Chapter 5
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5. MLLN A/T 5-1 General:- Managed leased line network, why managed? It is centrally monitored and allotment of circuits, deletion of circuits, fault monitoring and intimation to the maintenance staff, all these functions is being carried out by main NMS at Bangalore and Pune disaster NMS. MLLN system comprises of following entities starting from customer to Bangalore NMS, 5-1.1 Abbreviations :- 1. NTU: - Network Terminating Unit (At customer end) 2. V-MUX: - Versatile Multiplexer. 3. DXC/ DACC: - Digital Cross Connect/ Digital Access Cross Connect. 4. ROT: - Remote Operator Terminal. 5. NMS: - Network Management System. Please see the block schematic of the network. V-Mux is installed at every station and all V-MUX are brought to DXC slave rack which after all controlled by DXC second master and cluster rack. Some salient features:- - Allotment of point to point and point to multipoint circuits. - Bandwidth 64 Kbps or N X 64 Kbps Maximum 2240 Kbps. - Provides fully managed and controlled service by using NMS. - Continuous performance monitoring, Fault monitoring is possible. - DXC is Tellabs 8170 where as V-MUX Tellabs 8150 and NMS is Tellabs. - Phase II version was 5.0 whereas phase III version is 6.0. 5-1.2 There are four types of V-MUX which are as follows:- Type Requirements 64 Kbps N x 64 Kbps Hot line E1 Type 1 32 8-12 Type 2 16 4-4 Type 3 ( DC version) 8 4 4 2 Type 3 (AC version) 8 4 4 2 There are four types of DXC- - 64 ports up gradable to 128 ports - 96 ports up gradable to 128 ports - 128 ports up gradable to 256 ports - 256 ports (32 ports x 8 slave sub rack) V- MUX sub rack contains following modules, PFU, VCM, OMH HCQ, QMH, QMH G.703, XCG and CCS. DXC Slave sub rack contains following modules:- PFU, QMH-8, SXU, SCU DXC Cluster Master Sub rack contains following modules:- PFU, CXU, CCU. Please see MLLN DXC, V-MUX Rack in Fig. 5-1 and block schematic, internal wiring of MLLN network in Fig. no.s 5-2, 5-3 & 5-4. 149 127
5-1.3 Some important abbreviations of Modules:- SR DXC : - Sub regional DXC. R- DXC : - Regional DXC. OMH : - Octet Module Housing, 8 customer of 2 MB. QMH/ HCG: - Quadrate Module Housing, 4 E1 Termination. XCG : - Cross Connect Grooming. QMH/G 703:- Quadrate Module Housing PFU : - Power Fuse Unit SXU : - Slave X- Connection Unit SCU : - Slave Control Unit CCU : - Cluster Control Unit 5-1.4 Acceptance Testing comprises of - 1] V- MUX A/T, 2] DXC A/T, 3] ROT A/T. 4]Validation of NMS at NOC (Network Operating Center) at Pune is over in phase I, DXX,GATEWAY Server in phase II and DXX, fault, GATEWAY, HP OV Server, LAN switch in phase III,DCN to be offered. There are two types of tests. 1. Pre power on test. 2. Post power on test. Pre power on tests: - This test is related with infra structure and Hardware conformity along with physical verification. Post power on test: - All tests are NMS related by using ROT at DXC station. Open Toolbox -- 1. Select for object selection and its parameters. 2. Move - To move Nodes, NTUs, locations to new positions. 3. 8150 Basic - for the addition of new nodes and locations. 4. CTUR To add new modems. 5. 2 M To create new trunks between the nodes. 6. SCC - To add system control computer. 7. Node Editor- To add units and modules. 8. Interface binder- To bind the trunks and modems. 9. Node Manager - To open Node Manager for the selected Nodes. MLLN THREE RACKS: - DXC SLAVE DXC CLUSTER MASTER V- MUX SLAVE-1,8150 BASIC MODE 8170 MASTER POWER VMUX-1 SLAVE-2 8170 CLUSTER VMUX-2 TERMINATION DDF 1 DDF 2 SLAVE- 3 SLAVE -4 VMUX-3 Fig. 5-2 150 128
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5-1.5The NTU types: - - 64/128 Kbps NTU with v.35 interface - 64/128 Kbps NTU with G.703 interface - 64/128 Kbps NTU with Ethernet interface - N x 64 Kbps NTU with V.35 interface - N x 64 Kbps NTU with G.703 interface - N x 64 Kbps NTU with Ethernet interface NMS is at Bangalore and disaster NMS is in Pune 5-2 V- Mux and DXC A/T:- A/T should be offered now in atoms: - In Acceptance testing of MLLN all tests are related to NMS Bangalore and that too, you have to check all these commands on ROT. 5-2.1Infra structure check: - - Obtain layout of floor plan. - Check of earthing system: - Mostly earthing system is existing only, you have to note down earth resistance within six months taken by maintenance staff, if not, carry out earth measurement. - Fire alarm system whether FD s are provided or not? - All details about A/C availability, type of A/C and temperature to be noted down. - All details about Power plant, Battery and Engine alternator to be noted down. - Check location, Rigidity and Alignment. - See whether all documents are related to MLLN available or not? - Voltage drop to be measured as usual Limit 1.0 V - Get purchase order and check hardware as per purchase order. - See cable laying and termination as per BSNL standard done or not? 5-2.2 Acceptance Testing - Physical verification test to be done as per schedule, actual A/T test starts from Post power on Test from Test no 1.0, V- Mux nodes creation test to last Test no.11 Messaging system test. All these tests commands/ steps are mentioned in test schedule and printout of circuit creation etc. can be taken out. In through test BER test is to be conducted between 64 Kbps/ 2 Mbps. circuits of different NTU s connected to different V-Mux for 60 minutes to be taken. For example DXC loop test, proceed as Node Editor- click nodes sub rack viewnew DXC- open Router window- click circuit-add- PDH 1/0 PP add cct windowtype name as AT TEST slave no as S1 add select node as new DXC 544-1 st node-cnds (Center Node Data Server)-view sub rack close window-next node- CNDS-click on required slave double click, color changes, close.-bind MUAP(Multi User Access Point)-Edit, Auto bind, Edit, save all. 5-2.3 ROT Test: - ROT test also to be carried out when MLLN is first time installed at a station. It includes physical verification and basic level tests, Start up, and shut down test all the tests no. 1 to 5 proceed as per steps given in tests schedule which are very clear for acceptance testing. N.B. Please see Trunk creation in DXC, DXC sub rack and loop test on ROT in Fig. 5-5,5-6, & 5-7 respectively. 130
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