Concept of ASON

7/31/2019 Concept of ASON

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10/25/2012 Rajesh JTO RTTC Rajpura 1

Concept of Automatically switchedOptical Network

- Rajesh, JTO


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What is ASON?The automatically switched optical network is a newgeneration optical transmission Network.

OverviewRecently SDH optical communication system widely used

an telecommunication in backbone layer, metropolitan layer &

in access layer in transport network. SDH offers first

protection and excellent management performance.

with the development of telecommunication network and

increasing user demands some problems in SDH systems

appear more than more serious such as low bandwidth utilize

and monotonous protection.


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ASON just come to solve the above problems

The ASON is an optical transport network composed

of ASON Network elements. ASON performance

signaling transmission and switching. These NEs can

store the topology, routing information of the whole

network, automatically create and remove services

through signaling.



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What is ASON / GMPLS

CP(Control Plane)

TP(Transport Plane)

CCI

UNI data

UNI control

NMI

NNI E-NNI

CCI

NMI

The purpose of the control plane isto:

Enhance Network Reliability andStability

Lower Network TCO(Total Cost ofOwnership)

Simplify Network Operation

ASON/GMPLS Introduces control

plane to ON.Its the first time to adopt dynamic

switching function.

Distributed control plane is thetrend.

Network Management Interface

MP(Manage Plane)

ASON: Automatic Switched OpticalNetwork, Requirements

defined by ITU-T.

GMPLS: Generalized Multi-ProtocolLabel Switching, A seriesprotocols (LMP, RSVP-TE,OSPF) defined by IETF.

NENE

NENE NE

OCCOCC

OCC OCC

OCC

Connection

Control Interface

NMS


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The Logical Architecture of an ASON can be divided into 3

planes:

Transport Plane

Control Plane

Management Plane

The Transport Plane contains a number switches ( optical orotherwise) responsible for transporting user data via

connections. These switches are connected to each other via

PI (Physical Interface).


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The Control Plane is responsible for the actual

resource and connection management within an ASNnetwork. It consists of a series of OCC (OpticalConnection Controllers), interconnected via NNIs (Network to Network Interfaces).

These OCCs have the following functions:Network Topology discovery (Resource discovery)Signaling, Routing, Address AssignmentConnection Set-up/Tear-downConnection protection/restoration

Traffic EngineeringWavelength assignment



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Management Plane is basically a complementplane of control plane. It maintain the transport plane,

the control plane and the whole system. Its mainfunctions are as follows:-

1- Performance management

2- Fault management 3-Configuration management

4- Security management




How does ASON/GMPLS work ?

Automatic Resource Discovery (LMP)

Lower OPEX

Mesh Networking (OSPF)Improve resource utilization

Automatic Restoration (RSVP)

Enhance reliability

?

?

? ?


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Where does ASON/GMPLS work


Internet Traditional Voice ServiceVPN3G&NGNIPTV

Mesh networking improvesresource utilization Plug & play

Fast expansion and upgrade

SLAs

IP Core

Optical Transport Network

Edge layer Router

ASON node

Inter-city Network

Metro/Regional Network


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In an optical network without ASON, when-ever a user

requires more bandwidth, a new connection has to be requested

and the service provider has to manually plan and configure the

route in the network.

This is not only time consuming, but also wastes bandwidth

when the user economically uses the connection.The bandwidth

demand is going to increse with every momemts &IT has

become precious resource.We have the expectations from future

optical networks that they will be able to efficiently handleresources as quickly as possible .

The Need for ASON


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The Need for ASON

ASON will be able to fulfill the requirements for thenewer generation of optical networks such as:

Fast and automatic end-to-end provisioning

Fast and efficient re-routing

Support of different clients, but optimized for IP Dynamic set up of connections

Support of Optical Virtual Private Networks (OVPNs)

Support of different levels of quality of service

(These requirements are not restricted to optical networks and canbe applied to any transport network (including SDH Networks)


P f tl i t ki ith


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Perfectly inter-working withtraditional SDH network

TraditionalNetwork

NMS: T2000

Hybrid Network of ASON network and traditional MSP-Ring

Unified NMS of ASON NE and legacy NE

E2E service point&click provisioning between traditional and ASON NE by Unified NMS

The timeslot of ASON NE can be configured as static circuit

Supports virtual TE-link

ASON Network

Traditional circuit

Intelligent circuitThe same fiber

Traditional NE

ASON NE

Virtual TE-link

Intelligent circuit


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Supported optical transport services

Permanent OCh:- Permanent connection is a serviceconnection computed before hand and created through NM.The traditional SDH connections are permanent connection.

Switched OCh:-Switched connection is a service connectionrequested by a terminal user like Router and then created in the ASON

control plane through signaling at the UNISoft Permanent connection :-.setup from the management

system using routing capabilities embedded in the network. It requiresrouting and signaling at the NNI to establish the connection.

Optical Virtual private Network

Lamda trunking:



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Resource Reservation

The time slot created with ASON Services are managed bythe ASON software and cannot be used by the any software tocreate permanent connection.

Level Switching Path (LSP) The LSP is the path of ASON services passing through in

ASON to create ASON services is to crate LSPs.

Control Channel (CC) Control channels are created and maintained between

adjacent nodes by link management protocols (LMP). Controlchannels divided into two types:-

1. In fiber Control Channel:- Usage DCC channel (D4 to D12) andcan be discovered automatically.

2. Out of fiber Control Channel:- Usage the Ethernet link and needmanual configuration.



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High Reliability Control Plane: controlchannel backup


Dm~Dn Dm~Dn

Dm~DnDm~Dn

Dm~Dn

Dm~Dn

Dm~DnNMS

Out-of-Band (DCN)

In-Band (D-byte)

Supports in-band (D-byte) and/or out-of-band control channel.

Provides 1+1 stand-by for control channels when both in-band and out-of-band are deployed.

The working channel will switch to the backup one in case of working channel failure.


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Control Link:- Controls links are detected and maintained byOSPF protocol. All ASON NEs get the control topology of thenetwork.

Traffic Engineering Link (T E Link):- T E Link is thetraffic engineering link. The ASON, NEs sends its bandwidthinformation to other ASON NEs through the T E Link to provide fordata route computation.

Rerouting :-rerouting is means of resuming services .when anLSP is disconnected, the source node queries and finds a best routeto resume services.

Rerouting Lockout :-rerouting is not required after failure ofLSP in some cases then we need rerouting lockout

Rerouting Priority :-when several LSPs have the samesource node reroute simultaneously ,the LSP of higher priorityreroutes first and has more possibility to reroute successfully.



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Shared risk link group (SR LG) :-fibers in the sameoptical cable have the same risks, when the cable is cut ,all fibersare cut. therefore ASON services should not be rerouted to another

link that has the same risk.


Topology Auto-Discovery

Control Topology Auto-Discovery :-after the fibers in anASON network are connected correctly ,each ASON NE discovers control

links automatically through OSPF and floods its own control link to the

whole network.

Service Topology Auto -Discovery :-After an ASON NEcreates a control channel between neighbors NEs through LMP,TE linkverification can be started. Each ASON NE floods its own TE links to the

whole network through OSPF-TE. Each NE then gets the network wide

TE links. this is network wise service Topology.


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Control topology auto-discovery


R1

R2

R3

R4

:ASON NE

:User equipment


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Service topology auto-discovery


:ASON NE

:User equipment

R1

R2

R3

R4


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End To End Configuration


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End-To-End Configuration

The ASON supports both SDH permanent connections and end-to-end

ASON services. To configure an ASON service, we only need to

specify its source node, sink node, bandwidth requirement and

protection level. Service routing and cross connection at intermediate

n o d e s a r e a l l a u t o m a t i c a l l y c o m p l e t e d b y t h e n e t w o r k .

As compared with the service configuration of the SDH network, it fully

utilizes the routing and signaling functions of ASON NEs and thus it is

convenient to configure the service.



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Provide Multiple levels of service: SLA

Index Diamond Gold Silver Copper Iron

Service level

Protection

scheme

Permanent 11

Protection

1 + 1 Protection +

Restoration

1 + 1 Protection

Virtual Ring

Protection

Virtual Ring

Protection +

Restoration

Dynamic Restoration

Pre-Calculating

Restoration

Shared Mesh

Restoration

None None

Description

Provide permanent

protection for service

when network resource

is utilizable

Performs as protection

most of the time, if

protection is invalid,

restoration works

Real-time restoration

of service, no need of

standby resource

Index Protection time


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Different kinds of service for different customers needs.

Protection and restoration combine for multi failures,improves the reliability

Supports High and Low Restoration Priority

Hitless interchanging on line between SLAs


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D i a m o n d s e r v i c e s h a v e t h e b e s t p r o t e c t i o n a b i l i t y .W h e n t h e r e a r e e n o u g h r e s o u r c e s i n t h e n e t w o r k ,

Diamond services provide a permanent 1+1 protection &

ASON/GMPLS based restoration. Diamond services are

a p p l i c a b l e t o v o i c e a n d d a t a s e r v i c e s , V I P p r i v a t e

L i n e , s u c h a s B a n k i n g , S e c u r i t y a n d A v i a t i o n .

DIAMOND SERVICE (PLATINUM SERVICE)

Di d S i P t 1 1 P t ti


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Diamond Service: Permanent 1+1 Protection

Working Path

Protection Path

Any change of resource will be indicated on the NMS immediately

Provide permanent protection for service when network resource is utilizable

The highest quality private-line solution: 99.9999%

NMS

Di d S i P i R i


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Diamond Service 1+1Protection+Restoration


Provide once 50ms protection and multi restoration, Anti multi fiber-failures

NMS

Working Path

Protection Path


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Diamond Service 1+1 Protection

NMS

Working Path

Protection Path


Provide 50ms protection for once fiber-failure


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GOLD SERVICE

Gold services are applicable to voice and significant

data services. Compared with diamond services, gold

services have greater bandwidth utilization.

When a fiber on the path of a gold service is cut, the

ASON triggers MSP switching to protect the service at

first. If the multiplex section protection fails, The ASON

triggers rerouting to restore the service.


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Gold Service: Virtual RingProtection + Restoration


NMS

Virtual Ring

Protection Route

Restoration Route


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Gold Service: Virtual RingProtection + Restoration

When the first fiber cut happens, virtual ring will performprotection(


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SILVER SERVICE

Silver services, the revertive time is hundreds ofmilliseconds to several seconds. The silver level

Service is suitable for those data or internet services

that have low real-time requirement. Silver servicesare also called rerouting services. When an LSP

failure, the ASON triggers rerouting to restore the

service. If there are not enough resources, service

may be interrupted.

Silver Service: No Dedicated Resource is


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Silver Service: No Dedicated Resource isNeeded

NMS

original path

rerouting path

Revertible


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Silver Service: No Dedicated Resource isNeeded

When service is fall down, it will be restored to the newroute. Service rerouting can be set as Revertible or Non-revertible.

All restoration service can be treat as High or Low priority,

When resource is limited, High priority service isguaranteed to be reroute

Rerouting can be locked / unlocked.

Improves the bandwidth utilization dramatically and providecontrolled networking


Sil S i P C l l i /P l R i


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Silver Service Pre-Calculating/Preplan Restoration

MDS6600

iManager T2000

Preplan path

preplan path

original path

rerouting path

Rerouting according to the preplan path

Controllable and predictable circuit resource managing

Silver Service Shared Mesh Restoration


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Silver Service Shared Mesh Restoration

MDS6600iManager T2000

Bandwidth Resource Reserved Path

reserved path

original path

rerouting path

Rerouting according to the reserved path

1

2

shared restorationresource

Insure service restoration

100% successfully

VC4

Sil S i Sh d M h


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Silver Service Shared MeshRestoration

The pre-defined path will be dispatched to nodesthrough the T2000 after simulating by MDS6600


The pre-defined path will be dispatched to nodes through the

T2000 after simulating by MDS6600.

The overlapped timeslot resources can share by multiple

reserved routes

Ensure the success of 100% of rerouting and guarantee the

reliability of rerouting for key services


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COPPER SERVICE

The copper services are seldom used. Generally,

temporary services, such as the abrupt services in

holidays, are configured as copper services.

Copper services are also called non-protection

services. If an LSP fails, services do not reroute

and are interrupted.


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IRON SERVICE

The iron services are also seldom used. Generally, temporary

services are configured as iron services. For example, when service

volume soars, during holidays, the services can be configured as

iron services to fully use the bandwidth resources.


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Best Effort Rerouting When No Many

Directions


Original Route

Other Route

Bandwidth availabilityis improved by reusing

part of the original route

When there are not so many directions, Best effort rerouting can succeed in

finding a route to go, so that network reliability is enhanced


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Concept of ASON

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