Question

Write a brief note in your own words on Leased lines with brief introduction of its type of services.

Write a brief note in your own words on Leased lines with brief introduction of its type of services.

Answer 1

Leased line

A leased lines are a private telephone network, established by a contractual arrangement between two or more places. Often it's called a separate connection and a telephone line in the United Kingdom. Leased lines are typically used by companies to connect remote locations.

As contrast to conventional telephone lines licensed on public telecom (PSTN) telecommunication networks, there are not normally circuits transferred and thus no telephone number connected to them. Any side of the line is linked, involved and continuously dedicated to the other side. Leased lines may be used for telephone , Internet or other facilities. Many of them are downloadable applications and some link to a PBX or network router.

A disparity between the end stations and the circuit bandwidth is the key factors impacting the renewed lease rates. The connection is not connected to third parties, so that a certain quality level can be ensured by the carrier.

Internet leased line is a premium Internet connectivity device, usually provided via fiber, that provides full duplex traffic with an unregulated, symmetrical bandwidth. The Ethernet licensed unit, the reserved panel, the network device or the private unit. This is often called.

History

The Bell backbone network was converted from analog to digital in the 1970s by leased lines services (or private line services). Dataphone Digital Services (later rebranded, digital data services), which began to connect ISDN and T1 lines to customers[1], were provided by AT&T.

Licensed lines were used for mainframe device communications by IBM Systems Network Architecture (created 1974) and DECnet (created 1975) to terminals and remote sites.

In order to connect consumer premises to the frame relay or ATM networks, the expansion of digital infrastructure in the 1980s has used leased cables. Data access rates increased with a maximum transmission speed of 986.544 Mbit / s to T3 from the original T1 option.

Throughout the 1990s, as the Internet progressed, leased lines were often used to link client premises with the ISP presence level, although in the ensuing decade, such networks (frame transfer, ATM, Web for companies) converged with the MPLS optimized service offerings.

Owing to the increase in Internet and growing bid of long-range optical networks or metropolitan area network link prices in the early 21st century have significantly expanded to levels up to 10 Gbit / s.

Applications

Located lines are used in the construction of remote, remote telecommunications networks (through PBX connection) or internet connectivity or a joint (extranet) network.

Here is a analysis over time of the leased-line implementations for network designs:

• Link from site to site

The completion of a leased line with two routers will improve network bandwidth on sites. Leased lines had first been used by a corporation in the 1970s for proprietary protocols such as DECnet and TCP / IP in academic and research networks before the internet was commonly available . In fact, leased lines were first used in the 1970s. Note that before TCP / PI became widespread in the 2000s, additional Layer 3 protocols such as Novell IPX were used on business networks. Point-to - point network links are usually commonly accessible as TDM, Ethernet, or MPLS layers 3.

• PBX access from location to location

Closing a two PBX rental line allows customers to bypass PSTN for cross-site telephony. The customers thus had the ability to manage their own telephone dial plans and to make significant savings when sufficient voice traffic was transportable across the line (particularly when savings on the telephone bill exceeded the fixed cost of the leased line). The cost was also significant.

• Connectivity site to network

With increasing demand from data network telecoms, packet switches began to build more evolved networks. There have therefore been added to your service portfolio by a number of telecommunications companies ATM, Frame-relay or ISDN services. Connecting the consumer site to the telco network access point was achieved through leasing tracks.

• Commercial rental network regional

A private leased international (IPLC) circuit is a private dot-to-dot line. IPLCs are typically multiplexing time division (TDM) circuits, used by several clients on the same circuit. In TDM 's design, a CSU / DSU and router are needed. The CSU / DSU usually comes with the router. It was then the Internet (in the mid-1990s) and the most popular leased line application since then has been to connect a client to its ISP site. As the Internet introduced new technologies into the world of networking, it developed alternative frame-relaying or ATM networks (e.g., VPNs (hardware and software) and MPLS (e.g. upgraded ATM / frame-relay / infrastructure TCP / IP).

Private network (with leased lines) Telco network Regional Office Head-office 4 DORAS Regional Office PSTN Remote/ roaming users

Frame-relay network Frame relay cloud Regional Office Head-ofice DRAG Regional Office PSTN E-டியா Remote / roaming users

Availability

• Across the United Kingdom

In UK, the rented lines are available on the channel E1 tail circuit and on speeds ranging from 2.048 Mbit / s in increments of 64Kbit / s to 2.048 Mbit / s on the channeled E3 tail circuit. The NTE terminates the circuit and more commonly gives X.21, although faster speed interfaces like G.703 or 10baseT are possible. However, some ISPs more openly use the phrase, which describes a leased line as "any dedicated bandwidth service supplied by a leased fiber link.". Leased line networks in the range of 100 Mbit / s-1 Gbit / s are typically available as of March 2018. Speeds of 10 Gbit / s was reached in bigger areas , for example, London.

• The United States

Generally analog modems are equipped with low speed leased lines (56 kbit / s and below) in the U.S. The FT1 (Fractional T1) is typically found in high intensity rented lines: the T1 bearer circuit with one to 24, 56k or 64k timeslots. Customers usually operate their own channel control units and data service units (CSU / DSU) through a network termination unit.

• Hong Kong, Germany

Hong Kong offers leased lines at 64k, 128k, 256k, 512k, T1 (canneled or not) or E1 (less common). Regardless of the pace, telcos typically have the CSU / DSU and show the V.35 gui to consumers. Slowly fibre circuits replace classical circuits and almost every bandwidth is available.

• India

Located lines are available in India at 64 kbit / s, 128 kbit / s, 256 kbit / s, 512 Kbit / s, 1 Mbit / s, 2 Mbit / s, 4 Mbit / s, 8 Mbit / s, 1000 Mbit / s, T1(1.544 Mbit / s). Customers are either linked through OFC, ADSL or WIFI telephone lines. Customers would have to operate their own channel unit and data service unit for their network termination equipment.

• Italy

In Italy, the leased lines are available in digital form (PDH operation, defined as CDN Circuito Diretto Numerico) at speeds up to 64 kbit / s (déclaré modem DCE2 or DCE2plus), or multiple lines up to a speed from 128 kbit / s to a network or unframed E1 (DCE3 modem). CDA (Circuito directto analogico) can also be provided by local phones, which are a clear copper pair between two buildings, without any line termination. A complete analog base band was supplied in the past (pre-2002), which give customers the option to use xDSL technology between the places. Licensed lines are slowly substituted for DSL and Metro Ethernet for other purposes.

Leased line alternatives

Leased lines charges more than other connectivity services, like (ADSL, SDSL, etc.) as they are exclusively reserved for the leaser. Several Internet service companies have also developed solutions aimed at offering leased-line forms of networks with more modest capacity, leveraging the existing UK regional broadband network (carrier Ethernet powered, nil contentions, assured availability). While a leased line is full duplex, most leased line approaches only provide half duplex or asymmetric operation in many situations.