[[overview]]
== Overview

The synchronization work described in this engineering report is a continuation
of work that was begun in Testbed 11 and described in the document OGC 15-011r1,
OWS-11 Reference Case Study of Multiple WFS-T Interoperability ER.

Although the synchronization protocol describe in this engineering report is
generic, the primary concern of this document is describing synchronization
between web feature services.

The synchronization protocol is based on the concept of a change set.  A change
set is a list of data objects that have changed, from some specified checkpoint,
that is exchanged between synchronization peers.

Clause <<Components>> describe the components used in Testbed 12 as the test
platform for synchronization .

Clause <<SynchronizingFeatures>> describes how features listed in a changes set
should be processed by a requesting peer.

Clause <<AccessingTheChangeSet>> defines the operations, resources and messages
that are necessary of accessing the change set of a server.