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114056 Rev. A
Things to Remember .........................................................................................1-7
Selecting Protocols ............................................................................................1-8
Adding PVCs ............................................................................................................1-8
Where to Go Next ...........................................................................................................1-9
Chapter 2
Understanding ATM Concepts
ATM General Information ................................................................................................2-1
ATM Cells .................................................................................................................2-1
Cell Headers ......................................................................................................2-2
The Cell Information Field .................................................................................2-3
Data Transmission ....................................................................................................2-3
Permanent and Switched Virtual Connections .........................................................2-5
Physical Layer ................................................................................................................2-5
ATM Layer .......................................................................................................................2-6
ATM Adaptation Layer (AAL5) ........................................................................................2-7
Service Records and Virtual Circuits ..............................................................................2-8
Data Encapsulation ........................................................................................................2-9
Encapsulation Methods ............................................................................................2-9
LANE .................................................................................................................2-9
LLC/SNAP Encapsulation ..................................................................................2-9
NULL Encapsulation ........................................................................................2-10
NLPID Encapsulation ......................................................................................2-10
Selecting a Data Encapsulation Method ................................................................2-10
LLC/SNAP Encapsulation ................................................................................2-11
NULL Encapsulation (VC-Based Multiplexing) ................................................2-11
Encapsulation Rules for PVCs ...............................................................................2-12
PVC Access Methods ...................................................................................................2-13
Multiple PVCs .........................................................................................................2-13
One PVC ................................................................................................................2-14
Hybrid Access ........................................................................................................2-15
Using Hybrid PVCs for Transparent Bridging .........................................................2-16
SVC Access Methods ...................................................................................................2-18
ATM Traffic Parameters .................................................................................................2-18
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