Chapter 5 WAN Setup
P-660H-Tx 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.
Содержание P-660H-T1 v2
Страница 1: ...www zyxel com P 660H Tx v2 ADSL 2 4 port Gateway User s Guide Version 3 40 2 2007 Edition 1...
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Страница 7: ...Safety Warnings P 660H Tx v2 User s Guide 7...
Страница 8: ...Safety Warnings P 660H Tx v2 User s Guide 8...
Страница 10: ...Contents Overview P 660H Tx v2 User s Guide 10...
Страница 24: ...List of Figures P 660H Tx v2 User s Guide 24...
Страница 28: ...List of Tables P 660H Tx v2 User s Guide 28 Table 125 NetBIOS Filter Default Settings 296...
Страница 29: ...29 PART I Introduction Introducing the ZyXEL Device 31 Introducing the Web Configurator 37...
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Страница 36: ...Chapter 1 Introducing the ZyXEL Device P 660H Tx v2 User s Guide 36...
Страница 49: ...49 PART II Wizards Wizard Setup for Internet Access 51 Bandwidth Management Wizard 59...
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Страница 58: ...Chapter 3 Wizard Setup for Internet Access P 660H Tx v2 User s Guide 58 Figure 27 Connection Test Failed 2...
Страница 64: ...Chapter 4 Bandwidth Management Wizard P 660H Tx v2 User s Guide 64...
Страница 65: ...65 PART III Network WAN Setup 67 LAN Setup 85 Network Address Translation NAT Screens 97...
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Страница 84: ...Chapter 5 WAN Setup P 660H Tx v2 User s Guide 84...
Страница 109: ...109 PART IV Security Firewalls 111 Firewall Configuration 123 Content Filtering 145...
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Страница 130: ...Chapter 9 Firewall Configuration P 660H Tx v2 User s Guide 130 Figure 65 Firewall Edit Rule...
Страница 144: ...Chapter 9 Firewall Configuration P 660H Tx v2 User s Guide 144...
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Страница 154: ...Chapter 11 Static Route P 660H Tx v2 User s Guide 154...
Страница 168: ...Chapter 13 Dynamic DNS Setup P 660H Tx v2 User s Guide 168...
Страница 180: ...Chapter 14 Remote Management Configuration P 660H Tx v2 User s Guide 180...
Страница 192: ...Chapter 15 Universal Plug and Play UPnP P 660H Tx v2 User s Guide 192...
Страница 193: ...193 PART VI Maintenance and Troubleshooting System 195 Tools 201 Diagnostic 207 Logs 209 Troubleshooting 227...
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Страница 200: ...Chapter 16 System P 660H Tx v2 User s Guide 200...
Страница 206: ...Chapter 17 Tools P 660H Tx v2 User s Guide 206...
Страница 226: ...Chapter 19 Logs P 660H Tx v2 User s Guide 226...
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Страница 239: ...Appendix A Product Specifications P 660H Tx v2 User s Guide 239...
Страница 240: ...Appendix A Product Specifications P 660H Tx v2 User s Guide 240...
Страница 256: ...Appendix B Internal SPTGEN P 660H Tx v2 User s Guide 256...
Страница 302: ...Appendix I Legal Information P 660H Tx v2 User s Guide 302...