Apple Open Transport

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Definition of Apple Open Transport in Network Encyclopedia.

What is Apple Open Transport?

Apple Open Transport is an Apple networking technology for transport-independent networking that is part of the networking and communication subsystem of the Macintosh operating system. Apple Open Transport is designed to make it easy to set up and configure networking on the Macintosh computer and to increase the performance of file, print, and other networking services on a MacOS server.

Apple Open Transport
Apple Open Transport

Open Transport provides a consistent interface for configuring network services across supported protocols and a uniform set of application programming interfaces (APIs) for accessing networking and communication services on the Macintosh.

Open Transport enables protocols to be loaded and unloaded on demand, provides a networking naming scheme plus consistent network services over the TCP/IP and AppleTalk protocols, and includes support for TCP/IP services such as Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS). Open Transport also provides consistent API access to serial communication on the Macintosh, while third-party support is available for PPP, NCP/IPX, SMB/TCP/NetBIOS, DECnet, LAT, and X.25.

The Open Transport/AppleTalk protocol stack supports both the dynamic self-addressing of traditional AppleTalk clients and newer manually assigned static addressing. The Open Transport/TCP/IP protocol stack supports DHCP, bootstrap protocol (BOOTP), both local hosts files and DNS, Internet Protocol (IP) multicasting, both Ethernet Version 2.0 and IEEE 802.3 framing, TCP wildcard source port assignments, PPP connectivity, IP multihoming, and almost unlimited simultaneous TCP connections (limited only by installed memory and processor power).

An Apple Macintosh running Open Transport/TCP/IP can function as a DHCP client to a Microsoft Windows NT server running as a DHCP server, but not as a WINS client.

Open Transport from Apple is part of the MAC OS system tha allows compatibility for windows networks.

Apple Open Transport History

Apple Open Transport was introduced in May 1995 with the Power Mac 9500. It was included with System 7.5.2, a release for the new PCI based Power Macs, and became available for older hardware later. MacTCP was not supported on PCI-based Macs, but older systems could switch between MacTCP and Open Transport using a Control Panel called Network Software Selector. Unlike MacTCP, Open Transport allowed users to save and switch between configuration sets.

Developer opinion on Open Transport was divided. Some felt it offered enormous speed improvements over MacTCP. Some developers also liked it because it was flexible in the way it allowed protocols to be “stacked” to apply filters and other such duties. However, the system was also large and complex. The flexibility of the Open Transport architecture, into which one could plug any desired protocol, was felt by some to be thoroughly overcomplicated. Additionally, most Unix code still used sockets, not STREAMS, and so MacTCP offered real advantages in terms of porting software to the Mac.

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