diff --git a/engine/callcost.go b/engine/callcost.go
index 367789cd4..499e1c09b 100644
--- a/engine/callcost.go
+++ b/engine/callcost.go
@@ -66,3 +66,10 @@ func (cc *CallCost) GetStartTime() time.Time {
 	}
 	return cc.Timespans[0].TimeStart
 }
+
+func (cc *CallCost) GetTotalDuration() (td time.Duration) {
+	for _, ts := range cc.Timespans {
+		td += ts.GetDuration()
+	}
+	return
+}
diff --git a/sessionmanager/fssessionmanager.go b/sessionmanager/fssessionmanager.go
index fe989f0a9..130971b66 100644
--- a/sessionmanager/fssessionmanager.go
+++ b/sessionmanager/fssessionmanager.go
@@ -315,8 +315,8 @@ func (sm *FSSessionManager) OnChannelHangupComplete(ev Event) {
 
 }
 
-func (sm *FSSessionManager) LoopAction(s *Session, cd *engine.CallDescriptor, index float64) {
-	cc := &engine.CallCost{}
+func (sm *FSSessionManager) LoopAction(s *Session, cd *engine.CallDescriptor, index float64) (cc *engine.CallCost) {
+	cc = &engine.CallCost{}
 	cd.LoopIndex = index
 	cd.Amount = sm.debitPeriod.Seconds()
 	cd.CallDuration += time.Duration(cd.Amount) * time.Second
@@ -326,18 +326,14 @@ func (sm *FSSessionManager) LoopAction(s *Session, cd *engine.CallDescriptor, in
 		// disconnect session
 		s.sessionManager.DisconnectSession(s, SYSTEM_ERROR)
 	}
-	nbts := len(cc.Timespans)
-	remainingSeconds := 0.0
 	engine.Logger.Debug(fmt.Sprintf("Result of MaxDebit call: %v", cc))
-	if nbts > 0 {
-		remainingSeconds = cc.Timespans[nbts-1].TimeEnd.Sub(cc.Timespans[0].TimeStart).Seconds()
-	}
-	if remainingSeconds == 0 || err != nil {
+	if cc.GetTotalDuration() == 0 || err != nil {
 		engine.Logger.Info(fmt.Sprintf("No credit left: Disconnect %v", s))
 		sm.DisconnectSession(s, INSUFFICIENT_FUNDS)
 		return
 	}
 	s.CallCosts = append(s.CallCosts, cc)
+	return
 }
 
 func (sm *FSSessionManager) GetDebitPeriod() time.Duration {
diff --git a/sessionmanager/session.go b/sessionmanager/session.go
index efa703124..3e5cadb20 100644
--- a/sessionmanager/session.go
+++ b/sessionmanager/session.go
@@ -86,8 +86,8 @@ func (s *Session) startDebitLoop() {
 			nextCd.TimeStart = nextCd.TimeEnd
 		}
 		nextCd.TimeEnd = nextCd.TimeStart.Add(s.sessionManager.GetDebitPeriod())
-		s.sessionManager.LoopAction(s, &nextCd, index)
-		time.Sleep(s.sessionManager.GetDebitPeriod())
+		cc := s.sessionManager.LoopAction(s, &nextCd, index)
+		time.Sleep(cc.GetTotalDuration())
 		index++
 	}
 }
diff --git a/sessionmanager/sessionmanager.go b/sessionmanager/sessionmanager.go
index ef7311e75..9eb2f68ae 100644
--- a/sessionmanager/sessionmanager.go
+++ b/sessionmanager/sessionmanager.go
@@ -28,7 +28,7 @@ type SessionManager interface {
 	Connect(*config.CGRConfig) error
 	DisconnectSession(*Session, string)
 	RemoveSession(*Session)
-	LoopAction(*Session, *engine.CallDescriptor, float64)
+	LoopAction(*Session, *engine.CallDescriptor, float64) *engine.CallCost
 	GetDebitPeriod() time.Duration
 	GetDbLogger() engine.LogStorage
 	Shutdown() error