The real-time total call legs object is a real-time snapshot
metric indicating a count of the number of SIP call legs
being handled by the SIP service. A call leg is also known
as a SIP dialog. The object value includes incoming,
outgoing and ringtone type call legs. For each active call
in the SIP subsystem, there will be an incoming call leg and
an outgoing call leg to the destination of the transfer
label.