ForeRunner
ATM Switch Network Configuration Manual
4 - 7
MPOA
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4.3 An Introduction to Multi-Protocol Over ATM
MPOA builds upon the foundation of LANE.
4.3.1 LANE Without MPOA
ATM networks co-exist with and support network applications which may not be ATM-
aware. Consequently, ATM protocols are needed to monitor legacy network protocol (IP, IPX,
Appletalk, etc.) packets and perform translation into ATM cells and circuits. This monitoring
and translation can be performed in one of the following ways:
•
in a host protocol stack after packet construction and before packet transmission
•
in a LAN-to-ATM edge device as packets move through the network
LANE is one example of such a protocol. It resolves datalink layer addresses into ATM
addresses and establishes circuits to the destination addresses. Network addresses within a
subnet can be learned using LANE’s broadcast support.
However, LANE relies on physical routers to deliver packets across subnets (see Figure 4.2).
Because routers must examine – and modify – every packet, ATM cells must be reassembled
into packets, modified, and re-segmented at every router hop. This process imposes significant
transmission delays between the source and destination of the network traffic.
Figure 4.2 -
LANE without MPOA
ATM Cloud
R outer
E LAN
engineering
E LAN
marketing
Summary of Contents for forerunner series
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Page 16: ...TOC 10 ForeRunner ATM Switch Network Configuration Manual Table of Contents ...
Page 20: ...LOF 4 ForeRunner ATM Switch Network Configuration Manual List of Figures ...
Page 22: ...LOT 2 ForeRunner ATM Switch Network Configuration Manual List of Tables ...
Page 30: ...viii ForeRunner ATM Switch Network Configuration Manual Preface ...
Page 144: ...3 58 ForeRunner ATM Switch Network Configuration Manual Configuring an Emulated LAN ...
Page 180: ...6 12 ForeRunner ATM Switch Network Configuration Manual ATM Forum PNNI ...
Page 220: ...9 6 ForeRunner ATM Switch Network Configuration Manual Configuring Timing ...
Page 300: ...D 24 ForeRunner ATM Switch Network Configuration Manual Configuring FramePlus Modules ...
Page 308: ...Acronyms 8 ForeRunner ATM Switch Network Configuration Manual Acronyms ...
Page 346: ...Glossary 38 ForeRunner ATM Switch Network Configuration Manual Glossary ...
Page 352: ...Index 6 ForeRunner ATM Switch Network Configuration Manual Index ...