The ALIEN project extends the OpenFlow Control Framework developed within the OFELIA project. It will allow to support abstraction of network information of equipment that are alien to the OpenFlow technology such as optical network elements, legacy Layer2 switches, network processors and programmable hardware platforms.
This activity focuses on:
- Definition of requirements of the integration with the OFELIA facility
- Definition of interfaces toward the OFELIA Control Framework, including the functional specifications for the ALIEN-specific Resource Manager (RM) and Aggregate Manager (AM)
- Development of ALIEN-RM and ALIEN-AM within the OFELIA Control Framework
- Validation of the implemented software
OCF extensions architecture
The focus of this activity is to integrate the ALIEN resources inside the OFELIA Control Framework (OCF), in order to allow an experimenter to seamlessly access to both “standard” OFv1.0 devices and ALIEN Hardware, and of course to share these resources among all OFELIA users. For this reason, the OCF has to be extended to support the new features deployed within ALIEN project, in particular the ability of the ALIEN hardware to go beyond the OpenFlow v1.0.
In order to overcome the current limitations of OCF, it has been envisioned to implement a “time-based” sharing mechanism in order to share ALIEN hardware among experimenters within an OFELIA island. This solution can be integrated inside the OCF and can coexist with the standard OpenFlow Aggregate Manager as an extension, not as its replacement (thus being backward compatible with the current OCF running on existing OFELIA islands, letting each and every island administrator to decide if they want to enable or not this specific extension into their testbed).
Time-based resource sharing
The Time-Based sharing is an alternative to FlowVisor, which avoids inspection of the OpenFlow protocol. This characteristic makes the approach more general and future proof. Opposite to the FlowVisor solution, the Time-Based approach redirects the whole control (i.e. the OpenFlow control interface) to the adequate Controller and adapts the data plane to be consistent with the legacy infrastructure in OFELIA.
The new extension to OCF will allow on:
- Book a specific subset of ALIEN resources for a fixed amount of time
- Release the resources either automatically at the end of the time interval, or manually if the user wants to leave the project sooner
- Modify both the amount of resources booked and the time interval of the project
- Inform (via email) the user and the ALIEN resources manager about all the relevant operations executed with their related status
- Manage concurrent requests (e.g.: inform the user that another user is interested in the same resources so it can release them if unused)
Time-Based Aggregate Manager (TBAM)
In the following the detailed description of the software modules that are being implemented (or extended) in order to realize the TBAM is presented:
- Graphical User Interface Plugin (GUI): The current OCF GUI is being extended to support the new TBAM, both at the user frontend and in the plugin core system. Moreover, the GUI has to be extended to include a specific module to manage the resources exposed by the TBAM.
- Time-based Aggregate Manager (TBAM): The AM will expose to the GUI all the diverse “time-based” resources coming from different Resource Managers (named OFGW). Each AM is responsible of the management of an homogeneous set of specific elements (such as switches or servers). In this scenario, the TBAM will maintain the status of the resources, the association between users/projects and booked elements, and all the information related to the specific management.
- Resource Manager: OpenFlow Gateway (OFGW):The OFGW will be the only entry point to access the “time-based” resources under its control. It will act both as specific manager for the resources and as gateway for the data and control network.
This Resource Manager is in charge of:
- Hardware Management Plane: the OFGW manages the credentials to access all the resources through hardware specific interfaces (e.g. console, telnet, ssh)
- Control Plane: OFGW acts as the unique entry point for the OpenFlow control plane
- Data Plane: the packets exchanged between OFELIA and ALIEN nodes must go through a tagging/untagging process performed by the OFGW. For this reason, the OFGW will be equipped with an OpenFlow capable software switch (OpenVSwitch) and an open-source OF Controller (Floodlight or Beacon), directly managed by the control framework
