Chapter 5 WAN Setup
P-660HW-Dx v2 User’s Guide
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5.1.1.3 PPPoA
PPPoA stands for Point to Point Protocol over ATM Adaptation Layer 5 (AAL5). A PPPoA
connection functions like a dial-up Internet connection. The ZyXEL Device encapsulates the
PPP session based on RFC1483 and sends it through an ATM PVC (Permanent Virtual
Circuit) to the Internet Service Provider’s (ISP) DSLAM (digital access multiplexer). Please
refer to RFC 2364 for more information on PPPoA. Refer to RFC 1661 for more information
on PPP.
5.1.1.4 RFC 1483
RFC 1483 describes two methods for Multiprotocol Encapsulation over ATM Adaptation
Layer 5 (AAL5). The first method allows multiplexing of multiple protocols over a single
ATM virtual circuit (LLC-based multiplexing) and the second method assumes that each
protocol is carried over a separate ATM virtual circuit (VC-based multiplexing). Please refer
to the RFC for more detailed information.
5.1.2 Multiplexing
There are two conventions to identify what protocols the virtual circuit (VC) is carrying. Be
sure to use the multiplexing method required by your ISP.
5.1.2.1 VC-based Multiplexing
In this case, by prior mutual agreement, each protocol is assigned to a specific virtual circuit;
for example, VC1 carries IP, etc. VC-based multiplexing may be dominant in environments
where dynamic creation of large numbers of ATM VCs is fast and economical.
5.1.2.2 LLC-based Multiplexing
In this case one VC carries multiple protocols with protocol identifying information being
contained in each packet header. Despite the extra bandwidth and processing overhead, this
method may be advantageous if it is not practical to have a separate VC for each carried
protocol, for example, if charging heavily depends on the number of simultaneous VCs.
5.1.3 Encapsulation and Multiplexing Scenarios
For Internet access you should use the encapsulation and multiplexing methods used by your
ISP. Consult your telephone company for information on encapsulation and multiplexing
methods for LAN-to-LAN applications, for example between a branch office and corporate
headquarters. There must be prior agreement on encapsulation and multiplexing methods
because they cannot be automatically determined. What method(s) you use also depends on
how many VCs you have and how many different network protocols you need. The extra
overhead that ENET ENCAP encapsulation entails makes it a poor choice in a LAN-to-LAN
application. Here are some examples of more suitable combinations in such an application.
5.1.3.1 Scenario 1: One VC, Multiple Protocols
PPPoA
(RFC-2364) encapsulation with
VC-based
multiplexing is the best combination
because no extra protocol identifying headers are needed. The
PPP
protocol already contains
this information.
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Страница 7: ...Safety Warnings P 660HW Dx v2 User s Guide 7...
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Страница 10: ...Contents Overview P 660HW Dx v2 User s Guide 10...
Страница 19: ...Table of Contents P 660HW Dx v2 User s Guide 19 Index 351...
Страница 20: ...Table of Contents P 660HW Dx v2 User s Guide 20...
Страница 26: ...List of Figures P 660HW Dx v2 User s Guide 26...
Страница 31: ...31 PART I Introduction Introducing the ZyXEL Device 33 Introducing the Web Configurator 39...
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Страница 51: ...51 PART II Wizards Wizard Setup for Internet Access 53 Bandwidth Management Wizard 67...
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Страница 66: ...Chapter 3 Wizard Setup for Internet Access P 660HW Dx v2 User s Guide 66...
Страница 72: ...Chapter 4 Bandwidth Management Wizard P 660HW Dx v2 User s Guide 72...
Страница 73: ...73 PART III Network WAN Setup 75 LAN Setup 93 Wireless LAN 105 Network Address Translation NAT Screens 129...
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Страница 92: ...Chapter 5 WAN Setup P 660HW Dx v2 User s Guide 92...
Страница 128: ...Chapter 7 Wireless LAN P 660HW Dx v2 User s Guide 128...
Страница 141: ...141 PART IV Security Firewalls 143 Firewall Configuration 155 Content Filtering 177 Certificates 145...
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Страница 162: ...Chapter 10 Firewall Configuration P 660HW Dx v2 User s Guide 162 Figure 92 Firewall Edit Rule...
Страница 176: ...Chapter 10 Firewall Configuration P 660HW Dx v2 User s Guide 176...
Страница 180: ...Chapter 11 Content Filtering P 660HW Dx v2 User s Guide 180...
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Страница 186: ...Chapter 12 Static Route P 660HW Dx v2 User s Guide 186...
Страница 202: ...Chapter 14 Dynamic DNS Setup P 660HW Dx v2 User s Guide 202...
Страница 224: ...Chapter 16 Universal Plug and Play UPnP P 660HW Dx v2 User s Guide 224...
Страница 225: ...225 PART VI Maintenance and Troubleshooting System 227 Logs 233 Tools 251 Diagnostic 257 Troubleshooting 259...
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Страница 232: ...Chapter 17 System P 660HW Dx v2 User s Guide 232...
Страница 250: ...Chapter 18 Logs P 660HW Dx v2 User s Guide 250...
Страница 256: ...Chapter 19 Tools P 660HW Dx v2 User s Guide 256...
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Страница 332: ...Appendix F Internal SPTGEN P 660HW Dx v2 User s Guide 332...
Страница 346: ...Appendix J Legal Information P 660HW Dx v2 User s Guide 346...
Страница 358: ...Index P 660HW Dx v2 User s Guide 358...