The Network Model File

The network model file contains basic information about the network topology:

Interfaces
Nodes (layer 3 node/router)
Demands (traffic)
RSVP LSPs

Since there is a lot of information needed to create a model, using the model file to load network data is recommended.

The network model file is a tab-separated values file.

The sections below describe the model file’s table headers.

Model File Interface Headers

Interfaces represent the logical interfaces on a layer 3 Node (Router). In the context of a simulation, demands (traffic) egress interfaces. A circuit is created when two matching interfaces (one in each direction) are paired to form a bi-directional connection between layer 3 nodes.

The model supports two interface table formats, which are auto-detected based on the header line:

Without circuit_id - interfaces between the same two nodes are automatically paired into circuits
With circuit_id - a circuit_id column is used to explicitly match interfaces into circuits, which is required when there are multiple parallel circuits between the same nodes

INTERFACES_TABLE (without circuit_id)

node_object_name - name of node where interface resides
remote_node_object_name - name of remote node
name - interface name
cost - IGP cost/metric for interface
capacity - capacity
rsvp_enabled (optional) - is interface allowed to carry RSVP LSPs? True|False; default is True
percent_reservable_bandwidth (optional) - percent of capacity allowed to be reserved by RSVP LSPs; this value should be given as a percentage value - ie 80% would be given as 80, NOT .80. Default is 100

INTERFACES_TABLE (with circuit_id)

node_object_name - name of node where interface resides
remote_node_object_name - name of remote node
name - interface name
cost - IGP cost/metric for interface
capacity - capacity
circuit_id - id of the circuit; used to match two Interfaces into Circuits
- each circuit_id value can only appear twice in the model
- circuit_id can be string or integer
rsvp_enabled (optional) - is interface allowed to carry RSVP LSPs? True|False; default is True
percent_reservable_bandwidth (optional) - percent of capacity allowed to be reserved by RSVP LSPs; this value should be given as a percentage value - ie 80% would be given as 80, NOT .80. Default is 100

Important

Column order matters. If you wish to use an optional column to the right of an optional column you don’t want to specify a value for, you must still include the optional headers to the left of the column you wish to specify a value for.

For example, if you wish to specify a percent_reservable_bandwidth for an interface but not explicitly specify rsvp_enabled, you must also include the rsvp_enabled columns and then leave those row values blank in each unused column.

This example specifies percent_reservable_bandwidth of 30 for interface A-to-B_1:

INTERFACES_TABLE
node_object_name    remote_node_object_name name    cost    capacity    circuit_id  rsvp_enabled    percent_reservable_bandwidth
A   B       A-to-B_1    20  120 1       30
B   A       B-to-A_1    20  120 1   True  50

Model File Node Headers

Nodes represent layer 3 devices in the topology. Many nodes can be inferred by the presence of an interface on the node_object column in the INTERFACES_TABLE in the model file. Any node inferred by the node_object column in the INTERFACES table does not have to be explicitly declared in the NODES table. However, the NODES table does have a couple of use cases:

It can be used to add attributes to inferred nodes: lat (latitude, or y-coordinate), lon (longitude, or x-coordinate), and igp_shortcuts_enabled (whether IGP shortcuts are enabled for the node)
It can be used to declare a node that does not have any interfaces yet (aka an orphan node)

Note

lat and lon can be used instead for (y, x) grid coordinates; there are no restrictions on the integer values those attributes can have.

NODES_TABLE

name - name of node
lon - longitude (or y-coordinate) (optional)
lat - latitude (or x-coordinate) (optional)
igp_shortcuts_enabled (default=``False``) - Indicates if IGP shortcuts enabled for the Node (optional)
- If True, network internal traffic transiting the layer 3 node can now use LSPs en route to the destination, if they are available

Important

Column order matters. If you wish to use an optional column to the right of an optional column you don’t want to specify a value for, you must still include the optional headers to the left of the column you wish to specify a value for.

If you wish to include igp_shortcuts_enabled values for a given node, you must include the name, lon and lat column headers and then leave the unused row values for those columns blank.

For example, to enable igp_shortcuts_enabled for the SLC node, but not specify lon or lat:

NODES_TABLE
name lon lat igp_shortcuts_enabled
SLC           True

Model File Demand Headers

Demands represent traffic on the network. Each demand represents an amount of traffic ingressing the network at a specific layer 3 (source) node and egressing the network at a specific layer 3 (destination) node.

DEMANDS_TABLE

The DEMANDS_TABLE table has four headers, all of which are required:

source - the source node for the traffic; the node in the model where the traffic originates
dest - the destination node for the traffic; the node in the model where the traffic terminates
traffic - the amount of traffic in the demand
name - the name of the demand; there can be multiple demands with matching source and dest nodes - the name is the differentiator
- there cannot be multiple demands with matching source, dest, and name values

RSVP LSPs

RSVP_LSP_TABLE

The RSVP_LSP_TABLE has the following columns:

source - the source node for the LSP; the node in the model where the LSP originates
dest - the destination node for the LSP; the node in the model where the LSP terminates
name - the name of the LSP; there can be multiple LSPs with matching source and dest nodes - the name is the differentiator
- There cannot be multiple LSPs with matching source, dest, and name values
configured_setup_bw (optional) - if LSP has a fixed, static configured setup bandwidth, place that static value here, if LSP is auto-bandwidth, then leave this blank for the LSP
manual_metric (optional) - manually assigned metric for LSP, if not using default metric from topology shortest path

Important

Column order matters. If you wish to use an optional column to the right of an optional column you don’t want to specify a value for, you must still include the optional headers to the left of the column you wish to specify a value for.

If you wish to specify a manual_metric for an LSP but not explicitly specify configured_setup_bw, you must also include the configured_setup_bw column and then leave those row values blank in each unused column.

For example, to specify a manual_metric for the LSP with name lsp_a_b_2 but not specify configured_setup_bw:

RSVP_LSP_TABLE
source      dest    name    configured_setup_bw manual_metric
A   B       lsp_a_b_1   10  19
A   B       lsp_a_b_2       6