Available
communication apparatus
Electronic
commerce clearly depends on the availability of reliable, inexpensive, and
ubiquitous connectivity. There are five
relevant elements:
1.
Organizations own enterprise networks
which house appropriate information, usually beyond the organization’s firewall
apparatuses.
2.
The public-switched telephone network.
This is generally constituted of Local Exchange Carriers (LECs) and Competitive
LEC (CLECs) at the local level and a multitude of Interexchange Carriers (IXCs)
at the national backbone level.
3.
The internet. As describes, this
consists of ISPs and NSPs and provides a large interenterprise infrastructure.
4.
On-line networks such as America Online,
which utilize their own communication and information (storage) facilities.
They can be accessed by dial-up or private lines and now have access to the
Internet.
5.
Specializes industry networks, such as
those to support EDI.
Internet
traffic routing rules are, generally, as follows:
v If
a user tries to reach a resource located on the same ISP’s network to which the
user is connected, the traffic is examined by the ISP router which in turn
forwards it to the destination (this applies to both backbone providers and regional’s).
v If
a user tries to reach a resource not located on the same ISP’s network to which
the user is connected, the traffic is examined by the ISP/NSP router, which in
turn finds the nearest point at which it can hand off data to an exchange point
(e.g., MAE-East). The traffic is then transferred to the appropriated target
network.
v Backbone
ISPs, that is, NSPs, do not want to incur the cost of carrying traffic destined
for another provider’s network. So, they hand off the traffic to the nearest
exchange point, destination network, or intermediate transit provider.
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