Virtual Channels; Super Channel; Llc; Vc Mux - ZyXEL Communications IES-1248-71 User Manual

16.8 Virtual Channels

Defining virtual channels (also called Permanent Virtual Circuits or PVCs) allows you to set
priorities for different services or subscribers. You can define up to eight channels on each
DSL port and use them for different services or levels of service. You set the PVID that is
assigned to untagged frames received on each channel. You also set an IEEE 802.1p priority
for each of the PVIDs. In this way you can assign different priorities to different channels (and
consequently the services that get carried on them or the subscribers that use them).
For example, you want to give high priority to voice service on one of the ADSL ports.
Use the Edit Static VLAN screen to configure a static VLAN on the IES-1248 for voice on
the port.
Use the ADSL Edit Port Channel Setup screen to:
• Configure a channel on the port for voice service.
• Set the channel to use the PVID of the static VLAN you configured.
• Assign the channel a high priority.

16.8.1 Super Channel

The IES-1248 forwards frames belonging to VLAN groups that are not assigned to specific
channels to the super channel. Enable the super channel option to allow a channel forward
frames belonging to multiple VLAN groups (that are not assigned to other channels). The
super channel functions in the same way as the channel in a single channel environment. One
port can have only one super channel.

16.8.2 LLC

LLC is a type of encapsulation where one VC (Virtual Circuit) carries multiple protocols with
each packet header containing protocol identifying information. Despite the extra bandwidth
and processing overhead, this method may be advantageous if it is not practical to have a
separate VC for each carried protocol, for example, if charging heavily depends on the number
of simultaneous VCs.

16.8.3 VC Mux

VC Mux is a type of encapsulation where, by prior mutual agreement, each protocol is
assigned to a specific virtual circuit, for example, VC1 carries IP, VC2 carries IPX, and so on.
VC-based multiplexing may be dominant in environments where dynamic creation of large
numbers of ATM VCs is fast and economical.

16.8.4 Virtual Channel Profile

Virtual channel profiles allow you to configure the virtual channels efficiently. You can
configure all of the virtual channels with the same profile, thus removing the need to configure
the virtual channels one-by-one. You can also change an individual virtual channel by
assigning it a different profile.
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