ADVANTECH UDP Communication Watchdog Router App User Guide

: June 14, 2024
: Advantech

Table of Contents

UDP Communication Watchdog
- Used symbols
1. Changelog
- 1.1 UDP Communication Watchdog Changelog
2. Description of the Router App
3. Configuration
4. Behavior and System Log
References
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UDP Communication Watchdog

Advantech Czech s.r.o., Sokolska 71, 562 04 Usti nad Orlici, Czech Republic
Document No. APP-0099-EN, revision from 26th October, 2023.

© 2023 Advantech Czech s.r.o. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photography, recording, or any information storage and retrieval system without written consent. Information in this manual is subject to change without notice, and it does not represent a commitment on the part of Advantech.

Advantech Czech s.r.o. shall not be liable for incidental or consequential damages resulting from the furnishing, performance, or use of this manual.

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designations in this publication is for reference purposes only and does not constitute an endorsement by the trademark holder.

Used symbols

Danger - Information regarding user safety or potential damage to the router.
Attention - Problems that can arise in specific situations.
Information - Useful tips or information of special interest.
Example - Example of function, command or script.

1. Changelog

1.1 UDP Communication Watchdog Changelog

v1.0.0 (2021-03-02)

First release.

2. Description of the Router App

Router app is not contained in the standard router firmware. Uploading of this router app is described in the Configuration manual (see Chapter Related Documents).

This router app is a UDP communication watchdog - it checks the specific UDP packet responses in Smart Router and if no responses come back, it switches the PPP (cellular) connection to other SIM card in the Smart Router. It is intended for reliable connection of lottery terminals sending UDP packets via Smart Router to the responder server in Internet. See the operating principle on Figure 1 bellow.

Figure 1: UDP Communication Watchdog operating principle

UDP Communication Watchdog UM (No responses? Switch SIM)
UDP
Cellular
Lottery Terminal
Smart Router
Internet
Responder Server

The router app interface has only one Configuration item in the menu and the Return item to return back to the routers’s GUI. When enabled with default settings, it switches the cellular connection after 4 UDP responses missed. Error and SIM switch logging is accessible on System Log page of the router’s GUI.

UDP Communication Watchdog

Figure 2: UDP Communication Watchdog Router App

3. Configuration

In this chapter, the configuration of the UDP Communication Watchdog is described. Go to the Configuration page in the Communication Watchdog section of the UDP Communication Watchdog router app - it is also the landing page of the router app. To enable, tick the Enable UDP Communication Watchdog checkbox and click Apply button. The other configuration items are described in the table below.

Figure 3: UDP Communication Watchdog Configuration

Item	Description
Enable UDP communication watchdog	Enable the UDP Communication Watchdog. This

is necessary for UDP packet checker to run and switch SIMs in case of failure.
Responder address| IP address of the responder server in the Internet. Either IPv4, IPv6 or domain name is allowed. The default value is 10.70.150.230.
Responder port| Port of the responder server in the Internet. Default 53401.
Terminal start port| First port (UDP) of the Lottery terminal connected to the router. Default is 50000. There can be a pool of more connected terminals.
Terminal end point | Last port (UDP) of the Lottery terminal connected to the router. Default is 50156. There can be a pool of more connected terminals.
Max. response time| Time to wait for the answer before considering it the lost packet. Default is 15 seconds.
Switch SIM after X packets lost| Number of lost packets to switch to other cellular connection. Default is 4.

Table 1: UDP Communication Watchdog Configuration

4. Behavior and System Log

Behavior related notes and logging information are described in this Chapter.

4.1 Supervised UDP traffic

Only specific UDP packets are monitored these going from a local device (lottery terminal) to the Internet responder and specific responses back. Only UDP packets from configured ports range are tracked.

The UDP packets are matched by a destination IP (when going from local device to responder) and source IP and the port number when going back from the responder to the local device (lottery terminal). Only source and destination of UDP traffic is monitored. The payload of UDP packets is not monitored.

4.2 Switching of the SIM cards

If the packets are going forth (being received from local device) but there are no responses, cellular connection is switched to another SIM card than the active one.

It is done by powering off the cellular module, setting another SIM card as default and powering on the cellular module to establish the new connection. There is no need of any additional SIM switching configuration in the router, but the Smart Router has to be in version with two SIM cards and both SIM cards has to be configured properly on Mobile WAN page in the Configuration section of the router’s Web GUI (typically for two different carriers, both with same APN).

4.3 System Log

Figure 4: System Log

The router app logs are accessible on the System Log page of the router’s main menu. The UDP Communication Watchdog logs start with the string as seen on the Figure 4.

Errors are logged by the router app. When it comes to switching the SIM cards, the following message is shown on the log:

missing responses from responder – > changing SIM
Then there are messages from cellular module being restarted and the new cellular connection being established.

You can obtain product-related documents on Engineering Portal at icr.advantech.cz address.

To get your router’s Quick Start Guide, User Manual, Configuration Manual, or Firmware go to the Router Models page, find the required model, and switch to the Manuals or Firmware tab, respectively.

The Router Apps installation packages and manuals are available on the Router Apps page.

For the Development Documents, go to the DevZone page.

UDP Communication Watchdog Manual