02-OptiX OSN Series Networking and Application ISSUE1.30

HUAWEI TECHNOLOGIES CO., LTD. All rights reserved

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OTA105105 OptiX OSN series Networking and Application

ISSUE 1.30

HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 2

Upon completion this course, you will be able to:

Outline network topology structures.

Illustrate basic SDH network elements.

Describe the survivable network and protection

mechanisms.


References

OptiX OSN series Networking and

Application Technical Manual.

ITU-T Recommendation G.841 (Oct, 1998)

Types and characteristics of SDH network

protection architectures.

ITU-T Recommendation G.810 (Aug, 1996)

Definitions and terminology for

synchronization networks ITU-T

Recommendation G.803.

ITU-T Recommendation G.803 (Aug, 2003)

Architecture of transport networks based on

the synchronous digital hierarchy (SDH).


Chapter 1 Network Topology Structures

Chapter 2 Common Network Elements

Chapter 3 Survivable Network and

Protection Mechanisms


Introduction

An SDH network consists of Network

Elements (NE) interconnected with optical

fiber. The geometrical layout of NEs and

transmission lines is called the network

topology.

The efficiency, reliability and the cost

performance of the network highly depend

on its topology.


Classification of Topology Structures

Network Topology Structures

Chain Network

Star Network

Tree Network

Ring Network

Mesh Network

Note: Chain network, ring network and mesh network

are normally used.


A

Chain Network

In chain network, all nodes are connected one after another

on a line with both ends open.

Chain network is used when the networks nodes are arranged in a long

line, e. g. along railway lines, highways, power supply lines, etc.

B C D E


Star Network In star network there is a central node to which the other nodes are

directly connected. There are no direct links between other nodes.

Star network is mainly used in access networks or rural telephone networks in which nodes are scattered here and there and the services are not important.

FB

A

E

D

C


E

Tree Network A tree network can be considered as a combination of the chain

and the star topologies.

D

Tree network is suitable for broadcast services.

A

CB


Ring Network Ring network is such structure in which all nodes are connected

one after another to form a circle.

A

D

Ring network is widely used in SDH networking due to its high

survivability.

E

C

B


Mesh Network Mesh network is such a structure in which many nodes are

interconnected together via direct links.

Mesh network is suitable for the regions with large amount of

traffic and for high hierarchy communication networks.

D

E

A

B

C


Sub-Network

In backbone networks or large region networks, there

are a large number of NEs and links. In order to simplify

the network management, a large network can be

divided into several sub-networks according to the

administrative regions.

A sub-network functions as a

container. It can include NEs,

links and even the lower level

sub-networks.


NE

NE

NE

NE

NE

NE

SubnetNE

NE

NENENENE

NE

NE

NE

Sub-Network

Sub-network A Sub-network B

Sub-network CSub-network D


Summary

Network topology structures can be classified into five basic categories:

Chain Network

Star Network

Tree Network

Ring Network

Mesh Network

Sub-Network plays an important role when managing large networks.







Common Network Elements

Terminal Multiplexer (TM)

Add/Drop Multiplexer (ADM)

Multiple ADD/Drop Multiplexer (MADM)

Regenerator (REG)


TM

STM-1/4/16/64

Low-rate SDH signal

PDH signal. etc.


TM Applications:

Point-to-Point Network

Chain Network

Ring-Chain Combination

TM TM

TM TMADM

TM

ADM

ADM

ADM ADM


Configure a TM:

Tributary Unit

: 2M

PD1: slot 7

Line Unit :

STM-16

SL16: slot 12

TM

SLOT 5 CXL1/4, CXL16


SLOT 17

SLOT 16

SLOT 15 D75S

SLOT 14

SLOT 6

SLOT 7 PD1

SLOT 8

SLOT 9

SLOT 10 AUX

SLOT 18 PIU

SLOT 19 PIU

Slot 20

FANSLOT 13

SLOT 12 SL16

SLOT 11

OSN 1500B


TM

Configure a TM:

Tributary Unit : 2M

PL1: slot 6, 7

Line Unit : STM-16

SL16: slot 12

OSN 1500A



SLOT 6 PL1

SLOT 7 PL1

SLOT 8

SLOT 9

SLOT 10 AUX

SLOT 20

FAN SLOT 13

SLOT 12 SL16

SLOT 1 PIU SLOT 11 PIU


Configure a TM:

Tributary Unit : 2M

PQ1: slot 6

Line Unit : STM-16

SL16: slot 8

TM

SLOT3

SLOT2

D75S

SLOT1

D75S

SLOT4

Fiber routing panelSLOT 22

PIUSLOT 25

PIUSLOT 23

FANSLOT 24

FAN

SLOT17

SLOT16

SLOT15

SLOT18

SLOT8

SL16

SLOT9

CXL1/4or16

SLOT10

CXL1/4or16

SLOT11

SLOT12

SLOT13

SLOT14

SAP

SLOT5

SLOT6

PQ1

SLOT7

OSN 2500


Configure a TM:

Tributary Unit : 2M

PQ1: slot 2

Line Unit : STM-64

SL64: slot 8

TM

OSN 3500

Fiber Routing

FAN FAN FAN

SLOT 1

SLOT 2

PQ1

SLOT 3

SLOT 4

SLOT 5

SLOT 6

SLOT 7

SLOT 8

SL64

SLOT 11

SLOT 12

SLOT 13

SLOT 14

SLOT 15

SLOT 16

SLOT 9

XCS

SLOT 10

XCS

SLOT 19

D75S

SLOT 20

D75S

SLOT 21

SLOT 22

SLOT 23

SLOT 24

SLOT 25

SLOT 26

SLOT 29

SLOT 30

SLOT 31

SLOT 32

SLOT 33

SLOT 34

SLOT 35

SLOT 36

SLOT 27

PIU

SLOT 28

PIU

SLOT 37

AUX

SLOT 17

SCC

SLOT 18

SCC


Configure a TM:

Tributary Unit : 2M

PQ1: slot 2

Line Unit : STM-64

SL64: slot 8

TM

OSN 7500

SLOT1

SLOT2

SLOT3

SLOT4

SLOT5

SLOT6

SLOT7

SLOT8

SLOT9

SLOT11

SLOT12

SLOT13

SLOT14

SLOT15

SLOT16

SLOT18

X

C

S

A

SLOT17

Fiber routing Fiber routing

SLOT26

SLOT27

SLOT28

SLOT29

SLOT30

SLOT31

Fiber routingFiber routing Fiber routing

SLOT25

SLOT24

S

C

C

A

SLOT19

SLOT20

SLOT21

SLOT22

SLOT23

EO

W

PIU

AP

IUB

SLOT32

SLOT33

SLOT34

SLOT35

SLOT36

SLOT37

SLOT38

AU

X

P

Q

1

S

L

6

4

FAN FAN FAN

S

C

C

B

D

7

5

S

D

7

5

S

SLOT10

X

C

S

B


ADM

STM-1/4/16/64 STM-1/4/16/64

Low-rate SDH signal

PDH signal. etc.


Applications:

Chain Network

Ring Network

ADM

TM TMADM ADM

ADM

ADM

ADM ADM


Configure an ADM:

Tributary Unit : 2M

PD1: slot 7

Line Unit : STM-16

SL16: slot 12, 13

ADM

OSN 1500B



SLOT 17

SLOT 16

SLOT 15 D75S

SLOT 14

SLOT 6

SLOT 7 PD1

SLOT 8

SLOT 9

SLOT 10 AUX

SLOT 18 PIU

SLOT 19 PIU

Slot 20

FAN SLOT 13 SL16

SLOT 12 SL16

SLOT 11


Configure an ADM:

Tributary Unit : 2M

PL1: slot 6, 7

Line Unit : STM-16

SL16: slot 12, 13

ADM

OSN 1500A



SLOT 6 PL1

SLOT 7 PL1

SLOT 8

SLOT 9

SLOT 10 AUX

SLOT 20

FAN SLOT 13 SL16

SLOT 12 SL16



Configure an ADM:

Tributary Unit : 2M

PQ1: slot 6

Line Unit : STM-16

SL16: slot 8, 11

ADM

OSN 2500

SLOT3

SLOT2

D75S

SLOT1

D75S

SLOT4


PIUSLOT 25

PIUSLOT 23

FANSLOT 24

FAN

SLOT17

SLOT16

SLOT15

SLOT18

SLOT8

SL16

SLOT9

CXL1/4or16

SLOT10

CXL1/4or16

SLOT11

SL16

SLOT12

SLOT13

SLOT14

SAP

SLOT5

SLOT6

PQ1

SLOT7


Configure an ADM:

Tributary Unit : 2M

PQ1: slot 2

Line Unit : STM-64

SL64: slot 8, 11

ADM

OSN 3500Fiber Routing

FAN FAN FAN

SLOT 1

SLOT 2

PQ1

SLOT 3

SLOT 4

SLOT 5

SLOT 6

SLOT 7

SLOT 8

SL64

SLOT 12

SLOT 13

SLOT 14

SLOT 15

SLOT 16

SLOT 9

XCS

SLOT 10

XCS

SLOT 19

D75S

SLOT 20

D75S

SLOT 21

SLOT 22

SLOT 23

SLOT 24

SLOT 25

SLOT 26

SLOT 29

SLOT 30

SLOT 31

SLOT 32

SLOT 33

SLOT 34

SLOT 35

SLOT 36

SLOT 27

PIU

SLOT 28

PIU

SLOT 37

AUX

SLOT 17

SCC

SLOT 18

SCC

SLOT 11

SL64


Configure an ADM:

Tributary Unit : 2M

PQ1: slot 2

Line Unit : STM-64

SL64: slot 8, 11

ADM

OSN 7500

SLOT1

SLOT2

SLOT3

SLOT4

SLOT5

SLOT6

SLOT7

SLOT8

SLOT9

SLOT10

SLOT11

SLOT12

SLOT13

SLOT14

SLOT15

SLOT16

SLOT18

X

C

S

A

SLOT17


SLOT26

SLOT27

SLOT28

SLOT29

SLOT30

SLOT31


SLOT25

SLOT24

S

C

C

A

SLOT19

SLOT20

SLOT21

SLOT22

SLOT23

EO

W

PIU

AP

IUB

SLOT32

SLOT33

SLOT34

SLOT35

SLOT36

SLOT37

SLOT38

AU

X

P

Q

1

S

L

6

4

FAN FAN FAN

X

C

S

B

S

C

C

B

D

7

5

S

D

7

5

S

S

L

6

4


MADM

ADM ADM

MADM


MADM

STM-1/4/16/64STM-1/4/16/64

STM-1/4/16/64 STM-1/4/16/64

Low-rate SDH signal

PDH signal. etc.

...


Configure a double ADM:

Tributary Unit : 2M

PD1: slot 7

Line Unit : STM-16

SL16: slot 4, 5, 12, 13

MADM

OSN 1500B

SLOT 5 CXL16

SLOT 4 CXL16

SLOT 17

SLOT 16

SLOT 15 D75S

SLOT 14

SLOT 6

SLOT 7 PD1

SLOT 8

SLOT 9

SLOT 10 AUX

SLOT 18 PIU

SLOT 19 PIU

Slot 20

FAN SLOT 13 SL16

SLOT 12 SL16

SLOT 11



Tributary Unit : 2M

PL1: slot 6, 7

Line Unit : STM-16

SL16: slot 4, 5, 12, 13

MADM

OSN 1500A

SLOT 5 CXL16

SLOT 4 CXL16

SLOT 6 PL1

SLOT 7 PL1

SLOT 8

SLOT 9

SLOT 10 AUX

SLOT 20

FAN SLOT 13 SL16

SLOT 12 SL16




Tributary Unit : 2M

PQ1: slot 6

Line Unit : STM-16

SL16: slot 8, 9, 10,

11

MADM

OSN 2500

SLOT3

SLOT2

D75S

SLOT1

D75S

SLOT4


PIUSLOT 25

PIUSLOT 23

FANSLOT 24

FAN

SLOT17

SLOT16

SLOT15

SLOT18

SLOT8

SL16

SLOT9

CXL16

SLOT10

CXL16

SLOT11

SL16

SLOT12

SLOT13

SLOT14

SAP

SLOT5

SLOT6

PQ1

SLOT7


Configure a double

ADM:

Tributary Unit : 2M

PQ1: slot 2

Line Unit : STM-64

SL64: slot 8, 11

slot 7, 12

MADM

OSN 3500

Fiber Routing

FAN FAN FAN

SLOT 1

SLOT 2

PQ1

SLOT 3

SLOT 4

SLOT 5

SLOT 6

SLOT 7

SL64

SLOT 8

SL64

SLOT 12

SL64

SLOT 13

SLOT 14

SLOT 15

SLOT 16

SLOT 9

XCS

SLOT 10

XCS

SLOT 19

D75S

SLOT 20

D75S

SLOT 21

SLOT 22

SLOT 23

SLOT 24

SLOT 25

SLOT 26

SLOT 29

SLOT 30

SLOT 31

SLOT 32

SLOT 33

SLOT 34

SLOT 35

SLOT 36

SLOT 27

PIU

SLOT 28

PIU

SLOT 37

AUX

SLOT 17

SCC

SLOT 18

SCC

SLOT 11

SL64


Configure a double

ADM:

Tributary Unit : 2M

PQ1: slot 2

Line Unit : STM-64

SL64: slot 8, 11

slot 7, 12

MADM

OSN 7500

SLOT1

SLOT2

SLOT3

SLOT4

SLOT5

SLOT6

SLOT7

SLOT8

SLOT9

SLOT10

SLOT11

SLOT12

SLOT13

SLOT14

SLOT15

SLOT16

SLOT18

X

C

S

A

SLOT17


SLOT26

SLOT27

SLOT28

SLOT29

SLOT30

SLOT31


SLOT25

SLOT24

S

C

C

A

SLOT19

SLOT20

SLOT21

SLOT22

SLOT23

EO

W

PIU

AP

IUB

SLOT32

SLOT33

SLOT34

SLOT35

SLOT36

SLOT37

SLOT38

AU

X

P

Q

1

S

L

6

4

FAN FAN FAN

X

C

S

B

S

C

C

B

D

7

5

S

D

7

5

S

S

L

6

4

S

L

6

4

S

L

6

4


STM-1/4/16/64 STM-1/4/16/64

REG


Configure a REG:

Line Unit : STM-64

SL64: slot 8, 11

REG

SLOT3

SLOT2

SLOT1

SLOT4


PIUSLOT 25

PIUSLOT 23

FANSLOT 24

FAN

SLOT17

SLOT16

SLOT15

SLOT18

SLOT8

SL64

SLOT9

CRG

SLOT10

CRG

SLOT11

SL64

SLOT12

SLOT13

SLOT14

SAP

SLOT5

SLOT6

SLOT7

UnusedSF64/16SL64/16

OSN 2500 Sub-rack


Summary

There are four NE types for SDH network

elements: TM, ADM, MADM and REG.

TM is used at the end stations.

ADM is used at the intermediate stations.

MADM is a multi-ADM NE, functioning as core

unit for constructing various networks.







What is a Survivable Network?

A network that is capable of restoring services within a very

short period and without any human intervention in the event of

a failure is called a survivable network.

Requirements for survivability of network includes…

Standby routes.

Powerful cross-connect capability.

Intelligence of Nodes.


Classification of Protection MechanismProtection Mechanism of survivable network can be classified as follows:

Linear Multiplex Section Protection

Protection Rings

Sub-Network Connection Protection (SNCP)

1+1 MSP1:N MSP

Path Protection (PP) Ring *

Multiplex Section Protection (MSP) Ring

2-fiber unidirectional PP Ring (Diverse Route)

2-fiber bidirectional PP Ring (Uniform Route)

2-fiber unidirectional MSP Ring (2f_MS DPRing)

2-fiber bidirectional MSP Ring (2f_MS SPRing)

4-fiber bidirectional MSP Ring (4f_MS SPRing)


Chapter 3 Survivable Network and Protection Mechanisms

3.1 Linear Protection

3.2 MSP Ring

3.3 Sub-Network Connection Protection (SNCP)


Linear Protection System

Linear protection systems are the simplest among the

protection mechanism and are mainly used in traditional

systems.

Protection Channel

Working Channel

A B C D


1+1 Linear MSP SystemIn 1+1 linear MSP system, protection is realized via the “concurrent sending and selective receiving” function.

When the working channel fails, both sides switch to receive from the protection channel.

Each side sends the service on both working and protection channels, but receives only from working channel.

Switching

BA


1+1 Linear MSP System

Switching modes of 1+1 linear MSP system:

Unidirectional switching or Bidirectional switching

Revertible mode or Non-revertible mode

Result:

Unidirectional switching in revertible mode

Unidirectional switching in non-revertible mode

Bidirectional switching in revertible mode

Bidirectional switching in non-revertible mode

APS protocol necessity:

Unnecessary for unidirectional switching in non-revertible mode

Necessary for other modes


1:N Linear MSP SystemIn 1:N linear MSP system, one protection channel protects the services on N working channels.

Protection Channel

Working Channel 1

Working Channel 2

Working Channel N

NE A NE B

Extra TrafficNormal Traffic

SwitchingSwitching Switching Switching


1:N Linear MSP System

Switching modes of 1:N linear MSP system:

Bidirectional switching

Revertible mode

APS protocol necessity:

Necessary


Linear Protection System

Features:

Based on TM (Terminal Multiplexer)

Switch within point and point

2 minutes later after configuration, APS protocol starts

automatically


Summary: Linear Protection System

Protection switching criteria are SF and SD:

SF (Signal Fail): R_LOS, R_LOF, MS_AIS, B2_EXC.

SD (Signal Degrade): B2_SD.

APS Necessity:

Except for unidirectional switching in non-revertible mode

1+1 MSP system, the others require the APS protocol.

Network Capacity:

1+1 linear MSP system: 1STM-N.

1:N linear MSP system without extra traffic: NSTM-N.

1:N linear MSP system with extra traffic: (1+N) STM-N.


Questions

Which protection switches fastest?

Which one can carry extra traffic?




3.2 MSP Ring



Protection Rings: Classification

Protection rings can be classified as follows:

Based on traffic protection levels

Path Protection (PP) Ring *

Multiplex Section Protection (MSP) Ring

Sub-Network Connection Protection (SNCP) Based on traffic direction

Unidirectional protection ring

Bidirectional protection ring Based on the number of fibers

Two-fiber protection ring

Four-fiber protection ring


NE AE W

W E NE C

NE BW

E

E

WNE D

Two-fiber Bidirectional MSP Ring (2f_MS SPRing)

Fiber connection:

Dual slots are necessary.

West is in the left dual slot,

East is in the right dual slot.

out

in


Two-fiber Bidirectional MSP Ring (2f_MS SPRing) Half of each fiber (1~N/2 VC4) is defined as the working channel (S) and

another half (N/2+1~N VC4) is defined as the protection channel (P).

NE B

NE C

NE D

NE A

2f_MS SPRing

STM-16

Working channel (S): :#1VC4~#8VC4

S1S2 P1

Protection channel (P): #9VC4~#16VC4

P2



The profile view of one fiber for STM-16 2f_MS SPRing is shown below.

VC-4 #1VC-4 #2VC-4 #3VC-4 #4VC-4 #5VC-4 #6VC-4 #7VC-4 #8VC-4 #9VC-4 #10VC-4 #11VC-4 #12VC-4 #13VC-4 #14VC-4 #15VC-4 #16

Working channel

Protection channel

Fiber


NE B

NE C

NE D

NE A

2f_MS SPRingSTM-16


S1

S2

Normal traffic flow between NE A and NE C:


NE C

NE D

NE A

2f_MS SPRingSTM-16

Two-fiber Bidirectional MSP Ring (2f_MS SPRing) If the fibers between A and B are broken, the service between A and C will

NE B

S1

P1

S2

P2

P2 be switched to the protection channels.

Bridging


NE B

NE C

NE D

NE A

2f_MS SPRingSTM-16


S1

S2

After the fibers between A and B are restored, the service will be normal 10minutes later.



Protection switching trigger conditions: Automatic protection switching

− SF (Signal Failure): R_LOS, R_LOF, MS_AIS, B2_EXC− SD (Signal Degrade): B2_SD

External initiated protection switching− Forced switch− Manual switch− Exercise switch

Protection switching restoration: Automatic protection switching

− Clear of SF (Signal Failure): R_LOS, R_LOF, MS_AIS, B2_EXC− Clear of SD (Signal Degrade): B2_SD− WTR (Wait to Restore): 10 minutes (5-12 minutes provisionable)

External commands− Clear of Forced switch− Clear of Manual switch


Two-fiber Bidirectional MSP Ring (2f_MS SPRing) APS controller:

Processes APS protocol and algorithm

− APS protocol is carried in the K1, K2 bytes.

Transition of APS controller status:

I = Idle

P = Pass-through

S = Switching

WTR = Wait to Restore

P

WTR

WTR P

I

I

I I

P

S

S P



Features of 2f_MS SPRing:

Advantages:

− Time slots can be reused

− High network capacity: ½ x M x STM-N

Disadvantages:

− Mechanism is complicated

− Maximum number of nodes on one ring is limited to 16

Application:

− Mainly for STM-4 and STM-16 or above systems

− Scattered traffic distribution


Four-fiber Bidirectional MSP Ring (4f_MS SPRing) Structure:

Four fibers

Working channels--S1,S2, carry normal traffic

Protection channels--P1,P2, protect normal traffic

A

DC

EF

B

S1

S2

P1

P2


A

DC

EF

B

A->DD->A

A->DD->A

S1

S2

P1

P2

Traffic flow when network is normal:

Working channels=S1, S2

Protection channels=P1, P2

Four-fiber Bidirectional MSP Ring (4f_MS SPRing)


Traffic flow after the working channel (s) is (are) broken only:

Span switching


A

DC

EF

B

A->DD->A

A->DD->A

S1

S2

P1

P2


A

DC

EF

B

S1

S2

P1

P2

A->D

A->DD->A

D->A

Traffic flow after the working and protection channels are broken:

Ring switching




Protection switching trigger conditions:

Automatic protection switching: Ring or Span

− SF (Signal Failure): R_LOS, R_LOF, MS_AIS, B2_EXC

− SD (Signal Degrade): B2_SD

External initiated protection switching: Ring or Span

− Forced switch

− Manual switch

− Exercise switch



Protection switching restoration:

Automatic protection switching: Ring or Span

− Clear of SF (Signal Failure): R_LOS, R_LOF, MS_AIS, B2_EXC

− Clear of SD (Signal Degrade): B2_SD

− WTR (Wait to Restore): 10 minutes (5-12 minutes provisionable)

External command: Ring or Span

− Clear of Forced switch

− Clear of Manual switch

APS controller status:

Idle

Switching

Pass-through

WTR



Features of 4f_MS SPRing:

Advantages:

− Time slots can be reused

− High network capacity: M*STM-N

Disadvantages:

− Mechanism is complicated

− Maximum number of nodes on one ring is limited to 16

− Expensive

Application:

− Mainly STM-16 or above system

− Scattered traffic distribution

− Backbone system


Summary: MSP Ring

MSP ring 2f_MS SPRing 4f_MS SPRing

Similarity

APS protocol necessary

Nodes number on MSP ring ≤16

SCC unit configures MSP protocol

Dual slots

Bidirectional and dispersed services

Difference

K*STM-N/2 capacity

(without extra service)

K*STM-N capacity

(without extra service)

Unique span switch

K1&K2 in protection fiber




3.2 MSP Ring




Description:

Protect one Sub-Network

Connection

Can be adapted to all networks

SNCStarting Node

SNCTerminationNode

ProtectionSNC

WorkingSNC

Sub-Network 1

Sub-Network 2

NE A NE B

Selector


Protection mechanism

Concurrent sending

(transmitting end)

Selective receiving

(receiving end)

A

B

C

D

in

out

out

out

out

out

out

out

in

in

in

in

in

in

in

SNCP Ring

2M

2M

STM-N

Sub-Network 1

Sub-Network 2

Sub-Network Connection Protection (SNCP)Concurrent sending

Selective receiving

out


Protection mechanism

Concurrent sending

(transmitting end)

Selective receiving

(receiving end)

A

B

C

D

in

out

out

out

out

out

out

out

in

in

in

in

in

in

in

SNCP Ring

2M

2M

STM-N

Sub-Network 1

Sub-Network 2


Concurrent sending

Selective receivingSwitching

out


Protection Restoration:

Restoration time - 10 minutes (5-12 minutes provisionable)


10 minutes later

A

B

C

D

switching

S1

P1A

B

C

D

S1

P1


Working source Protection source

Service sink

Detection point

Protection switching trigger conditions

Default

− AU_AIS, AU_LOP, TU_AIS, TU_LOP, HP_LOM, HP_UNEQ

B3_EXC, Unplug the line card

Optional

− HP_TIM, HP_SLM, B3_SD


SNCP service


Summary

A survivable network is capable of restoring services within a very short

time and without any human intervention in the event of a failure.

Linear protection networks can be classified into 1+1 linear MSP system

and 1:N linear MSP system.

Ring protection networks can be classified into Path Protection (PP) ring,

Multiplex Section Protection (MSP) ring, and Sub-Network Protection

(SNCP).


Summary

Item 2f_MS SPRing SNCP

APS protocol necessary unnecessary

Typical services Bidirectional and distributed unidirectional and centralized

Switch level (objective) MS SNC services

Suitable networking Only ring All topology

Switching implementing boards

LU, XC LU, XC

Switch time ≤50ms ≤50ms

Network Capacity (without extra service)

K*STM-N/2 STM-N

Extra traffic Supported Not supported


Questions

What is the difference between unidirectional ring and bidirectional

one?

What’s the difference between SNCP and MSP?

Which protection network can carry extra traffic?

www.huawei.com

Thank You

Documents

02-OptiX OSN Series Networking and Application ISSUE1.30