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April 24, 2026
Question

ST67W611M1 UDP client socket blocked (mission_t01)

  • April 24, 2026
  • 0 replies
  • 52 views

Hi,

while integrating the module, we noticed that UDP client connections appear to be explicitly blocked in the driver (w61_at_net.c) for mission_t01 firmware (LwIP offload). The following code only allows TCP and SSL connections:

if ((conn->Protocol != W61_NET_TCP_CONNECTION) && (conn->Protocol != W61_NET_TCP_SSL_CONNECTION)
#if (W61_NET_IPV6_ENABLE == 1)
&& (conn->Protocol != W61_NET_TCPV6_CONNECTION) && (conn->Protocol != W61_NET_TCPV6_SSL_CONNECTION)
#endif /* W61_NET_IPV6_ENABLE */
)
{
NET_LOG_ERROR("Only TCP and SSL protocols are supported for client connections\n");
return W61_STATUS_ERROR;
}

However, according to the official AT command documentation, UDP client connections are supported:
https://applist67.github.io/Web_AT_Documentation_ST67/v2.0.106/index.html#establish-udp-connection

After commenting out this restriction, I was able to establish a UDP client connection successfully, and communication seems to work.

Is there a specific reason why UDP client sockets are blocked at this level?
Are there any known limitations or risks when enabling UDP this way?

Thanks in advance for your clarification.