Data Format

Repetita uses a straightforward format for its topology and demands data.

Topology Format

The topology format describes nodes and directed edges of the topology. Each node has a label and a geographical position, each edge has a label, a source node, a destination node, an IGP weight, a bandwidth, and a delay.

The node geographical positions can be useful for visualization purposes. The edge bandwidth can be in any unit, since the usage depends on the corresponding demands file(s); we use kilobits per second. Similarly, we use delays in microseconds.

For instance, file Arpanet196912.graph looks like:

NODES 4
label x y
0_SRI -122.18219 37.45383
1_USCB -119.69819 34.42083
2_UCLA -118.24368 34.05223
3_UTAH -111.89105 40.76078

EDGES 8
label src dest weight bw delay
edge_0 0 1 1 1000000 678
edge_1 1 0 1 1000000 678
edge_2 0 2 1 1000000 869
edge_3 2 0 1 1000000 869
edge_4 0 3 1 1000000 1604
edge_5 3 0 1 1000000 1604
edge_6 1 2 1 1000000 237
edge_7 2 1 1 1000000 237

The first line is NODES followed by the number of nodes, then a 1-line memo for a human editor, one line per node, one empty line a line containing EDGES followed by the number of edges, a memo line, and one line per edge. There might be several edges with the same source, destination pair.

Demands Format

A demands file is associated to a topology. It contains a list of demands, that each have a name, source node, destination node and a bandwidth.

For instance, a demands file for the above Arpanet graph might look like:

DEMANDS 12
label src dest bw
demand_0 0 1 435117
demand_1 0 2 532282
demand_2 0 3 170697
demand_3 1 0 598778
demand_4 1 2 265255
demand_5 1 3 85065
demand_6 2 0 977314
demand_7 2 1 353915
demand_8 2 3 138841
demand_9 3 0 184807
demand_10 3 1 66923
demand_11 3 2 81868

The first line is DEMANDS followed by the number of demands, then a memo line, and one line per demand. Notice that source and destination are the number of the node in the topology’s list, so as to not force the node names to be different. There might be several demands with the same source, destination pair.