ZyXEL Communications P-873HNU-51B, Руководство пользователя

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Chapter 6 Broadband
P-873HNU(P)-51B User’s Guide
70
Encapsulation
Mode Select the method of multiplexing used by your ISP from the drop-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 VDSL Router 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 Category Select UBR Without PCR or UBR With PCR for applications that are 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 Rate The Sustain Cell Rate (SCR) sets the average cell rate (long-term) that 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
Size Maximum Burst Size (MBS) refers to the maximum number of cells that 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 User Name 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.
PPP Auto Connect Select this option if you do not want the connection to time out.
Idle Timeout This value specifies the time in minutes that elapses before the router
automatically disconnects from the PPPoE server.
This field is not configurable if you select PPP Auto Connect.
PPPoE Service
Name Enter the name of your PPPoE service here.
Table 7
Broadband: Add/Edit: PPPoE Encapsulation (continued)
LABEL DESCRIPTION