ZyXEL Communications ALC1248G, User Manual

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Chapter 1 Introducing the ALC1248G
ALC1248G User’s Guide
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System Error Logging
The system error log will record error logs locally to the management switch card memory.
Remote Firmware Upgrade
You can use FTP or SFTP to perform configuration backup/restore and firmware upgrade
from a remote location.
Anti-IP Address Spoofing
With DHCP snooping, the ALC records which IP addresses are assigned on each port. The
ALC drops packets from a device using a different IP address.
Anti-MAC Address Spoofing
The ALC checks to make sure the MAC addresses of the devices connected to the DSL ports
are not the same as MAC addresses of devices connected to the Ethernet network. This
protects the network from disruptions of service caused by subscriber devices spoofing the
MAC address of ISP servers.
Multiple PVC and ATM QoS
The ALC allows you to use different channels (also called Permanent Virtual Circuits or
PVCs) for different services or subscribers. Define channels on each DSL port for different
services or levels of service and assign each channel a priority. ATM Quality of Service (QoS)
allows you to regulate the average rate and fluctuations of data transmission. This helps
eliminate congestion to allow the transmission of real time data (such as audio and video).
Priority-based PVCs
The system provides Priority-based PVCs (PPVCs) to give different priorities to PVCs that are
members of the same VLAN. Use up to eight priority queues for the member PVCs. The
system maps frames with certain IEEE 802.1p priorities to a PVC with a particular priority
queue.
PPPoA-to-PPPoE (PAE) PVC
This feature allows the system to translate PPPoA packets to PPPoE packets (and vice versa)
to allow communication between CPE clients and an access concentrator (such as a BRAS)
through the switch.
PPPoE Intermediate Agent Information
Similar to DHCP relay option82, you can set the system to insert line information into client
PPPoE Discover Initialization (PODI) packets. This allows a PPPoE termination server to
identify and authenticate a PPPoE client.
Transparent LAN Service (TLS)
Use TLS (also known as VLAN stacking) to add an outer VLAN tag to the inner IEEE 802.1Q
tagged frames that enter the network. By tagging the tagged frames (“double-tagged” frames),
the service provider can manage up to 4,094 VLAN groups with each group containing up to
4,094 customer VLANs. This allows a service provider to provide different services based on
specific VLANs, for many different customers.