Router FAQ

Intra-Device Cross-Port Costs File

The CSIM router has been expanded to allow assignments of cross-port route costs within a device. You specify the cross-port route costs in a text-file table. To use that feature invoke the router with the command: router netinfo -cpc filename
where filename is the name of the file containing the cross-port cost assignments.

To specify cross-port routing costs, you must generate a cross-port costs file. All devices in the topology which do not have cost assignments will have no cost added to their intra-device port transfer. Costs may be assigned to devices by either device type or by device instance name. Only port names that end with a unique integer value may be assigned costs. When assigning costs by device type, all devices of that type will assume those costs. When assigning costs by device instance name, the full hierarchical name including the leading '/' must be given. Refer to the netinfo file for the correct device name assignments. Port-to-port transfers that have no assignments will be defaulted to a cost of 0. Assignment of costs must be given in each direction of transfer when they are to assume a cost other than 0.

The cost file has the following format:

<DEFINE_XPORT_COSTS>
    <TYPE>   device_type
          from-port       to-port       cost
          from-port       to-port       cost
          ...
          from-port       to-port       cost
    </TYPE>
    ...
    <TYPE>   device_type
          from-port       to-port       cost
          from-port       to-port       cost
          ...
          from-port       to-port       cost
    </TYPE>
    <INSTANCE>   device_instance
          from-port       to-port       cost
          from-port       to-port       cost
          ...
          from-port       to-port       cost
    </INSTANCE>
    ...
    <INSTANCE>   device_instance
          from-port       to-port       cost
          from-port       to-port       cost
          ...
          from-port       to-port       cost
    </INSTANCE>
</DEFINE_XPORT_COSTS>

Where:

device_type - is the device type name as it appears in the netinfo file without the enclosed parentheses or as it appears in the GUI.
device_instance - is the full hierarchical device instance name inluding the leading '/' as it appeare in the netinfo file.
- from-port - is a non-negative integer corresponding to the port name ending with that interger. It may also be a wildcard * which refers to all numbered ports.
- to-port - is a non-negative integer corresponding to the port name ending with that interger. It may also be a wildcard * which refers to all numbered ports.
- cost - is the user's cost assignment which may be an integer or floating-point number. It may also be the letter 'I' or 'i' which implies infinite cost or invalid connection.
All three fields must appear on each cost assignment line.

Assignments of device types and instances are done in the order that they appear. Therefore, overlapping assignments will assume the values assigned last. In general, INSTANCE assignments will follow TYPE assignments. Otherwise, TYPE assignments may override the values of previously assigned INSTANCE assignments.

Comments may be used almost anywhere in the file except within the <TYPE> </TYPE> and <INSTANCE> </INSTANCE> blocks. The comments do not have any delimiters and they may not contain the keywords: <DEFINE_XPORT_COSTS>, </DEFINE_XPORT_COSTS>, <TYPE>, </TYPE>, <INSTANCE> and </INSTANCE>.