User`s guide
Table Of Contents
- VMG8924-B10A and VMG8924- B30A Series
- User’s Guide
- Technical Reference
- Network Map and Status Screens
- Broadband
- Wireless
- Home Networking
- 7.1 Overview
- 7.2 The LAN Setup Screen
- 7.3 The Static DHCP Screen
- 7.4 The UPnP Screen
- 7.5 Installing UPnP in Windows Example
- 7.6 Using UPnP in Windows XP Example
- 7.7 The Additional Subnet Screen
- 7.8 The STB Vendor ID Screen
- 7.9 The 5th Ethernet Port Screen
- 7.10 The LAN VLAN Screen
- 7.11 The Wake on LAN Screen
- 7.12 Technical Reference
- Routing
- Quality of Service (QoS)
- Network Address Translation (NAT)
- Dynamic DNS Setup
- Interface Group
- USB Service
- Power Management
- Firewall
- MAC Filter
- Parental Control
- Scheduler Rule
- Certificates
- VPN
- Voice
- Log
- Traffic Status
- VoIP Status
- ARP Table
- Routing Table
- IGMP/MLD Status
- xDSL Statistics
- 3G Statistics
- User Account
- Remote Management
- TR-069 Client
- TR-064
- SNMP
- Time Settings
- E-mail Notification
- Logs Setting
- Firmware Upgrade
- Configuration
- Diagnostic
- Troubleshooting
- Customer Support
- Setting up Your Computer’s IP Address
- IP Addresses and Subnetting
- Pop-up Windows, JavaScripts and Java Permissions
- Wireless LANs
- IPv6
- Services
- Legal Information
- Index

Chapter 5 Broadband
VMG8924-B10A and VMG8924-B30A Series User’s Guide
67
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.
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 RFC 1483 for more detailed
information.
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.
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.
LLC-based Multiplexing