diff --git a/pfcp/api/far_interface.go b/pfcp/api/far_interface.go
index 7c08d97..e43a2bc 100644
--- a/pfcp/api/far_interface.go
+++ b/pfcp/api/far_interface.go
@@ -12,9 +12,7 @@ type FARID = uint32
 type FARInterface interface {
 	ID() (FARID, error)
 	ApplyAction() *ie.IE
-	SetApplyAction(*ie.IE) error
 	ForwardingParameters() (*ie.IE, error)
-	SetForwardingParameters(*ie.IE) error
 	NewCreateFAR() *ie.IE
-	NewUpdateFAR() *ie.IE
+	Update(FARUpdateInterface) error
 }
diff --git a/pfcp/api/far_map_interface.go b/pfcp/api/far_map_interface.go
index a8f4599..07b1589 100644
--- a/pfcp/api/far_map_interface.go
+++ b/pfcp/api/far_map_interface.go
@@ -12,12 +12,11 @@ import (
 type FARMapInterface interface {
 	Get(key FARID) (FARInterface, error)
 	Add(far FARInterface) error
-	Update(far FARInterface) error
+	Update(far FARUpdateInterface) error
 	Remove(key FARID) error
 	SimulateAdd(far FARInterface) error
-	SimulateUpdate(far FARInterface) error
+	SimulateUpdate(far FARUpdateInterface) error
 	SimulateRemove(key FARID) error
 	Foreach(func(FARInterface) error) error
 	IntoCreateFAR() []*ie.IE
-	IntoUpdateFAR() []*ie.IE
 }
diff --git a/pfcp/api/far_map_update_interface.go b/pfcp/api/far_map_update_interface.go
new file mode 100644
index 0000000..0ed7661
--- /dev/null
+++ b/pfcp/api/far_map_update_interface.go
@@ -0,0 +1,14 @@
+// Copyright Louis Royer and the NextMN contributors. All rights reserved.
+// Use of this source code is governed by a MIT-style license that can be
+// found in the LICENSE file.
+// SPDX-License-Identifier: MIT
+
+package api
+
+import "github.com/wmnsk/go-pfcp/ie"
+
+type FARMapUpdateInterface interface {
+	Add(far FARUpdateInterface) error
+	IntoUpdateFAR() []*ie.IE
+	Foreach(f func(FARUpdateInterface) error) error
+}
diff --git a/pfcp/api/far_update_interface.go b/pfcp/api/far_update_interface.go
new file mode 100644
index 0000000..bc8fec5
--- /dev/null
+++ b/pfcp/api/far_update_interface.go
@@ -0,0 +1,15 @@
+// Copyright Louis Royer and the NextMN contributors. All rights reserved.
+// Use of this source code is governed by a MIT-style license that can be
+// found in the LICENSE file.
+// SPDX-License-Identifier: MIT
+
+package api
+
+import "github.com/wmnsk/go-pfcp/ie"
+
+type FARUpdateInterface interface {
+	ID() (FARID, error)
+	ApplyAction() *ie.IE
+	UpdateForwardingParameters() *ie.IE
+	NewUpdateFAR() *ie.IE
+}
diff --git a/pfcp/api/session_interface.go b/pfcp/api/session_interface.go
index 6397f5b..589c492 100644
--- a/pfcp/api/session_interface.go
+++ b/pfcp/api/session_interface.go
@@ -21,7 +21,7 @@ type PFCPSessionInterface interface {
 	GetSortedPDRIDs() []PDRID
 	GetPDR(pdrid PDRID) (PDRInterface, error)
 	GetFAR(farid FARID) (FARInterface, error)
-	AddUpdatePDRsFARs(createpdrs PDRMapInterface, createfars FARMapInterface, updatepdr PDRMapInterface, updatefars FARMapInterface) error
+	AddUpdatePDRsFARs(createpdrs PDRMapInterface, createfars FARMapInterface, updatepdr PDRMapInterface, updatefars FARMapUpdateInterface) error
 	//	SetRemoteFSEID(FSEID *ie.IE)
 	Setup() error
 	ForeachUnsortedPDR(f func(pdr PDRInterface) error) error
diff --git a/pfcp/far.go b/pfcp/far.go
index f4a36c1..198a9aa 100644
--- a/pfcp/far.go
+++ b/pfcp/far.go
@@ -33,11 +33,6 @@ func (far *FAR) ApplyAction() *ie.IE {
 	return far.applyAction
 }
 
-func (far *FAR) SetApplyAction(aa *ie.IE) error {
-	far.applyAction = aa
-	return nil
-}
-
 func (far *FAR) ForwardingParameters() (*ie.IE, error) {
 	// This IE shall be present when the Apply Action requests
 	// the packets to be forwarded. It may be present otherwise.
@@ -48,11 +43,6 @@ func (far *FAR) ForwardingParameters() (*ie.IE, error) {
 
 }
 
-func (far *FAR) SetForwardingParameters(fp *ie.IE) error {
-	far.forwardingParameters = fp
-	return nil
-}
-
 func (far *FAR) NewCreateFAR() *ie.IE {
 	ies := make([]*ie.IE, 0)
 	ies = append(ies, far.id)
@@ -63,12 +53,45 @@ func (far *FAR) NewCreateFAR() *ie.IE {
 	return ie.NewCreateFAR(ies...)
 }
 
-func (far *FAR) NewUpdateFAR() *ie.IE {
-	ies := make([]*ie.IE, 0)
-	ies = append(ies, far.id)
-	ies = append(ies, far.applyAction)
-	if far.forwardingParameters != nil {
-		ies = append(ies, far.forwardingParameters)
+func (far *FAR) Update(farUpdate api.FARUpdateInterface) error {
+	// Check FARID
+	farUpdateId, err := farUpdate.ID()
+	if err != nil {
+		return err
+	}
+	farId, err := far.ID()
+	if err != nil {
+		return err
+	}
+	if farId != farUpdateId {
+		return fmt.Errorf("Wrong FAR ID")
+	}
+
+	// Update ApplyAction
+	if aa := farUpdate.ApplyAction(); aa != nil {
+		far.applyAction = aa
 	}
-	return ie.NewUpdateFAR(ies...)
+
+	// Update Forwarding Parameters
+	ForwParam := make([]*ie.IE, 0)
+	if fp := farUpdate.UpdateForwardingParameters(); fp != nil {
+		if di, err := fp.DestinationInterface(); err == nil {
+			ForwParam = append(ForwParam, ie.NewDestinationInterface(di))
+		} else if diorg, err := far.forwardingParameters.DestinationInterface(); err == nil {
+			ForwParam = append(ForwParam, ie.NewDestinationInterface(diorg))
+		}
+		if ni, err := fp.NetworkInstance(); err == nil {
+			ForwParam = append(ForwParam, ie.NewNetworkInstance(ni))
+		} else if niorg, err := far.forwardingParameters.NetworkInstance(); err == nil {
+			ForwParam = append(ForwParam, ie.NewNetworkInstance(niorg))
+		}
+		if ohc, err := fp.OuterHeaderCreation(); err == nil {
+			ForwParam = append(ForwParam, ie.NewOuterHeaderCreation(ohc.OuterHeaderCreationDescription, ohc.TEID, ohc.IPv4Address.String(), ohc.IPv6Address.String(), ohc.PortNumber, ohc.CTag, ohc.STag))
+		} else if ohcorg, err := far.forwardingParameters.OuterHeaderCreation(); err == nil {
+			ForwParam = append(ForwParam, ie.NewOuterHeaderCreation(ohcorg.OuterHeaderCreationDescription, ohcorg.TEID, ohcorg.IPv4Address.String(), ohcorg.IPv6Address.String(), ohcorg.PortNumber, ohcorg.CTag, ohcorg.STag))
+		}
+		far.forwardingParameters = ie.NewForwardingParameters(ForwParam...)
+	}
+
+	return nil
 }
diff --git a/pfcp/far_map.go b/pfcp/far_map.go
index 5b8ecdb..27de007 100644
--- a/pfcp/far_map.go
+++ b/pfcp/far_map.go
@@ -68,41 +68,25 @@ func (m *FARMap) SimulateAdd(far api.FARInterface) error {
 	return nil
 }
 
-func (m *FARMap) Update(far api.FARInterface) error {
+func (m *FARMap) Update(farUpdate api.FARUpdateInterface) error {
 	logrus.Trace("Inside farmap.Update()")
 	// only present fields are replaced
-	id, err := far.ID()
+	id, err := farUpdate.ID()
 	if err != nil {
 		return err
 	}
 	m.mu.Lock()
 	defer m.mu.Unlock()
-	if _, exists := m.farmap[id]; !exists {
+	if far, exists := m.farmap[id]; !exists {
 		logrus.WithFields(logrus.Fields{"far-id": id, "current_map": m.farmap}).Trace("Updating FAR: this FAR id does not exist")
 		return fmt.Errorf("FAR %d does not exist.", id)
 	} else {
 		logrus.WithFields(logrus.Fields{"far-id": id}).Trace("Updating FAR")
-		if far.ApplyAction() != nil {
-			m.farmap[id].SetApplyAction(far.ApplyAction())
-			logrus.WithFields(logrus.Fields{"far-id": id}).Trace("Updating FAR Apply Action")
-		}
-		// XXX: update fields in forwarding parameters instead of replacing
-		if fp, err := far.ForwardingParameters(); err == nil {
-			if fp == nil {
-				logrus.Warn("Removing forwarding parameters. aborting")
-				return nil
-			}
-			m.farmap[id].SetForwardingParameters(fp)
-			logrus.WithFields(logrus.Fields{"far-id": id}).Trace("Updating FAR Forwarding Parameters")
-		} else {
-			logrus.WithFields(logrus.Fields{"far-id": id}).Trace("Updating FAR but not Forwarding Parameters")
-		}
-
-		return nil
+		return far.Update(farUpdate)
 	}
 }
 
-func (m *FARMap) SimulateUpdate(far api.FARInterface) error {
+func (m *FARMap) SimulateUpdate(far api.FARUpdateInterface) error {
 	logrus.Trace("Inside farmap.SimulateUpdate()")
 	id, err := far.ID()
 	if err != nil {
@@ -202,39 +186,6 @@ func NewFARMap(fars []*ie.IE) (farmap *FARMap, err error, cause uint8, offending
 
 }
 
-func NewFARMapUpdate(fars []*ie.IE) (*FARMap, error, uint8, uint16) {
-	f := FARMap{
-		farmap: make(farmapInternal),
-		mu:     sync.RWMutex{},
-	}
-	for _, far := range fars {
-		id, err := far.FARID()
-		if err != nil {
-			switch err {
-			case io.ErrUnexpectedEOF:
-				return nil, err, ie.CauseInvalidLength, ie.FARID
-			case ie.ErrIENotFound:
-				return nil, err, ie.CauseMandatoryIEMissing, ie.FARID
-			default:
-				return nil, err, ie.CauseMandatoryIEIncorrect, ie.CreateFAR
-			}
-		}
-		var ieaa *ie.IE = nil
-		aa, err := far.ApplyAction()
-		if err == nil {
-			ieaa = ie.NewApplyAction(aa...)
-		}
-		var iefp *ie.IE = nil
-		fp, err := far.UpdateForwardingParameters()
-		if err == nil {
-			iefp = ie.NewForwardingParameters(fp...)
-		}
-		f.Add(NewFAR(ie.NewFARID(id), ieaa, iefp))
-	}
-	return &f, nil, 0, 0
-
-}
-
 func (m *FARMap) IntoCreateFAR() []*ie.IE {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
@@ -248,17 +199,3 @@ func (m *FARMap) IntoCreateFAR() []*ie.IE {
 	}
 	return r
 }
-
-func (m *FARMap) IntoUpdateFAR() []*ie.IE {
-	m.mu.RLock()
-	defer m.mu.RUnlock()
-	r := make([]*ie.IE, len(m.farmap))
-
-	// _ is farID, which is different from index
-	i := 0
-	for _, far := range m.farmap {
-		r[i] = far.NewUpdateFAR()
-		i++
-	}
-	return r
-}
diff --git a/pfcp/far_map_update.go b/pfcp/far_map_update.go
new file mode 100644
index 0000000..d8b6050
--- /dev/null
+++ b/pfcp/far_map_update.go
@@ -0,0 +1,94 @@
+// Copyright Louis Royer and the NextMN contributors. All rights reserved.
+// Use of this source code is governed by a MIT-style license that can be
+// found in the LICENSE file.
+// SPDX-License-Identifier: MIT
+
+package pfcp_networking
+
+import (
+	"fmt"
+	"io"
+	"sync"
+
+	"github.com/nextmn/go-pfcp-networking/pfcp/api"
+
+	"github.com/wmnsk/go-pfcp/ie"
+)
+
+type farmapUpdateInternal = map[api.FARID]api.FARUpdateInterface
+
+type FARMapUpdate struct {
+	farmap farmapUpdateInternal
+	mu     sync.RWMutex
+}
+
+func NewFARMapUpdate(fars []*ie.IE) (*FARMapUpdate, error, uint8, uint16) {
+	f := FARMapUpdate{
+		farmap: make(farmapUpdateInternal),
+		mu:     sync.RWMutex{},
+	}
+	for _, far := range fars {
+		id, err := far.FARID()
+		if err != nil {
+			switch err {
+			case io.ErrUnexpectedEOF:
+				return nil, err, ie.CauseInvalidLength, ie.FARID
+			case ie.ErrIENotFound:
+				return nil, err, ie.CauseMandatoryIEMissing, ie.FARID
+			default:
+				return nil, err, ie.CauseMandatoryIEIncorrect, ie.CreateFAR
+			}
+		}
+		var ieaa *ie.IE = nil
+		aa, err := far.ApplyAction()
+		if err == nil {
+			ieaa = ie.NewApplyAction(aa...)
+		}
+		var iefp *ie.IE = nil
+		fp, err := far.UpdateForwardingParameters()
+		if err == nil {
+			iefp = ie.NewUpdateForwardingParameters(fp...)
+		}
+		f.Add(NewFARUpdate(ie.NewFARID(id), ieaa, iefp))
+	}
+	return &f, nil, 0, 0
+
+}
+
+func (m *FARMapUpdate) Add(far api.FARUpdateInterface) error {
+	id, err := far.ID()
+	if err != nil {
+		return err
+	}
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if _, exists := m.farmap[id]; exists {
+		return fmt.Errorf("FAR %d already exists.", id)
+	}
+	m.farmap[id] = far
+	return nil
+}
+
+func (m *FARMapUpdate) IntoUpdateFAR() []*ie.IE {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	r := make([]*ie.IE, len(m.farmap))
+
+	// _ is farID, which is different from index
+	i := 0
+	for _, far := range m.farmap {
+		r[i] = far.NewUpdateFAR()
+		i++
+	}
+	return r
+}
+
+func (m *FARMapUpdate) Foreach(f func(api.FARUpdateInterface) error) error {
+	for _, far := range m.farmap {
+		err := f(far)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/pfcp/far_update.go b/pfcp/far_update.go
new file mode 100644
index 0000000..73a57ea
--- /dev/null
+++ b/pfcp/far_update.go
@@ -0,0 +1,50 @@
+// Copyright Louis Royer and the NextMN contributors. All rights reserved.
+// Use of this source code is governed by a MIT-style license that can be
+// found in the LICENSE file.
+// SPDX-License-Identifier: MIT
+
+package pfcp_networking
+
+import (
+	"github.com/nextmn/go-pfcp-networking/pfcp/api"
+
+	"github.com/wmnsk/go-pfcp/ie"
+)
+
+type FARUpdate struct {
+	id                         *ie.IE
+	applyAction                *ie.IE
+	updateForwardingParameters *ie.IE
+}
+
+func NewFARUpdate(id *ie.IE, applyAction *ie.IE, updateForwardingParameters *ie.IE) *FARUpdate {
+	return &FARUpdate{
+		id:                         id,
+		applyAction:                applyAction,
+		updateForwardingParameters: updateForwardingParameters,
+	}
+}
+
+func (far *FARUpdate) ID() (api.FARID, error) {
+	return far.id.FARID()
+}
+
+func (far *FARUpdate) ApplyAction() *ie.IE {
+	return far.applyAction
+}
+
+func (far *FARUpdate) UpdateForwardingParameters() *ie.IE {
+	return far.updateForwardingParameters
+}
+
+func (far *FARUpdate) NewUpdateFAR() *ie.IE {
+	ies := make([]*ie.IE, 0)
+	ies = append(ies, far.id)
+	if far.applyAction != nil {
+		ies = append(ies, far.applyAction)
+	}
+	if far.updateForwardingParameters != nil {
+		ies = append(ies, far.updateForwardingParameters)
+	}
+	return ie.NewUpdateFAR(ies...)
+}
diff --git a/pfcp/session.go b/pfcp/session.go
index ea25525..83cdb11 100644
--- a/pfcp/session.go
+++ b/pfcp/session.go
@@ -173,7 +173,7 @@ func (s *PFCPSession) GetFAR(farid api.FARID) (api.FARInterface, error) {
 }
 
 // Add/Update PDRs and FARs to the session
-func (s *PFCPSession) AddUpdatePDRsFARs(createpdrs api.PDRMapInterface, createfars api.FARMapInterface, updatepdrs api.PDRMapInterface, updatefars api.FARMapInterface) error {
+func (s *PFCPSession) AddUpdatePDRsFARs(createpdrs api.PDRMapInterface, createfars api.FARMapInterface, updatepdrs api.PDRMapInterface, updatefars api.FARMapUpdateInterface) error {
 	// Transactions must be atomic to avoid having a PDR referring to a deleted FAR / not yet created FAR
 	s.atomicMu.Lock()
 	defer s.atomicMu.Unlock()
@@ -186,7 +186,7 @@ func (s *PFCPSession) AddUpdatePDRsFARs(createpdrs api.PDRMapInterface, createfa
 	}); err != nil {
 		return err
 	}
-	if err := updatefars.Foreach(func(far api.FARInterface) error {
+	if err := updatefars.Foreach(func(far api.FARUpdateInterface) error {
 		return s.far.SimulateUpdate(far)
 	}); err != nil {
 		return err
@@ -212,7 +212,7 @@ func (s *PFCPSession) AddUpdatePDRsFARs(createpdrs api.PDRMapInterface, createfa
 	}); err != nil {
 		return err
 	}
-	if err := updatefars.Foreach(func(far api.FARInterface) error {
+	if err := updatefars.Foreach(func(far api.FARUpdateInterface) error {
 		return s.far.Update(far)
 	}); err != nil {
 		return err