Frame Relay is an
International Telecommunication Union Telecommunication
Standardization Sector (ITU-T; formerly the Consultative Committee
for International Telegraph and Telephone [CCITT]) and American
National Standards Institute (ANSI) standard that defines the
process for sending data over a public data network (PDN). It is a
connection-oriented, data-link technology that is streamlined to
provide high performance and efficiency, as shown in the Figure. It
relies on upper-layer protocols for error correction, and todays
more dependable fiber and digital networks.
It uses the services of many different
physical-layer facilities at speeds that typically range from 56 Kbps
up to 2 Mbps.
Note that Frame Relay defines the
interconnection process between your customer premises equipment (CPE-also
known as data terminal equipment [DTE]), such as a router, and the
service provider’s local access-switching equipment (known as data
communications equipment or data circuit-terminating equipment [DCE]). It does not define the way the data
is transmitted within the service provider’s Frame Relay cloud.
Frame Relay differs significantly
from X.25 in its functionality and format. In particular, Frame
Relay is a more streamlined protocol. It does not have the windowing
and retransmission strategies of X.25. This simplicity facilitates
higher performance and greater efficiency that is appropriate for
use over faster, less-error-prone networks. As a result, Frame Relay
is appropriate for uses that require high throughput, such as LAN
interconnection. The network providing the Frame Relay service can
be either a carrier-provided public network or a network of
privately owned equipment serving a single enterprise.