ZyXEL SBG3300-NB00 User Guide - Page 143

Encapsulation, IP over Ethernet, PPP over ATM PPPoA, PPP over Ethernet PPPoE, ATM Traffic Classes

Page 143 highlights

Chapter 6 Broadband Encapsulation Be sure to use the encapsulation method required by your ISP. The Device can work in bridge mode or routing mode. When the Device is in routing mode, it supports the following methods. IP over Ethernet IP over Ethernet (IPoE) is an alternative to PPPoE. IP packets are being delivered across an Ethernet network, without using PPP encapsulation. They are routed between the Ethernet interface and the WAN interface and then formatted so that they can be understood in a bridged environment. For instance, it encapsulates routed Ethernet frames into bridged Ethernet cells. PPP over ATM (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 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. PPP over Ethernet (PPPoE) Point-to-Point Protocol over Ethernet (PPPoE) provides access control and billing functionality in a manner similar to dial-up services using PPP. PPPoE is an IETF standard (RFC 2516) specifying how a personal computer (PC) interacts with a broadband modem (DSL, cable, wireless, etc.) connection. For the service provider, PPPoE offers an access and authentication method that works with existing access control systems (for example RADIUS). One of the benefits of PPPoE is the ability to let you access one of multiple network services, a function known as dynamic service selection. This enables the service provider to easily create and offer new IP services for individuals. Operationally, PPPoE saves significant effort for both you and the ISP or carrier, as it requires no specific configuration of the broadband modem at the customer site. By implementing PPPoE directly on the Device (rather than individual computers), the computers on the LAN do not need PPPoE software installed, since the Device does that part of the task. Furthermore, with NAT, all of the LANs' computers will have access. ATM Traffic Classes These are the basic ATM traffic classes defined by the ATM Forum Traffic Management 4.0 Specification. Constant Bit Rate (CBR) Constant Bit Rate (CBR) provides fixed bandwidth that is always available even if no data is being sent. CBR traffic is generally time-sensitive (doesn't tolerate delay). CBR is used for connections that continuously require a specific amount of bandwidth. A PCR is specified and if traffic exceeds this rate, cells may be dropped. Examples of connections that need CBR would be high-resolution video and voice. SBG3300-N Series User's Guide 143

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Chapter 6 Broadband
SBG3300-N Series User’s Guide
143
Encapsulation
Be sure to use the encapsulation method required by your ISP. The Device can work in bridge mode
or routing mode. When the Device is in routing mode, it supports the following methods.
IP over Ethernet
IP over Ethernet (IPoE) is an alternative to PPPoE. IP packets are being delivered across an
Ethernet network, without using PPP encapsulation. They are routed between the Ethernet interface
and the WAN interface and then formatted so that they can be understood in a bridged
environment. For instance, it encapsulates routed Ethernet frames into bridged Ethernet cells.
PPP over ATM (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 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.
PPP over Ethernet (PPPoE)
Point-to-Point Protocol over Ethernet (PPPoE) provides access control and billing functionality in a
manner similar to dial-up services using PPP. PPPoE is an IETF standard (RFC 2516) specifying how
a personal computer (PC) interacts with a broadband modem (DSL, cable, wireless, etc.)
connection.
For the service provider, PPPoE offers an access and authentication method that works with existing
access control systems (for example RADIUS).
One of the benefits of PPPoE is the ability to let you access one of multiple network services, a
function known as dynamic service selection. This enables the service provider to easily create and
offer new IP services for individuals.
Operationally, PPPoE saves significant effort for both you and the ISP or carrier, as it requires no
specific configuration of the broadband modem at the customer site.
By implementing PPPoE directly on the Device (rather than individual computers), the computers on
the LAN do not need PPPoE software installed, since the Device does that part of the task.
Furthermore, with NAT, all of the LANs’ computers will have access.
ATM Traffic Classes
These are the basic ATM traffic classes defined by the ATM Forum Traffic Management 4.0
Specification.
Constant Bit Rate (CBR)
Constant Bit Rate (CBR) provides fixed bandwidth that is always available even if no data is being
sent. CBR traffic is generally time-sensitive (doesn't tolerate delay). CBR is used for connections
that continuously require a specific amount of bandwidth. A PCR is specified and if traffic exceeds
this rate, cells may be dropped. Examples of connections that need CBR would be high-resolution
video and voice.