Understanding Frame Relay

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Understanding Frame Relay
Frame Relay Presentation by Jeff K. Esquibel
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Presentation Overview

• Frame Relay Benefits
• Frame Relay Components
• Understanding Frame Relay Services
• Competing Technologies
• Frame Relays Market Success
• Future Competition
• Frame Relay Vs. ATM
• Frame Relay Vs. IP
• Co-Existence
• Frame Relays Continued Success

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Benefits of Frame Relay

• Savings over Private Lines
• Reduces number of dedicated devices which reduces
  equipment costs
• Reduces complexity for network managers
• Greater Bandwidth Flexibility than Private Lines
• Higher Reliability and Resiliency than Private
  Lines
• Lower Cost of Ownership and Better Bandwidth
  Utilization
• Growth of Branch Office Networks

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Benefits of Frame Relay (contd)

• Consolidation of LAN, SNA, On-net Voice, and/or
  Packetized Video
• Simplifies Network Architecture
• Reduces Operations and Administrative Costs
• Improves Application Performance and Network
  Efficiency
• Smooth migration to ATM
• Service and Network Interworking with ATM (FRF.5
  and FRF.8)

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Frame Relay Basics Terms And Definitions

• User to Network Interface (UNI)
• Specifies signaling and management functions
  between a frame relay network device and the end
  users device
• Network to Network Interface (NNI)
• Specifies signaling and management functions
  between two frame relay networks
• Virtual Circuit (VC)
• The connection between two frame relay ports
• Permanent Virtual Circuit (PVC)
• A pre-defined VC
• Switched Virtual Circuit (SVC)
• A VC that is established dynamically
• Data Link Connection Identifier (DLCI)
• Virtual Circuit Identification Number

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Differences between PVCs And SVCs

• PVCs
• Staticly Defined at Configuration, Unless PVC
  Parameters Need to be Modified
• Connection is Always Configured Whether There is
  Information to Send or Not

• SVCs
• Dynamically Established When There is Information
  to Send (Call-by-Call Basis)
• Connection is Released When There is No More
  Information to Send

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Benefits Of SVCs

• Simplified Network Design, Particularly for Large
  and Highly Meshed Networks
• Scalable Network Design
• Provisioning N(N-1)/2 Connections Not Required
• Easier to Maintain and Manage
• Supports Any-to-AnyConnectivity

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Benefits Of SVCs

• Can Offer a More Cost-Effective Solution
• Pay Based on Usage Call Length, Bandwidth Used,
  Number of Frames Sent, Etc.
• Only Pay When Using the Network
• Offers a Migration Path to PVCs
• Locations Already Have Connectionsto the Frame
  Relay Network
• Can Easily Transition to PVCs as Traffic Volumes
  Increase

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How Does Frame Relay Work?
Frame Relay Structure
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Frame Relay Terms And Definitions (contd)

• Committed Information Rate (CIR)
• The bandwidth defined for a VC
• Bc Committed Burst
• Maximum number of committed bits to be
  transmitted over time interval
• Be Excess Burst
• Number of Excess bits that will be transmitted
  over time
• Tc Time interval
• Time measurement based how much bandwidth is
  available for data to burst on to the network

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Frame Relay Terms And Definitions (contd)

• FECN Forward Explicit Congestion Notification
• Bit set by the network node (FR Switch) that is
  experiencing congestion
• Sent in the direction of the receiver
  (destination)
• BECN Backward Explicit Congestion Notification
• Bit set by the network node that is experiencing
  congestion
• Sent in the direction of the sender (source)
• DE Discard Eligible bit
• Set by either the DTE (access device FRAD, router
  etc.) or the network nodes (switches)
• May be set selectively by some DTE devices
• May be set by network nodes in the event the user
  has exceeded CIR and the network is experiencing
  congestion

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Frame Relay Components
Frame Relay Network
NNI
UNI
Frame Relay Network
DCE
PVC
DTE
DTE
DCE
DCE
SVC
DCE
DTE
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Service Comparison
Private Lines (TDM)
Frame Relay
Engineer Network for Average Traffic
Needs CSU/DSU per Leased Line that can access
many remote sites Statistical Multiplexing and
Burst Capability Resiliency is Inherent in
Network
Engineer Network for Peak Traffic Needs CSU/DSU
per Leased Line per remote site Time Division
Multiplexing Resiliency is Not Inherent
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Networking for the New Millennium
Frame Relay
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Frame Relays Market Success - U.S.
9.6B
10.4B
10.9B
11.3B
11.8B
PL Revs
(in Ms)
Source Vertical Systems Group - 1997
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Frame Relays Market Success International
10.3B
12.2B
12.6B
13.1B
13.5B
PL Revs
(in Ms)
Source Vertical Systems Group - 1997
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Market Forecast by WAN Technology
Leased Lines
27.7B

Network Service Market Worldwide 1997 and 2000
Estimates
22.6B
Frame Relay
6.8B
3.9B
X.25
2.7B 2.6B
ATM
1.6B
SMDS
.242B
.128B .167B
Sources Vertical Systems Group 1997 and Data
Comm 1998 Forecast
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Frame Relay Complements Other Technologies
Technology
Application
LAN LAN SNA Data On-net Voice Data, On-net
Voice Packetized Video
FR, SMDS, ATM FR, ATM FR, ATM FR, ATM
Agreement
Interworking
FR or ATM
FR - ATM FR - SMDS
FRF.5 and FRF.8 SIP
HQ
FR or ATM
Regional Sites
Dedicated or Dial FR
Remote Sites
Dial Remote Access or Dial FR
Mobile Workers Telecommuters
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Technology Comparison
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The Competitive Road Ahead

• ATM / Frame Relay Battle Joined By IP
• Deployment of VPDNs (i.e. Intra/Extranets) Power
  IP adoption for Businesses
• Majority of End Users Migrating Private Line
  Networks Will Look to Frame Relay and IP
• Legacy Applications Demanding Frame Relay
  Performance New Applications a Result of IP
  Features and Benefits
• Frame Relay at the Edge, ATM at the Core
• Frame Relay Transport for IP Services

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High Speed IP Environments

• Solutions/Technologies Outside Frame Relays
  Intended Scope are Servicing the Very High Speed
  IP Environments and Campus Backbone
• IP Over SONET Offers Users a Simple and Efficient
  High Speed Transport Option for IP at OC-3 and
  Greater Speeds
• Gigabit Ethernet Delivers the Mass Bandwidth Many
  Campus Backbones Operating in a Pure Data
  Environment Require

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Co-Existence

• Even as Buying Decisions Move Away from
  Underlying Connectivity, Frame Relay will
  Continue to Play a Major Role In Service Delivery

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Summary

• Frame Relay is Widely Accepted and Deployed,
  Building Upon its Own Momentum
• Frame Relays Longevity and Visibility as a
  Technology is Fostered by its Ability to Co-exist
  and Complement Legacy as well as Emerging
  Technologies
• Standards Continue to Evolve to Meet Changing End
  User Environments and Requirements
• Frame Relay Will Continue to Play an Integral
  Part in Layer 2 Connectivity
• Accelerated Growth in Frame Relay Implementations
  is Expected to Continue
• Market Maturity of ATM and IP Still Years Away

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Frame Relay Reference Material

• Frame Relay Forum Web page www.frforum.com
• Data Communications Magazine www.datacomm.com
• Network World www.nwfusion.com
• Internet Week (formerly CommWeek)
  www.internetwk.com
• Black, Uyless. Frame Relay Networks
  Specifications and Implementations. 2nd ed. New
  York McGraw-Hill, 1996.
• Smith, Philip. Frame Relay Principles and
  Applications Wokingham, England Addison-Wesley,
  1995.

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Questions?

• If not, you applause is greatly appreciated!!!