diff --git a/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/server/DefaultLwM2mTransportService.java b/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/server/DefaultLwM2mTransportService.java
index 2ca0249b46..52859eab2f 100644
--- a/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/server/DefaultLwM2mTransportService.java
+++ b/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/server/DefaultLwM2mTransportService.java
@@ -20,6 +20,7 @@ import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.eclipse.californium.core.CoapResource;
 import org.eclipse.californium.core.CoapServer;
+import org.eclipse.californium.core.config.CoapConfig;
 import org.eclipse.californium.elements.config.Configuration;
 import org.eclipse.californium.scandium.config.DtlsConfig;
 import org.eclipse.californium.scandium.dtls.cipher.CipherSuite;
@@ -194,8 +195,8 @@ public class DefaultLwM2mTransportService implements LwM2MTransportService {
                 root = new CoapResource("");
                 coapServer.add(root);
             }
-            root.add(new LwM2mTransportCoapResource(otaPackageDataCache, FIRMWARE_UPDATE_COAP_RESOURCE));
-            root.add(new LwM2mTransportCoapResource(otaPackageDataCache, SOFTWARE_UPDATE_COAP_RESOURCE));
+            root.add(new LwM2mTransportCoapResource(otaPackageDataCache, FIRMWARE_UPDATE_COAP_RESOURCE, serverCoapConfig.get(CoapConfig.PREFERRED_BLOCK_SIZE), serverCoapConfig.get(CoapConfig.MAX_RESOURCE_BODY_SIZE)));
+            root.add(new LwM2mTransportCoapResource(otaPackageDataCache, SOFTWARE_UPDATE_COAP_RESOURCE,serverCoapConfig.get(CoapConfig.PREFERRED_BLOCK_SIZE), serverCoapConfig.get(CoapConfig.MAX_RESOURCE_BODY_SIZE)));
         }
         return leshanServer;
     }
diff --git a/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/server/LwM2mTransportCoapResource.java b/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/server/LwM2mTransportCoapResource.java
index 7e9841ea9f..c46b57fb3f 100644
--- a/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/server/LwM2mTransportCoapResource.java
+++ b/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/server/LwM2mTransportCoapResource.java
@@ -34,16 +34,21 @@ import java.util.concurrent.atomic.AtomicInteger;
 
 import static org.thingsboard.server.transport.lwm2m.server.ota.DefaultLwM2MOtaUpdateService.FIRMWARE_UPDATE_COAP_RESOURCE;
 import static org.thingsboard.server.transport.lwm2m.server.ota.DefaultLwM2MOtaUpdateService.SOFTWARE_UPDATE_COAP_RESOURCE;
+import static org.thingsboard.server.transport.lwm2m.utils.LwM2MTransportUtil.calculateSzx;
 
 @Slf4j
 public class LwM2mTransportCoapResource extends AbstractLwM2mTransportResource {
     private final ConcurrentMap<String, ObserveRelation> tokenToObserveRelationMap = new ConcurrentHashMap<>();
     private final ConcurrentMap<String, AtomicInteger> tokenToObserveNotificationSeqMap = new ConcurrentHashMap<>();
     private final OtaPackageDataCache otaPackageDataCache;
+    private final int chunkSize;
+    private final int maxResourceBodySize;
 
-    public LwM2mTransportCoapResource(OtaPackageDataCache otaPackageDataCache, String name) {
+    public LwM2mTransportCoapResource(OtaPackageDataCache otaPackageDataCache, String name, int chunkSize, int maxResourceBodySize) {
         super(name);
         this.otaPackageDataCache = otaPackageDataCache;
+        this.chunkSize = chunkSize;
+        this.maxResourceBodySize = maxResourceBodySize;
         this.setObservable(true); // enable observing
         this.addObserver(new CoapResourceObserver());
     }
@@ -136,22 +141,29 @@ public class LwM2mTransportCoapResource extends AbstractLwM2mTransportResource {
         String idStr = exchange.getRequestOptions().getUriPath().get(exchange.getRequestOptions().getUriPath().size() - 1
         );
         UUID currentId = UUID.fromString(idStr);
+        log.info("Start Read ota data (path): [{}]", exchange.getRequestOptions().getUriPath().toString());
         Response response = new Response(CoAP.ResponseCode.CONTENT);
         byte[] otaData = this.getOtaData(currentId);
         if (otaData != null && otaData.length > 0) {
-            log.debug("Read ota data (length): [{}]", otaData.length);
-            response.setPayload(otaData);
-            if (exchange.getRequestOptions().getBlock2() != null) {
-                int chunkSize = exchange.getRequestOptions().getBlock2().getSzx();
-                boolean lastFlag = otaData.length <= chunkSize;
+            if (otaData.length <= this.maxResourceBodySize) {
+                log.info("Read ota data (length): [{}]", otaData.length);
+                response.setPayload(otaData);
+                int chunkSize = calculateSzx(this.chunkSize);
+                if (exchange.getRequestOptions().hasBlock2()) {
+                    chunkSize = exchange.getRequestOptions().getBlock2().getSzx();
+                } else if (exchange.getRequestOptions().hasBlock1()) {
+                    chunkSize = exchange.getRequestOptions().getBlock1().getSzx();
+                }
+                log.info("With block2 Send currentId: [{}], length: [{}], chunkSize [{}], moreFlag [{}]", currentId.toString(), otaData.length, chunkSize, false);
+                boolean lastFlag = otaData.length <= this.chunkSize;
                 response.getOptions().setBlock2(chunkSize, lastFlag, 0);
-                log.trace("With block2 Send currentId: [{}], length: [{}], chunkSize [{}], moreFlag [{}]", currentId.toString(), otaData.length, chunkSize, lastFlag);
+                response.setType(CoAP.Type.CON);
+                exchange.respond(response);
             } else {
-                log.trace("With block1 Send currentId: [{}], length: [{}], ", currentId.toString(), otaData.length);
+                log.info("Ota package size: [{}] is larger than server's MAX_RESOURCE_BODY_SIZE [{}]", otaData.length, this.maxResourceBodySize);
             }
-            exchange.respond(response);
         } else {
-            log.trace("Ota packaged currentId: [{}] is not found.", currentId.toString());
+            log.info("Ota packaged currentId: [{}] is not found.", currentId.toString());
         }
     }
 
diff --git a/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/utils/LwM2MTransportUtil.java b/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/utils/LwM2MTransportUtil.java
index 438bb752aa..3ee83766fe 100644
--- a/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/utils/LwM2MTransportUtil.java
+++ b/common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/utils/LwM2MTransportUtil.java
@@ -393,4 +393,11 @@ public class LwM2MTransportUtil {
             serverCoapConfig.set(DTLS_CONNECTION_ID_NODE_ID, null);
         }
     }
+
+    public static int calculateSzx(int size) {
+        if (size < 16 || size > 1024 || (size & (size - 1)) != 0) {
+            throw new IllegalArgumentException("Size must be a power of 2 between 16 and 1024.");
+        }
+        return (int) (Math.log(size / 16) / Math.log(2));
+    }
 }