Broadband NetworkBy

Lav Gupta, BSNL

Introduction

Operators need long-term revenue streams Must have convergent networks to offer voice,

data, and video services Must use right architecture and technologies Ethernet offers scalable, low-cost bandwidth IP provides the efficiency for viable video and

data services MPLS offers traffic engineering

Broadband Deployment of BSNL

BSNL’s state-of-the–art broadband deployment has three parts:• Broadband access network• Broadband backbone network• Operations Support System

backbone

OSS

access

Broadband Access Network

backbone

OSS

access

Features…

ITU-T 992.5 compliant ADSL 2+, High speed Internet connectivity

Primary source of Internet bandwidth for retail users for applications such as web browsing, e-Commerce, etc.

Provide multicast video services, video-on-demand, etc.

Provides customers option to select services through web server.

Features

Supports flexible time-based or volume-based billing

Support for both pre-paid and post paid broadband services

Connects broadband customers to the MPLS VPN set up

Broadband access architecture

BB

Broadband RAS

480 Port DSLAM

SDH RING Layer 2 Aggregation

SW

GigE

GigE

GigE

LAN Switch

Core router

GigE & FE

FE FE

FE

B city B city

120 Port DSLAM

48 Port DSLAM

ADSL

terminals ADSL terminals ADSL

terminals

FE

64 Port DSLAM

GE 240 Port DSLAM

ADSL terminals

GigE

FE

GigE

24 Port DSLAM

FE

• Content • Server

• SSSS FE

Backbone

Access

Management of the access network

Centralized provisioning and management from NOC

Redundant servers in clusters run eMS of DSLAM, LAN Switches, BRAS etc to provide FCAPS functionality

eMSs are integrated with NMS for network wide view

Management of the access network

SSSS gives portal for service registration, automated provisioning, personalization

Periodic and Interim accounting

records generation is supported

Broadband Backbone Network

backbone

OSS

access

Broadband backbone infrastructure

BSNL has established a multi-gigabit, Multiprotocol Label Switching (MPLS) IP Network in the form of a 2-layered centrally managed IP backbone network

A convergent network supporting data, voice and video applications

Provides peering interfaces to other Internet domains.

The network architecture will accommodate existing networks viz. NIB-I and MPLS VPN

Motivation

Fast and efficient routing of IP traffic generated anywhere in the country to any destination within or outside the country.

A common IP infrastructure for broadband triple play, narrowband Internet, Corporate VPNs, Class 4 PSTN IP switches, DLCs etc

Provide QoS guarantees and SLAs with measurements of service delivery, availability, latency, throughput and restoration times etc

Motivation

Scalability and flexibility for large scale deployment.

Managed services including security, encryption, firewalls and NAT

Management reports providing information on customer network configuration and changes, faults and achievement against the SLAs.

Allowing classes of customers, prioritization of different types of traffic from a single customer

Inter-ISP operability of VPNs. Capability to allow excess of committed

bandwidth for Customers during non-congested periods.

Support for multicast traffic

What is MPLS?

MPLS stands for “Multiprotocol Label Switching”

Incoming packets are assigned a “label” by a “label edge router (LER)”, packets are forwarded along a “label switch path (LSP)” where each “label switch router (LSR)” makes forwarding decisions based solely on the contents of the label

At each hop, the LSR strips off the existing label and applies a new label which tells the next hop how to forward the packet

What problems does MPLS solve?

Routers make faster forwarding decisions based on simple labels rather than complex route lookup based on destination IP address

IP lacks QoS features MPLS good for business-grade applications Traffic Engineering - the ability to set the path

traffic will take through the network, and the ability to set performance characteristics for a class of traffic

What problems MPLS solves?

Brings performance enhancements and service creation facilities

Packet payloads are not examined so multiple protocols can be carried

Can carry layer 2 services like Ethernet, SDH, ATM, FR etc

Packets travel circuit like fixed paths(VPN) VPNs - service providers can create IP tunnels throughout their network

Back to the backbone…

The backbone network consists of the following two layers:

• Layer 1: The Core network• Layer 2: The Edge network

The core network

High-speed packet forwarding between the core nodes spread all over the country

The Core network consists of powerful core routers connected with STM-16 links

Core routers in bigger cities are meshed Routers in other cities are dual homed to these to

provide redundancy and diversity

The core network

Backbone Core Network

2

4

3

1

Core Router

Route Reflector

Core Router

STM-16

STM-1

The edge network

The edge network forms the second layer of the backbone network and supports MPLS edge functionality

Edge routers are connected to the core through GigE or STM-1 links

Provides for aggregation of customer traffic, enforcement of QoS and administrative policies and gives managed access to the customers

The edge network

Provides customer access through (a) Dialup (b) Dedicated Access and (c) Broadband Access. The layer also provides connectivity to secure VPNs as well as to Internet Data Centers.

Other routers

Other routers required to completer backbone functionality

International Gateway routers Internet exchange routers IDC routers

Operations Support System

The network is managed centrally from NOC

Interface to the NMS back-office facility is provided behind Firewall security in the Internet Data Center

All customer provisioning is done from NOC

The Telecom Management Network Architecture for NIB-II is based on the five Layer TMN Model of the ITU(T)• Business Management Layer (BML)• Service Management Layer (SML)• Network Management Layer (NML)• Element Management Layer (EML), and• Network Element Layer (NEL)

A conceptual view of management framework

NMS/PMS

Core Network

MPLS VPN Network

Vendor specific or Standard Interface (SNMP,

CMISE, TL1)

Standard NMS-PMS /NEM

Interface (CORBA, SNMP)

Broadband Network

Narrowband Network

NIB I Network

Standard Interface

(Java, Corba,

XML API)

NEM of Eqpt A

NEM of Eqpt B

NEM of Eqpt C

NEM of Cisco Eqpt

NEM of Juniper / Dorado

EMS OSS/BSS

NetworkElement

Layer (NEL)

ElementManagement

Layer (EML)

Network ManagementLayer (NML)

Services offered & proposed

High speed Internet access Video-on-Demand, Time shifted video,

streaming video, tv broadcast Telemedicine & tele-education on demand

capabilities Interactive Gaming Voice over IP/Video Conferencing capabilities Data center facilities