Metropolitan area network

[4]: 11 To interconnect local area networks more effectively, it was suggested that office buildings are connected using the single-mode optical fiber lines, which were by that time widely used in long-haul telephone trunks.

In West Berlin the BERCOM project built up a multifunctional broadband communications system to connect the mainframe computers that publicly funded universities and research institutions in the city housed.

The BERCOM MAN project could progress at speed because the Deutsche Bundespost had already installed hundreds of miles of fibre optic cable in West Berlin.

[4]: 57 The productive use of dense wavelength-division multiplexing (DWDM) provided another impetus for the development of metropolitan area networks in the 2000s.

[5]: 14  With DWDM companies could build dedicated MANs using the existing dark fibre network of a provider in a city.

The Sprint metro rings routed voice and data, were connected to several local telecom exchange points and totalled 189 miles of fibre optic cable.

[5]: 41  Capsuling protocols, such as Multiprotocol Label Switching (MPLS), were also deployed to address the drawbacks of operating L2 metro Ethernet rings.

[9] While the IEEE tried to standardise the emerging Ethernet-based proprietary protocols, industry forums such as the MEF filled the gap and in January 2013 launched a certification for network equipment that can be configured to meet Carrier Ethernet 2.0 specifications.

[11] Verizon put into operation three regional metropolitan exchanges to interconnect MANs and give them access to the Internet.

[14]: 105  Similarly Frankfurt has become a magnet for data centres of international companies because it hosts the non-profit DE-CIX, the largest Internet exchange in the world.

[14]: 116  The business model of the metro DE-CIX is to reduce the transit cost for local carriers by keeping data in the metropolitan area or region, while at the same time allowing long-haul low-latency peering globally with other major MANs.