N-GEN Communications Web-based Seminars ©NGCS

Seminar - An Overview of Communications Technologies

Module 4 - ATM Technology                                                                                                                      Slide 5 of 46 _________________                                                                                  __________

                            Technologies Used in Broadband Networks

                                Fiber Distributed Data Interface (FDDI)

                                Frame Relay

                                Asynchronous Transfer Mode (ATM)

                                Synchronous Optical Network (SONET)

                                Switched Multimegabit Data Service (SMDS)

                                Distributed Queue Dual Bus (DQDB) MAN (802.6)

                                Gigabit Ethernet

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Broadband technologies are implemented in a high performance with large bandwidth networks.

Fiber Distributed Data Interface (FDDI) - A high speed networking technology supporting 100 M bps user data rate. The FDDI networks are implemented by using single-mode and multi-mode optical fiber facilities. Earlier metropolitan Area Networks were set up using the FDDI technology. The FDDI technology supports data applications such as LAN internetworking.

Frame Relay - A high speed networking technology supporting 1.544 M bps and 45 M bps user data rate. Frame Relay standards support voice and data applications

Asynchronous Transfer Mode (ATM) - A very high speed networking technology supporting multi-mega bps user data rate. ATM can be used for LAN and WAN by first implementing an ATM private network and then transforming it to a public ATM network. ATM is very popular with carriers to support Frame Relay, voice traffic and other high speed data services. FDDI, Frame Relay, LAN traffic, and other data traffic (DS-1, DS-3) can be mapped into ATM traffic.

Synchronous Optical Network (SONET) - A very high speed networking technology supporting giga bps user data rate. The basic transmission rate for this technology is 51.84 M bps. SONET is a North American standard similar to Synchronous Digital Hierarchy (SDH) used outside of North America.

Switched Multimegabit Data Service (SMDS) - A high speed networking service supporting T-1, T-3 user data rates. In Europe, SMDS supports E-1 and E-3 rates. SMDS is based on the IEEE 802.6 Metropolitan Area Network (MAN) standard. SMDS is used for Ethernet and Token Ring LAN networking.

Distributed Queue Dual Bus ( DQDB) MAN (802.6) - DQDB is an access mechanism for a MAN. It is defined in the IEEE's 802.6 MAN specification.

Gigabit Ethernet - It is a faster version of 10 M bps Ethernet. It is available for 100 M bps (100Base-T) and 1 G bps (1000Base-SX, LX, CX, T) transmission speeds. Gigabit Ethernet is much less expensive and simpler than ATM. Some feel it may replace ATM.