SDH is first and foremost an efficient, scalable and relatively simple technique for managing high transmission capacities, currently up to 40 Gbit. The SDH network offers a high degree of compatability with previous transport networks (PDH) and offers new possibilities to switching networks like ATM or IP datagrams.

Transparency is another of its important features, letting it support networks of very different characteristics: those oriented towards voice transmission, such as the PSTN, data transmission like Frame Relay, voice and data like ISDN, datagrams like IP and multimedia like ATM, all of them simultaneously over the same infrastructure.

The widespread acceptance of the SDH architecture is also due to its capacities for remote management using computers of the whole of an advanced transmission system.

The standardization of SDH facilitates internetworking between networks from different countries. It allows ETSI and ANSI systems to be combined, the unification of technologies and subsequent extension of knowledge to wide sectors of industry and society and as whole, as well as the benefits brought from competition between manufacturers: The network elements used are few and are highly versatile.

Currently there are no serious drawbacks that suggest SDH systems may be replaced by other alternatives. Nonetheless, they are thought of as very complex systems. In specific areas, such as IP (Internet Protocol), they would not be needed if advanced systems like DWDM (Dense Wavelength Division Multiplexing) were available.

In any case, there are some installations in which the implantation of SDH is not suitable, such as a local network (unless it were especially complex).

The fact that SDH is a synchronous, byte-oriented network has important consequences with regard to the phenomena of jitter and wander, since greater synchronization of the network is required. The ideal situation would be for all the elements in the network to use a universal clock source and in practice this adds to the complexity, since each operator has its own source.