menu "esp-modem" config ESP_MODEM_CMUX_DEFRAGMENT_PAYLOAD bool "Defragment CMUX messages internally" default y help If enabled (default), the esp-modem automatically defragments CMUX messages to only pass the completed CMUX message to higher layers. This is useful for messages in command mode (if they're received fragmented). It's not a problem for messages in data mode as the upper layer (PPP protocol) defines message boundaries. Keep the default to true for most cases (as most devices use simply 1 byte CMUX length, as the internal Rx buffer of size >= 256 bytes won't overflow) Set to false if your devices uses 2 byte CMUX payload (e.g. A7672S). The operation would work without an issue in data mode, but some replies in command mode might come fragmented in rare cases so might need to retry AT commands. config ESP_MODEM_CMUX_DELAY_AFTER_DLCI_SETUP int "Delay in ms to wait before creating another virtual terminal" default 0 help Some devices might need a pause before sending SABM command that creates virtual terminal. This delay applies only to establishing a CMUX mode. The typical reason for failing SABM request without a delay is that some devices (SIM800) send MSC requests just after opening a new DLCI. endmenu