Socket Behavior; Supported Sockets; Best Practices When Using Sockets; Sockets And Remote Manager - Digi XBee 3 Cellular LTE-M User Manual

Socket behavior

Supported sockets

The XBee Smart Modem supports the following number of sockets:
6 maximum: 4 TLS sockets maximum.
n
Note For NB-IoT, TCP support is dependent on the network. Contact your network provider for
details.

Best practices when using sockets

Sockets and Remote Manager

If you use Remote Manager to remotely communicate with and configure your XBee Cellular device,
you must leave at least two sockets available in the system: one UDP socket (for periodic low-data-
usage check-ins), and one TCP/TLS socket (to be used when a full connection is needed).
If your application allocates so many sockets that Remote Manager functionality in the firmware
cannot get the sockets that it requires, Remote Manager functionality will be prevented from working
until sockets become available.
For example, each call to socket.socket() in MicroPython will allocate a socket, and this socket will
remain allocated to MicroPython until the socket's close method is called, or the MicroPython REPL is
restarted using Ctrl-D.
See Supported sockets

Sockets and API mode

When using API mode to transmit TCP/TLS data to a remote destination (using the 0x20 or 0x23 API
frames), sending a large amount of data as a single API frame is preferable to multiple smaller API
frames. Using a single large API frame allows the XBee to transmit the data using fewer operations
than transmitting multiple pieces of data in sequence, which improves overall throughput.
Additionally, one API frame consumes less dynamic memory in the system than multiple smaller API
frames, which means there will be more memory available to process incoming IP data as well as
subsequent API frames sent into the XBee Cellular device.

Socket timeouts

The XBee Smart Modem implicitly opens the socket any time there is data to be sent, and closes it
according to the timeout settings. The
timeout settings.
Note For NB-IoT, TCP support is dependent on the network. Contact your network provider for
details.
1 1 TCP socket is used for Remote Manager, so if you have Remote Manager enabled, subtract 1 socket from the
values above.
Digi XBee® 3 Cellular LTE-M/NB-IoT Global Smart Modem User Guide
1
for more information on the total number of sockets supported by the device.
TM (IP Client Connection Timeout)
Supported sockets
command controls the
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