Target markets are: Telco & Media, Industry & Manufacturing, Energy & Transport, Banking & Insurance, Healthcare and Public Administration.

Italtel played a major role in the development of telecommunication systems in Italy, most notably as one of the main equipment providers for the Italian state monopoly telephone operator SIP (later Telecom Italia) and as the leading actor in the evolution of the Italian PSTN from analog to digital switching (enabled by Italtel's CT, TN, and UT systems in the 1980s).

[2] In the 1980s–1990s, Italtel experienced a period of crisis and downsizing due to major changes in its reference market (including the abolishment of the state monopoly and the privatization of SIP/Telecom), a situation that was further exacerbated by an unsuccessful merger leveraged buyout at the beginning of the 2000s.

[4][6] In the early 2000s, Italtel and Cisco played a leading role in another major evolution of the Italian telephone network, namely the creation of a national structure that allowed for most long-range telephone traffic to be transferred from the PSTN to an IP network (implemented by Italtel softswitches and Cisco media gateways).

[7] In 2013, Gartner Inc. has classified Italtel as a "visionary" player in the Magic Quadrant for Session border controller design, a title that is usually given to small companies that have a distinguished completeness of vision.

[9] This gradually changed in the late 1920s, when Siemens began to expand its manufacturing presence in Lombardy and Italy through the acquisition of small manufacturers (most notably Officine Isaria Contatori Elettrici, an electricity meter producer) as well as the establishment of new ones, such as OLAP (Officine Lombarde Apparecchi di Precisione) which produced telephones, pneumatic tubes, radio receivers, and other electrical appliances.

At the end of World War II, the German-owned Siemens S.p.A. was impounded to the Ministero del Tesoro (Department of the Treasury).

[2] In the 1970s, during the so-called Years of Lead (an era of socio-political turmoil in Italy), Sit-Siemens was involved in several terrorist acts performed by the Red Brigades,[12] including their first kidnapping.

[17][18] In the early 1990s, the state monopoly on telephony was abolished, and the state-owned operator SIP was turned into a private company, Telecom Italia.

The company shifted its core business towards voice over IP and network convergence technologies, and was forced to look for new customers, including so-called OLOs (Other Local Operators), foreign markets, public administration, and enterprises.

The multimedia activities (research, production and fixing of decoders for Stream TV and telephones, maintenance and fixing of the commutation centrals in the structure of Santa Maria Capua Vetere) are sold to Finmek-Access Media; Italtel Systems (project, maintenance and installation of telecommunications systems for Italtel) is sold to a group of companies guided by Tecneudosia.

When the partnership ends in 1999, Italtel S.p.a. becomes 100% owned by Telecom Italia, which in 2000 sells a majority stake to Clayton, Dubilier & Rice and Cisco Systems.