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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

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Requirement at Customer End

• BSNL’s BFone

• Computer of minimum configuration, with

10/100 Mbps Ethernet Card

• DSL Modem + Splitter

• PPPoE software to be loaded in the Client

• Broadband Account (Username and Password)

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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

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CPE

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Customer Premises Installation

Splitter ADSLRJ 11 RJ 11

RJ 11

RJ 11

RJ 45

Line

Single User with Voice and Data

Splitter ADSL

STB

RJ 11 RJ 11

RJ 11 RJ 45 RJ 45

RJ 45

AV Port

Single User with Voice, Data and Video

Line RJ 11

Splitter ADSL

Switch

Multi user BusinessCustomer

Line

RJ 11 RJ 11

RJ 11

RJ 45

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How to connect Multiple Telephones

(1) Phone Socket (2)&(3) Phone

(4) ,(6) & (7)

RJ-11 Tel cable

(5) Splitter

(8) Phone Jack

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highpassfilter

LINEDSL

lowpassfilter

TELE

Functions of A POTS Splitter

Splitter Separates the 300 Hz to 3500 Hz

voice channel from upstream and downstream channels

Reduces traffic congestion Pass voice, dial tone, ringing and

on/off hook signals Consists of a lowpass filter (LPF)

for POTS and a highpass filter (HPF) for upstream/downstream channels

Passive device Contains lighting protection

circuitry

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CPE Installation

• CPE(ADSL MODEM) can be utilized in two different ways– 1. Transparent Bridge – In this mode we need to

configure PPPoE 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 PPPoE 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.

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CPE Installation

BRASCPE

PPPoE Session

T2 SwitchT1 Switch

BRASCPE

PPPoE Session

T2 SwitchT1 Switch

Bridge Mode

DSLAM

IP Address is allocated to PC By BRAS

Router ModeIP Address is allocated to CPE

By BRAS

IP Address is allocated

to PC By CPE

NATDSLA

M

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Multi User Customer

BRASCPE

T2 SwitchT1 Switch

Router Mode

DSLAM

IP Address is allocated to PCs By CPE

Multi User Customer

In this mode PPPoE is configured on CPE and onlyOne session is established between CPE and BRAS.CPE gets IP Address from BRAS. DHCP in CPE Allocates IP addresses to machines. In this case allThe machines share the bandwidth allowed for thatAccount. CPE has to do NAT also.

Switch PPPoE Session

NAT

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DSLAM

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•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.

DSLAM: Functions

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DSLAM

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

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DSLAM DSLAM aggregates the subscriber lines

DSLAM separates Voice and Data of the Subscriber

Voice is given to the exchange switch

Data is fed to the IP Network through the LAN Switch

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

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DSLAM

Two types of DSLAMs have been proposed to address BSNL requirement.

SMARTAX MA5300 IP DSLAM

–Large Capacity (480,240,120 Ports)

- Deployed in A1, A2, A3, A4, B1, B2 Cities

SMARTAX MA5105 IP DSLAM

–Small Capacity (64,32,16 Ports)

- 64 Ports deployed in A1, A2, A3, A4, B1, B2 Cities

- 32 & 16 Ports Deployed in Other Cities

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Rear view of the M 5105

SLOT0 SLOT1

SLOT2Uplink board

DC -48V

© GService board

Service board

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MFCE/MFCS/MFCM

Uplink

Level 3MA5105

Level 1MA5105

Level 2MA5105

SupremeMA5105

Service boardService board

MFCE

Service boardService board

MFCE

Service boardService board

MFCE/MIFE

Service boardService board

Subtending connection of the MA5105 FE (100BASE-TX) ports

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Tier 1 and Tier 2 LAN switches

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LAN SWITCH

LAN Switches provide Gigabit Ethernet ( GE ) interfaces and Fast Ethernet ( FE ) interfaces for connecting internetworking elements such as BRAS, DSLAMS etc.,

Tier 1 switches are Gigabit Ethernet Aggregation switches to which B-RAS and Tier 2 LAN switches are connected through GE / FE interfaces

All DSLAMs are aggregated to Tier 2 switches through FE interfaces except 480 ports DSLAMs are aggregated through GE interfaces

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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

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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

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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.

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BRAS (Broad band Remote Access Server)

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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

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SSSS (Subscriber Service Selection System.)

Selection of various range of service.

This provides on demand service without manual intervention

www.dataone.in

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RADIUS

This in conjunction with BRAS

AAA function

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LDAP (Light Weight Directory Access Protocol Server)

It stores customer database viz username, password and the default services that it can subscribe to.

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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 A1 sites) and 4 Gbps (in other A sites)

• Can handle 480000 concurrent sessions (A1 sites)

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Brief Functions of DSL Components…contd.

Provisioning: This is the most critical components for ensuring quick delivery of service. It ensures end-to-end provisioning of service right from DSL CPEs to DSLAM to Switch to BRAS to LDAP

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END