Specifies when the Node will establish an ISUP connection with the SS7 Gateway.
This parameter is used to minimize unnecessary connections to the SS7 Gateway
for ISUP services, allowing the GSX to only establish the ISUP connections that
are required by ISUP circuits on a particular shelf. When set to always,
the ISUP service connection will be established when the node is enabled. When
set to asNeeded, the ISUP service connection will be established only if there
are ISUP circuits assigned to this node. This parameter only applies to ISUP
service registration.