The SDH/SONET (Synchronous Digital Hierachy) system is the result of developments and evolution in the transmission networks that form the basic transport platforms for all kinds of telecommunications networks and services.

SDH can be defined as a series of recommendations and network elements that allow large transmission infrastructures to be managed in a standardized way. The result is an architecture that is relatively simple to implement and makes it easier to develop and connect networks on a worldwide scale, all at a reasonable cost.

Link to Victoria Combo Product Page
Trend's Victoria Combo is a hand-held/portable test unit for the analysis and evaluation of SDH, SONET, PDH and T-Carrier networks and equipment. Combo is fully modular enabling you to easily add or remove modules according to your needs.