Packet Switching Types: ATM, Frame Relay, TCP/IP, X.25

Transmission: SONET T-Carrier

Services: [3G] [4G] [Bluetooth] [I-Mode] [WAP] [Wireless and packet switching]

Frame Relay

Frame relay is another fast packet switching scheme, this one with much less overhead than the earlier X.25 networks. Errors or bad frames are discarded, not retransmitted or checked, so things move along quickly. Packets vary in length and are called frames for this protocol. Commercial service began in 1992 and is now widely deployed. An internet service provider might use this technology to connect to the internet over a T-1 or T-3 line. Meant mostly for clean metallic lines or preferably fiber optic cable. Runs over SONET or T-Carrier.

Communications Technology Guide for Business by Richard Downey, Sean Boland, Philip Walsh

Mostly on the internet but explains the role of frame relay in connecting to the net (280K, 17 pages in .pdf)

Nathan Muller also writes well on frame relay, and a thousand other topics, :-) in his Desktop Encyclopedia of Telecommunications from McGraw Hill. Book comes with the entire title on CD ROM. Look for the latest edition with the Amazon.com search engine below. Or click here to go there.

The FCC's definition of Frame relay:

Frame relay is essentially an enhancement of X.25, and takes advantage of the widespread implementation of fiber optic communication links by long-distance carriers. Fiber is much less prone to introducing errors in a data stream, so frame relay does not use most of X.25's extensive checking at switching nodes; these processes are instead completed by the sending and receiving devices.

Frame relay is designed to operate at speeds up to 1.5 Mbps, but may be enhanced to operate at higher speeds in the future. It is particularly well-suited to the interconnection of LANs which generate bursty traffic consisting of variable-length frames of data. Frame relay accepts this traffic as is, adding only a wide area network address at the front and its own check sequence at the end of each frame. Frame relay interfaces for customer premise equipment such as routers, bridges, and hubs are available from a number of vendors.

Frame relay switches are also available, and numerous carriers offer public frame relay services. As the technology and standards are refined and carrier tariffs are clarified, frame relay networks are expected to replace many X.25 networks during the next several years. Frame relay is not well-suited to the transmission of real-time voice or video, however, because of the variable delay allowed between frames.

The Death of Frame Relay?

Hyatt Turns To Telstra To Modernize Its Network

In a three-year deal detailed this week, Telstra will modernize and watch over the hotelier's network, which had relied on frame-relay technology.

By Tony Kontzer, InformationWeek, July 16, 2004
Copyright 2004, Information Week, all rights reserved

For Hyatt International Corp., the decision to outsource the upgrade and operation of its network came down to an essential business problem: It couldn't roll out new applications or prioritize its bandwidth to protect its critical central-reservations system. That system's performance had to be improved, so in an $8.4 million, three-year deal detailed this week, Hyatt International brought in Telstra Corp. Ltd. to modernize and watch over its network, which had relied on antiquated frame-relay technology.

It's been two months since the company completed its move to an IP-based multiprotocol label switching network, and the benefits are clear, says Gebhard Rainer, VP of hotel finance and technology for Hyatt International, the Hyatt Hotel Corp. unit that operates the chain's 90 hotels outside North America. It's rolling out new applications--such as new Hyperion Solutions tools for budgeting and forecasting, and several marketing databases that leverage customer information using Cognos' business-intelligence technology--and is able to guarantee better application performance, particularly in its central-reservations system. It's also allowing information to move more fluidly throughout the company, whereas the old network's bandwidth limitations forced hotels to store much of their information in local databases.

Other benefits include quicker reservation confirmations, better access to customer profiles during the booking process, and more rapid response to service issues.

The decision to outsource management of its network allowed Hyatt International to refrain from hiring the kind of network expertise needed to ensure the technology continued to operate smoothly. "We aren't in the communications business," Rainer says. "We said, 'let's come back and focus on our core business.'"

Dan Kerth, president of Telstra Inc., the U.S. subsidiary of the Australian telecommunications company, says network outsourcing is becoming an increasingly popular option for travel companies because of the dispersed nature of their facilities. Adding a property onto a hotel's network, or an airport into an airline's infrastructure, is a labor-intensive undertaking that takes hotels and airlines away from their core operations.

http://www.informationweek.com (external link)

Packet Switching Types: ATM, Frame Relay, TCP/IP, X.25

Transmission: SONET T-Carrier

Services: [3G] [4G] [Bluetooth] [I-Mode] [WAP] [Wireless and packet switching]