This specifies the number of simultaneous incoming broadcast messages this node can receive at once. This caps the node's capacity to be a recipient of broadcast traffic from elsewhere in the X.25 network; an admin at a busy hub node receiving broadcasts from many source nodes simultaneously would need this set high enough to avoid dropping broadcast messages that arrive concurrently. For example, a value of 2 would mean only 2 broadcast messages can be received by this node simultaneously; a third arriving while both channels are busy would presumably be rejected or queued.