Module I. Origins of Frame Relay- Purpose and Application
The role of the Frame Relay Forum and Implementation Agreements is explained. We also discover how Frame Relay transfers data, how it differs from X.25 and how network congestion is handled.
Background to Frame Relay
Frame Relay Standards and the role of the Frame Relay Forum - Overview of Implementation Agreements
Frame Relay and X.25
C and U Plane concepts
PVCs and SVCs and their use
The Frame Relay Frame structure - Multiplexing and the Link Layer Address structure - Congestion Indicators (FECN and BECN) - Discard Eligibility (DE)
Basic switching functions
Traffic contracts and parameters - Committed Information Rate (CIR), Committed Burst size (Bc), Excess Burst Size (Be) and measurement time interval.
Congestion Control and Management
Module II. User-to-Network and Network-to-Network Interfaces
The majority of Frame Relay service offerings are based on PVCs. In this section we investigate how the user-to-network interface is managed for PVCs. Carriers in the USA and Europe are now beginning to deploy SVCs. We then extend the discussion to see how SVCs might be useful and how they are supported.
Physical Interfaces - From X.21 to SDH/SONET
PVC management procedures - Management messages - Adding and Deleting PVCs - Limitations of polling procedures and possible solutions - Alternative event driven PVC management procedures
Switched Virtual Circuits (SVCs) - Numbering scheme - Call Control signalling Call set-up and tear-down - Supporting PVCs using SVCs
Module III. High Speed Frame Relay and ATM to Frame Relay Interworking
The ability of ATM to operate at very high speeds and to carry a wide range of traffic types has given it an important role as a trunk or backbone technology. Many of todays Frame Relay services are supported by an ATM network. We will see how this is achieved. Furthermore, as end users require higher speeds there may be a choice between high speed Frame Relay and a migration to ATM service interworking. The benefits of each approach are explained.
How fast can Frame Relay go?
Multilink Frame Relay (combining several virtual connections)
When does High Speed Frame Relay make sense?
Clarifying the role of Frame-based ATM solutions - The Frame-based User to Network Interface (FUNI) - The Frame-based Network to Network Interface (FB-NNI)
When does interworking make sense?
Using ATM as a backbone technology carrying Frame Relay traffic - Frame Relay to ATM Network Interworking
Complete service interworking between Frame Relay and ATM - Service interworking using PVCs - Service interworking using SVCs
Module IX. Handling Real-World and Time Sensitive Traffic
Although Frame Relay was originally aimed at carrying data traffic, it is quite capable of carrying time sensitive traffic including voice and video. Various enhancements have improved the way that time critical traffic can be handled by Frame Relay. They are explained. Frame Relay is also used extensively to carry a wide range of legacy protocols we shall see how this is achieved.
Transporting multiple user protocols and Multiprotocol Encapsulation
Using Service Classes and Prioritisation to achieve QOS
ITU-T Service Classes - Prioritisation by the network - Prioritisation by the CPE
The use of Fragmentation procedures - End-to end fragmentation - Fragmentation across the UNI/NNI
Frame Relay and SNA traffic
Frame Relay over satellite links
Module X. Voice and Video over Frame Relay
There are definite trends towards carrying voice traffic over packet networks. In this section we will examine how Frame Relay can be used to carry voice traffic. We will also consider how Frame Relay can be used to carry video traffic e.g. for videoconferencing.
Voice over Frame Relay (VoFR) - Service description - Encoding voice and the issue of voice quality - Primary Payloads and Signaled Payloads - Multiplexing voice and data - Frame Formats - Frame Relay Forum conformance classes for Voice transfer - Fax relay
Video over Frame Relay - Example based on currently available CPE
Module XI. Defining and Measuring Service Levels
Service Level Agreements (SLAs) are an important element in the procurement and operation of Frame Relay networks. In this part, we examine how service levels are defined and how these definitions provide a common basis for measurements and SLAs.
Service Level Definitions (SLD) - What are SLDs? - The reference model and measurement reference points - Measurement Parameters
Frame Relay Operations Administration and Maintenance (OAM) - Defining an OAM protocol
Module XII. Synergies Frame Relay, IP and ATM - new developments
Connectionless services using IP are striving to achieve a measure of Quality of Service. The different approaches are explained. Other developments seek to integrate the world of IP with underlying layer 2 technologies such as Frame Relay and ATM. These developments and their implications are discussed.
Approaches to QOS - RSVP - Diffserv - The role of SVCs: Frame Transfer Priorities - Using ATMs PNNI routing - Multiprotocol Label Switching (MPLS)
Frame Relay and MPLS
Multiprotocol over ATM (MPOA) - Using the MPOA architecture with Frame Relay
Module XIII. Further Aspects of Frame Relay
This section introduces and explains features that provide added value to Frame Relay solutions.
Frame Relay Multicast
Data Compression over Frame Relay
Frame Relay Encryption