Error establishing SFTP connection

Hi ,

We are using 'receive file over SFTP' configured as MNI node for getting files from SFTP location.

but we are getting connection timeout error intermittently . Restarting process node resolves issues but can anyone help to resolve this issue?

com.jcraft.jsch.JSchException: java.net.ConnectException: Connection timed out (Connection timed out)
	at com.jcraft.jsch.Util.createSocket(Util.java:349)
	at com.jcraft.jsch.Session.connect(Session.java:215)
	at com.jcraft.jsch.Session.connect(Session.java:183)
	at com.appian.ps.plugins.sftpsmartservices.SFTPConfig.connect(SFTPConfig.java:179)
	at com.appian.ps.plugins.sftpsmartservices.GetRemoteDirectoryContentsOverSFTP.run(GetRemoteDirectoryContentsOverSFTP.java:66)
	at com.appiancorp.process.runtime.framework.DefaultActivityExecutor$1.lambda$call$0(DefaultActivityExecutor.java:136)
	at com.appiancorp.plugins.PluginUsageLogger.runWithPluginInformation(PluginUsageLogger.java:52)
	at com.appiancorp.process.runtime.framework.DefaultActivityExecutor$1.call(DefaultActivityExecutor.java:136)
	at com.appiancorp.process.runtime.framework.DefaultActivityExecutor$1.call(DefaultActivityExecutor.java:130)
	at com.appiancorp.common.ContextClassLoaderSwitcher.runInContext(ContextClassLoaderSwitcher.java:27)
	at com.appiancorp.process.runtime.framework.DefaultActivityExecutor.execute(DefaultActivityExecutor.java:130)
	at com.appiancorp.process.engine.UnattendedJavaActivityRequest.execute(UnattendedJavaActivityRequest.java:88)
	at com.appiancorp.process.engine.UnattendedJavaActivityRequestResponseCreator.getJavaActivityResultResponse(UnattendedJavaActivityRequestResponseCreator.java:21)
	at com.appiancorp.process.engine.UnattendedJavaActivityRequest.getJavaActivityResultResponse(UnattendedJavaActivityRequest.java:67)
	at com.appiancorp.process.engine.UnattendedJavaActivityRequest.execute0(UnattendedJavaActivityRequest.java:55)
	at com.appiancorp.common.persistence.data.AppianDataUserContextProvider.executeWithConsistentDataReads(AppianDataUserContextProvider.java:143)
	at com.appiancorp.process.engine.ProcessContinuationRequest.executeOuter(ProcessContinuationRequest.java:68)
	at com.appiancorp.process.engine.ContinuationRequest.execute(ContinuationRequest.java:129)
	at com.appiancorp.process.workpoller.UnattendedRequestHandlerBean.onMessage(UnattendedRequestHandlerBean.java:36)
	at com.appiancorp.process.workpoller.WorkItem.run(WorkItem.java:110)
	at org.springframework.jca.work.SimpleTaskWorkManager$DelegatingWorkAdapter.run(SimpleTaskWorkManager.java:239)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:750)
Caused by: java.net.ConnectException: Connection timed out (Connection timed out)
	at java