Chapter 6 Broadband

 

Table 7 Broadband: Add/Edit: Routing Mode

 

LABEL

DESCRIPTION

 

Encapsulation

Select the method of multiplexing used by your ISP from the drop-

 

Mode

down list box. Choices are:

 

 

• LLC/SNAP-BRIDGING:In LCC encapsulation, bridged PDUs are

 

 

encapsulated by identifying the type of the bridged media in the

 

 

SNAP header. This is available only when you select IPoE or PPPoE

 

 

in the Select DSL Link Type field.

 

 

• VC/MUX: In VC multiplexing, each protocol is carried on a single

 

 

ATM virtual circuit (VC). To transport multiple protocols, the ZyXEL

 

 

Device needs separate VCs. There is a binding between a VC and

 

 

the type of the network protocol carried on the VC. This reduces

 

 

payload overhead since there is no need to carry protocol

 

 

information in each Protocol Data Unit (PDU) payload.

 

 

• LLC/ENCAPSULATION: More than one protocol can be carried

 

 

over the same VC. This is available only when you select PPPoA in

 

 

the Encapsulation field.

 

 

• LLC/SNAP-ROUTING:In LCC encapsulation, an IEEE 802.2

 

 

Logical Link Control (LLC) header is prefixed to each routed PDU to

 

 

identify the PDUs. The LCC header can be followed by an IEEE

 

 

802.1a SubNetwork Attachment Point (SNAP) header. This is

 

 

available only when you select IPoA in the Encapsulation field.

 

 

 

 

Service

Select UBR Without PCR or UBR With PCR for applications that are

 

Category

non-time sensitive, such as e-mail.

 

 

Select CBR (Continuous Bit Rate) to specify fixed (always-on)

 

 

bandwidth for voice or data traffic.

 

 

Select Non Realtime VBR (non real-time Variable Bit Rate) for

 

 

connections that do not require closely controlled delay and delay

 

 

variation.

 

 

Select Realtime VBR (real-time Variable Bit Rate) for applications with

 

 

bursty connections that require closely controlled delay and delay

 

 

variation.

 

 

 

 

Peak Cell Rate

Divide the DSL line rate (bps) by 424 (the size of an ATM cell) to find

 

 

the Peak Cell Rate (PCR). This is the maximum rate at which the sender

 

 

can send cells. Type the PCR here.This field is not available when you

 

 

select UBR Without PCR.

 

 

 

 

Sustain Cell

The Sustain Cell Rate (SCR) sets the average cell rate (long-term) that

 

Rate

can be transmitted. Type the SCR, which must be less than the PCR.

 

 

Note that system default is 0 cells/sec.

 

 

This field is available only when you select Non Realtime VBR or

 

 

Realtime VBR.

 

 

 

 

Maximum Burst

Maximum Burst Size (MBS) refers to the maximum number of cells that

 

Size

can be sent at the peak rate. Type the MBS, which is less than 65535.

 

 

This field is available only when you select Non Realtime VBR or

 

 

Realtime VBR.

 

 

 

 

PPP Information

This is available only when you select PPPoE or PPPoA in the Mode

 

 

field.

 

 

 

 

PPP Username

Enter the user name exactly as your ISP assigned. If assigned a name

 

 

in the form user@domain where domain identifies a service name, then

 

 

enter both components exactly as given.

 

 

 

 

PPP Password

Enter the password associated with the user name above.

 

 

 

 

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VSG1432-B101 Series User’s Guide