Optical Transport Networks (OTN)


Operators of carrier and service provider networks are always under immense pressure to reduce operational and capital expenditures. As if that pressure weren't enough, they must also contend with preserving legacy technologies while addressing the continuous shift in traffic type (most notable: the shift from circuit to packet traffic). The ITU's Optical Transport Network (OTN) recommendation provides a network-wide framework that truly delivers on the carrier requirements for reduced costs, greater flexibility, and increased efficiencies.

Often, operators attempt to address the CAPEX/OPEX quest by converging a number of functions onto a single Network Element. While a new class of a Network Element may answer some of their prayers, it's a solution that only addresses a microcosm of the overall network, and hence the savings are limited. The introduction of the OTN provides a network-wide architecture that encompasses multiple aspects of networking, such as framing, management, hierarchy, signaling, and routing. It is this architecture that enables carriers to reduce costs throughout the network, utilize legacy infrastructure, and address shifts in traffic/service types.

The OTN, which is defined by the ITU-T G.709 and G.872 specifications, creates a transparent, hierarchical network designed for use on both Time Division Multiplexed (TDM) and Wavelength Switched Optical Network (WSON) devices. Two switching layers are formed (TDM and WSON) and functions of transport, multiplexing, routing, management, supervision and survivability are defined. The OTN control plane, which is based on GMPLS, automates many of these functions, with corresponding operational benefits relative to a statically provisioned OTN network.

Metaswitch, which has always been on the forefront of delivering portable packet and optical control plane solutions to system vendors, supports GMPLS signaling and routing for G.709 and OTN per the ITU and IETF standards.

Solutions and Benefits

  • Delivers industry-standard routing and signaling of OTN TDM and WSON Layers as per the ITU G.709/G.872 and IETF RFC 4328, 4202, 4203, and 4205 specifications
  • Interoperable with 3rd party PCE solutions
  • Fully integrated control plane solution for ease of deployment
  • Delivers carrier grade scale and high availability via Metaswitch's well proven N-BASE and High Availability Framework

Solution Elements

The Metaswitch solution for equipment manufacturers of OTN devices is based on the following elements:

  • DC-RSVP extensions for control of G.709 OTNs
  • DC-OSPF and/or DC-ISIS extensions for control of G.709 OTNs
  • N-BASE, Metaswitch's portable operating environment for its network software products
  • High Availability Framework (HAF), Metaswitch's architecture for delivering fault tolerance and reduced downtime across its range of network software products
  • Metaswitch engineering services which include professional services, training, and support directly from our Metaswitch engineering organization