined in Section 3.1 of , network observation timestamping describes when the
state change was observed or from when to when the data was accounted.
This is essential for understanding the timely relationship among these
different planes and YANG push subscription types.With the delay
between the YANG Notification export and the arrival at the downstream
system storing the data can be measured. With network observation
timestamping described in this document, the delay between the network
observation and the data export of the YANG push publisher process can
be measured as well, extending the delay measurement scope from the time
the network observation and storing the data.By extending the YANG Notification header with the YANG objects
observation-time for periodical and state-changed-observation-time for
on-change subscriptions these use cases can be addressed
accordingly.The following terms are defined in and are
not redefined here:PublisherReceiverSubscriptionIn addition, this document defines the following terms:Observation-time: Describes the measurement observation time for the
"push-update" notification in a "periodical" subscription.State-changed-observation-time: Describes the time when the network
state change was observed.Besides the Subscription ID as described in Section 3.7 of , the following network observation time metadata
objects are part of "push-update" and "push-change-update"
notifications.
observation-time:
Describes the measurement observation time for the "push-update"
notification in a "periodical" subscription. By comparing the
"observation-time" of two "push-update" notifications, the collector
can deduce the actual cadence of the measurements, and compare it with
the configured one.
state-changed-observation-time:
Describes in the "push-change-update" notification in a
"on-change" subscription the time when the network state change was
observed after the subscription was initially established. In case of
an "on-change sync on start" subscription it describes the time when
the network state change was observed before the subscription was
established.
provides an
example of a JSON encoded, ,
"push-change-update" notification message over HTTPS-based or UDP-based transport for the same
subscription.This YANG module augments the "ietf-yang-push" module with the
observation-time in the "push-update" and "push-change-update" streaming
update notifications.The following is the YANG tree diagram
for the ietf-yang-push-netobs-timestamping YANG moduleThe following is the YANG tree diagram
for the ietf-yang-push-netobs-timestamping augmentation within the
ietf-subscribed-notifications, including the RPCs and
notifications.The YANG module has one leave augmenting the model of Subscription to YANG Notifications.The security considerations for the YANG notifications subscription
mechanism are described in . This document adds
no additional security considerations.This document describes the URI used for the IETF XML Registry and
registers a new YANG module name.IANA is requested to add this document as a reference in the
following URI in the IETF XML Registry .
For "on-change sync on start" subscriptions, if the timestamp for
the network state change was observed before the subscription was
established and is not recorded in the YANG datastore, then no
timestamp should be populated to state-changed-observation-time.The authors would like to thank Rob Wilton, Nick Corran, Pierre
Francois Ahmed Elhassany and Jean Quilbeuf for their review and valuable
comments.Support of Hostname and Sequencing in YANG
NotificationsSwisscomHuaweiINSA-Lyon