ZyXEL Communications VMG1312-B Series User Manual Download

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Chapter 6 Broadband

VMG1312-B Series User’s Guide

6.3 The 3G Backup Screen

Use t his screen t o configure your 3G set t ings. Click

N e t w or k Se t t in g > Br oa dba n d > 3 G

Ba ck u p

Encapsulat ion
Mode

Select t he m et hod of m ult iplexing used by your I SP from t he drop- dow n list box. Choices
are:

•

LLC/ SN AP- BRI D GI N G:

I n LCC encapsulat ion, bridged PDUs are encapsulat ed by

ident ifying t he t ype of t he bridged m edia in t he SNAP header. This is available only when
you select

I PoE

PPPoE

in t he Select DSL Link Type field.

•

V C/ M UX:

I n VC m ult iplexing, each prot ocol is carried on a single ATM virt ual circuit

( VC) . To t ranspor t m ult iple pr ot ocols, t he Device needs separat e VCs. There is a binding
bet w een a VC and t he t ype of t he net work prot ocol carried on t he VC. This reduces
payload overhead since t here is no need t o carry prot ocol inform at ion in each Prot ocol
Dat a Unit ( PDU) payload.

•

LLC/ EN CAPSULATI ON :

More t han one prot ocol can be car r ied over t he sam e VC. This

is available only when you select

PPPoA

in t he

En ca psu la t ion

field.

•

LLC/ SN AP- ROUTI N G:

I n LCC encapsulat ion, an I EEE 802.2 Logical Link Cont rol ( LLC)

header is prefixed t o each rout ed PDU t o ident ify t he PDUs. The LCC header  can be
follow ed by an I EEE 802.1a SubNet w ork At t achm ent  Point  ( SNAP)  header. This is
available only when you select

I PoA

in t he

En ca psu la t ion

field.

Service
Cat egory

Select

UBR W it hou t PCR

UBR W it h PCR

for applicat ions t hat are non- t im e sensit ive,

such as e- m ail.

Select

CBR

( Cont inuous Bit Rat e) t o specify fixed ( always- on) bandw idt h for voice or dat a

t raffic.

Select

N on Re a lt im e V BR

( non real- t im e Variable Bit Rat e) for connect ions t hat do not

r equire closely cont r olled delay and delay variat ion.

Select

Re a lt im e V BR

( real- t im e Variable Bit Rat e) for applicat ions wit h burst y connect ions

t hat require closely cont rolled delay and delay var iat ion.

Peak Cell Rat e

Divide t he DSL line rat e ( bps)  by 424 ( t he size of an ATM cell)  t o find t he Peak Cell Rat e
( PCR) . This is t he m axim um  rat e at  which t he sender can send cells. Type t he PCR here.This
field is not  available when you select

UBR W it h ou t PCR

Sust ainable Cell
Rat e

The Sust ainable Cell Rat e ( SCR) set s t he average cell rat e ( long- t erm ) t hat can be
t ransm it t ed. Type t he SCR, w hich m ust be less t han t he PCR. Not e t hat syst em default is 0
cells/ sec.

This field is available only w hen you select

N on Re a lt im e V BR

Re a lt im e V BR

Maxim um Bur st
Size

Maxim um Burst Size ( MBS) refers t o t he m axim um num ber of cells t hat can be sent at t he
peak rat e. Type t he MBS, w hich is less t han 65535.

This field is available only w hen you select

N on Re a lt im e V BR

Re a lt im e V BR

QoS

Rat e Lim it

Ent er t he rat e lim it for t he connect ion. This is t he m axim um t ransm ission rat e allow ed for
t raffic on t his connect ion.

Apply

Click

Apply

t o save your changes.

Cancel

Click