diff --git a/src/java/com/android/internal/telephony/ServiceStateTracker.java b/src/java/com/android/internal/telephony/ServiceStateTracker.java
index 2933bd9..8817a76 100755
--- a/src/java/com/android/internal/telephony/ServiceStateTracker.java
+++ b/src/java/com/android/internal/telephony/ServiceStateTracker.java
@@ -117,9 +117,11 @@
 import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Objects;
+import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.regex.Matcher;
@@ -216,6 +218,7 @@
     private RegistrantList mPsRestrictEnabledRegistrants = new RegistrantList();
     private RegistrantList mPsRestrictDisabledRegistrants = new RegistrantList();
     private RegistrantList mImsCapabilityChangedRegistrants = new RegistrantList();
+    private RegistrantList mNrStateChangedRegistrants = new RegistrantList();
 
     /* Radio power off pending flag and tag counter */
     private boolean mPendingRadioPowerOffAfterDataOff = false;
@@ -1553,8 +1556,10 @@
                     mLastPhysicalChannelConfigList = list;
                     boolean hasChanged =
                             updateNrFrequencyRangeFromPhysicalChannelConfigs(list, mSS);
-                    hasChanged |= updateNrStateFromPhysicalChannelConfigs(
-                            list, mSS);
+                    if (updateNrStateFromPhysicalChannelConfigs(list, mSS)) {
+                        mNrStateChangedRegistrants.notifyRegistrants();
+                        hasChanged = true;
+                    }
 
                     // Notify NR frequency, NR connection status or bandwidths changed.
                     if (hasChanged
@@ -5504,4 +5509,43 @@
         }
         return ServiceState.networkTypeToRilRadioTechnology(networkType);
     }
+
+    /**
+     * Registers for 5G NR state changed.
+     * @param h handler to notify
+     * @param what what code of message when delivered
+     * @param obj placed in Message.obj
+     */
+    public void registerForNrStateChanged(Handler h, int what, Object obj) {
+        Registrant r = new Registrant(h, what, obj);
+        mNrStateChangedRegistrants.add(r);
+    }
+
+    /**
+     * Unregisters for 5G NR state changed.
+     * @param h handler to notify
+     */
+    public void unregisterForNrStateChanged(Handler h) {
+        mNrStateChangedRegistrants.remove(h);
+    }
+
+    /**
+     * Get the NR data connection context ids.
+     *
+     * @return data connection context ids.
+     */
+    @NonNull
+    public Set<Integer> getNrContextIds() {
+        Set<Integer> idSet = new HashSet<>();
+
+        for (PhysicalChannelConfig config : mLastPhysicalChannelConfigList) {
+            if (isNrPhysicalChannelConfig(config)) {
+                for (int id : config.getContextIds()) {
+                    idSet.add(id);
+                }
+            }
+        }
+
+        return idSet;
+    }
 }
diff --git a/src/java/com/android/internal/telephony/dataconnection/DataConnection.java b/src/java/com/android/internal/telephony/dataconnection/DataConnection.java
index 1b59c94..41d4bef 100644
--- a/src/java/com/android/internal/telephony/dataconnection/DataConnection.java
+++ b/src/java/com/android/internal/telephony/dataconnection/DataConnection.java
@@ -265,7 +265,7 @@
     private static final String NULL_IP = "0.0.0.0";
     private Object mUserData;
     private int mSubscriptionOverride;
-    private int mRilRat = Integer.MAX_VALUE;
+    private int mRilRat = ServiceState.RIL_RADIO_TECHNOLOGY_UNKNOWN;
     private int mDataRegState = Integer.MAX_VALUE;
     private NetworkInfo mNetworkInfo;
 
@@ -281,6 +281,8 @@
     private int mDisabledApnTypeBitMask = 0;
 
     int mTag;
+
+    /** Data connection id assigned by the modem. This is unique across transports */
     public int mCid;
 
     @HandoverState
@@ -316,9 +318,10 @@
     static final int EVENT_RESET = BASE + 24;
     static final int EVENT_REEVALUATE_RESTRICTED_STATE = BASE + 25;
     static final int EVENT_REEVALUATE_DATA_CONNECTION_PROPERTIES = BASE + 26;
+    static final int EVENT_NR_STATE_CHANGED = BASE + 27;
 
     private static final int CMD_TO_STRING_COUNT =
-            EVENT_REEVALUATE_DATA_CONNECTION_PROPERTIES - BASE + 1;
+            EVENT_NR_STATE_CHANGED - BASE + 1;
 
     private static String[] sCmdToString = new String[CMD_TO_STRING_COUNT];
     static {
@@ -354,6 +357,8 @@
                 "EVENT_REEVALUATE_RESTRICTED_STATE";
         sCmdToString[EVENT_REEVALUATE_DATA_CONNECTION_PROPERTIES - BASE] =
                 "EVENT_REEVALUATE_DATA_CONNECTION_PROPERTIES";
+        sCmdToString[EVENT_NR_STATE_CHANGED - BASE] =
+                "EVENT_NR_STATE_CHANGED";
     }
     // Convert cmd to string or null if unknown
     static String cmdToString(int cmd) {
@@ -584,7 +589,6 @@
         mId = id;
         mCid = -1;
         ServiceState ss = mPhone.getServiceState();
-        mRilRat = ss.getRilDataRadioTechnology();
         mDataRegState = mPhone.getServiceState().getDataRegState();
         int networkType = TelephonyManager.NETWORK_TYPE_UNKNOWN;
 
@@ -592,6 +596,7 @@
                 NetworkRegistrationInfo.DOMAIN_PS, mTransportType);
         if (nri != null) {
             networkType = nri.getAccessNetworkTechnology();
+            mRilRat = ServiceState.networkTypeToRilRadioTechnology(networkType);
         }
 
         mNetworkInfo = new NetworkInfo(ConnectivityManager.TYPE_MOBILE,
@@ -1006,10 +1011,14 @@
 
         // NR 5G Non-Standalone use LTE cell as the primary cell, the ril technology is LTE in this
         // case. We use NR 5G TCP buffer size when connected to NR 5G Non-Standalone network.
-        if (rilRat == ServiceState.RIL_RADIO_TECHNOLOGY_LTE && isNRConnected()) {
+        if (mTransportType == AccessNetworkConstants.TRANSPORT_TYPE_WWAN
+                && rilRat == ServiceState.RIL_RADIO_TECHNOLOGY_LTE && isNRConnected()
+                && mPhone.getServiceStateTracker().getNrContextIds().contains(mCid)) {
             ratName = RAT_NAME_5G;
         }
 
+        log("updateTcpBufferSizes: " + ratName);
+
         // in the form: "ratname:rmem_min,rmem_def,rmem_max,wmem_min,wmem_def,wmem_max"
         String[] configOverride = mPhone.getContext().getResources().getStringArray(
                 com.android.internal.R.array.config_mobile_tcp_buffers);
@@ -1056,7 +1065,7 @@
                 case ServiceState.RIL_RADIO_TECHNOLOGY_LTE:
                 case ServiceState.RIL_RADIO_TECHNOLOGY_LTE_CA:
                     // Use NR 5G TCP buffer size when connected to NR 5G Non-Standalone network.
-                    if (isNRConnected()) {
+                    if (RAT_NAME_5G.equals(ratName)) {
                         sizes = TCP_BUFFER_SIZES_NR;
                     } else {
                         sizes = TCP_BUFFER_SIZES_LTE;
@@ -1065,6 +1074,9 @@
                 case ServiceState.RIL_RADIO_TECHNOLOGY_HSPAP:
                     sizes = TCP_BUFFER_SIZES_HSPAP;
                     break;
+                case ServiceState.RIL_RADIO_TECHNOLOGY_NR:
+                    sizes = TCP_BUFFER_SIZES_NR;
+                    break;
                 default:
                     // Leave empty - this will let ConnectivityService use the system default.
                     break;
@@ -1501,6 +1513,8 @@
                     DataConnection.EVENT_DATA_CONNECTION_ROAM_ON, null);
             mPhone.getServiceStateTracker().registerForDataRoamingOff(getHandler(),
                     DataConnection.EVENT_DATA_CONNECTION_ROAM_OFF, null, true);
+            mPhone.getServiceStateTracker().registerForNrStateChanged(getHandler(),
+                    DataConnection.EVENT_NR_STATE_CHANGED, null);
 
             // Add ourselves to the list of data connections
             mDcController.addDc(DataConnection.this);
@@ -1617,8 +1631,7 @@
                     break;
                 default:
                     if (DBG) {
-                        log("DcDefaultState: shouldn't happen but ignore msg.what="
-                                + getWhatToString(msg.what));
+                        log("DcDefaultState: ignore msg.what=" + getWhatToString(msg.what));
                     }
                     break;
             }
@@ -2381,6 +2394,14 @@
                     retVal = HANDLED;
                     break;
                 }
+                case EVENT_NR_STATE_CHANGED: {
+                    updateTcpBufferSizes(mRilRat);
+                    if (mNetworkAgent != null) {
+                        mNetworkAgent.sendLinkProperties(mLinkProperties, DataConnection.this);
+                    }
+                    retVal = HANDLED;
+                    break;
+                }
                 default:
                     if (VDBG) {
                         log("DcActiveState not handled msg.what=" + getWhatToString(msg.what));