ASPECTS OF NETWORK MIGRATION FROM ATM TO MPLS

gascitytankΔίκτυα και Επικοινωνίες

28 Οκτ 2013 (πριν από 3 χρόνια και 8 μήνες)

76 εμφανίσεις

ASPECTSOFNETWORKMIGRATIONFROM
ATMTOMPLS
AdrianMintaGh.
gygy@rdslink.ro
phd.studentincomputernetworksat"Politehnica"University,Bucharest,Romania,ComputerSciencedepartment
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.1/12
DELAYOFIPPACKETSINATMNETWORKS
ClassicalIPoverATM
!"#$%"&'*+,-&.
/01#"&'*+,-&.

Separateroutingandswitchingplane
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.2/12
DELAYOFIPPACKETSINATMNETWORKS
MPLSnetwork
!"
!"
!"
!"
#"
#"
#"

Onenetworkplane

Rotingattheedge

Switchinginthecore
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.3/12
ATMCELLOVERHEAD

ATMcell=48databytes+5bytesheader
Ecell
=48=53=0:9

IPdatagramsarebetween100and1500bytes(MTU)
Epadd
=
MTU
(int[
MTU
48
]+1)48
=
500
(10+1)48
=0:9467

Overallefficiencyfor500bytesMTUis:
Epvc
=E
cell
Epadd
=0:90:94=0:85=85%
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.4/12
ATMCELLOVERHEAD
IPdatagramencapsulationinATMcells
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*+"#$%&$'
*+",%-./%&
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,%&&1:;
<<<
<<<

EfficiencystronglydependsontheMTU

Celllosesinthenetworkdecreasetheefficiency

IfacellislostthewholeIPpacketislost,butisdiscardedonlyattheexit

PPD(PartialPacketDiscard)mayalleviatethis
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.5/12
NETWORKINSTABILITY

ATMandIPbothhaveroutingfunctionality.Thiscauseaundesiredeffectknown
as"IGRPstress".

Possiblesolution:staticroutes.Unfortunately,thissolutionrequiretheuseofn
2
staticroutesandPVC’s.
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.6/12
MPLSDEPLOYMENTMODELS
"Shipsinthenight"deploymentmodel
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-/,
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,445
5,#0123%'&
6.,7#10#589,
!"#$:%3;<#=*>0%;
!"#?@
",-.#-.,
!"#?@
",-.#-.,

SeparateATManMPLScontrolplanes

Sameswitchfabric
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.7/12
MPLSDEPLOYMENTMODELS
ATMtoMPLSmigrationPATH
!"
"Ships in the Night"
ATM and MPLS
separate control Planes
( cell based MPLS )
Separate ATM and MPLS
network on the same platform
( frame based MPLS )
ATM and MPLS
separate networks
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.8/12
MPLSEXTENSIONS
Proposedextensions:

VirtualPrivateWireServicesVPWS

VirtualPrivateLANServicesVPLS

VoiceoverMPLS

Frame-RelayoverMPLS
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.9/12
MPLSEXTENSIONS
PWE3NetworkReferenceModel
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!
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"&'*+,-&.
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C0st'3-&.
!,/-.#
C0st'3-&.
!,/-.$
"45.6077-8
"s-0,'.%+&-
!3089t-,.4-&*+:-
"%.!7,
4-&*+:-
"%.!7,
4-&*+:-
79t+*-.
s-&*+:-
79t+*-.
s-&*+:-
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.10/12
MPLSEXTENSIONS
VPLSandVPWSservices
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-./$-0
.11*.*-./$-*
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>>>
>>>
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.11/12
CONCLUSION

ATMisoptimizedforvoicetransportandMPLSisoptimizedforpackettransport

DependingonthedeploymentmodelMPLSoffersoperationalefficiencyand
majoradvantageswhenisusedforIPtraffic

MPLSallowsserviceproviderstoconvergetheirnetworkintoasingle
infrastructure

AtransitionfromATMtoMPLScouldprovidesomeimportantadvantages.
CSCS14,ASPECTSOFNETWORKMIGRATIONFROMATMTOMPLS–p.12/12