diff --git a/advanced/upf.rst b/advanced/upf.rst
index 48ab38c..7ea7f02 100644
--- a/advanced/upf.rst
+++ b/advanced/upf.rst
@@ -156,21 +156,29 @@
   list must include all the leaf switches in the topology. The UPF state is
   replicated on all devices specified in this configuration field. The devices
   specified in this list must use a P4 pipeline implementing the UPF
-  functionality. *Required*
+  functionality. **Required**
 
-* ``s1uAddr``: The IP address of the S1-U interface (equivalent to N3 for 5G).
-  It can be an arbitrary IP address. *Required*
+* ``s1uAddr``: **Deprecated**. Use ``n3Addr`` instead.
 
-* ``uePools``: A list of subnets that are in use by the UEs. *Required*
+* ``n3Addr``: The IP address of the N3 interface (equivalent to S1-U for 4G).
+  It can be an arbitrary IP address. **Optional**
+  (PFCP agent can insert interface table entry if not supplied)
+
+* ``uePools``: A list of subnets that are in use by the UEs. **Optional**
+  (PFCP agent can insert interface table entry if not supplied)
+
+* ``sliceId``: Network slice ID used by mobile traffic. **Optional**
+  Required only when either ``n3Addr`` or ``uePools`` is specified.
 
 * ``dbufDrainAddr``: The IP address of the UPF data plane interface that the
-  DBUF service will drain packets towards. *Optional*
+  DBUF service will drain packets towards. **Optional**
 
 * ``pscEncapEnabled``: Set whether the UPF should use GTP-U extension PDU
-  Session Container when doing encapsulation of downlink packets. *Optional*
+  Session Container when doing encapsulation of downlink packets. **Optional**
+  (Should set to true for 5G)
 
 * ``defaultQfi``: The default QoS Flow Identifier to use when the PDU Session
-  Container encapsulation is enabled. *Optional*
+  Container encapsulation is enabled. **Optional**
 
 Here is an example of netcfg JSON for UP4:
 
@@ -184,19 +192,20 @@
                     "device:leaf1",
                     "device:leaf2"
                   ],
-                  "s1uAddr": "10.32.11.126",
+                  "n3Addr": "10.32.11.126",
                   "uePools": [
                     "10.240.0.0/16"
                   ],
-                "dbufDrainAddr": "10.32.11.126",
-                "pscEncapEnabled": false,
-                "defaultQfi": 0
+                  "sliceId": 0
+                  "dbufDrainAddr": "10.32.11.126",
+                  "pscEncapEnabled": false,
+                  "defaultQfi": 0
                 }
             }
         }
     }
 
-The DBUF configuration block is all *optional*, we can use UP4 without the
+The DBUF configuration block is all **Optional**, we can use UP4 without the
 downlink buffering functionality. Here's a list of fields that you can
 configure: