Broadband Network

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• Broadband Network
• By
• Lav Gupta, BSNL

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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

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Broadband Deployment of BSNL

• BSNLs state-of-theart broadband deployment has
  three parts
• Broadband access network
• Broadband backbone network
• Operations Support System

OSS
backbone
access
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Broadband Access Network
OSS
backbone
access
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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.

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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

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Broadband access architecture


Backbone

Core



router


FE


SSSS



GigE
FE
Broadband

RAS





Content


GigE
BB

Server

GigE


FE
FE


Layer 2
SDH RING


GigE
Aggregation


SW
B city
B city

GigE


LAN Switch
GigE FE

FE


FE
FE



GE


48 Port
24 Port


DSLAM
DSLAM


480 Port
240 Port


120 Port
64 Port


DSLAM
DSLAM
DSLAM
DSLAM



ADSL
ADSL



ADSL

ADSL terminals
terminals
terminals
terminals
Access
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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

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Management of the access network

• SSSS gives portal for service registration,
  automated provisioning, personalization
• Periodic and Interim accounting records
  generation is supported

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Broadband Backbone Network
OSS
backbone
access
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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

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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

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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

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• Inter-ISP operability of VPNs.
• Capability to allow excess of committed bandwidth
  for Customers during non-congested periods.
• Support for multicast traffic

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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

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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

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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

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Back to the backbone

• The backbone network consists of the following
  two layers
• Layer 1 The Core network
• Layer 2 The Edge network

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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

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The core network
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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

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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.

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Other routers

• Other routers required to completer backbone
  functionality
• International Gateway routers
• Internet exchange routers
• IDC routers

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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

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• 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)

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A conceptual view of management framework
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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