10.1

10 Protection and Restoration

10.2

Protection and RestorationSession presentation

Objective: to be able to describe the different kinds of protection in SDH

program: Equipment Protection : EPS Network Protection Network Restoration

10.3

Protection and Restoration Equipment Protection: EPS

W

P

Equipment Protection Switching(EPS)

Multiplex Section Protection Linear Trail (MSP)

2

Protection against equipment failure Protection against equipment failure and line failure

P

2

1+1 1:N

W

W

W

W

P

W

P

1+1

10.4

Protection and Restoration EPS 1+1

Equipment 1

Equipment 2

10.5

Protection and Restoration EPS 1:N

Equipment 1

Equipment 2

Equipment N

Equipment P

Line 1

Line 2

Line N

10.6

Protection and Restoration Protection Mechanisms against Network Faults

Linear structure

Item to be protectedProtection architecture

Protection mechanism

SNCP/I

SNCP/N

Linear MSP

MS-SPRING

connection dedicatedto a Path

Section

Linear structure

Ring structure

10.7

Protection and Restoration Sub Network Connection Protection: SNCP

Sub Network

Sub Network

VC-n VC-n

broadcast

selection

_____ working path ----- protecting path

broadcast

selection

10.8

Protection and Restoration SNCP: switch criteria

Switching criteria(external commands)

Switching criteria(automatic)

Sub Network

Sub Network

_____ working path----- protecting path

10.9

10 Protection and Restoration Section Protection on a Linear Network: MSP

Multiplex SectionNE A NE B

TX

TX

TX

TX

TX

RX 1+1 protection

RX 1:1 protection

RX

RX 1:N protection

RXX

Protecting

Working

Protecting

Working

Working

Low priority lineProtecting

High priority lineWorking

10.10

10 Protection and Restoration MSP 1+1

TX

RX

Line A

Multiplex section

Line B

RX

TX

selectionbroadcast

broadcastselection

10.11

Protection and Restoration MSP 1:1

TX

TX

RX

RX Low priority line

High priority line

RX

RX

TX

TX

Multiplex section

RX

TX

RX

TX

TX

RX

TX

RXextra traffic extra traffic

10.12

10 Protection and Restoration Section Protection on a Ring Network: MS-SPRING (2 fiber)

Overview of the ring

Detailed view of the ring

Node A Node B

Node D Node C

Node A Node BTransmission direction

Section overheadNormal traffic channels

Protection channels

Section overheadNormal traffic channels

Protection channelsSTM-16 fiber:Normal channel: AU4 #1-8Protection channel: AU4 #9-16

10.13

10 Protection and Restoration Two fiber MS-SPRING: failure study

WORKING CHANNELS

PROTECTING CHANNELS

(*) All protecting AU-4 are put in passthrough in the 1st, 4th, 5th and 6th NE

PROTECTEDSIGNAL

PROTECTEDSIGNAL

(*)

1

6

2

5

3

4

1 fiber carries bothtype of channels

BRIDGE SWITCH BRIDGE

Failure

(*) (*)

SWITCH

10.14

10 Protection and Restoration Span Protection on a Ring Network: MS-SPRING (4 fiber)

Fiber carrying the normal trafficFiber carrying the protection traffic

Overview of the ring

Detailed view of the ring

Node A Node B

Node D Node C

Node A Node BTransmission direction

Section overheadNormal traffic channels

Section overheadNormal traffic channels

Section overheadProtection channels

Section overheadProtection channels

10.15

10 Protection and Restoration Four fiber MS-SPRING: failure study

1 2 3

Failure

Working channel

Protection channel

Normal path Path after span failure

1 fiber carries one type of channel

6 5 4

10.16

10 Protection and Restoration Network Restoration

A B C

F E

D

VC-n

A B C

F E

D

VC-n

Failure

Failure

DXC

any NE

A few seconds later

VC-n

VC-n