overlay-ppp-cmux-linux.conf

#
# Copyright (c) 2025 Nordic Semiconductor ASA
#
# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
#

CONFIG_SLM_SKIP_READY_MSG=y
CONFIG_SLM_CMUX=y
CONFIG_SLM_PPP=y
CONFIG_SLM_CR_TERMINATION=y

# Assume at least baudrate 115200 for UART
# so CMUX frame can be received in 12 ms (134*10/115200)
CONFIG_MODEM_BACKEND_UART_ASYNC_RECEIVE_IDLE_TIMEOUT_MS=12
CONFIG_MODEM_CMUX_MTU=127
CONFIG_MODEM_CMUX_WORK_BUFFER_SIZE=536
CONFIG_SLM_CMUX_UART_BUFFER_SIZE=6000
# For sending full 6000 bytes at 115200 baudrate
# 6000 * 10 / 115200 = 521 ms
CONFIG_MODEM_BACKEND_UART_ASYNC_TRANSMIT_TIMEOUT_MS=521

# These buffers are unused after AT#CMUX is enabled
# so use minimal buffer size
CONFIG_SLM_UART_RX_BUF_COUNT=3
CONFIG_SLM_UART_RX_BUF_SIZE=128
CONFIG_SLM_UART_TX_BUF_SIZE=128

# When using PPP, disable commands of IP-based protocols to save flash space.
CONFIG_SLM_FTPC=n
CONFIG_SLM_TFTPC=n
CONFIG_SLM_HTTPC=n
CONFIG_SLM_MQTTC=n

# nRF Connect SDK modules
CONFIG_PDN=y
CONFIG_AT_CMD_CUSTOM=y
CONFIG_NRF_MODEM_LIB_SHMEM_TX_SIZE=22528

# Zephyr modules
CONFIG_NET_NATIVE=y
CONFIG_NET_L2_PPP=y
CONFIG_MODEM_MODULES=y
CONFIG_MODEM_CMUX=y
CONFIG_MODEM_PPP=y
CONFIG_MODEM_BACKEND_UART=y

# L2 protocol
CONFIG_NET_L2_PPP_MGMT=y
CONFIG_NET_L2_PPP_OPTION_MRU=y
CONFIG_NET_L2_PPP_OPTION_SERVE_IP=y
CONFIG_NET_L2_PPP_OPTION_SERVE_DNS=y
CONFIG_NET_L2_PPP_TIMEOUT=5000

# IP stack
CONFIG_NET_IP_ADDR_CHECK=n
CONFIG_NET_SOCKETS_PACKET=y

# network buffering
CONFIG_NET_BUF=y
CONFIG_NET_BUF_POOL_USAGE=y
CONFIG_NET_PKT_RX_COUNT=44
CONFIG_NET_BUF_RX_COUNT=88
CONFIG_NET_PKT_TX_COUNT=44
CONFIG_NET_BUF_TX_COUNT=88
CONFIG_NET_TC_RX_COUNT=0