Why devices often reconnect?
The speed of delivery of events depends on from the stability of communication. Therefore, the object devices seek to restore and maintain communication with the Security Center. When connecting / disconnecting the devices, the Security Center generates events about it, generation of these events is described in detail in the article on communication control setup. Let’s consider the cases when there are a lot of events like this, and what to do about it. It looks approximately like this:
First determine the scale of the problem. This can be done using the Report Manager module. Select report template 1-07-Statistics, all objects, a few days interval and the event class Communication lost. In the created report, the number of communication loss events will be displayed in the right column:
We are nterested in objects where there was a large number of communication losses. The example shows that the problem is only with objects 163 and 1234. I.e. the cause must be sought and rectified at these sites and the problem is not massive. If the report on all devices has a lot of losses, then most often the reason is on the side of the security console.
Let’s consider the common causes of unstable communication.
The port for receiving events is used in other sources or programs
If the same TCP port is specified in other event sources or is used by another program, then, roughly speaking, there will be a constant "pulling" of this port. Because of this, there will be frequent reconnections of devices.
To check whether the port is used somewhere else you can use the command line. Enter the command:
netstat -ano | find "xxxx" | find "LISTENING" , where xxxx - port to which devices are connected (which is specified in the CML event source). If the result is only one line, then everything is fine, the port is occupied only by the source of CML:
If there are more than one line, then the port is busy with something else. You can find which other process is listening to the port using the task manager:
What to do: Check what other service can use the port. Often the problem is that the CML Event Source (services) and the usual TCP \ IP Event Source are created for the same port. Disable unnecessary event source (program) or split by ports.
SIM cards / operators
Devices can work with two SIM-cards. Primary SIM - which is in the bottom slot. In the configuration of the device there is a Transition interval to the main channel (5 minutes, by default). If two SIM cards are used and the first one has failed or the money balance is negative, the device will switch to SIM2 and will make constant attempts to return to the first main SIM. As a result, there will be constant reconnections.
Or another situation: they put only one SIM into the device, but mistakenly installed it in the second slot (top one). Then the device will also constantly make attempts to switch to the main SIM, which is not put into the slot.
What to do: If reconnections occur on many objects - check the balance on SIM-cards, whether there is money in the corporate account. If the connection is lost with several objects, then try connecting to them through the Engineer Panel and check which SIM card the device using. If it’s the second, then there’s a problem with the first one or it is mistakenly installed in the second slot.
You can temporarily disable the transition to the main channel before the arrival of the technician at the site. To do this, through the Engineer Panel, set the zero transition interval to the main channel.
When installing and selecting the installation location of the device, it is necessary to find a place with the best network coverage. If this has not been done, the device may lose connection due to a weak signal. Or if an external GSM antenna was installed, but attached it to the metal (device case, profile sheets, suspended ceiling frame ...) or close to what it may cause interferences (power lines, other radiators / antennas). Because of this the device can also lose connection due to poor signal level or interference.
What to do: Connect to the object through the Engineer Panel and check the signal level in the Status Panel-Communication Channels. If the level is low (RSSI is less than 10), deploy a technician to the site to inspect and find the optimal place for the device or install the remote antenna.
Network equipment, network protection
The connection of devices with the Security Center may interrupt due to faulty network equipment of the provider or in the local network. For example, a network card, switch or router fails or is not capable to manage a large number of connections. Reconnections may occur in case of incorrectly configured protection: filtering for connections in the router or on the server, antiviruses, defenders, firewalls.
What to do: Ask your system administrators to check the stability of the LAN equipment and server. Check that all the modules, services and ports of the Security Center are included as exceptions. Try to temporarily disable protection and monitor repeatability of failures.