Hong Kong is one of the most expensive cities in the world to live in. Over there, one million dollars can buy you a 200 square foot home. In a recent AWS-3 spectrum auction in the US, AT&T spent $18.2 billion for a nationwide 20 MHz airway. The same one million dollars can rent you 1KHz of licensed spectrum for a few years. Why are operators spending so much money to secure the rights to send some electromagnetic pulses through the air?
Let’s take a deeper look at MPLS-TP OAM and the new extensions needed to OpenFlow as we pave the way to carrier grade SDNs. MPLS-TP has explicit requirements for fault monitoring and protection switching, while OpenFlow currently has no explicit support for fault monitoring or failure recovery.
Fault monitoring is performed in the NNI to UNI direction. OAM packets will be extracted from the MPLS-TP traffic streams and redirected to monitoring entities at the appropriate level, e.g. section, LSP and PW. Fault monitoring with Y.1731 makes use of entities called RMEPs (Remote MEPs or Maintenance Endpoints). RMEPs monitor the ‘liveness’ of a connection between a MEP and its peer MEP by terminating and processing the continuity check messages (CCMs) being transmitted by the remote end.
The OPEX and CAPEX benefits of Software-Defined Networks (SDNs) realized from facilitating the separation of the data, control and management planes (to allow for the orchestration and management of network resources from a central location) are widely accepted. All of us as subscribers stand to benefit from this transformation as this centralized view of network resources will create a manageable, easy-to-automate, flexible platform allowing Carriers to allocate on-demand resources and define services in real-time to keep up with our ever-changing approach of adding and using content from the Internet. One of the major hurdles to achieving these, however, is that current SDN standards, including the industry favored OpenFlow, have not yet been augmented to specify carrier-grade functionalities.