SERVICE PROVIDERS T&M: High tech Testing

VoicenData Bureau
Updated On
New Update

Synchronous optical network (SONET) and synchronous digital hierarchy (SDH)

achieve synchronous data transmission over fiber optic networks. SONET is the US

version of the standard published by American National Standard Institute

(ANSI). SDH is the international version of the standard published by ITU.


The first-generation SONET/SDH equipment was added drop multiplexer (ADM)

which was based on the original set of standards. Next generation test equipment

was SONET/SDH switch, with the mechanism of mapping Ethernet on SONET. The third

generation test equipment uses tools like virtual concatenation (VCAT), generic

framing procedure (GFP), and Link capacity adjustment scheme (LCAS). Next

generation SONET/SDH devices are supporting resilient packet ring (RPR) for

scalability, bandwidth efficiency, and class of service support features.

SONET/SDH is preferred more than plesiochronous digital hierarchy (PDH)

because of its compatibility with standard equipment from different vendors.

When sophisticated services with high bandwidth are required, SONET/SDH finds

its importance. SONET/SDH capitalizes the voice transport ability with high

vendor interoperability.


the constantly evolving standards interoperability poses a serious challenge as

compatibility between the equipment and network is required VCAT in next

generation products improves the Ethernet transport efficiency and LCAS can

change the transport bandwidth required. Scalability and interoperability are

the two major challenges to the next-generation SONET/SDH equipments.


The major factors determining market growth of the world SONET/SDH test

equipment market include:


  • User demand for Ethernet-based services is the major driver for this

  • High bandwidth requirement, along with the integrated product

    functionality (generic framing procedures and virtual concatenation) drive

    the world SONET/SDH test equipment market.
  • Movement towards optical and data convergence is also driving demand for

    SONET/SDH test equipment.


  • End user spending condenses demand in the SONET/SDH test equipment market.
  • There is a slow adoption rate of next generation SONET/SDH test equipment

    as users are not willing to let go off their existing equipment and hence

    are not upgrading.
  • As there is not much technological development, sale in the new test

    equipment market is retarded.


  • The Slow capital expenditure (CAPEX) situation is

    dampening demand for SONET/SDH test equipment market.

  • The complexity of Next generation SONET/SDH test

    equipment poses a serious challenge to test vendors.

  • End user requirements challenging vendors of SONET/SDH

    test equipment in terms of product development. Quality of service is also

    representing a significant challenge for vendors.

Future Outlook

The SONET/SDH market experienced a downward spiral in the last few years.

However, the future looks positive. The price of this equipment is in parity

with asynchronous equipment and is expected to decline further. Next generation

SONET/SDH technologies are main driver for the growth of SONET/SDH test

equipment market.

Prathima Bommakanti, Research Analyst, Frost & Sullivan