Constant PENDING_QUEUE_COUNT 

pub const PENDING_QUEUE_COUNT: usize = raw::PENDING_QUEUE_COUNT; // 16usize

Max packets parked at once waiting for neighbor resolution.

A packet whose next hop is not in the neighbor cache is parked here while ARP or NDISC resolves it. Parking one on a full queue drops the oldest.

This is a limit with and without alloc. Default: 16.