Comtech EF Data CDM-570/570L Vipersat - Manual (Page 172)

General
D-2 Vipersat CDM-570/570L User Guide
All other standard controls for access into dSCPC are maintained, but because
of a new fixed entry switch type, VMS version 3.9.2 or greater is required.
Because most networks are likely to have Remote sites off-the-air for various
reasons, the task of upgrading all locations during a planned maintenance period
introduces complexity, particularly where the upgrade breaks current protocol.
If this is the case, it will be required to provide additional resources during the
migration to assure all sites—active or inactive—make the transition.
Sites that are active are much simpler to upgrade and modify, but sites that are
inactive must have the old (current) hardware or configuration running to assure
that an upgrade path is available when they reactivate.
These additional resources typically have at least one STDMA Burst Controller
programmed for the inactive sites. This will assure that, when the Remote acti-
vates, it can enter the network as always and allow the operator to upgrade and
migrate the site to the new ECMv2 channel.