diff --git a/Tethering/apishim/31/com/android/networkstack/tethering/apishim/api31/BpfCoordinatorShimImpl.java b/Tethering/apishim/31/com/android/networkstack/tethering/apishim/api31/BpfCoordinatorShimImpl.java
index f537e90..611c828 100644
--- a/Tethering/apishim/31/com/android/networkstack/tethering/apishim/api31/BpfCoordinatorShimImpl.java
+++ b/Tethering/apishim/31/com/android/networkstack/tethering/apishim/api31/BpfCoordinatorShimImpl.java
@@ -371,7 +371,6 @@
         } catch (IllegalStateException e) {
             // Silent if the rule already exists. Note that the errno EEXIST was rethrown as
             // IllegalStateException. See BpfMap#insertEntry.
-            return false;
         }
         return true;
     }
diff --git a/Tethering/apishim/common/com/android/networkstack/tethering/apishim/common/BpfCoordinatorShim.java b/Tethering/apishim/common/com/android/networkstack/tethering/apishim/common/BpfCoordinatorShim.java
index 3c2ce0f..08ab9ca 100644
--- a/Tethering/apishim/common/com/android/networkstack/tethering/apishim/common/BpfCoordinatorShim.java
+++ b/Tethering/apishim/common/com/android/networkstack/tethering/apishim/common/BpfCoordinatorShim.java
@@ -141,11 +141,6 @@
 
     /**
      * Adds a tethering IPv4 offload rule to appropriate BPF map.
-     *
-     * @param downstream true if downstream, false if upstream.
-     * @param key the key to add.
-     * @param value the value to add.
-     * @return true iff the map was modified, false if the key exists or there was an error.
      */
     public abstract boolean tetherOffloadRuleAdd(boolean downstream, @NonNull Tether4Key key,
             @NonNull Tether4Value value);
diff --git a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
index 97ef380..f8a9251 100644
--- a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
+++ b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
@@ -130,14 +130,8 @@
     static final int CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS = 60_000;
     @VisibleForTesting
     static final int CONNTRACK_TIMEOUT_UPDATE_SLACK_MS = 20_000;
-
-    // Default timeouts sync from /proc/sys/net/netfilter/nf_conntrack_*
-    // See also kernel document nf_conntrack-sysctl.txt.
     @VisibleForTesting
     static final int NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED = 432_000;
-    static final int NF_CONNTRACK_TCP_TIMEOUT_UNACKNOWLEDGED = 300;
-    // The default value is 120 for 5.10 and that thus the periodicity of the updates of 60s is
-    // low enough to support all ACK kernels.
     @VisibleForTesting
     static final int NF_CONNTRACK_UDP_TIMEOUT_STREAM = 180;
 
@@ -1572,18 +1566,6 @@
             final Tether4Key downstream4Key = makeTetherDownstream4Key(e, tetherClient,
                     upstreamIndex);
 
-            // Using the timeout to distinguish tcp state is not a decent way. Need to fix.
-            // The received IPCTNL_MSG_CT_NEW must pass ConntrackMonitor#isEstablishedNatSession
-            // which checks CTA_STATUS. It implies that this entry has at least reached tcp
-            // state "established". For safety, treat any timeout which is equal or larger than 300
-            // seconds (UNACKNOWLEDGED, ESTABLISHED, ..) to be "established".
-            // TODO: parse tcp state in conntrack monitor.
-            final boolean isTcpEstablished =
-                    e.msgType == (NetlinkConstants.NFNL_SUBSYS_CTNETLINK << 8
-                    | NetlinkConstants.IPCTNL_MSG_CT_NEW)
-                    && e.tupleOrig.protoNum == OsConstants.IPPROTO_TCP
-                    && (e.timeoutSec >= NF_CONNTRACK_TCP_TIMEOUT_UNACKNOWLEDGED);
-
             if (e.msgType == (NetlinkConstants.NFNL_SUBSYS_CTNETLINK << 8
                     | NetlinkConstants.IPCTNL_MSG_CT_DELETE)) {
                 final boolean deletedUpstream = mBpfCoordinatorShim.tetherOffloadRuleRemove(
@@ -1610,41 +1592,11 @@
             final Tether4Value upstream4Value = makeTetherUpstream4Value(e, upstreamIndex);
             final Tether4Value downstream4Value = makeTetherDownstream4Value(e, tetherClient,
                     upstreamIndex);
+
             maybeAddDevMap(upstreamIndex, tetherClient.downstreamIfindex);
             maybeSetLimit(upstreamIndex);
-
-            final boolean upstreamAdded = mBpfCoordinatorShim.tetherOffloadRuleAdd(UPSTREAM,
-                    upstream4Key, upstream4Value);
-            final boolean downstreamAdded = mBpfCoordinatorShim.tetherOffloadRuleAdd(DOWNSTREAM,
-                    downstream4Key, downstream4Value);
-
-            if (upstreamAdded != downstreamAdded) {
-                mLog.e("The bidirectional rules should be added or not added concurrently ("
-                        + "upstream: " + upstreamAdded
-                        + ", downstream: " + downstreamAdded + "). "
-                        + "Remove the added rules.");
-                if (upstreamAdded) {
-                    mBpfCoordinatorShim.tetherOffloadRuleRemove(UPSTREAM, upstream4Key);
-                }
-                if (downstreamAdded) {
-                    mBpfCoordinatorShim.tetherOffloadRuleRemove(DOWNSTREAM, downstream4Key);
-                }
-                return;
-            }
-
-            // Update TCP timeout iif it is first time we're adding the rules. Needed because a
-            // payload data packet may have gone through non-offload path, before we added offload
-            // rules, and that this may result in in-kernel conntrack state being in ESTABLISHED
-            // but pending ACK (ie. UNACKED) state. But the in-kernel conntrack might never see the
-            // ACK because we just added offload rules. As such after adding the rules we need to
-            // force the timeout back to the normal ESTABLISHED timeout of 5 days. Note that
-            // updating the timeout will trigger another netlink event with the updated timeout.
-            // TODO: Remove this once the tcp state is parsed.
-            if (isTcpEstablished && upstreamAdded && downstreamAdded) {
-                updateConntrackTimeout((byte) upstream4Key.l4proto,
-                        parseIPv4Address(upstream4Key.src4), (short) upstream4Key.srcPort,
-                        parseIPv4Address(upstream4Key.dst4), (short) upstream4Key.dstPort);
-            }
+            mBpfCoordinatorShim.tetherOffloadRuleAdd(UPSTREAM, upstream4Key, upstream4Value);
+            mBpfCoordinatorShim.tetherOffloadRuleAdd(DOWNSTREAM, downstream4Key, downstream4Value);
         }
     }
 
@@ -1927,7 +1879,6 @@
         // - proc/sys/net/netfilter/nf_conntrack_tcp_timeout_established
         // - proc/sys/net/netfilter/nf_conntrack_udp_timeout_stream
         // See kernel document nf_conntrack-sysctl.txt.
-        // TODO: we should account for the fact that lastUsed is in the past and not exactly now.
         final int timeoutSec = (proto == OsConstants.IPPROTO_TCP)
                 ? NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED
                 : NF_CONNTRACK_UDP_TIMEOUT_STREAM;
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
index 32d7e5f..bcdedc7 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
@@ -42,7 +42,6 @@
 import static com.android.dx.mockito.inline.extended.ExtendedMockito.staticMockMarker;
 import static com.android.networkstack.tethering.BpfCoordinator.CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS;
 import static com.android.networkstack.tethering.BpfCoordinator.CONNTRACK_TIMEOUT_UPDATE_SLACK_MS;
-import static com.android.networkstack.tethering.BpfCoordinator.NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED;
 import static com.android.networkstack.tethering.BpfCoordinator.NF_CONNTRACK_UDP_TIMEOUT_STREAM;
 import static com.android.networkstack.tethering.BpfCoordinator.StatsType;
 import static com.android.networkstack.tethering.BpfCoordinator.StatsType.STATS_PER_IFACE;
@@ -1370,14 +1369,8 @@
         }
 
         final int status = (msgType == IPCTNL_MSG_CT_NEW) ? ESTABLISHED_MASK : DYING_MASK;
-        int timeoutSec;
-        if (msgType == IPCTNL_MSG_CT_NEW) {
-            timeoutSec = (proto == IPPROTO_TCP)
-                    ? NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED
-                    : NF_CONNTRACK_UDP_TIMEOUT_STREAM;
-        } else {
-            timeoutSec = 0; /* unused, CT_DELETE */
-        }
+        final int timeoutSec = (msgType == IPCTNL_MSG_CT_NEW) ? 100 /* nonzero, new */
+                : 0 /* unused, delete */;
         return new ConntrackEvent(
                 (short) (NetlinkConstants.NFNL_SUBSYS_CTNETLINK << 8 | msgType),
                 new Tuple(new TupleIpv4(PRIVATE_ADDR, REMOTE_ADDR),