The 3G Backup Screen - ZyXEL Communications VMG1312-B Series User Manual

Chapter 6 Broadband
Table 10 Bridge Mode (ADSL over ATM) (continued)
LABEL
Encapsulation
Mode
Service
Category
Peak Cell Rate
Sustainable Cell
Rate
Maximum Burst
Size
QoS
Rate Limit
Apply
Cancel

6.3 The 3G Backup Screen

Use this screen to configure your 3G settings. Click Network Setting > Broadband > 3G
Backup.
92
DESCRIPTION
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 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.
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.
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.
The Sustainable 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 (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.
Enter the rate limit for the connection. This is the maximum transmission rate allowed for
traffic on this connection.
Click Apply to save your changes.
Click Cancel to exit this screen without saving.
VMG1312-B Series User's Guide