LEASED LINE Leased lines Limited to point-to-point communication Limits who you can talk to Carriers offer leased lines at an attractive price per bit sent to keep high-volume customers Leased Line
LEASED LINE Leased line are basically point to point connection given on lease basis. To transmit the data between computer and electronic information device we uses a leased line. Leased circuits are provided to subscribers for internal communication between their offices/factories at various sites within a city/town or different cities/town on point to point basis, or on a network basis interconnecting
LEASED LINE CONTD. For dedicated point to point speech, private wire, tele- printer and data circuits are given on lease basis. Leased lines are used to build up private networks, private telephone networks (by interconnecting PBX's) or access the internet or a partner network (extranet).PBXextranet
TYPES OF LEASED LINE Point to point connection. Multi-label-protocol-switching(MPLS) VPN. Internet Leased Line.
POINT TO POINT CONNECTION A dedicated link through the service providers network. This link is not shared with other customers, and provides a dedicated circuit between two locations it is a permanently established circuit through the service providers switched network, similar to what is illustrated in the figure below.
POINT TO POINT CONNECTION CONTD. It is a good choice for customers who require consistent bandwidth between two locations.
FIGURE DEPICTING POINT TO POINT CONNECTION
Point to point connection using vmux
ADVANATAGE This connection is directly "laid in" for you - thus you end up with a dedicated connection - for high end business's usually, with higher speeds, lower contention and faster response times to any problems. Data security.
DISADVANTAGE As the organization grows present networking solution becomes costly since we will have to invest on Multiple links and Networking equipments. Provisioning & Commissioning.
MPLS VPN MPLS VPN stands for MULTIPROTOCOL LABEL SWITCHINGVIRTUAL PRIVATE NETWORK. An MPLS Network is formed by connecting each location with a single link to a service provider MPLS network.
MPLS VPN NETWORK
BSNL – VPN Core Network STM1 Links M40e Router Chennai Kolkatta Mumbai Pune Ernakulam Delhi Hyderabad Lucknow Ahmedabad Bangalore
BSNL – MPLS VPN Network POP Layout Core Router (M40e) Gigabit Ethernet Switch Edge Router (M40e/M20) STM-1 Link Gigabit Ethernet E3 Link
MPLS Benefits The performance characteristics of layer 2 networks The connectivity and network services of layer 3 networks Improves the price/performance of network layer routing Improved scalability 16
MPLS Benefits contd.. Improves the possibilities for traffic engineering Supports the delivery of services with QoS guarantees Avoids need for coordination of IP and ATM address allocation and routing information 17
Advantage of MPLS VAN over POINT TO POINT CONNECTION Quality of Service: Since MPLS network enables traffic engineering, it is possible to send (for example) – data traffic over a lower priority path and real time delay sensitive voice/ video packets over a high priority/ lesser used/ shorter path. This enables network convergence (The Wide Area Network becomes more suitable for introduction of new services like voice, video, multicast traffic, hosting etc). Connection oriented network: MPLS is a connection-oriented network unlike connection less networks like IP. So, it is more reliable. Bandwidth Allocation: MPLS networks allow for dynamic bandwidth allocation and hence can be used to provide bandwidth on demand (for a specific period etc) to customers. Further, rate limiting and other bandwidth management parameters allow a certain bandwidth to be dedicated for mission critical applications.
ADVANTAGE (CONTD.) Easy and Cost effective Expansion: Let us assume that the cost of connecting two sites by using Point to Point Leased Lines versus MPLS circuits comes to a ratio of 1:1 (For two sites there is only a single link required for both and hence the cost is same). But when it comes to interconnecting five sites (as shown in the above diagram), the number of links required for Point-to-Point Leased Lines would be 10 while for MPLS circuits, it would be only five and hence the corresponding cost ratio would be around 5:1 (Point to Point Leased Lines : MPLS Circuits). Protocol Independent forwarding: MPLS networks can carry any type of packets – be it IP, frame relay or ATM using the same infrastructure. This is because, what ever type of packets comes in, MPLS labels would be attached to it for transmitting them over the MPLS network and these labels are protocol independent.
DISADVANATAGE MPLS port and loop rates were higher than expected. Had the network been more geographically diverse, this factor would have been less noticeable, but for sites that were all close together and yet some distance from the closest POP, the pricing was out of line. MPLS requires greater IT overhead to manage all of the routers at each site. The customer was looking to decrease the IT burden, not increase it.
MPLS VPN USING VMUX
INTERNET LEASED LINE An Internet Leased Line is usually a dedicated line which offers direct connectivity to the Internet. This is done by connecting the nearest service provider nodal point and the customer premises with a dedicated copper line, optical fiber cable, radio links
INTERNET LEASED LINE(CONTD.) Internet Leased Lines are preferred over broadband connections for providing internet connectivity to larger organizations like colleges, corporate offices, hospitals, etc.
BASIC MODEL FOR INTERNET LEASED LINE
ADVANTAGE Internet Leased Lines offer same speed for both uploads and downloads (symmetric connectivity), while in broadband (through DSL technology) the speeds are always optimized for downloads and the upload speeds are much lesser. etc. all of which are used by medium and large businesses regularly. Generally, broadband connectivity is shared with multiple users in a locality. Broadband plans generally denote the best bandwidth that can be attained and not the assured bandwidth levels. But a 2 Mbps Internet Leased Line should give 2 Mbps of performance as it is a dedicated connection without any sharing.
ADVANTAGE(CONTD.) There is a wider choice of bandwidth selection (64 Kbps, 128 Kbps,… 2 Mbps,… 155 Mbps etc) with Internet Leased Lines. With broadband, the selection is more restricted. Internet Leased lines are provided through multiple media – Copper, Fiber, Radio links or a combination of the above. Optical media communication is more reliable and offers better fault tolerance/ performance/ monitoring abilities, especially for higher bandwidths. Internet Leased Lines offer a pool of permanent IP addresses which enables organizations to run their own mail servers, web servers and other applications.
TYPES OF LEASED CIRCUIT G-4 MUX MLLN VMUX
E-1 CARRIER(P.C.M) P.C.M stand for pulse coded modulation. A dedicated phone connection supporting data rates of 2.048Mbits per second. An E- 1 line actually consists of 32 individual channels, each of which supports 64Kbits per second. Each 64Kbit/second channel can be configured to carry voice or data traffic.
E-1 CARRIER(P.C.M) contd. An E1 link operates over two separate sets of wires, usually coaxial cable. A nominal 2.4 Volt signal is encoded with pulses using a method that avoids long periods without polarity changes. The line data rate is Mbit/s (full duplex, i.e Mbit/s downstream and Mbit/s upstream) which is split into 32 time slots, each being allocated 8 bits in turn Thus each time slot sends and receives an 8-bit sample 8000 times per second (8 x 8000 x 32= 2,048, 000). This is ideal for voice telephone calls where the voice is sampled into an 8 bit number at that data rate and reconstructed at the other end.
E-1 FRAME STRUCTURE 32 Timeslots Total. Each channel holds 8 Bits. Each channel repeats 64,000 times a second (64 Kbps). 30 TIME SLOTS for voice calls.
MLLN VMUX The MLLN is an integrated, fully managed, multi-service digital network platform through which service provider can offer a wide range of services at an optimal cost to Business Subscribers. Backed by a flexible Network Management System with powerful diagnostics and maintenance tools, the MLLN can be used to provide high-speed leased lines with improved QoS (Quality of Service), high availability and reliability. The Network Management System also supports Service Provisioning, Network Optimization, Planning and Service Monitoring. The system offers features such as end to end circuit creation and monitoring, Circuit Loop Test and fault isolation, Alternate re-routing of traffic in case of trunk failure, Software programmability of NTUs, etc.
MLLN USING VMUX
ADVANTAGE Circuit fault reports generated proactively. On demand the bandwidth can be increased. Protection against the failure of the circuit. Centrally managed from Network Management System. Easy re-routing and configuration