Internet Technologies 简明教程

Extranet Overview

Extranet

外联网是指组织内部使用互联网以受控方式连接到外部人员的网络。它有助于企业与其客户和供应商建立联系，因此允许以协作方式工作。

Extranet refers to network within an organization, using internet to connect to the outsiders in controlled manner. It helps to connect businesses with their customers and suppliers and therefore allows working in a collaborative manner.

Implementation

外联网作为虚拟专用网 (VPN) 实施，因为它使用互联网连接到企业组织，信息安全始终受到威胁。VPN 在公共基础设施（互联网）中提供安全网络。

Extranet is implemented as a Virtual Private Networks (VPN) because it uses internet to connect to corporate organization and there is always a threat to information security. VPN offers a secure network in public infrastructure (Internet).

Key Points

The packet is encapsulated at boundary of networks in IPSEC complaint routers.
It uses an encryption key to encapsulate packets and IP addresses as well.
The packet is decoded only by the IPSEC complaint routers or servers.
The message is sent over VPN via VPN Tunnel and this process is known as tunneling.

VPN 使用 Internet Protocol Security Architecture (IPSEC) 协议通过在 TCP/IP 协议中添加额外的安全层来提供安全交易。通过将 IP 数据包封装到如图所示的新 IP 数据包中，创建此层：

VPN uses Internet Protocol Security Architecture (IPSEC) Protocol to provide secure transactions by adding an additional security layer to TCP/IP protocol. This layer is created by encapsulating the IP packet to a new IP packet as shown in the following diagram:

Benefits

外联网被证明是适用于各种规模的企业的一个成功模型。以下是一些外联网对员工、供应商、业务合作伙伴和客户的优势：

Extranet proves to be a successful model for all kind of businesses whether small or big. Here are some of the advantages of extranet for employees, suppliers, business partners, and customers:

Issues

除了优点之外，外联网还存在一些问题。以下讨论了这些问题：

Apart for advantages there are also some issues associated with extranet. These issues are discussed below:

Hosting

放置外联网页面的地方，即由谁来托管外联网页面。在此上下文中，有两个选择：

Where the extranet pages will be held i.e. who will host the extranet pages. In this context there are two choices:

Host it on your own server.
Host it with an Internet Service Provider (ISP) in the same way as web pages.

但是，在自己的服务器上托管外部网络页面需要高带宽互联网连接，而这会非常昂贵。

But hosting extranet pages on your own server requires high bandwidth internet connection which is very costly.

Security

如果您在自己的服务器上托管外部网络页面，则需要额外的防火墙安全，这会导致安全机制复杂化并提高工作量。

Additional firewall security is required if you host extranet pages on your own server which result in a complex security mechanism and increase work load.

Accessing Issues

如果没有互联网连接，则无法访问信息。但是，在没有互联网连接的情况下可以在 Intranet 内访问信息。

Information can not be accessed without internet connection. However, information can be accessed in Intranet without internet connection.

Decreased Interaction

这减少了业务中的面对面互动，从而导致客户、业务合作伙伴和供应商之间缺乏交流。

It decreases the face to face interaction in the business which results in lack of communication among customers, business partners and suppliers.

Extranet vs. Intranet

下表显示了外部网络与内部网之间的差异：

The following table shows differences between Extranet and Intranet:

Extranet

Intranet

Internal network that can be accessed externally.

Internal network that can not be accessed externally.

Extranet is extension of company’s Intranet.

Only limited users of a company.

For limited external communication between customers, suppliers and business partners.

Only for communication within a company.