ATM
Technology
ATM is a fast switching and multiplexing technique that uses constant-length packets (cells) as the basic data units. The concept of ATM has been appreciated by manufactues of computer systems and local area networks as a flexible technique for wide area of applications. Following are some of the attributes of ATM technology.
- Usable bandwidth is segmented into information-bearing units called cells.
- Cells are fixed Length
- Cells contain a header and an information field
- Uses virtual circuits
- Can support high bandwidth, delay sensitive services
- Capacity is assigned statiscally
Services
ATM supports multiple services and applications. Following are some of the network services supported by ATM:
- Cell Relay
- FrameRelay
- SMDS
- X.25
- Switched DS1/DS3
- Support at the physical layer: DS3 ( 45 Mps), SONET OC3 ( 155 Mbps), SONET OC12c (622 Mbps), FDDI ( 100 Mbps), Fiber Channel (155 Mbps)
Following are some of the application supported by ATM:
- Video Conferencing
- Distance Learning
- Remote file access
- Lan Interconnection
- Multimedia email
- Collaborative work
Major Service Providers:
- US WEST
- Ameritech
- Bell Atlantic
- PacBell
- Southwesten Bell
Cost
These are the tariffs that Pacific Bell published on its ATM tariff information page on the WWW:
Current tariff is classified as a market trial. Full product offering is
expected 2Q 1995
Basic required pricing components are:
- Access facility and network port
Single price for both the access
facility from customer location to serving wire center and the ATM Cell Relay
network port. Access options include DS3 (45 Mb/s, electrical interface) and
OC3c (155 Mb/s, optical interface)
Port Costs:
- 45 Mb/s = $5,000 one-time installation plus $4,850 per month, including
access costs
- 155 Mb/s = $8,500 one-time installation plus $7,899 per month, including
access costs
Sources
WAN Technologies