Hi Folks,

happy new year.
In continuation of my previous work I followed Kevin's suggestion and resolved the connection error problem. Thanks, Kevin for your suggestion.
Right now I am trying decoupling the device simulator from GXF core. Running GXF core in a container and simulator in another container. The simulator container opens only ports 12123 and 12124. Device registration is successful for the simulator. But when trying to manage a device from the web demo app, the protocol adapter layer(Elster) tried to get the device status from the simulator and the connection failed due to the wrong port number. It is trying to connect to the simulator over port 12122. But the simulator doesn't have port 12122. So what configuration I am doing wrong. Can anyone please suggest?
Below changes has been done:
1. simulator container running
  - web-device-simulator.war
2. web-device-simulator.properties change:
    oslp.address.client=gxf-core >>>>> This is docker container name of gxf core(in this case 172.18.0.2)
3. Device info:
   Device Identification: SSLD_000-00-18
   Ip Address: gxf-simulator  >>>>> This is docker container name of simulator (in this case 172.18.0.4)
   Device type: SSLD
   Protocol: OSLP_ELSTER
   Firmware version: R01
   ...

Error Log:
2022-01-05 13:24:45.023] [2d5c3528f954] [protocolOslpInboundOsgpCoreRequestsMessageListenerContainer-1] INFO o.o.a.p.o.e.i.m.DeviceRequestMessageListener@onMessage:50 - Received message of type: GET_LIGHT_STATUS with message priority: 4
2022-01-05 13:24:45.024] [2d5c3528f954] [protocolOslpInboundOsgpCoreRequestsMessageListenerContainer-1] INFO o.o.a.p.o.e.i.m.p.PublicLightingGetStatusRequestMessageProcessor@processMessage:53 - Processing public lighting get status request message
2022-01-05 13:24:45.024] [2d5c3528f954] [protocolOslpInboundOsgpCoreRequestsMessageListenerContainer-1] INFO o.o.a.p.o.e.i.m.DeviceRequestMessageProcessor@printDomainInfo:69 - Calling DeviceService function: GET_LIGHT_STATUS for domain: PUBLIC_LIGHTING 1.0
2022-01-05 13:24:45.025] [2d5c3528f954] [protocolOslpInboundOsgpCoreRequestsMessageListenerContainer-1] INFO o.o.a.p.o.e.i.n.OslpDeviceService@getStatus:1279 - getStatus() for device: SSLD_000-00-18.
2022-01-05 13:24:45.026] [2d5c3528f954] [protocolOslpInboundOsgpCoreRequestsMessageListenerContainer-1] INFO o.o.a.p.o.e.a.s.o.OslpDeviceSettingsService@getDeviceByDeviceIdentification:64 - get device by device identification: SSLD_000-00-18
2022-01-05 13:24:45.029] [2d5c3528f954] [protocolOslpInboundOsgpCoreRequestsMessageListenerContainer-1] INFO o.o.a.p.o.e.i.m.SigningServerRequestMessageSender@send:45 - Sending request message to signing server, with reply-to-queue: queue://signing-server.1_0.responses-2d5c3528f954.
2022-01-05 13:24:45.034] [2d5c3528f954] [ActiveMQ Task-1] INFO o.a.a.t.failover.FailoverTransport@doReconnect:1054 - Successfully connected to tcp://localhost:61616
2022-01-05 13:24:45.061] [2d5c3528f954] [protocolOslpInboundSigningServerResponsesMessageListenerContainer-5] INFO o.o.a.p.o.e.i.m.SigningServerResponsesMessageListener@onMessage:36 - Received message of type: SIGNING_RESPONSE
2022-01-05 13:24:45.063] [2d5c3528f954] [protocolOslpInboundSigningServerResponsesMessageListenerContainer-5] INFO o.o.a.p.o.e.i.m.SigningServerResponsesMessageListener@onMessage:57 - Read signed message, messageType: SIGNING_RESPONSE, messagePriority: 4, deviceIdentification: SSLD_000-00-18, result: OK, correlationId: test-org|||SSLD_000-00-18|||20220105132444821|||1a1c43a2-46a9-4177-8ab0-9f2337c9e630
2022-01-05 13:24:45.064] [2d5c3528f954] [protocolOslpInboundSigningServerResponsesMessageListenerContainer-5] INFO o.o.a.p.o.e.a.s.o.OslpSigningService@handleSignedOslpRequest:152 - oslpEnvelope.size: 146 for message type: GET_LIGHT_STATUS
2022-01-05 13:24:45.064] [2d5c3528f954] [protocolOslpInboundSigningServerResponsesMessageListenerContainer-5] INFO o.o.a.p.o.e.i.n.OslpDeviceService@doGetStatus:1291 - doGetStatus() for device: SSLD_000-00-18.
2022-01-05 13:24:45.065] [2d5c3528f954] [protocolOslpInboundSigningServerResponsesMessageListenerContainer-5] INFO o.o.a.p.o.e.a.s.o.OslpDeviceSettingsService@getDeviceByDeviceIdentification:64 - get device by device identification: SSLD_000-00-18
2022-01-05 13:24:45.076] [2d5c3528f954] [ActiveMQ Task-1] INFO o.a.a.t.failover.FailoverTransport@doReconnect:1054 - Successfully connected to tcp://localhost:61616
2022-01-05 13:24:45.088] [2d5c3528f954] [protocolOslpInboundSigningServerResponsesMessageListenerContainer-5] INFO o.o.a.p.o.e.i.n.OslpChannelHandlerClient@send:120 - Sending OSLP request: getStatusRequest {
}

2022-01-05 13:24:45.111] [2d5c3528f954] [disposableNioEventLoopGroup-2-2] INFO i.n.handler.logging.LoggingHandler@log:148 - [id: 0xd7c8160f] REGISTERED
2022-01-05 13:24:45.112] [2d5c3528f954] [disposableNioEventLoopGroup-2-2] INFO i.n.handler.logging.LoggingHandler@log:148 - [id: 0xd7c8160f] CONNECT: /172.18.0.4:12122
2022-01-05 13:24:45.114] [2d5c3528f954] [disposableNioEventLoopGroup-2-2] INFO o.o.a.p.o.e.i.n.OslpChannelHandlerClient@operationComplete:141 - The connection to the device SSLD_000-00-18 is not successful
2022-01-05 13:24:45.115] [2d5c3528f954] [disposableNioEventLoopGroup-2-2] ERROR o.o.a.p.o.e.i.m.DeviceRequestMessageProcessor@handleUnableToConnectDeviceResponse:235 - Error while connecting to or communicating with device
org.opensmartgridplatform.shared.exceptionhandling.ConnectionFailureException: Connection failure
at org.opensmartgridplatform.adapter.protocol.oslp.elster.infra.networking.OslpDeviceService.handleException(OslpDeviceService.java:780)
at org.opensmartgridplatform.adapter.protocol.oslp.elster.infra.networking.OslpDeviceService$18.handleException(OslpDeviceService.java:1306)
at org.opensmartgridplatform.adapter.protocol.oslp.elster.infra.networking.OslpChannelHandlerClient$1.operationComplete(OslpChannelHandlerClient.java:143)
at org.opensmartgridplatform.adapter.protocol.oslp.elster.infra.networking.OslpChannelHandlerClient$1.operationComplete(OslpChannelHandlerClient.java:129)
at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:577)
at io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:570)
at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:549)
at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:490)
at io.netty.util.concurrent.DefaultPromise.setValue0(DefaultPromise.java:615)
at io.netty.util.concurrent.DefaultPromise.setFailure0(DefaultPromise.java:608)
at io.netty.util.concurrent.DefaultPromise.tryFailure(DefaultPromise.java:117)
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.fulfillConnectPromise(AbstractNioChannel.java:321)
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:337)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:702)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:650)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:576)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.lang.Thread.run(Thread.java:748)
2022-01-05 13:24:45.115] [2d5c3528f954] [disposableNioEventLoopGroup-2-2] INFO o.o.a.p.o.e.i.m.DeviceResponseMessageSender@sendMessage:55 - Sending protocol response message for device: SSLD_000-00-18 of message type: GET_LIGHT_STATUS with message priority: 4
2022-01-05 13:24:45.118] [2d5c3528f954] [ActiveMQ Task-1] INFO o.a.a.t.failover.FailoverTransport@doReconnect:1054 - Successfully connected to tcp://localhost:61616
2022-01-05 13:24:45.129] [2d5c3528f954] [disposableNioEventLoopGroup-2-2] INFO i.n.handler.logging.LoggingHandler@log:148 - [id: 0xd7c8160f] CLOSE
2022-01-05 13:24:45.130] [2d5c3528f954] [disposableNioEventLoopGroup-2-2] INFO i.n.handler.logging.LoggingHandler@log:148 - [id: 0xd7c8160f] UNREGISTERED