Chapter 1 Introducing the ALC1248G

Multicast VLAN

Multicast VLAN is designed for applications (such as Media-on-Demand (MoD)) using multicast traffic across an Ethernet ring-based service provider network. Multicast VLAN allows one single multicast VLAN to be shared among different subscriber VLANs on the network. This improves bandwidth utilization by reducing multicast traffic in the subscriber VLANs and simplifies multicast group management.

IEEE 802.1x Port-based Authentication

The ALC supports the IEEE 802.1x standard for centralized user authentication and accounting management through an optional network authentication (RADIUS) server.

Port Isolation

The ALC's port isolation feature allows each port to communicate with the uplink port but not communicate with each other. This option is the most limiting but also the most secure.

Isolation (per-VLAN)

Use isolation to block the DSL subscribers in a specific VLAN from sending traffic directly to each other.

Packet Filter

The ALC supports packet filtering based on protocol. You can configure the ALC to accept all packets, accept PPPoE packets only or block any combination of the following protocols: IP, ARP, DHCP, EAPOL, PPPoE, NetBios or IGMP.

MAC (Media Access Control) Filters

Use the MAC filter to filter incoming frames based on MAC (Media Access Control) address(es) or the OUI (Organizational Unit Identifier) that you specify. You may enable/ disable the MAC filter on specific ports. You may specify up to ten MAC addresses per port.

MAC (Media Access Control) Count Limit

You can limit the number of MAC addresses that may be dynamically learned on a port. You may enable/disable the MAC count limit on individual ports.

IGMP Snooping

The ALC supports IGMP snooping enabling group multicast traffic to be only forwarded to ports that are members of that group; thus allowing you to significantly reduce multicast traffic passing through your ALC.

IGMP Filter

The IGMP filter defines multicast groups a port can join. You can create IGMP filter profiles which allow access to a multicast group, then assign the IGMP filter to a specific DSL port.

Multicast Group Limit

You can limit the number of IGMP multicast groups a subscriber on a port can join. You may enable/disable the multicast group limit on individual ports.

 

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ALC1248G User’s Guide