Broadband Components Customer Premises EquipmentCPE Digital Subscriber Line

Broadband Components • Customer Premises Equipment(CPE) • Digital Subscriber Line Access Multiplexer (DSLAM) • LAN Switches: for aggregating DSLAM • Broadband Remote Access Server (BRAS) • RADIUS and LDAP (SSSC) • Provisioning System 10/31/2021 1

Requirement at Customer End • BSNL’s BFone • Computer of minimum configuration, with 10/100 Mbps Ethernet Card • DSL Modem + Splitter • PPPo. E software to be loaded in the Client • Broadband Account (Username and Password) 10/31/2021 2

Brief Functions of DSL Components • DSL CPEs: At customer premises. On one end it connects telephone cable coming from exchange via splitter. At the other end, it connects to PC through Ethernet / USB Port. • DSLAM: called as DSL Access Multiplexer. It has a built in splitter which splits voice and data. While voice follows the normal conventional path through exchange, data is aggregated and up linked through Ethernet Port (Gigabit Ethernet for 480 port and Fast Ethernet for lower DSLAM) • LAN Switch: For aggregating multiple DSLAM and providing a common uplink to the core 10/31/2021 3

CPE 10/31/2021 4

Customer Premises Installation Line RJ 11 Splitter RJ 11 Line ADSL RJ 11 RJ 11 RJ 45 Single User with Voice, Data and Video Single User with Voice and Data Line Splitter RJ 11 ADSL RJ 45 STB AV Port ADSL RJ 45 Switch Multi user Business 10/31/2021 Customer 5

How to connect Multiple Telephones (1) Phone Socket (2)&(3) Phone 10/31/2021 (4) , (6) & (7) RJ-11 Tel cable (5) Splitter (8) Phone Jack 6

Functions of A POTS Splitter DSL o highpass filter Splitter o Separates the 300 Hz to 3500 Hz voice channel from upstream and downstream channels o Reduces traffic congestion o Pass voice, dial tone, ringing and on/off hook signals o Consists of a lowpass filter (LPF) for POTS and a highpass filter (HPF) for upstream/downstream channels o Passive device o Contains lighting protection circuitry 10/31/2021 LINE lowpass filter TELE 7

CPE Installation • CPE(ADSL MODEM) can be utilized in two different ways – 1. Transparent Bridge – In this mode we need to configure PPPo. E in the customer’s PC and modem simply passes ethernet frames from one side to other side in transparent fashion. Customer’s PC authenticates itself with BRAS – 2. Router Mode- In this mode PPPo. E is configured in modem. Modem authenticates itself to BRAS and gets IP address. Modem provides different address from its DHCP server to PC. Modem also performs the NAT function in this mode. 10/31/2021 8

CPE Installation Bridge Mode IP Address is allocated to PC By BRAS CPE DSLAM T 2 Switch T 1 Switch BRAS PPPo. E Session Router Mode IP Address is allocated to CPE By BRAS CPE IP Address is allocated to PC By CPE 10/31/2021 NAT DSLAM T 2 Switch T 1 Switch BRAS PPPo. E Session 9

Multi User Customer Router Mode NAT CPE Switch Multi User Customer IP Address is allocated to PCs By CPE 10/31/2021 DSLAM T 2 Switch T 1 Switch BRAS PPPo. E Session In this mode PPPo. E is configured on CPE and only One session is established between CPE and BRAS. CPE gets IP Address from BRAS. DHCP in CPE Allocates IP addresses to machines. In this case all The machines share the bandwidth allowed for that Account. CPE has to do NAT also. 11

DSLAM 10/31/2021 12

DSLAM: Functions • Houses a set of ATU-C interfaces. • Multiplex traffic from multiple ATU-Cs on to a single, high speed link to the transport network. • Demultiplex traffic from the transport network and assigns it to the correct ATU-C • Negotiate line speed. • Splits the voice and data coming through ADSL line. 10/31/2021 13

DSLAM Ø DSLAM is an integrated hardware and software system that allows the user to access Broadband services as well as originate and terminate telephone calls over the same single pair of copper wires 10/31/2021 14

DSLAM Ø DSLAM aggregates the subscriber lines Ø DSLAM separates Voice and Data of the Subscriber Ø Voice is given to the exchange switch Ø Data is fed to the IP Network through the LAN Switch Ø DSLAMs have been categorized in to 6 types based on no. of ports (480, 240, 120, 64, 32 & 16) provided and planned for deployment based on the expected demand 10/31/2021 15

DSLAM Two types of DSLAMs have been proposed to address BSNL requirement. Ø SMARTAX MA 5300 IP DSLAM –Large Capacity (480, 240, 120 Ports) - Deployed in A 1, A 2, A 3, A 4, B 1, B 2 Cities Ø SMARTAX MA 5105 IP DSLAM –Small Capacity (64, 32, 16 Ports) - 64 Ports deployed in A 1, A 2, A 3, A 4, B 1, B 2 Cities - 10/31/2021 32 & 16 Ports Deployed in Other Cities 16

Rear view of the M 5105 10/31/2021 17

Subtending connection of the MA 5105 FE (100 BASE-TX) ports 10/31/2021 18

Tier 1 and Tier 2 LAN switches 10/31/2021 19

LAN SWITCH Ø LAN Switches provide Gigabit Ethernet ( GE ) interfaces and Fast Ethernet ( FE ) interfaces for connecting internetworking elements such as BRAS, DSLAMS etc. , Ø Tier 1 switches are Gigabit Ethernet Aggregation switches to which B-RAS and Tier 2 LAN switches are connected through GE / FE interfaces Ø All DSLAMs are aggregated to Tier 2 switches through FE interfaces except 480 ports DSLAMs are aggregated through GE interfaces 10/31/2021 20

Interfaces • • • Gigabit Ethernet – optical Fast Ethernet – Optical Fast Ethernet – Electrical Ethernet – Optical Ethernet – Electrical • Optical Interface Types – LX – 40 Km range – Available for Tier I to Tier II – SX – 10 Km range – Available for Tier II to DSLAM 10/31/2021 21

Distance Limitations • Tier I to Tier II – Dark Fiber – 40 Km – SDH Transport – Any distance • Tier I / II LAN Switch to DSLAM – Dark Fiber – 10 Km – SDH Transport – Any Distance 10/31/2021 22

Functions of TIER I and TIER II switches. • It act as an interface between DSLAM and BRAS. • Management of statistical data. • Fast forwarding and control of data packets. • Capable of unblocked switching. • Monitoring and fault diagnosis. • Managing and calculating the route. 10/31/2021 23

BRAS (Broad band Remote Access Server) 10/31/2021 24

Functions of BRAS • • Supports termination of DSL customers. Allottment of IP address to customer Bandwidth control using rate limiting Act as an edge router for terminating VPN traffic. • Protocols: OSPF, BGP, MP-BGP and LDP • Supports Lawful interception and monitoring • AAA function 10/31/2021 25

SSSS (Subscriber Service Selection System. ) n n n Selection of various range of service. This provides on demand service without manual intervention www. dataone. in 10/31/2021 26

RADIUS n This in conjunction with BRAS n AAA function 10/31/2021 27

LDAP (Light Weight Directory Access Protocol Server) n It stores customer database viz username, password and the default services that it can subscribe to. 10/31/2021 28

BRAS Architecture • Deployed at the edge of the NIB-II network • Installed in all the A sites (except Mumbai). Total 23 • Capacity of 8 Gbps (in A 1 sites) and 4 Gbps (in other A sites) • Can handle 480000 concurrent sessions (A 1 sites) 10/31/2021 29

Brief Functions of DSL Components…contd. Provisioning: This is the most critical components for ensuring quick delivery of service. It ensures endto-end provisioning of service right from DSL CPEs to DSLAM to Switch to BRAS to LDAP n 10/31/2021 30

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