“Banyan VINES”的意思、由来-开放百科全书

Banyan VINES was a network operating system developed by Banyan Systems for computers running AT&T's UNIX System V.

VINES is an acronym for Virtual Integrated NEtwork Service. Like Novell NetWare, VINES's network services were based on the archetypical Xerox XNS stack.

James Allchin, who later worked as Group Vice President for Platforms at Microsoft until his retirement on January 30, 2007, was the chief architect of Banyan VINES.

VINES technology

VINES ran on a low-level protocol known as VIP—the VINES Internetwork Protocol—that was essentially identical to the lower layers of the Xerox Network Systems (XNS) protocols. Addresses consisted of a 32-bit address and a 16-bit subnet that mapped to the 48-bit Ethernet address to route to machines. This meant that, like other XNS-based systems, VINES could only support a two-level internet.

A set of routing algorithms, however, set VINES apart from other XNS systems at this level. The key differentiator, ARP (Address Resolution Protocol), allowed VINES clients to automatically set up their own network addresses. When a client first booted up it broadcast a request on the subnet asking for servers, which would respond with suggested addresses. The client would use the first to respond, although the servers could hand off "better" routing instructions to the client if the network changed. The overall concept very much resembled AppleTalk's AARP system, with the exception that VINES required at least one server, whereas AARP functioned completely "headlessly". Like AARP, VINES required an inherently "chatty" network, sending updates about the status of clients to other servers on the internetwork.

Rounding out its lower-level system, VINES used RTP (the Routing Table Protocol), a low-overhead message system for passing around information about changes to the routing, and ARP to determine the address of other nodes on the system. These closely resembled the similar systems used in other XNS-based protocols. VINES also included ICP (the Internet Control Protocol), which it used to pass error-messages and metrics.

At the middle layer level, VINES used fairly standard software. The unreliable datagram service and data-stream service operated essentially identically to UDP and TCP on top of IP. However VINES also added a reliable message service as well, a sort of hybrid of the two that offered guaranteed delivery of a single packet.

Banyan offered customers TCP/IP as an extra cost option to customers of standard Vines servers. This extra charge for TCP/IP on Vines servers continued long after TCP/IP server availability had become commoditized.

At the topmost layer, VINES provided the standard file and print services, as well as the unique StreetTalk, likely the first truly practical globally consistent name-service for an entire internetwork. Using a globally distributed, partially replicated database, StreetTalk could meld multiple widely separated networks into a single network that allowed seamless resource-sharing. It accomplished this through its rigidly hierarchical naming-scheme; entries in the directory always had the form item@group@organization. This applied to user accounts as well as to resources like printers and file servers.

Protocol stack

VINES client software

VINES client-software ran on most PC-based operating systems, including MS-DOS and earlier versions of Microsoft Windows. It was fairly light-weight on the client, and hence remained in use during the later half of the 1990s on many older machines that couldn't run other networking stacks then in widespread use. This occurred on the server side as well, as VINES generally offered good performance, even from mediocre hardware.

Initial market release

With StreetTalk's inherent low bandwidth requirements, global companies and governments that grasped the advantages of worldwide directory services seamlessly spanning multiple time zones recognized VINE's technological edge. Users included gas and oil companies, power companies, public utilities—and U.S. Government agencies including the State Department, Treasury Department, Department of Agriculture, and Department of Defense.

The U.S. State Department, for example, was an early adopter of the VINES technology. Able to take advantage of the then high-speed 56k modems for telephonic connectivity of the developed world to the limited telephone modem speeds of 300 baud over bad analog telephone systems in the Third World, VINES was able to link embassies around the world. VINES also came with built-in point-to-point and group chat capability that was useful for basic communication over secure lines.

Defense Department adoption

By the late 1980s the US Marine Corps was searching for simple, off-the-shelf worldwide network connectivity with rich built-in email, file, and print features. By 1988 the Marine Corps had standardized on VINES^[1] as both its garrison (base) and forward-deployed ground-based battlefield email-centric network operating system.

Using both ground-based secure radio channels and satellite and military tactical phone switches, the Marine Corps was ready for its first big test of VINES: the 1990-1991 Gulf War. Units were able to seamlessly coordinate ground, naval, and air strikes across military boundaries by using the chat function to pass target lists and adjust naval gun fire on the fly. Ground fire support coordination agencies used VINES up and down command channels—from Battalion-to-Regiment through Division-to-Corps and Squadron-to-Group to Aircraft Wing-to-Corps, as well as in peer-to-peer unit communication. {{Citation needed|date=August 2009}}

VINES competitors

For a decade, Banyan's OS competitors, Novell and Microsoft, dismissed the utility of directory services. Consequently, VINES dominated what came to be called the "directory services" space from 1985 to 1995. While seeming to ignore VINES, Novell and eventually Microsoft—companies with a flat server or domain-based network model—came to realize the strategic value of directory services. With little warning, Novell went from playing down the value of directory services to announcing its own: NetWare Directory Services (NDS). Eventually, Novell changed NDS to mean Novell Directory Services, and then renamed that to eDirectory.

Microsoft had gone through its own round of operating system development. Initially, they partnered with IBM to develop an Intel-based disk operating system called PC DOS, and its Microsoft twin, MS-DOS. Eventually, Microsoft shared true network operating system development with IBM LAN Manager and its Microsoft twin, Microsoft LAN Manager. Microsoft parted company with IBM and continued developing LAN Manager into what became Windows NT. Essentially, its OS 4.0. NT was originally a flat server or domain-based operating system with none of the advantages of VINES or NDS.

For Windows 2000 however, Microsoft included Active Directory, an LDAP directory service based on the directory from its Exchange mail server. Active Directory was as robust as and, in several key ways, superior to VINES. While VINES was limited to a three-part name, user.company.org, like Novell's NDS structure, Active Directory was not bound by such a naming convention. Active Directory had developed an additional capability that both NDS and VINES lacked, its "forest and trees" organizational model. The combination of better architecture and a marketing company the size of Microsoft doomed StreetTalk, VINES as an OS, and finally Banyan itself.

Decline

By the late 1990s, VINES' once-touted StreetTalk Services' non-flat, non-domain model with its built-in messaging, efficiency and onetime performance edge had lost ground to newer technology. Banyan was unable to market its product far beyond its initial base of multi-national and government entities.

Because Banyan could not quickly develop an OS to take advantage of newer hardware, and apparently did not understand that the StreetTalk directory services, not the shrink-wrapped OS, was the prime value added—the company lost ground in the networking market. VINES sales rapidly dried up, both because of these problems and because of the rapid rise of Windows NT. Banyan increasingly turned to StreetTalk as a differentiator, eventually porting it to NT as a stand-alone product and offering it as an interface to LDAP systems. {{Citation needed|date=August 2009}}

Also, Banyan continued to operate a closed OS. This required hardware manufacturers to submit hardware and driver requirements so that Banyan could write drivers for each peripheral. When more open systems with published APIs began to appear, Banyan did not alter their model. This made it difficult for client-side support to handle the explosive growth in, for example, printers. As competitors began to adopt some of VINES' outstanding wide area networking protocols and services, manufacturers were less inclined to send a unit to Banyan for VINES specific drivers when competitors let them write their own.

Dropping the Banyan brand for ePresence in 1999, as a general Internet services company, the firm sold its services division to Unisys in late 2003 and liquidated its remaining holdings in its Switchboard.com subsidiary.

Version history

References

1. ^[https://books.google.co.nz/books?id=1T0EAAAAMBAJ&pg=PA76&lpg=PA76&dq=banyan+vines+marines&source=bl&ots=xph_KsYc_K&sig=p6MMI1aK_IBWF7hN7rRbFDeak0E&hl=en&sa=X&ei=nPeWVfaSJZH98AXq3K7wAg&ved=0CCYQ6AEwAg#v=onepage&q=banyan%20vines%20marines&f=false"The U.S. Marines' Network-Linked War Units"], 14 Oct 1991, p576, InfoWorld

Resource