ZyXEL Communications MSC1024G Series User Manual page 50

Chapter 1 Getting to Know Your MSC
Link Aggregation Control Protocol (LACP)
The MSC supports the link aggregation IEEE 802.3ad protocol. Link aggregation (trunking) is
the grouping of physical ports into one logical higher-capacity link. You may want to trunk
ports if for example, it is cheaper to use multiple lower-speed links than to under-utilize a
high-speed, but more costly, single-port link.
IEEE 802.1Q Tagged VLAN
Your MSC uses the IEEE 802.1Q Tagged VLAN (Virtual Local Area Network), which allows
your device to deliver tagged/untagged frames to and from its ports.
Subnet Based VLAN
Subnet based VLAN allows you to group traffic into logical VLANs based on the source IP
subnet you specify. When a frame is received on a port, the MSC checks if a tag is added
already and the IP subnet it came from. The untagged packets from the same IP subnet are then
placed in the same subnet based VLAN. One advantage of using subnet based VLANs is that
priority can be assigned to traffic from the same IP subnet.
xVLAN (VLAN Translation)
xVLAN (VLAN translation) changes the VLAN tag on traffic received from a subscriber port
to another VLAN ID for the service provider's network. This makes it easier to deploy
customer-specific VLANs because all the CPE devices can use the same VLAN configuration.
You only need to configure xVLAN on the DSLAM to use unique VLAN IDs for each
subscriber's traffic. xVLAN on the VLC13XXGs also supports translating single-tagged
frames to double-tagged frames.
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.
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.
Double-Tag PVC (DTPVC)
DTPVCs (Double-Tag Permanent Virtual Circuits) add double VLAN tags to untagged frames
received from an ADSL or SHDSL subscriber on the specified PVC. These double VLAN tags
consist of an inner c-tag (customer tag) and an outer s-tag (service provider tag). The line card
drops any tagged frames received on the DTPVC. DTPVCs support DHCP relay, IGMP, IEEE
802.1x and PPPoE agent.
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MSC1000G/1024G/1224G Series User's Guide