FAQ
1. What Is INTRANET ?
It is a network connecting an affiliated set of clients using standard internet protocols, esp. TCP/IP and HTTP. It is an IP-based network of nodes behind a firewall, or behind several firewalls connected by secure, possibly virtual, networks.
2. What is an "internal web"? A corporate web?
In general, a web is an unstructured client/server network that uses HTTP as its transaction protocol. The World Wide Web comprises all HTTP nodes on the public Internet. An internal web comprises all HTTP nodes on a private network, such as an organization's LAN or WAN. If the organization is a corporation, the internal web is also a corporate web.
If a corporate web connects two or more trading partners, it is often referred to as a business-to-business web, or an extranet.
Note that internal webs - also known as intranets - are only logically "internal" to an organization. Physically they can span the globe, as long as access is limited to a defined community of interest.
3. How big can an INTRANET be?
As a big as a community of interest. Scale is an important factor in web implementation, but it has no bearing on the logical association of clients that make up an intranet. For example, a workgroup with one web server, a company with several hundred web servers, and a professional organization with ten thousand web servers can each be considered an intranet.
4. How do intranet relate to groupware?
Groupware, a term coined by marketeers around 1995 to mean "software that facilitiates group work," never emerged as a well-defined software category. Today the term is used less and tends to be narrowly identified with three products: Lotus Notes, Microsoft Exchange and Novell GroupWise.
Groupware functionality is roughly synonomous with collaborative computing and embraces the following:
Intranet technology is well-suited to many of these tasks, having matured in areas where it was initially weak, such as security and integrated search. The major groupware products have shifted from their early proprietary roots to internet-based architectures. For instance, Microsoft Exchange 5.5 supports POP3 and IMAP4 Internet mail, NNTP-based newsgroups, and LDAP directory services.
Perspectives. For an early, lucid explanation of groupware, see Lotus' seminal white paper, "Groupware -- Communication, Collaboration, Coordination" (1995). Lotus has since recast Notes as a type of Knowledge Management (KM) software, as has Lotus-competitor Open Text Corporation regarding its flagship product Livelink Intranet. IDM maintains a listing of additional products in the KM / Content Management / Portal space, which some consider the successor to groupware.
5. How do Intranet Relate to E-Mails?
It's a marriage made in CyberHeaven. E-mail is networking's killer app and the foundation of Internet messaging. Intranets inherit Simple Mail Transport Protocol (SMTP, RFC-822) from the TCP/IP suite. On top of SMTP, which enables plain text messaging, intranets use Multipurpose Internet Mail Extensions (MIME, RFC-2045) to carry diverse content. In fact, the MIME content types are the Web's content types -- adding a new format such as streaming audio amounts to defining a new MIME type.
Because intranets have established Internet mail as the de facto messaging standard, they are replacing proprietary mail systems such as Lotus VIM and Microsoft MAPI in much the same way they have other proprietary network protocols.
6. Is TCP/IP required to run Intranet?
Yes and no. Yes, TCP/IP is required on the web server, since HTTP is a TCP/IP service. At the client, where concern about protocol explosion is greatest, you don't actually need an IP stack. Gateway products that run IP packets over IPX enable NetWare shops to build an intranet without complex additions to each desktop.
7.How do intranets relate to client/server systems?
Intranets follow a multi-tier application architecture with roughly the following correspondences:
Browser = Client.
Web server and Application servers = Business logic tiers.
CGI, proprietary server API, JDBC driver or Message Queueing = Middleware.
Component Transaction Server = Transaction Manager
Database servers = Back-end data stores.
8.What is Extranet?
It is a business-to-business intranet that allows limited, controlled, secure access between a company's intranet and designated, authenticated users from remote locations.It is an intranet that allows controlled access by authenticated parties.
Commentary: the terms intranet and extranet are roughly web-based analogs of LAN [Local Area Network] and WAN [Wide Area Network], as the following charts make clear:
|
|
LAN |
WAN |
|
Bandwidth |
high |
low |
|
Scope |
building or campus |
city to global |
|
Protocols |
diverse |
diverse |
|
Security |
very high |
high |
|
|
Intranet |
Extranet |
|
Bandwidth |
high |
low |
|
Scope |
building or campus |
city to global |
|
Protocols |
internet |
internet |
|
Security |
moderate to high |
low to moderate |
Differences appear with regard to protocol (by definition) and security. The weaker security of internet communications relative to leased lines is the reason that terms like "controlled" and "authenticated" figure prominently in the definition of extranet.
9.What is relation between Intranet , Extranet , E-Commerce?
The answer has three parts. First, intranets, extranets and e-commerce have in common the use of internet (predominantly web) protocols to connect business users.Second, intranets are more localized and can therefore move data faster than more distributed extranets. (Bandwidth limitations also apply to e-commerce.) Third, the amount of control that network managers can exert over users is different for the three technologies.
On an Intranet, administrators can narrowly prescribe access and policy for a fixed group of users. For example, a company could specify Red Hat Linux as its standard desktop operating system, and Netscape Communicator 5 as its standard browser and mail client. The company could then write intranet workflow applications that leverage the uniform computing environment, over which it exercises strong control.
On a business-to-business Extranet, system architects at each of the participating companies must collaborate to ensure a common interface and consistent semantics (data meanings). Since one company cannot reasonably enforce standards on its trading partners, extranet application developers must take into account a wider range of technologies than is the case for intranets. For example, one company participating in an extranet might be using Microsoft Internet Explorer, another Netscape Navigator 4.5, and another Navigator Gold 3.x. In order to collaborate via extranet the applications have to perform adequately on all represented platforms.
The same is true, only moreso, for e-commerce, in which the trading partners may be completely unknown to one another. This is the case when you walk into a supermarket: the common interest in communication is based on the need to transact business, and not necessarily on a long-term trust relationship. Thus e-commerce applications often support a level of security and transactional integrity (for instance, non-repudiation of orders) not present in intranet or extranet applications.