This object represents the total number of upstream
bytes sent on this SGSN data path. Data flow from
MS to PDN is considered to be upstream traffic.
When the throughput intervals (cGgsnThruputIntervalOne or
cGgsnThruputIntervalTwo) is set to some valid value this
object is set to '0' (meaning, a fresh throughput collection
is started). Until the first expiry of the throughput
interval , this object will be '0'. On further periodic expiry,
the throughput upstream byte count per SGSN is collected and
updated to this object