ADTRAN Vanta 1335 Manual do Utilizador descarregar pdf (Página 10)

US

8,443,065

B1

7

typically

as

a

printed

circuit

board

as

part

of

a

rack

mounted

module.

This

can

be

as

many

as

several

thousand

line

cards

at

one

facility.

These

line

cards

are

typically

held

in

slots

of

several

chassis

with

each

line

card

typically

interfaced

with

the

chassis

backplane

that

enables

the

line

card

to

communi

cate

with

various

network

devices

and

other

equipment.

Different

protocol

may

be

used

for

communication

between

a

central

of?ce

and

customer

premises,

for

example,

various

digital

subscriber

line

(DSL)

protocols,

such

as

asym

metric

digital

subscriber

line

(ADSL),

ADSL

2,

VDSL

2,

high-bit

rate

digital

subscriber

line

(HDSL),

HDSL

2,

HDSL

4,

very-high-data-rate

digital

subscriber

line

(VDSL),

and

other

protocols.

It

should

be

understood

that

the

communications

network

could

include

a

central

of?ce

that

connects

to

a

network

such

as

a

Public

Switch

Telephone

Network

(PSTN)

or

internet

that

routes

data.

The

central

of?ce

operates

as

a

network

facility

and

receives

network

data

destined

for

equipment

or

other

devices

at

customer

premises.

Typically,

a

central

of?ce

in

this

example

includes

at

least

one

telecommunications

access

module

that

includes

at

least

one

bonding

engine

and

a

transceiver

and

processor

that

could

be

separate or

integral

with

a

bonding

engine.

An

access

module

is

typically

formed

as

a

Physical

Medium

Entity

(PME)

and

the

bonding

engine

could

use

different

con?gurations,

including

an

ASIC,

pro

cessor,

or

Field

Programmable

Gate

Array

(FPGA).

A

provi

sioning

module

would

probably

be

included

and

a

switch

module

switches

data

between

access

modules

and

a

network.

Typically,

each

data

packet

includes

a

header

and

data

portion

and

control

and

routing

information

is

included

in

the

header

and

payload

data

is

included

in

the data

portion.

Other

examples

of

bonding

technology

are

disclosed

in

common

assigned

US.

patent

application

Ser.

No.

12/836,695

?led

Jul.

15,

2010,

the disclosure

which

is

hereby

incorporated

by

reference

in

its

entirety.

It

should

be

understood

that

the

discovery

protocol

frame

is

part

of

a

discovery

protocol

that

comprises

a

one-way

neigh

bor

discovery

protocol

such

as

the

Link

Layer

Discovery

Protocol

(LLDP).

At

each

network

element

42,

a

database

such

as

a

Management

Information

Base

(MIB)

could

be

accessed

such

as

using

the

Simple

Network

Management

Protocol

(SNMP).

Typically

in

one

example,

the

query

of

the

discovery

protocol

frame

is

a

user-de?ned

?eld

as

a

command

that

indicates

information

should

be

given

by

a

network

switch

concerning

any

knowledge

about

stored

MAC

addresses.

Although

the

description

relative

to

FIG.

2

shows

typically

Ethernet switches

or

routers,

it

shouldbe

understood

that

the

network

switches

can comprise

at

least

one

Local

Area

Network

(LAN)

access

point

in

a

non-limiting

example.

This

discovery

protocol

frame can

include

an

organization

ally

speci?c

Type

Length

Value

(TLV)

and

Organizationally

Unique

Identi?er

(OUI)

and

de?ned

information

string

to

de?ne

the

query

to

determine

the

physical

network

connec

tivity

data.

This

could

include

a

MAC

address.

There

now

follows

a

brief

description

of

LLDP

relative

to

the

communications

network

shown

in

FIG.

2

and

that

can

be

applied

for

purposes

of

understanding.

LLDP

is

a

common

protocol

used

to

exchange

information

between

network

devices

and

switches.

With

LLDP,

each

network

switch

has

visibility

of

its

neighboring

switches.

Network

devices,

such

as

Ethernet

devices

and

switches,

advertise

information

about themselves

and

store

information

in

local

Management

Information

Base

(MIB)

databases

and

are

associated

with

network

devices

and

accessible via the

Simple

Management

Network

Protocol

(SMNP).

This

infor

mation

can

be

used

to

build

a

network

topology

map

using

a

20

25

30

35

40

45

50

55

60

65

8

Network

Management

Station

(N

MS),

such

as

associated

with

the

network

manager

70

or

other

device

as

illustrated.

LLDP

is

a

technique

used

for

Ethernet

network

devices,

including

switches,

routers

and

wireless

LAN

access

points

and

other

network

devices

to

advertise

information

about

themselves

to

other

nodes

on

the

network

and

store

informa

tion

they

discover

using

the

MIB

in

one

non-limiting

example.

The

details

that

are

shared

include

the

network

device

capabilities,

identi?cation

(such

as

the

MAC

address),

and

device

con?guration.

LLDP

is

typically

a

one-way

neigh

bor

discovery

protocol

with

periodic

transmissions.

The

LLDP

frames

are

typically

constrained

to

a

single

length.

The

frames

contain

formatted

Type

LengthValues

(TLV’s),

which

carry

information

regarding

a

globally

unique

system

and

port

identi?cation,

time-to-live

information

for

aging

pur

poses, optional

system

capabilities

and

optional

system

names

and

descriptions

and

management

addresses

such

as

IPV4

and

IPV6.

LLDP

in

one

aspect

is

covered

by

the

IEEE

standard,

802.1AB

Link

Layer

Discovery

Protocol

(LLDP),

the

disclo

sure

which

is

hereby

incorporated

by

reference

in

its

entirety.

LLDP

is

advantageous

over

network-management

tools

such

as

reading

bridge

tables

from

an

SNMP

bridge

MIB

in

which

algorithms

decide

for

the

bridge

tables

and

map

the

port-to

MAC

address

entries.

For

example,

if

a

network

uses

the

spanning

tree

protocol,

the

switch

at

the

bottom

of

a

con?gu

ration

has

ports

of

a

single

segment

or

network

device

and

each

port

of

a root

switch

contains

the

sum

total

of

the net

work

devices

below

it

in

its

bridge

table.

Bridge

tables

are

not

always

accurate.

LLDP

is

also

advantageous

over

fractal

matching.

With

LLDP,

each

network

device

on

each

port

stores

infor

mation

de?ning

itself

and

sends

updates

to

a

connected

neigh

bor,

which

then

stores

the

information

in

standard

SNMP

MIB’s.

Thus,

information gathered

with

LLDP

is

stored

in

a

network

device

and

is

queried

with

SNMP

techniques.

Typi

cally,

the

topology of

an

LLDP-enabled

network

is

discov

ered

by

“crawling”

the hosts

and

querying

a

database.

This

is

time

consuming

as

noted

above.

“Crawling” can

obtain

infor

mation

regarding

a

system

name

and

description,

port

name

and

description,

VLAN

name,

IP

management

address,

sys

tem

capabilities

such

as

switching

and

routing,

the

MAC/

PHY

information

and

other

link

aggregation

information.

In

one

aspect,

LLDP

de?nes

a

set

of

common

advertise

ment

messages

and

a

protocol

for

transmitting the

advertise

ments

and

a

method

for

storing

information

contained

in

the

received

advertisements.

Typically,

LLDP-capable

network

devices

support

device

chassis

ID

and

port

ID

advertisements

and

support

system

name,

system

description

and

system

capabilities

advertisements.

Typically,

LLDP

information

is

transmitted

periodically

and

stored

for

a ?nite

period.

One

recommended

transmission

rate

is

about

30

seconds,

but

this

can

be

adjustable.

Usually,

the

information

stored

in

the

SNMP

MIB

is

valid

for

a

period

of time

de?ned

by

the

LLDP

“time

to live”

(TTL)

value

as

contained

within

a

received

packet.

One

recommendation

is

a

TTL

value

of

about

120

seconds,

but

it

can

be

set

to

a

maximum

value

of

about

65,000

seconds

or

a

minimum

value

of 0

seconds.

Typically,

a net

work

device

receives

an

LLDP

advertisement packet

and

stores

the

information

within

it

and

initializes

a

timer

that

will

be

compared

to

the

TTL

value.

If

the

timer

reaches

the

TTL

value,

the

network

device

deletes

the stored

information,

and

thus,

ensures

that

only

valid

LLDP

information

is

available

to

the

network

manager

as

part

of

any

Network

Management

Systems.

It

should

be

understood

that

LLDP

frames

typically

are

not forwarded,

but

constrained

to

a

single

link

and

contain

formatted

TLV’s

as

type

length values

that

carry the

globally

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