Path realization

PSS component notes

Overview

The PSS component is responsible for interfacing with the network to perform path setup and teardown. Moreover, it will forward path setup and teardown messages to other IDCs if necessary.

This component is by its nature very technology- and vendor-dependent. Currently it can configure network devices using the following methods:

Using the DRAGON VLSR

Sending Cisco-specific CLI commands

Sending Juniper-specific CLI commands

Moreover, PSS can communicate to network devices using SNMP to harvest required information. Currently this is used to detect whether a device is a Cisco or a Juniper, which helps OSCARS decide what sort of CLI commands to send.

It is expected that OSCARS developers will expand and adapt the PSS component to support more vendor devices or third-party network management applications.

Configuration

The administrator must configure PSS through oscars.properties. The relevant property is pss.method, and valid values are:

dragon to use the DRAGON VLSR subsystem

esnet to use either Cisco or Juniper-specific CLI commands

stub to not actually perform any changes to the network; used in testing

Development

To develop a new PSS method, the developer should implement the net.es.oscars.pss.PSS interface. Then a short name for the method must be chosen (in addition to "esnet", "dragon" and "stub"), and PSSFactory must be modified to load the appropriate class when the pss.method property has that value.