diff --git a/src/main/java/ru/serega6531/packmate/service/optimization/tls/TlsPacket.java b/src/main/java/ru/serega6531/packmate/service/optimization/tls/TlsPacket.java
index 9b5ddda..34b1c14 100644
--- a/src/main/java/ru/serega6531/packmate/service/optimization/tls/TlsPacket.java
+++ b/src/main/java/ru/serega6531/packmate/service/optimization/tls/TlsPacket.java
@@ -97,7 +97,7 @@ public class TlsPacket extends AbstractPacket {
         }
 
         private TlsHeader(byte[] rawData, int offset, int length) throws IllegalRawDataException {
-            //TODO check length
+            ByteArrays.validateBounds(rawData, offset, RECORD_OFFSET);
             this.contentType = ContentType.getInstance(ByteArrays.getByte(rawData, CONTENT_TYPE_OFFSET + offset));
             this.version = TlsVersion.getInstance(ByteArrays.getShort(rawData, VERSION_OFFSET + offset));
             this.recordLength = ByteArrays.getShort(rawData, LENGTH_OFFSET + offset);
@@ -109,9 +109,9 @@ public class TlsPacket extends AbstractPacket {
             } else if (contentType == ContentType.APPLICATION_DATA) {
                 this.record = ApplicationDataRecord.newInstance(rawData, offset + RECORD_OFFSET, recordLength);
             } else if (contentType == ContentType.ALERT) {
-                this.record = new AlertRecord(rawData, offset + RECORD_OFFSET, recordLength);
+                this.record = AlertRecord.newInstance(rawData, offset + RECORD_OFFSET, recordLength);
             } else if (contentType == ContentType.HEARTBEAT) {
-                //TODO
+                this.record = HeartbeatRecord.newInstance(rawData, offset + RECORD_OFFSET, recordLength);
             } else {
                 throw new IllegalArgumentException("Unknown content type: " + contentType);
             }
diff --git a/src/main/java/ru/serega6531/packmate/service/optimization/tls/numbers/AlertLevel.java b/src/main/java/ru/serega6531/packmate/service/optimization/tls/numbers/AlertLevel.java
index 5b15de9..1f2c069 100644
--- a/src/main/java/ru/serega6531/packmate/service/optimization/tls/numbers/AlertLevel.java
+++ b/src/main/java/ru/serega6531/packmate/service/optimization/tls/numbers/AlertLevel.java
@@ -13,7 +13,6 @@ public class AlertLevel extends NamedNumber<Byte, AlertLevel> {
     public static final AlertLevel WARNING = new AlertLevel((byte) 1, "warning");
     public static final AlertLevel FATAL = new AlertLevel((byte) 2, "fatal");
 
-
     public AlertLevel(Byte value, String name) {
         super(value, name);
         registry.put(value, this);
diff --git a/src/main/java/ru/serega6531/packmate/service/optimization/tls/numbers/HeartbeatMessageType.java b/src/main/java/ru/serega6531/packmate/service/optimization/tls/numbers/HeartbeatMessageType.java
new file mode 100644
index 0000000..a2c293a
--- /dev/null
+++ b/src/main/java/ru/serega6531/packmate/service/optimization/tls/numbers/HeartbeatMessageType.java
@@ -0,0 +1,33 @@
+package ru.serega6531.packmate.service.optimization.tls.numbers;
+
+import org.pcap4j.packet.namednumber.NamedNumber;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class HeartbeatMessageType extends NamedNumber<Byte, HeartbeatMessageType> {
+
+    private static final Map<Byte, HeartbeatMessageType> registry = new HashMap<>();
+
+    public static final HeartbeatMessageType HEARTBEAT_REQUEST = new HeartbeatMessageType((byte) 1, "heartbeat_request");
+    public static final HeartbeatMessageType HEARTBEAT_RESPONSE = new HeartbeatMessageType((byte) 2, "heartbeat_response");
+
+    public HeartbeatMessageType(Byte value, String name) {
+        super(value, name);
+        registry.put(value, this);
+    }
+
+    public static HeartbeatMessageType getInstance(Byte value) {
+        if (registry.containsKey(value)) {
+            return registry.get(value);
+        } else {
+            throw new IllegalArgumentException("Unknown heartbeat message type: " + value);
+        }
+    }
+
+    @Override
+    public int compareTo(HeartbeatMessageType o) {
+        return value().compareTo(o.value());
+    }
+
+}
diff --git a/src/main/java/ru/serega6531/packmate/service/optimization/tls/records/ChangeCipherSpecRecord.java b/src/main/java/ru/serega6531/packmate/service/optimization/tls/records/ChangeCipherSpecRecord.java
index f5147ae..b6db856 100644
--- a/src/main/java/ru/serega6531/packmate/service/optimization/tls/records/ChangeCipherSpecRecord.java
+++ b/src/main/java/ru/serega6531/packmate/service/optimization/tls/records/ChangeCipherSpecRecord.java
@@ -4,7 +4,7 @@ import org.pcap4j.util.ByteArrays;
 
 public class ChangeCipherSpecRecord implements TlsRecord {
 
-    /*
+    /**
     0x0 - Change Cipher Spec Message
     0x1 - End
      */
diff --git a/src/main/java/ru/serega6531/packmate/service/optimization/tls/records/HeartbeatRecord.java b/src/main/java/ru/serega6531/packmate/service/optimization/tls/records/HeartbeatRecord.java
new file mode 100644
index 0000000..8628d43
--- /dev/null
+++ b/src/main/java/ru/serega6531/packmate/service/optimization/tls/records/HeartbeatRecord.java
@@ -0,0 +1,53 @@
+package ru.serega6531.packmate.service.optimization.tls.records;
+
+import org.pcap4j.util.ByteArrays;
+import ru.serega6531.packmate.service.optimization.tls.numbers.HeartbeatMessageType;
+
+import static org.pcap4j.util.ByteArrays.BYTE_SIZE_IN_BYTES;
+import static org.pcap4j.util.ByteArrays.SHORT_SIZE_IN_BYTES;
+
+public class HeartbeatRecord implements TlsRecord {
+
+    //https://tools.ietf.org/html/rfc6520
+
+    private static final int TYPE_OFFSET = 0;
+    private static final int PAYLOAD_LENGTH_OFFSET = TYPE_OFFSET + BYTE_SIZE_IN_BYTES;
+    private static final int PAYLOAD_OFFSET = PAYLOAD_LENGTH_OFFSET + SHORT_SIZE_IN_BYTES;
+
+    private HeartbeatMessageType type;
+    private short payloadLength;
+    private byte[] payload;
+    private byte[] padding;
+
+    public static HeartbeatRecord newInstance(byte[] rawData, int offset, int length) {
+        ByteArrays.validateBounds(rawData, offset, length);
+        return new HeartbeatRecord(rawData, offset, length);
+    }
+
+    public HeartbeatRecord(byte[] rawData, int offset, int length) {
+        this.type = HeartbeatMessageType.getInstance(ByteArrays.getByte(rawData, TYPE_OFFSET + offset));
+        this.payloadLength = ByteArrays.getShort(rawData, PAYLOAD_LENGTH_OFFSET + offset);
+        this.payload = ByteArrays.getSubArray(rawData, PAYLOAD_OFFSET + offset, payloadLength);
+        this.padding = ByteArrays.getSubArray(rawData, PAYLOAD_OFFSET + payloadLength + offset);
+    }
+
+    public HeartbeatMessageType getType() {
+        return type;
+    }
+
+    public byte[] getPayload() {
+        return payload;
+    }
+
+    public byte[] getPadding() {
+        return padding;
+    }
+
+    @Override
+    public String toString() {
+        return "  Heartbeat (" + type.name() +
+                ") [" + payloadLength + " bytes payload, " +
+                padding.length + " bytes padding]";
+    }
+
+}