Constant UDP_RX_QUEUE_COUNT 

pub const UDP_RX_QUEUE_COUNT: usize = raw::UDP_RX_QUEUE_COUNT; // 4usize

Max datagrams a UDP socket queues for receiving.

Datagrams arriving on a full queue are dropped. Each queued datagram holds a packet buffer until the application receives it.

This is a limit with and without alloc. Default: 4.