digraph G {
    rankdir = "LR";
    
    subgraph cluster_region1 {
        label = "Region 1";
        user_1 [label = "User 1";];
        igate_1 [label = "IGate";];
    }
    internet [label = "Internet";];
    subgraph cluster_region2 {
        label = "Region 2";
        igate_2 [label = "IGate";];
    }
    subgraph cluster_region3 {
        label = "Region 3";
        digi [label = "Digipeater";];
        user_2 [label = "User 2";];
    }
    
    user_1 -> igate_1 [label = "RF";];
    igate_1 -> internet [label = "WAN";];
    internet -> igate_2 [label = "WAN";];
    igate_2 -> digi [label = "RF";];
    digi -> user_2 [label = "RF";];
}