CAUSE:

    Most latency issues are network problems due to limited bandwidth.
    When millions of people are on Zoom or other video conferencing,
    the networks get clogged or overloaded.

ISOLATION:

    Try to determine who IS and who IS NOT experiencing latency.
    If it is only one Zoom user, and it happens consistently, it is
    likely their equipment (routers, hubs, etc.) or that of their
    internet service provider (ISP: like SBC, Comcast, etc.).

    If many Zoom users experience latency, but at different times,
    the bottleneck is with the internet backbone (MCI, Sprint, ATT, etc.).