Broadband Network By 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 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 LAN Switch Core router GigE & FE FE 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 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

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