diff --git a/config/config.yaml b/config/config.yaml
index 71fbae6..b5cb051 100644
--- a/config/config.yaml
+++ b/config/config.yaml
@@ -8,7 +8,11 @@ slices:
   nextmn-lite:
     pool: "10.0.0.0/24"
     upfs:
-      - "203.0.113.2" # only the first upf is used for now
+      - node-id: "203.0.113.2" # only the first upf is used for now
+        interfaces:
+          - type: "N3"
+            addr: "198.51.100.11"
+
 
 logger:
   level: "trace"
diff --git a/internal/app/pdu_session.go b/internal/app/pdu_session.go
index 8611a56..bfe9195 100644
--- a/internal/app/pdu_session.go
+++ b/internal/app/pdu_session.go
@@ -13,6 +13,7 @@ import (
 	"math/rand"
 	"net/http"
 	"net/netip"
+	"strings"
 	"sync"
 	"time"
 
@@ -86,6 +87,7 @@ type PduSessions struct {
 
 type PduSession struct {
 	Upf          netip.Addr
+	UpfN3        netip.Addr
 	UplinkTeid   uint32
 	Gnb          netip.Addr
 	DownlinkTeid uint32
@@ -143,9 +145,9 @@ func (p *PduSessions) EstablishmentRequest(c *gin.Context) {
 
 	upf := p.Slices[ps.Dnn].Upfs[0]
 	upfTeids := &UpfTeids{}
-	l, ok := p.UpfMap.Load(upf)
+	l, ok := p.UpfMap.Load(upf.NodeID)
 	if !ok {
-		p.UpfMap.Store(upf, upfTeids)
+		p.UpfMap.Store(upf.NodeID, upfTeids)
 	} else {
 		upfTeids = l.(*UpfTeids)
 	}
@@ -170,9 +172,24 @@ func (p *PduSessions) EstablishmentRequest(c *gin.Context) {
 			}
 		}
 	}
+	var iface netip.Addr
+	ifacedone := false
+	for _, i := range upf.Interfaces {
+		if strings.ToLower(i.Type) == "n3" {
+			iface = i.Addr
+			ifacedone = true
+			break
+		}
+	}
+	if !ifacedone {
+		logrus.Error("could not find n3 interface on first upf")
+		c.JSON(http.StatusInternalServerError, jsonapi.MessageWithError{Message: "could not find n3 interface on first upf", Error: nil})
+		return
+	}
 	// allocate uplink teid
 	pduSession := PduSession{
-		Upf:        upf,
+		Upf:        upf.NodeID,
+		UpfN3:      iface,
 		UplinkTeid: teid,
 	}
 
@@ -231,14 +248,15 @@ func (p *PduSessions) N2EstablishmentResponse(c *gin.Context) {
 		"ue":                ps.UeInfo.Header.Ue.String(),
 		"gnb":               ps.UeInfo.Header.Gnb.String(),
 		"ip-addr":           ps.UeInfo.Addr,
-		"gtp-upf":           psStruct.Upf,
+		"upf-pfcp":          psStruct.Upf,
+		"gtp-upf":           psStruct.UpfN3,
 		"gtp-uplink-teid":   psStruct.UplinkTeid,
 		"gtp-downlink-teid": psStruct.DownlinkTeid,
 		"gtp-gnb":           psStruct.Gnb,
 		"dnn":               ps.UeInfo.Header.Dnn,
 	}).Info("New PDU Session Established")
 
-	err := p.pfcp.CreateSession(ps.UeInfo.Addr, psStruct.UplinkTeid, psStruct.DownlinkTeid, psStruct.Upf, psStruct.Gnb, ps.UeInfo.Header.Dnn)
+	err := p.pfcp.CreateSession(ps.UeInfo.Addr, psStruct.UplinkTeid, psStruct.DownlinkTeid, psStruct.Upf, psStruct.UpfN3, psStruct.Gnb, ps.UeInfo.Header.Dnn)
 	if err != nil {
 		logrus.WithError(err).Error("Could not configure PDR/FAR in UPF")
 		c.JSON(http.StatusInternalServerError, jsonapi.MessageWithError{Message: "could not configure PDR/FAR in UPF", Error: err})
diff --git a/internal/app/pfcp.go b/internal/app/pfcp.go
index 36afd2f..425f89c 100644
--- a/internal/app/pfcp.go
+++ b/internal/app/pfcp.go
@@ -59,21 +59,21 @@ func (p *PFCPServer) Start(ctx context.Context) error {
 	}
 	for _, slice := range p.slices {
 		for _, upf := range slice.Upfs {
-			association, err := p.srv.NewEstablishedPFCPAssociation(ie.NewNodeIDHeuristic(upf.String()))
+			association, err := p.srv.NewEstablishedPFCPAssociation(ie.NewNodeIDHeuristic(upf.NodeID.String()))
 			if err != nil {
 				logrus.WithError(err).WithFields(logrus.Fields{
-					"upf": upf,
+					"upf": upf.NodeID,
 				}).Error("Could not perform PFCP association")
 				return err
 			}
-			p.associations[upf] = association
+			p.associations[upf.NodeID] = association
 		}
 	}
 	logrus.Info("PFCP Associations complete")
 	return nil
 }
 
-func (p *PFCPServer) CreateSession(ue netip.Addr, uplinkTeid uint32, downlinkTeid uint32, upfI netip.Addr, gNB netip.Addr, slice string) error {
+func (p *PFCPServer) CreateSession(ue netip.Addr, uplinkTeid uint32, downlinkTeid uint32, upfI netip.Addr, upfIn3 netip.Addr, gNB netip.Addr, slice string) error {
 	a, ok := p.associations[upfI]
 	if !ok {
 		return fmt.Errorf("Could not create PFCP Session: not associated with UPF")
@@ -84,7 +84,7 @@ func (p *PFCPServer) CreateSession(ue netip.Addr, uplinkTeid uint32, downlinkTei
 		ie.NewCreatePDR(ie.NewPDRID(1), ie.NewPrecedence(255),
 			ie.NewPDI(
 				ie.NewSourceInterface(ie.SrcInterfaceAccess),
-				ie.NewFTEID(0x01, uplinkTeid, upfI.AsSlice(), nil, 0), // ipv4: 0x01
+				ie.NewFTEID(0x01, uplinkTeid, upfIn3.AsSlice(), nil, 0), // ipv4: 0x01
 				ie.NewNetworkInstance(slice),
 				ie.NewUEIPAddress(0x02, ue.String(), "", 0, 0), // ipv4: 0x02
 			),
diff --git a/internal/config/config.go b/internal/config/config.go
index 9467d15..60d3f86 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -45,5 +45,15 @@ type Control struct {
 
 type Slice struct {
 	Pool netip.Prefix `yaml:"pool"`
-	Upfs []netip.Addr `yaml:"upfs"`
+	Upfs []Upf        `yaml:"upfs"`
+}
+
+type Upf struct {
+	NodeID     netip.Addr  `yaml:"node-id"`
+	Interfaces []Interface `yaml:"interfaces"`
+}
+
+type Interface struct {
+	Type string     `yaml:"type"`
+	Addr netip.Addr `yaml:"addr"`
 }