CHAPTER-9 MLLN Page: 1
MLLN An Overview 1.0 Leased Line Introduction A leased circuit is a dedicated link provided between two fixed locations for exclusive use of the customer. It is a dedicated point to point line connecting the facilities of a Customer, for telephone sets, EPABX, Computers, etc., or for forming a VPN. 1.1 Need for Leased Line Connecting geographically spread out locations. Dedicated transmission. Security. Ease of communication. Stand by arrangement. Networking. Interconnection. 1.2 What makes Leased Line so important? Leased circuit provides us high revenue because customers use it for data services mainly. Expectations of customers are very high. They need high Q.O.S. & want to sign SLAs. These are dedicated circuits for exclusive use by the customer. Page: 2
In the changing economic environment dependence of activities on leased circuits is increasing because most of the customer needs heavy data exchange between different points. Due to emerging competition rates are bound to go further down with many more new features. Type of leased circuit services 1. Speech Circuits (Hot Line or P-Wire) - Local or Long distance circuits within a city or between two different cities provided for the same applicant. The terminating equipment at both ends is telephone without dialing facility. Both way signaling and speech is possible. 2. Data Circuits - Local or Long distance data circuits at different speeds viz. 2400 bps, 4800 bps, 9600 bps, 64 kbps, nx64 kbps and 2 Mbps. Closed User Group (CUG) Leased circuits can be used by more than one legal entity if they form closed user group. Categories of User Groups constitute closed user groups for the purpose of licensing Private Telecom Networks. 1. Producer of goods and his whole -sale traders /agents. 2. Provider of service (not being a telecommunication service) and his wholesale traders/agents. 3. Producers of same categories of goods. 4. Providers of the same category of service. 5. Holding company and its subsidiaries. 6. Interconnected undertakings. 7. Companies under the same management. 8. Travel agents issuing tickets on the member airlines, whose network they use including the network of a group of member airlines. 9. Computerized Reservations System (CRS) service providers owned by airlines. Page: 3
10.Shared networks of banks for use of Automatic Teller Machines (ATMs), Electronic Points of Sale (EPOS)/credit authorization terminals. 11. Financial institutions registered primarily to deal in securities and their agents/dealers. 12. Financial institutions registered as Mutual funds and their agents. 13. Financial institutions, which are registered as depositories and their agents/dealers. 14. Other non-banking financial institutions. 2.0 What is MLLN? MLLN is a Fully Managed Access Network, which allows the operator to keep an end-to-end control over the customer circuit and hence provide him guarantee of uptime of the circuit (QoS, SLA s). MLLN is a Next generation Digital Access Network which provides solutions to all the Data networking and Voice requirements of the customer. MLLN is an Overlay network realized through Tellabs Networking Elements, which offer Multiple Value-added and customized services to the customers 2.1 Segments addressed by MLLN Managed Bandwidth Leased Lines to Alternate Service Providers Paging, VAS, Cellular, ISP & Value added Service Providers Virtual Private Network (VPN) Stock exchanges, Banks, MNCs, Publishing Houses, Software Developers, Broadcasting companies Multi-Service Network for Governance applications State Wide Networks Enhanced support for legacy applications Hotlines, PABX-IC, Point to Multi-point circuits, ISDN Service extension, Data circuits for Security & Travel applications Page: 4
3.0 MLLN ARCHITECTURE A. Central Node: It will provide following functionality: (i) NMS Center (ii) Connectivity to second stage nodes. (iii) Leased line aggregation. B. Second stage Node: It will be located at major cities of a Telecom Circle, where demand for leased line is high. It will provide following functionality: (i) Connectivity to third stage nodes. (ii) Leased line aggregation. C. Third Stage Node: It will be located at smaller cities / towns of a Telecom Circle, where demand for leased line is lower (near 10). (i) It will provide Leased Line aggregation. Following figure shows the architecture: Page: 5
3.1 MLLN Elements DXC (Digital Cross-Connect) VMUX (Versatile Multiplexer) NTU (Network Terminating Unit) NMS (Network Management System) (Centralised NMS for the whole network having main NMS site at Bangalore and the Disaster Recovery(DR) site at Pune) Page: 6
3.2 Features of MLLN elements NTU Wide range to choose from as per customer requirements. HDSL Network interfaces Different types of CPE interfaces Long drive on copper (7 km) Full management from NMS NMS Best in the industry NMS User friendly GUI Open & redundant architecture Basic Node (VMUX) Built-in HDSL modem interfaces Full management from NMS Cluster Node (DXC) Modular DXC - 32 to 256 E1 Full management from NMS 4.0 features of BSNL MLLN network Covering around 600 cities nationwide 3 tier architecture of DXCs Core network of regional DXCs (R-DXCs) at Mumbai, Delhi, Kolkatta and Chennai and Sub Regional (SR-DXCs) at various locations in the four maintenance regions Mesh connectivity between R-DXCS Page: 7
Mesh connectivity between SR-DXCs of the same region. All SR-DXCs connected to R-DXCs. Major SSAs have been provided with SS DXCs. Remote Operater Terminal (ROT) planned for every station having more than 30 leased circuits. 5.0 Digital Cross Connect (DXC) Features of DXC Capacity DXC (64 ports upgradeable to 128 ports) DXC (96 ports upgradeable to 128 ports) DXC (128 ports upgradeable to 256 ports) DXC (256 ports) I/0 cross-connect capability Non-Blocking Architecture Redundancy Power Supply Switching Matrix Cross-connect Memory Expansion to be made possible by addition of cards only. Fully Managed from Centralized NMS 6.0 VERSATILE MULTIPLEXER (VMUX) Type 64 kbps N x 64kbps E1 VMUX Type 1 32 8 12 VMUX Type 2 16 4 4 VMUX Type 3 8 4 4 Expansion to be made possible on the same chassis by addition of cards Page: 8
Type 3 VMUX 230V AC Powered -48V DC Powered Point to point and Point to Multi-point circuit routing is possible. HDSL Driving Distance: 3.5km at 2Mbps 5 km at 1Mbps 7km for 64/128kbps (at 0.5mm dia copper cable) 7.0 NETWORK TERMINATION UNIT (NTU) Features of NTU Capacity 64/128kbps NTU with V.35 64/128kbps NTU with G.703 N x 64kbps NTU with V.35 N x 64kbps NTU with G.703 N x 64kbps NTU with Ethernet Interface Line Loop Testing 64kbps NTU to work upto 128kbps N x 64kbps NTU to work upto 2Mbps NTU to send power off signal to the NMS at the time of NTU getting switched off. Types of NTUs with different interfaces Tellabs 8110 STU-160/V.35 for 64/128 kbps NTU with V.35 interface Tellabs 8110 STU-160/G.703 for 64/128 kbps NTU with G.703 interface Page: 9
STU-160 works upto 128kbps CTU-S and CTU-R works upto 2Mbps on a single pair of copper 8.0 NETWORK MANAGEMENT SYSTEM (NMS) Features of NMS NMS (Network Management System) (Centralised NMS for the whole network having main NMS site at Bangalore and the Disaster Recovery(DR) site at Pune) MLLN NMS Billing and Accounting System Web Self-care system NMS MLLN NMS performs all the management functions on the network Provides complete functionalities Supports regional partitioning and VPN capabilities Performance Monitoring, Recovery, Reporting Packages Key requirements of the Billing and Web Self Care system System Capacity Requirement 150,000 subscriber base to be managed Functionality. Full Billing and Invoicing. Customer and Account Management. Security and Auditing. Comprehensive Reporting. Suite of Web Self Care functionalities. Page: 10
What is TVARIT? TVARIT is Sanskrit word for the term IMMEDIATE. TVARIT PLUS is newer version of TVARIT which is LEASED LINE ONLINE provisioning and upkeep system. It is computerized online system, simple to operate & self explanatory. Paperless. Reliable, Fast and Instant execution of transactions. All the manual activities are computerized. Numbering scheme of leased circuit An integrated numbering scheme for leased circuit to be used for identifying, monitoring, complaint booking as well as billing of leased circuits. This will have uniform applicability across the country. Every leased circuit will have a number as ABCD/JKLMN/XY/EFGH WHERE ABCD= originating SDCA code EFGH= Terminating SDCA code JKLMN = Circuit number XY = Circuit type For circuit within the same SDCA, ABCD=EFGH For 3 digit code, D= # and H= # For 2 digit code, C, D, = # and G, H = # For 5 digit SDCA code, for JKLMN = 00001 to 99999, the circuit number will be ABC#/JKL/XY/EFGH Page: 11
XY codes 11 Speech circuit (with HOT line relay set) 12 Speech circuit (on PAX) 13 Speech-cum-data circuit 14 Voice grade data circuit 15 VFT 16 64 kbps circuit 17 N x 64 kbps circuits 18 2 Mbps circuit 19 8 Mbps circuit 20 34 Mbps circuit 21 140 Mbps circuit 22 STM-1 23 STM-4 24 STM-16 25 STM-64 26 R&G copper cable 27 R&G OFC cable 28 R&G UHF microwave 29 Contribution work copper cable 30 Contribution work OFC 31 Contribution work UHF microwave Any additional series code, (XY) will be centrally allotted. 2 digit code, for each type of circuits (classified by XY of the leased circuit number) How to access TVARIT PLUS Page: 12
Main server is located at Banglore & disaster recovery (DR) site is at Pune. TVARIT PLUS is accessible through MPLS/VPN cloud. IP address for main server site is 10.192.174.7 & 10.192.174.8 IP address for DR server site is 10.192.174.67 & 10.192.174.68 Key Features of TVARIT PLUS System 1. Generation of the standard 15 digit unique number. 2. Generation of the Provisional and final demand notes, Advice notes, Receipts and other general feasibility and channel allocation reports. 3. Generation of Recurring bill. 4. Generation of a full fledge Managerial Information Reports (MIS). 5. Current accurate status viewing to all the concern authorities. 6. Address change and cancellation of the circuits Conventional Leased Circuits Upgradability : In steps 64K, 2M Monitoring : No Manageability Testing Coordination Problems Provisioning SLA Bandwidth on Demand :No :Fault localisation Lengthy (NFF) :Fault in Modem/ Last mile :Long (Patching) :No :No Leased Circuits on MLLN Page: 13
Upgradeability :In n * 64K Monitoring : Yes Manageability :Yes Testing :Fault localisation Faster Coordination : No Problem (Both Modem/ Last mile of BSNL) Provisioning : Fast (Config.) SLA :Yes Bandwidth on Demand :Yes MPLS VPN Upgradability : In n * 64K (even for non- MLLN) Monitoring : Yes (even for non- MLLN) Manageability : Yes Testing : Fault localisation Faster (Monitoring by NOC even for Non- MLLN) Coordination : Depends on last mile (MLLN?) Provisioning :Fast (Config.) SLA : Yes (even for non- MLLN) Bandwidth on Demand : Yes MPLS Vs MLLN MPLS MLLN Security Leased, 100% IP based PPP QOS, not 100% assured 100% available Shared dedicated Page: 14
Leased circuit media Leased circuits are available on Optical Fiber Media, Radio Media, Copper Wire and Satellite Media or a Combination of these media. Local media and national long distance media are by the BSNL/MTNL and International media by VSNL, Questions: 1. Which company has supplied MLLN equipment in BSNL? 2. What is the full form of NTU and where it is installed? 3. What is the purpose of VMUX in MLLN? 4. What is the minimum and maximum bandwidth we can give to subscriber? 5. What is the function of DXC in MLLN? 6. What is minimum and maximum capacity of DXC? 7. What for TVARIT is used? 8. What is the numbering scheme of leased circuit? 9. What is the access code for PSTN Dial-up? 10. What for CUG stands in leased circuits? Page: 15