Describe the architecture of an ATM network?

Answer 1

ATM Architecture

As in the case of many large systems, there are a range of components and connections involved in the ATM networks. Figure 2 shows an example network architecture. All connections in the ATM network are point-to-point, with traffic being switched through the network by the switching nodes. Two types of networks are included in the ATM architecture, Public Networks and Private Networks. Private Networks, often referred to as Customer Premises Networks, are typically concerned with end-user connections, or bridging services to other types of networks including circuit switched services, frame relay, and voice subsystems. The interface between the components in the Private Networks is referred to as the Private User Network Interface (UNI). ATM also extends into the wider area Public Networks.

Interfaces between the Public and Private network switches conform to the Public UNI. Interfaces between the switches within the Public network are the Network Node Interface (NNI). Specifications for both the Public and Private UNI can be found in the ATM Forum's publication "ATM User-Network Interface (UNI) Specification." The private networks often permit the use of lower speed short haul interconnects that are useful in LAN environments, but not of great use in wider area public networks. Three types of NNI have been developed, NNI-ISSI that connects switches in the same Local Area Transport Area (LATA), the NNI-ICI, that connects ATM networks of different carriers (InterCarrier), and finally, a Private NNI that permits the connection of different switches in a private network.

( www.cellsoft.de/telecom/atmconcepts.htm)