diff --git a/gb28181-mocking-service/src/main/java/cn/skcks/docking/gb28181/mocking/service/device/DeviceProxyService.java b/gb28181-mocking-service/src/main/java/cn/skcks/docking/gb28181/mocking/service/device/DeviceProxyService.java
index 9f29f72..ade7ee8 100644
--- a/gb28181-mocking-service/src/main/java/cn/skcks/docking/gb28181/mocking/service/device/DeviceProxyService.java
+++ b/gb28181-mocking-service/src/main/java/cn/skcks/docking/gb28181/mocking/service/device/DeviceProxyService.java
@@ -26,6 +26,7 @@ import cn.skcks.docking.gb28181.mocking.service.ffmpeg.FfmpegSupportService;
 import cn.skcks.docking.gb28181.mocking.service.zlm.hook.ZlmStreamChangeHookService;
 import cn.skcks.docking.gb28181.sdp.GB28181Description;
 import cn.skcks.docking.gb28181.sdp.parser.GB28181DescriptionParser;
+import cn.skcks.docking.gb28181.sip.method.invite.response.InviteResponseBuilder;
 import com.github.rholder.retry.Retryer;
 import com.github.rholder.retry.RetryerBuilder;
 import com.github.rholder.retry.StopStrategies;
@@ -92,11 +93,14 @@ public class DeviceProxyService {
             subscribe.getByeSubscribe().addSubscribe(key, subscriber);
             int num = taskNum.incrementAndGet();
             log.info("当前任务数 {}", num);
+
+            ScheduledFuture<?> schedule = trying(request);
             try {
                 GB28181Description gb28181Description = new GB28181DescriptionParser(new String(request.getRawContent())).parse();
                 MediaDescription mediaDescription = (MediaDescription)gb28181Description.getMediaDescriptions(true).get(0);
                 boolean tcp = StringUtils.containsIgnoreCase(mediaDescription.getMedia().getProtocol(), "TCP");
                 zlmStreamChangeHookService.getRegistHandler().put(callId,()->{
+                    schedule.cancel(false);
                     Retryer<StartSendRtpResp> retryer = RetryerBuilder.<StartSendRtpResp>newBuilder()
                             .retryIfResult(resp -> resp.getLocalPort() == null || resp.getLocalPort() <= 0)
                             .retryIfException()
@@ -121,6 +125,7 @@ public class DeviceProxyService {
                             return startSendRtpResp;
                         });
                     } catch (Exception e) {
+                        schedule.cancel(true);
                         Optional.ofNullable(zlmStreamChangeHookService.getUnregistHandler().remove(callId))
                                 .ifPresent(ZlmStreamChangeHookService.ZlmStreamChangeHookHandler::handler);
                         throw new RuntimeException(e);
@@ -136,6 +141,7 @@ public class DeviceProxyService {
                 callbackTask.put(device.getDeviceCode(), executor);
                 executeResultHandler.waitFor();
             } catch (Exception e) {
+                schedule.cancel(true);
                 throw new RuntimeException(e);
             }
         };
@@ -150,11 +156,13 @@ public class DeviceProxyService {
             subscribe.getByeSubscribe().addSubscribe(key, subscriber);
             int num = taskNum.incrementAndGet();
             log.info("当前任务数 {}", num);
+            ScheduledFuture<?> schedule = trying(request);
             try {
                 GB28181Description gb28181Description = new GB28181DescriptionParser(new String(request.getRawContent())).parse();
                 MediaDescription mediaDescription = (MediaDescription)gb28181Description.getMediaDescriptions(true).get(0);
                 boolean tcp = StringUtils.containsIgnoreCase(mediaDescription.getMedia().getProtocol(), "TCP");
                 zlmStreamChangeHookService.getRegistHandler().put(callId,()->{
+                    schedule.cancel(false);
                     Retryer<StartSendRtpResp> retryer = RetryerBuilder.<StartSendRtpResp>newBuilder()
                             .retryIfResult(resp -> resp.getLocalPort() == null || resp.getLocalPort() <= 0)
                             .retryIfException()
@@ -179,6 +187,7 @@ public class DeviceProxyService {
                             return startSendRtpResp;
                         });
                     } catch (Exception e) {
+                        schedule.cancel(true);
                         Optional.ofNullable(zlmStreamChangeHookService.getUnregistHandler().remove(callId))
                                 .ifPresent(ZlmStreamChangeHookService.ZlmStreamChangeHookHandler::handler);
                         throw new RuntimeException(e);
@@ -194,11 +203,22 @@ public class DeviceProxyService {
                 downloadTask.put(device.getDeviceCode(), executor);
                 executeResultHandler.waitFor();
             } catch (Exception e) {
+                schedule.cancel(true);
                 throw new RuntimeException(e);
             }
         };
     }
 
+    private ScheduledFuture<?> trying(SIPRequest request){
+        return scheduledExecutorService.schedule(() -> {
+            InviteResponseBuilder inviteRequestBuilder = InviteResponseBuilder.builder().build();
+            Response tryingInviteResponse = inviteRequestBuilder.createTryingInviteResponse(request);
+            String ip = request.getLocalAddress().getHostAddress();
+            String transPort = request.getTopmostViaHeader().getTransport();
+            sender.sendResponse(ip, transPort, ((provider, ip1, port) -> tryingInviteResponse));
+        }, 200, TimeUnit.MILLISECONDS);
+    }
+
     public Flow.Subscriber<SIPRequest> byeSubscriber(String key, MockingDevice device, ConcurrentHashMap<String, Executor> task){
         return new Flow.Subscriber<>() {
             @Override