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New and Changed Features


This section describes the new features and enhancements to existing features in the Junos OS main release and the maintenance releases for ACX Series Universal Metro Routers.

Release 17.4R2 New and Changed Features

There are no new features or enhancements to existing features for ACX Series in Junos OS Release 17.4R2.

Release 17.4R1 New and Changed Features


  • Support for multiple, smaller configuration YANG modules (ACX Series)—Starting in Junos OS Release 17.4R1, the YANG module for the Junos OS configuration schema is split into a root configuration module that is augmented by multiple, smaller modules. The root configuration module comprises the top-level configuration node and any nodes that are not emitted as separate modules. Separate, smaller modules augment the root configuration module for the different configuration statement hierarchies. Smaller configuration modules enable YANG tools and utilities to more quickly and efficiently compile and work with the modules, because they only need to import the modules required for the current operation.

    [See Understanding the YANG Modules That Define the Junos OS Configuration.]

Timing and Synchronization

  • Enterprise profile for Precision Time Protocol (PTP) (ACX1100 Router)—Starting with Junos OS Release 17.4R1, the enterprise profile, which is based on PTPv2, provides the ability for enterprise and financial markets to timestamp on different systems and to handle a range of latency and delays. The enterprise profile supports the following options:

    • IPv4 multicast transport

    • Boundary clocks

    • 512 downstream slave clocks

    You can enable the enterprise profile at the [edit protocols ptp profile-type] hierarchy.


    On ACX Series, the enterprise profile for PTP is supported only on ACX1100 AC router.