for fast and reliable Net access with zero downtime. A
leased line may be the answer to your access woes
you conduct business on the Internet, your company needs
access that is dependable and fast. Time is money, and
downtime or slow transfers can cost many times more than
what you actually pay for your connections. Leased lines
addresses these issues.
Leased lines are dedicated circuits provided by Basic
Service Providers (BSPs), which provide permanent connectivity
to the Internet. Leased lines provide the last mile access
from the user premises to the ISP. They provide permanent
connection as compared to the temporary connectivity through
dialup access. The quality of the connection is far superior
to what is normally available through dialup, thanks to
digital signaling, less noise, fewer exchanges etc.
Leased lines provides a scalable access method, important
particularly for organizations with large user groups,
including corporate, banks and financial institutions,
educational and R&D organizations, government, military
etc. Starting typically with 64 Kbps, it is possible to
deploy a scalable architecture, with multiples of E1 (2
MBPS) pipes, providing the necessary bandwidth. In fact,
leased access becomes a must for large organizations in
Since the access is "always on", it is possible
to associate a pool of permanent IP addresses with a particular
leased line. Normally, the ISP would provide 16/32 IP
addresses for each 64 Kbps chunk of bandwidth. Using these
IP addresses it becomes possible to deploy a variety of
services such as mail, FTP, WWW, DNS, and proxy, to name
the most common requirements of organizations. In other
words, leased lines enable hosting of services of all
types, and provide a platform for enterprise intranets
and extranets, apart from what we may term as "entry
level" services such as messaging, which still account
for over 70 percent of all Internet access.
We can look at two types of equipment requirements. The
first set of hardware is required for establishing the
last mile link between the customer premises and the ISP.
Currently, 64 Kbps and 2 Mbps leased line modems are commonly
deployed for terrestrial leased line access to the Net.
The equipment required is one pair of leased line modems
(one each with V.35 and G.703 interface) and one G.703/V.35
interface converter, supporting either 64 Kbps or 2 Mbps.
Depending on the bandwidth, there are some technical differences
between the 2 types of modems as well. This equipment
may be provided either by the ISP or the customer can
buy it himself.
The other set of equipment required is at the customer
premises. This includes a router and various servers as
needed in specific sites. The router establishes the link
with the ISP. Typically, users need to consider services
like DNS, mail, proxy, firewall,FTP, databases, file servers,
and security services which can be set up on the available
Applications of leased lines
Point-to-point: For Data Only
of the widely used applications of leased lines is having
a secure dedicated data circuit between two locations
via a private line, used to transmit data at a constant
speed equal to the bandwidth of the circuit.
Point-to-point: For Voice and Data
This kind of application allows transmission of voice
and data over the same connection. Here also two separate
locations are joined together. This type of configuration
is commonly provided on a higher bandwidth circuit. The
bandwidth of the circuit is divided into individual voice
channels and data channels.
Multiplexing basically connects multiple remote sites
to a single
centralized location. Typically a connection originating
at the host location is connected into a multiplexer at
a service provider's end. At the multiplexer, the host
circuit is split into smaller individual circuits, and
those are then delivered to the remote sites.
Rathod can be reached at email@example.com
It provides permanent, reliable, high-speed connectivity
as compared to the temporary connectivity of dial up access.
The quality of the connection is far superior to what
is normally available through dialup, because of the digital
signaling, less noise, fewer exchanges etc.
Leased bandwidth prices are quite high, compared to dialup
bandwidth of comparable size. Entry level annual port
prices are also high at present, so that this access method
is only feasible beyond a fairly high threshold level.
Permanent connectivity to the Net exposes the organization
to a variety of threats including hacking, malicious code
including active vandals, viruses, Trojan Horses, macros,
denial of service attacks etc.