Migration to an IP management of Sonet/SDH networks



"Migration to an IP Management of SONET/SDH" in Optical Fiber Communication Conference and Exposition and The National Fiber Optic Engineers Conference

I. Introduction

The SONET and SDH technologies have been revealed in the 80's. Although both standards were competing (SONET was introduced in the US by Bellcore while SDH was presented by CCITT in Europe), both were agreed to implement the OAM&P (Operation, Administration, Maintenance and Provisioning) functionality by using a Data Communication Network relying on OSI protocols. The OSI was the emerging and well-standardized model at that time, and TCP/IP had not yet taken the importance it has now (mainly due to the success of Internet).

As a consequence, the SONET and SDH Data Communication Network (DCN) have been relying for many years on OSI protocols. In a world that is now widely driven by IP networks, the deployment, support and maintenance of OSI networks raise high costs issues for carriers and telecom equipment manufacturers:

  • Maintaining OSI networks increases the operational expenses because of the OSI skills decrease and lack of rationalization of network infrastructures,
  • OSI increases the development complexity and costs for new equipment (and many new network elements are natively using IP management for that reason).

But there are also technical drivers to move to IP

  • Most of access DCN are already IP based
  • There is a need to be able to manage IP data equipment (routers) at the border of SONET/SDH rings (and possibly at customer premises),
  • And more important, OSI is a hurdle for moving to next generation optical network management and control planes.

If it is obvious that moving to a full IP management is a big benefit, how to achieve this is not so straightforward. The legacy SONET and SDH network elements installed base is now huge and very stable, and no telecom operator is ready to upgrade its whole networks at once for evident cost and feasibility reasons.

As a consequence, a slow migration process is starting, and the key issue is to have a migration as smooth as possible.

Read more ...