Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

Guide That Contains This Content
[+] Expand All
[-] Collapse All

    quality-level (Chassis Synchronization Source Interface)


    quality-level (prc | prs |sec | smc | ssu-a | ssu-b | st2 | st3 | st3e | st4 | stu | tnc);

    Hierarchy Level

    [edit chassis synchronization source (bits | gps | interfaces interface-name)]

    Release Information

    Statement introduced in Junos OS Release 12.2 for ACX Series routers.


    For ACX Series routers operating with Synchronous Ethernet, configure the quality level (QL) for a timing source so that the router can know the best available source with which to synchronize. The QL specifies the expected accuracy level of the clock and is transmitted across the network through Synchronization Status Messages (SSMs) over the Ethernet Synchronization Message Channel (ESMC).

    The quality level options are valid depending on the configured network-option; option-1 or option-2 at the [edit chassis synchronization] hierarchy level.

    Both option-1 and option-2 SSM quality levels (QL) are supported:

    • For option-1, QL must be configured for external clocks (gps or bits) whether or not QL is enabled.
    • For option-2, the default QL for external clocks is QL_STU whether or not QL is enabled.


    prc—Timing quality of a primary reference clock (option-1 only).

    prs—Clock traceable to a primary reference source (option-2 only).

    sec—Timing quality of an SDH equipment clock (option-1 only).

    smc— Clock traceable to a self-timed SONET (option-2 only).

    ssu-a—Timing quality of a type I or IV slave clock (option-1 only).

    ssu-b—Timing quality of a type VI slave clock (option-1 only).

    st2—Clock traceable to Stratum 2 (option-2 only).

    st3—Clock traceable to Stratum 3 (option-2 only).

    st3e—Clock traceable to Stratum 3E (option-2 only).

    st4—Clock traceable to Stratum 4 free-run (option-2 only).

    stu—Clock traceable to an unknown quality (option-2 only).

    tnc—Clock traceable to a transit node clock (option-2 only).

    Required Privilege Level

    interface—To view this statement in the configuration.

    interface-control—To add this statement to the configuration.

    Modified: 2016-11-02