Руководство Пользователя для Netopia 4741 2a4na

With transmission over a noisy line, the ability to recover encoded bits is significantly improved by using a 
Trellis Coder/Decoder. The Trellis Coder for ADSL can achieve a better coding gain. Trellis coding can be 
optionally used only for Multimode. The DSLAM and Netopia 4741 negotiate if Trellis Coding is enabled 
during par t of their initialization.

The default is enabled, so you probably do not need to change it unless your provider specifically tells you 
to do so.

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Select Cell Format and from the pop-up menu select either Scrambled (the default) or Unscrambled. This 
setting must match the format used by your ser vice provider. Scrambled is the most common, so you 
probably do not need to change it unless your provider specifically tells you to do so.

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Select Unused Cell Format and from the pop-up menu select either Idle (the default) or Empty. This setting 
must match the format used by your ser vice provider. Idle is the most common, so you probably do not 
need to change it unless your provider specifically tells you to do so.

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Select Data Link Encapsulation and from the pop-up menu choose your DLE. The DLE choices are PPP or 
RFC 1483 (the default).

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If you selected RFC1483, the next pop-up menu RFC1483 Mode offers the choice of Bridged 1483 or 
Routed 1483. If you select Bridged 1483, a new option PPP over Ethernet (PPPoE) appears. You can 
then toggle PPPoE On or Off. Choosing Routed 1483 hides the PPPoE option.

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If you selected PPP, the next pop-up menu PPP Mode offers the choice of VC Multiplexed or LLC SNAP.

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Select Display/Change Circuit, and from the pop-up menu choose the circuit to use for this connection. 
The default circuit is called Circuit 1, and uses the default values for data traffic and the WAN Default 
Profile for the connection. See 

 for more information.

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Add Circuit and Delete Circuit allow you to create or delete circuit settings "on the fly." This is useful if you 
want to manage sets of circuit values without deleting a previous set or delete sets that no longer apply. 
For more information on VPIs and VCIs, see 

 below.

The Netopia 4741 suppor ts up to eight permanent vir tual circuits.

On cell-based DSL WAN inter faces, the ATM connection between the device and the central office equipment 
(DSLAM) is divided logically into one or more vir tual circuits (VCs). A vir tual circuit may be either a permanent 
vir tual circuit (PVC) or a switched vir tual circuit (SVC). Netopia devices suppor t PVCs.

VCs are identified by a Vir tual Path Identifier (VPI) and Vir tual Channel Identifier (VCI). A VPI is an 8-bit value 
between 0 and 255, inclusive, while a VCI is a 16-bit value between 0 and 65535, inclusive.

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Circuits now suppor t attributes in addition to their VPI and VCI values. When configuring a circuit, you can 
specify an optional circuit name of up to 14 characters. The circuit name is used only to identify the circuit 
for management purposes as a convenience to aid in selecting circuits from lists. The default circuit name 
is “Circuit <n>”, where <n> is some number between one and eight corresponding to the circuit’s position 
in the list of up to eight circuits.

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You can also individually enable or disable a circuit without deleting it. This is useful for temporarily