nRF7002-DK TCP: Data buffer allocation failed

Question

Hello,

I am solving a problem with nRF7002-DK, I am using TCP sockets for communication. MTU can have up to 6800 bytes, unfortunately, both in STA and AP mode, the connection is interrupted and the following message is displayed in the terminal:

[00:25:28.479,705] <err> net_pkt: Data buffer (1133) allocation failed.
[00:25:28.486,968] <err> net_tcp: conn: 0x200624d8 packet allocation failed, len=1085
[00:25:28.495,452] <err> net_tcp: TCP failed to allocate buffer in retransmission
[00:25:28.604,309] <err> net_pkt: Data buffer (1413) allocation failed.
[00:25:28.611,572] <err> net_tcp: conn: 0x20062738 packet allocation failed, len=1365
[00:25:28.620,056] <err> net_tcp: TCP failed to allocate buffer in retransmission
[00:25:28.934,387] <err> net_pkt: Data buffer (1413) allocation failed.
[00:25:28.941,650] <err> net_tcp: conn: 0x20062738 packet allocation failed, len=1365
[00:25:28.950,134] <err> net_tcp: TCP failed to allocate buffer in retransmission
[00:25:29.072,448] <err> net_pkt: Data buffer (1260) allocation failed.
[00:25:29.079,742] <err> net_tcp: conn: 0x200624d8 packet allocation failed, len=1212
[00:25:29.088,226] <err> net_tcp: TCP failed to allocate buffer in retransmission

Sometimes the connection is restored, sometimes it drops completely. Please advise what to do about this. I am attaching prj.conf.

Thank you.

#
# Copyright (c) 2022 Nordic Semiconductor ASA
#
# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
#

# General
CONFIG_LOG=y
CONFIG_ASSERT=y
CONFIG_MAIN_STACK_SIZE=2048
CONFIG_TEST_RANDOM_GENERATOR=y
CONFIG_RESET_ON_FATAL_ERROR=n

CONFIG_CONSOLE=y
CONFIG_UART_CONSOLE=y
CONFIG_SERIAL=y


CONFIG_UART_ASYNC_API=y
CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_UART_1_ASYNC=y
CONFIG_UART_1_INTERRUPT_DRIVEN=n
CONFIG_UART_1_NRF_HW_ASYNC=y
CONFIG_UART_1_NRF_HW_ASYNC_TIMER=2
CONFIG_UART_1_NRF_ASYNC_LOW_POWER=y
CONFIG_NRFX_TIMER2=y

# Logging configuration
CONFIG_LOG_DEFAULT_LEVEL=3
CONFIG_LOG_MODE_IMMEDIATE=y

CONFIG_LOG_BUFFER_SIZE=2048
# ==========================================

CONFIG_ZVFS_OPEN_MAX=32


# WiFi Configuration - STA MODE
CONFIG_WIFI=y
CONFIG_WIFI_NRF70=y

# WPA supplicant pro STA mode
CONFIG_WIFI_NM_WPA_SUPPLICANT=y
CONFIG_WIFI_READY_LIB=y

# Logging pro WiFi
CONFIG_WIFI_NM_WPA_SUPPLICANT_LOG_LEVEL_INF=y

# Networking
CONFIG_NETWORKING=y
CONFIG_NET_CONNECTION_MANAGER=y
CONFIG_NET_SOCKETS=y
CONFIG_NET_LOG=y
CONFIG_NET_IPV4=y
CONFIG_NET_UDP=y
CONFIG_NET_TCP=y

CONFIG_POSIX_API=y

# Network buffer sizes
CONFIG_NET_PKT_RX_COUNT=98
CONFIG_NET_PKT_TX_COUNT=74
CONFIG_NET_BUF_RX_COUNT=130
CONFIG_NET_BUF_TX_COUNT=100


# Below section is the primary contributor to SRAM and is currently
# tuned for performance, but this will be revisited in the future.
CONFIG_NRF70_RX_NUM_BUFS=20

CONFIG_NRF_WIFI_CTRL_HEAP_SIZE=30000
CONFIG_NRF_WIFI_DATA_HEAP_SIZE=50000
CONFIG_NET_TC_TX_COUNT=1

CONFIG_NET_IF_UNICAST_IPV4_ADDR_COUNT=1

CONFIG_NET_MAX_CONN=10
CONFIG_NET_MAX_CONTEXTS=64
CONFIG_NET_CONTEXT_SYNC_RECV=y

CONFIG_INIT_STACKS=y

CONFIG_NET_L2_ETHERNET=y

# Network configuration pro STA (DHCP klient místo statické IP)
CONFIG_NET_CONFIG_SETTINGS=y
CONFIG_NET_CONFIG_INIT_TIMEOUT=0
CONFIG_NET_DHCPV4=y

CONFIG_NET_SOCKETS_POLL_MAX=10

# Memories
CONFIG_MAIN_STACK_SIZE=4096
CONFIG_NET_TX_STACK_SIZE=8192
CONFIG_NET_RX_STACK_SIZE=8192
CONFIG_MBEDTLS_HEAP_SIZE=512

# Debugging
CONFIG_STACK_SENTINEL=y
CONFIG_DEBUG_COREDUMP=y
CONFIG_DEBUG_COREDUMP_BACKEND_LOGGING=y
CONFIG_DEBUG_COREDUMP_MEMORY_DUMP_MIN=y
CONFIG_SHELL_CMDS_RESIZE=n

# Kernel options
CONFIG_ENTROPY_GENERATOR=y

# Logging
CONFIG_LOG=y
CONFIG_LOG_BUFFER_SIZE=2048
CONFIG_POSIX_CLOCK=y

# printing of scan results puts pressure on queues in new locking
# design in net_mgmt. So, use a higher timeout for a crowded
# environment.
CONFIG_NET_MGMT_EVENT_QUEUE_TIMEOUT=5000

CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=8192
CONFIG_NET_TCP_WORKQ_STACK_SIZE=8192