1. A method for carrying out connection and related input/output processing functions in a Synchronous Digital Hierarchy (SDH) transport node, the method comprising: performing payload connection functions in one single collapsed connection function; and performing input/output processing functions at input/output positions of the one single collapsed connection function, wherein the payload connection functions comprise switching a SDH payload at a multiplex section layer and a higher order path layer, and wherein the input/output processing functions comprise: adaptation of the SDH payload between the multiplex section layer and the higher order path layer based on higher order pointer processing; termination and monitoring of path overhead at the higher order path layer; pre-processing overhead bytes at the higher order path layer; collecting information related to the input/output processing functions including information on the pre-processed overhead bytes; carrying the collected information to a central shadow point via dedicated signaling; and shadow-processing the pre-processed and collected information in a centralized manner in the central shadow point, and transmitting the shadow-processed information as input to the payload connection functions so that the shadow processed information is used to configure the switching the SDH payload at the multiplex section layer and the higher order path layer, and wherein the shadow-processing is performed such that the adaptation and the termination appear to be performed after switching the SDH payload at the multiplex section layer and before switching the SDH payload at the higher order path layer.