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GSM channel (SMS)

Use the GSM channel to connect to a GSM device directly.

Find more information about channels in general here.

GSM channels are to send and receive a low to medium volume of SMS messages. The number of simultaneous GSM channel depends on the license tier of your Auron SMS Server installation.

Edit GSM channel

Edit GSM channel


The last page of the GSM channel wizard contains a GSM toolset for diagnostics and maintenance of your GSM device.

Edit GSM channel - Tools

Edit GSM channel – Tools

In this page you can check the signal of the GSM device as well as connect to the GSM device directly and issue AT or USSD commands.

The latter is especially useful for updating pre-paid SIM cards or to find out any other information from your provider, without having to remove the SIM from the device.

To use the Tools page the device must be disabled. This is because only one application can be connected to a GSM device at a time.


The following settings can be configured:

Property Description
Connection The GSM device to connect to. This can be either:

  • COM device – A COM port is listed
  • Windows TAPI device – A TAPI device name is listed
  • IP GSM – Use host/port/tcp mode to specify

In the case of ‘IP GSM’ the GSM device is connected using TCP/IP. Specify the hostname, port number and TCP mode. The TCP mode can be:

  • Raw – This is the most common option
  • Telnet – Use this when the Serial to TCP terminal sends NVT commands
  • Telnet with COM control – Use this when the serial to TCP terminal expects the Auron SMS Server to setup COM settings through NVT commands.
PIN This is the PIN code to use if the SIM is protected with a PIN code
Inter character delay Time (MS) to wait before sending the next character in the GSM protocol
Inter command delay Time (MS) to wait before sending the next GSM command
Command timeout Maximum time (MS) to wait for a response from the GSM device
From Address Phone number of the GSM device. This is used in the From address of sent SMS messages.
Message storage Storage where SMS messages are stored when they are received from the telecom operator. It depends on the type of GSM device where SMS messages are stored.
The most basic GSM devices are not equipped with device memory; these devices can store only a limited number of SMS messages on the SIM card.
Advanced GSM devices are equipped with extra memory on the device. SMS messages are stored directly on the device memory. The SMS Server can read incoming SMS messages from these different locations:

  • ALL Use all storage modes (default). Always tries to read all memory stores (SM / ME / MT).
    The Auron SMS Server removes the duplicates so that messages that are in multiple stores, are only inserted into the Server database once.
  • SM Retrieve messages directly from SIM card. Use this setting when the device doesn’t have a memory buffer to store SMS messages;
  • ME Retrieve messages from the device memory. Advanced GSM devices come with built-in memory to enlarge the number of stored SMS messages on the device;
  • MT Combined storage. The GSM should return all messages from both SM and ME storages.
Report storage Storage where delivery reports are stored when received from the network. Some devices do not have the ability to store reports.
These devices cannot be used to check the delivery of messages.
There are three values:

  • ALL Retrieve reports from all storage modes (default). Always tries to read from all memory stores (SM / ME / MT / SR)
  • SM Retrieve reports directly from SIM card.
    Use this setting when the device doesn’t have a memory buffer to store reports;
  • ME Retrieve reports from the device memory. Only applies to advanced GSM devices with built-in memory to enlarge the number of stored reports on the device;
  • MT Combined storage. The GSM should return all messages from both SM and ME storages;
  • SR Retrieve reports from the dedicated status report memory. Not all devices support this memory.
Large messages Indicates how large outgoing messages (i.e. messages longer than 160 characters) should be treated.
There are these options:

  • Truncate messages larger than 160 characters (part of the message will be lost);
  • Send the large messages as multi-part messages. Each part is sent as a separate SMS message. On the remote mobile phone, the parts are collected and displayed as one single message. Note that the costs for one SMS part in a multi-part message is the same as the costs for one single 160 character SMS message;
  • Don’t send the large message at all (message will fail).
Connection This can be one of these options:

  • Close after batch – This will open and re-initialize the GSM device after every send or receive batch. This options makes sending and receive a little bit slower but may work better on older GSM devices;
  • Keep open – Keeps the connection to the GSM device open. This is often the fastest option.
Leave a copy on the device Leave a copy of the incoming SMS or Report on the device or SIM card. This option does not delete anything from the SIM card. However, a disadvantage is that once the device is full, no new messages or reports will be received.
Request delivery report Always requests a delivery receipt for any message sent on this channel
Assemble multipart SMS Tries to automatically assemble a multipart message. This means that the Auron SMS Server will only receive a single message instead of all individual parts.
Extract application port Extract the application port of from an SMS message if it was sent to an application port. Some SMS messages can be sent not directly to the inbox but instead to a specific application on the phone.
To do this they use an ‘application port’ that is set in the UDH of the SMS message. With this option enabled the UDH is extracted from the SMS and the application port is integrated in the ‘ToAddress’ of the SMS message.
For example. An SMS message sent to +3112345678 with application port ‘1000’ will have its ‘ToAddress’: ‘+3112345678:1000’ with this setting enabled. With this setting disabled the message will be binary and the UDH will still be part of the message.
Use SMSC receive time Instead of using the receive time from the Auron SMS Server GSM channel, use the receive time that was embedded in the SMS by the SMSC that received the message.
Init string Use a customized initialization string. This can contain some extra AT commands that should be executed right after connecting to the GSM modem.
Init string timeout The maximum time (s) that the SMS Server GSM channel will wait for the init string to complete
Wait for device to register Wait for the GSM device to register on the network before trying to send or receive messages. If this is disabled then the first (couple of) messages send on a channel right after enable may fail because the device is not registered yet.
Network timeout The maximum time (s) to wait for a GSM device to register on the GSM network.
Report timeout The maximum time (s) to wait for a delivery report after the original message was sent.
Check interval The interval time (s) between checking the GSM modem for new messages.
Receive timeout The maximum time (s) to wait for the receive operation to complete.
Multipart timeout The maximum time (s) to wait for a multipart message to complete. If the multipart message is not completed within this time, the parts that are available will be assembled and received. In that case the message will contain ‘**Part Missing** markers.
Send interval Time (ms) to wait before sending the next message in a batch.
Send timeout The maximum time (ms) to wait for a GSM device to verify that a message was sent.
Encoding The default character encoding to use. This can be either the SMSC-default (GSM) character set or Unicode.
Language In case of GSM you can select the default language page to use.