Specifications

ATM Interface

Clicking on the ATM VC brings up the following screen. The ADSL Modem

Multiservices PSTN Voice uses ATM as its WAN interface. Protocols including

1483 Routing, 1483 Bridging, MAC Encapsulated Routing (MER), PPPoA and PPPoE

with LLC-SNAP and VC-Mux encapsulations are supported for each ATM PVC.

When you have finished entering your connection parameters, click ‘SAVE SETINGS.’

You can verify that you have established an ADSL connection by clicking Status at the

bottom of the left-hand menu. See ‘Status’ on page 23.

See the table below for a description of the parameters.

Parameter Description

Protocol

Disable Disables the connection.

1483 Bridging Bridging is a standardized layer 2 technology. It is typically used in

corporate networks to extend the physical reach of a single LAN

segment and increase the number of stations on a LAN without

compromising performance. Bridged data is encapsulated using

the RFC1483 protocol to enable data transport.

PPPoA Point-to-Point Protocol over ATM is a method of encapsulating

data for transmission to a far point.

1483 Routing 1483 Routing allows a simple, low-cost connection to the

Internet via a standard Ethernet port. The router looks up the

network address for each packet seen on the LAN port. If the

address is listed in the routing table as local, it is filtered. If the

address is listed under the ADSL port, it is forwarded. Or if the

address is not found, then it is automatically forwarded to the

default router (i.e., the ADSL Modem Multiservices PSTN Voice

at the head end).

PPPoE Point-to-Point over Ethernet is a common connection method

used for xDSL.

MAC Encapsulated

Routing If your ADSL service is a Bridged mode service and you want

to share the connection to multiple PC’s, please select MAC

Encapsulated Routing. MER is a protocol that allows you do IP

routing with NAT enabled.

VPI/VCI See Virtual Path Identifier (VPI) and Virtual Circuit Identifier

(VCI). Data flows are broken up into fixed length cells, each of

which contains a Virtual Path Identifier (VPI) that identifies the

path between two nodes, and a Virtual Circuit Identifier (VCI)

that identifies the data channel within that virtual path. Each

virtual circuit maintains a constant flow of cells between the

two end points. When there is no data to transmit, empty cells

are sent. When data needs to be transmitted, it is immediately

inserted into the cell flows.