Fanout Hub Two Line Trunk

Gallery / Multi-line Bundles

A two-line trunk (`a`, `b`) that fans out at a hub into two downstream sections. The two-line trunk bundle must render one `OFFSET_STEP` wide, not double-width with an empty centre lane, even though the hub's exit port re-centres its bundle on the fan-out feeder.

Mermaid source

%%metro title: Fan-out hub, two-line trunk
%%metro diamond_style: symmetric
%%metro style: dark
%%metro legend: bl
%%metro files: in_0 | IN | Input
%%metro files: out_main | OUT | Main output
%%metro file: out_a | AUX | Branch output
%%metro file: out_x1 | AUX | Output X1
%%metro dir: out_x2 | Out
%%metro files: out_y1 | OUT | Output Y1
%%metro file: out_y2 | OUT | Output Y2
%%metro line: a | Line A | #e6550d
%%metro line: b | Line B | #0570b0

graph LR
    subgraph sec_main [Stage 1]
        in_0[ ]
        s1[Step 1]
        s2[Step 2]
        hub[Fan-out\nhub]
        s3[Branch\nstep]
        out_main[ ]
        out_a[ ]

        in_0 -->|a,b| s1
        s1 -->|a,b| s2
        s2 -->|a,b| hub
        hub -->|a,b| out_main
        hub -->|b| s3
        s3 -->|b| out_a
    end

    subgraph sec_x [Stage 2]
        x1[Step X1]
        x2[Step X2]
        x3[Step X3]
        out_x1[ ]
        out_x2[ ]

        hub -->|a| x1
        x1 -->|a| out_x1
        hub -->|a| x2
        x2 -->|a| x3
        x3 -->|a| out_x2
    end

    subgraph sec_y [Stage 3]
        y1[Step Y1]
        y2[Step Y2]
        y3[Step Y3]
        out_y1[ ]
        out_y2[ ]

        s3 -->|b| y1
        y1 -->|b| y2
        y2 -->|b| out_y1
        y2 -->|b| y3
        y3 -->|b| out_y2
    end

CLI command

nf-metro render examples/topologies/fanout_hub_two_line_trunk.mmd -o fanout_hub_two_line_trunk.svg

Rendered map