MPLS SDN 2014 - Topology independant LFA

Topology Independent LFAOrange use case & applicability

Stéphane Litkowski, Orange ExpertBruno Decraene, Orange ExpertMPLS 2014

2 TI-LFA

Orange Business Service

MPLS 2014

One of the largest dedicated network for business•Worldwide :

• 172 countries, 900+ cities•France :

• more than 2 million business clients, SMBs and companies in France

IP VPNEthernetInternetCloudVoice & TelepresenceHigh value: availability, security, SLA

http://www.orange.com/

3 TI-LFA MPLS 2014

Agenda

Requirements

Topology Independent LFA

Applicability on Orange topologies

Simulation results


4 TI-LFA MPLS 2014

Agenda

Requirements



Simulation results


5 TI-LFA MPLS 2014

Why using Fast Reroute ?

Fast convergence is below 1sec BUT:– hard to have the same performance on all nodes– hard to maintain convergence time while network is growing

Applications are more and more sensitive (VoIP, CRM, Sync, transport)

Customers do not want to rewrite or customize their applications code to handle network failures


6 TI-LFA

FRR issue

MPLS 2014MPLS 2014MPLS 2014


7 TI-LFA

FRR issue Primary path


South East

5ms


8 TI-LFA

FRR issue Primary path Backup path


South East

8ms


9 TI-LFA MPLS 2014

FRR issue

MPLS 2014MPLS 2014


10 TI-LFA MPLS 2014

FRR issue

MPLS 2014MPLS 2014

Primary path5ms


11 TI-LFA MPLS 2014

FRR issue

MPLS 2014MPLS 2014


12 TI-LFA MPLS 2014

FRR issue

MPLS 2014MPLS 2014

FRR33ms


13 TI-LFA

Backup8ms

MPLS 2014

FRR issue

MPLS 2014MPLS 2014

FRR33ms


14 TI-LFA

Backup8ms

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FRR issue

MPLS 2014MPLS 2014

FRR33msCOMPLETELY

UNOPTIMAL !!!!


15 TI-LFA

Backup8ms

MPLS 2014

FRR issue

MPLS 2014MPLS 2014

FRR33msCOMPLETELY

UNOPTIMAL !!!!DAMAGE NETWORK


16 TI-LFA

Backup8ms

MPLS 2014

FRR issue

MPLS 2014MPLS 2014

FRR33msCOMPLETELY

UNOPTIMAL !!!!DAMAGE NETWORKDAMAGE CUSTOMER

SERVICE


17 TI-LFA

Backup8ms

MPLS 2014

FRR issue

MPLS 2014MPLS 2014

FRR33msCOMPLETELY

UNOPTIMAL !!!!DAMAGE NETWORKDAMAGE CUSTOMER

SERVICEFRR


18 TI-LFA MPLS 2014

How to improve ?

Requirements– 100% coverage link and node protection– No transient congestion– Optimal routing– Simple solution to operate and understand– Scalable solution


19 TI-LFA MPLS 2014

What is the more optimal and natural path upon a failure ?

Post-convergence path from the PLR

Benefits of using Postconvergence path :– Policy compliant and optimized– Well sized – Well known

D

S Potential backup Path

Postconvergence PathHow to use Post-convergence path

for FRR ?

How to improve ?


20 TI-LFA

Agenda

Requirements



Simulation results


21 TI-LFA

Providing 100% coverage (node/link/SRLG)

Segment Routing Fast-Reroute solution – SR allows to use « unlimited » number of paths

encoding any FRR path by using Segment Routing blocks :

– any Service Provider policy (LFA policy framework)– including post-convergence path as new criteria

Primary traffic does not require to be SR :– IP or LDP can be protected by SR

MPLS 2014



22 TI-LFA MPLS 2014


Cannot use a strict only Explicit Path due to depth of segment stack

We need to compress the stack Done by reusing rLFA/dLFA building blocks (P & Q space)

S R1 R2 R3 D

R4 R5 R6

MPLS MPLS MPLS MPLS

2

MPLS

AdjR5AdjR6AdjR3

MPLS

AdjR6AdjR3

MPLSAdjR3

MPLS

Primary

TI-LFA


23 TI-LFAMPLS 2014


FRR path is computed as follows :– Compute postconvergence shortest path (new SPF)– Enforce loop-freeness by :

– finding a P node on the path– finding a Q node on the path after P (P and Q may be

equal)– Only P to Q path would be explicit and may be

additionnaly compressed using nodal segments

S R1 R2 R3 D

R4 R5 R6

MPLS MPLS

2

MPLSNodeR5

MPLSNodeR5

MPLS

MPLS

PQ

S R1 R2 R3 D

R4 R5 R6

MPLS MPLS

2

MPLS

NodeR5

MPLS MPLS

MPLS

P50 Q

AdjR6

NodeR5AdjR6 AdjR6


24 TI-LFA MPLS 2014

Agenda

Requirements



Simulation results


25 TI-LFA

Analysis on topologies : case #1TI-LFA for path optimality

Paris

Paris

Paris

Paris STR

STR

Dijon

Lyon

Lyon

Paris

Lyon

Poitiers

Primary

MPLS 2014

Paris

Out of transitnode


26 TI-LFA


Paris

Paris

Paris

Paris STR

STR

Dijon

Lyon

Lyon

Paris

Lyon

Poitiers

Primary

MPLS 2014

Paris

Out of transitnode


27 TI-LFA


Paris

Paris

Paris

Paris STR

STR

Dijon

Lyon

Lyon

Paris

Lyon

Poitiers

Primary

BackupMPLS 2014

Paris

Out of transitnode


28 TI-LFA MPLS 2014


Paris

Paris

Paris

Paris STR

STR

Dijon

Lyon

Lyon

Paris

Lyon

Poitiers

FRR path

Paris

Out of transitnode


29 TI-LFA MPLS 2014


Paris

Paris

Paris

Paris STR

STR

Dijon

Lyon

Lyon

Paris

Lyon

Poitiers

MRT

FRR path

Paris

Out of transitnode


30 TI-LFA MPLS 2014


Paris

Paris

Paris

Paris STR

STR

Dijon

Lyon

Lyon

Paris

Lyon

Poitiers

MRT

FRR path

RSVP-TE link protection (1:n)

Paris

Out of transitnode


31 TI-LFA MPLS 2014


Paris

Paris

Paris

Paris STR

STR

Dijon

Lyon

Lyon

Paris

Lyon

Poitiers

LFA

MRT

FRR path

RSVP-TE link protection (1:n)

Paris

Out of transitnode


32 TI-LFA


Paris1

Paris2

Paris3

Paris5 STR

STR

Dijon

Lyon

Lyon

Paris4

Lyon

Poitiers

EPC FRR

Nodal

EPC stack composed of one segment

Protection stackNode_Pari

s4

MPLS 2014

Paris

Out of transitnode


33 TI-LFA MPLS 2014

Analysis on topologies : case #2TI-LFA using multiple segments

PE1

R1

PE2

R2R3

R4 R5

R6

R7

PE3

1

7

3

3

311 1

11

2

100 100

Primary

Backup

SR Segments


34 TI-LFA MPLS 2014


PE1

R1

PE2

R2R3

R4 R5

R6

R7

PE3

1

7

3

3

311 1

11

2

100 100

Primary

Backup

SR Segments


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PE1

R1

PE2

R2R3

R4 R5

R6

R7

PE3

1

7

3

3

311 1

11

2

100 100

Primary

Backup

SR Segments


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PE1

R1

PE2

R2R3

R4 R5

R6

R7

PE3

1

7

3

3

311 1

11

2

100 100

Primary

Backup

SR Segments

P

Q


37 TI-LFA MPLS 2014


PE1

R1

PE2

R2R3

R4 R5

R6

R7

PE3

1

7

3

3

311 1

11

2

100 100

Primary

Backup

SR Segments

P

QProtection stack (PQ)

Adj_R3

Adj_R4

Adj_R6

Adj_R7

Adj_PE3

Top

Bottom


38 TI-LFA MPLS 2014


PE1

R1

PE2

R2R3

R4 R5

R6

R7

PE3

1

7

3

3

311 1

11

2

100 100

Primary

Backup

SR Segments

Protection stack compressed

P


Adj_R3

Adj_R4

Adj_R6

Adj_R7

Adj_PE3

Top

Bottom


39 TI-LFA MPLS 2014


PE1

R1

PE2

R2R3

R4 R5

R6

R7

PE3

1

7

3

3

311 1

11

2

100 100

Primary

Backup

SR Segments


Node_R3

P


Adj_R3

Adj_R4

Adj_R6

Adj_R7

Adj_PE3

Top

Bottom

Top

Nodal to R3

Nodal to PE3


40 TI-LFA MPLS 2014


PE1

R1

PE2

R2R3

R4 R5

R6

R7

PE3

1

7

3

3

311 1

11

2

100 100

Primary

Backup

SR Segments

Nodal to PE3


Node_R3

Node_PE3

P


Adj_R3

Adj_R4

Adj_R6

Adj_R7

Adj_PE3

Top

Bottom

Top

Bottom

Nodal to R3

Nodal to PE3


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PE1

R1

PE2

R2R3

R4 R5

R6

R7

PE3

1

7

3

3

311 1

11

2

100 100

Primary

Backup

SR Segments

Nodal to PE3


Node_R3

Node_PE3

P


Adj_R3

Adj_R4

Adj_R6

Adj_R7

Adj_PE3

Top

Bottom

Top

Bottom

Nodal to R3

Nodal to PE3


42 TI-LFA MPLS 2014

Analysis on topologies : case #3Maximum observed stack depth

PE1

PE2

R1

R2

R3

R4

R5R6

100

100

21

23

3

1

3

13

1000

Primary

Backup

SR Segments


43 TI-LFA MPLS 2014


PE1

PE2

R1

R2

R3

R4

R5R6

100

100

21

23

3

1

3

13

1000

Primary

Backup

SR Segments


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PE1

PE2

R1

R2

R3

R4

R5R6

100

100

21

23

3

1

3

13

1000

P


Node_R3

Adj_R4

Adj_R5

Adj_R6

Adj_PE2

Primary

Backup

SR Segments

Top

Bottom


45 TI-LFA MPLS 2014


PE1

PE2

R1

R2

R3

R4

R5R6

100

100

21

23

3

1

3

13

1000

P


Node_R3

Adj_R4

Adj_R5

Adj_R6

Adj_PE2 Node_R3

Primary

Backup

SR Segments

Top

Bottom


46 TI-LFA MPLS 2014


PE1

PE2

R1

R2

R3

R4

R5R6

100

100

21

23

3

1

3

13

1000

P


Node_R3

Adj_R4

Adj_R5

Adj_R6

Adj_PE2

Node_R5

Node_R3

Primary

Backup

SR Segments

Top

Bottom


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PE1

PE2

R1

R2

R3

R4

R5R6

100

100

21

23

3

1

3

13

1000

P


Node_R3

Adj_R4

Adj_R5

Adj_R6

Adj_PE2

Node_R5

Node_R6

Node_R3

Primary

Backup

SR Segments

Top

Bottom


48 TI-LFA MPLS 2014


PE1

PE2

R1

R2

R3

R4

R5R6

100

100

21

23

3

1

3

13

1000

P


Node_R3

Adj_R4

Adj_R5

Adj_R6

Adj_PE2

Node_R5

Node_R6

Node_R3

Adj_PE2

Primary

Backup

SR Segments

Top

Bottom


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PE1

PE2

R1

R2

R3

R4

R5R6

100

100

21

23

3

1

3

13

1000

P


Node_R3

Adj_R4

Adj_R5

Adj_R6

Adj_PE2


Node_R5

Node_R6

Node_R3

Adj_PE2

Primary

Backup

SR Segments

Top

Bottom

Top

Bottom


50 TI-LFA MPLS 2014

Agenda

Requirements



Simulation results


51 TI-LFA MPLS 2014

Simulations results on 11 Orange NetworksDepth of protection stack

11 topologies have been analyzed including multiple network types and size


52 TI-LFA

Simulations results on 11 Orange Networks

MPLS 2014

80% of nodes have 12 or less distinct repair_lists


53 TI-LFA

100% FRR link/node protection is a requirement

Current FRR technics may cause some side effects :– Transient network congestion– Additionnal management for selection of the backup path

Topology Independent LFA :– Scalable : no additional state in the network– Simple to compute

– Provides 100% link/node protection– Prevents any side effect by using a well sized and optimal path– Simple to understand : well known path

MPLS 2014

Conclusion


Thank you !

MPLS SDN 2014 - Topology independant LFA

Technology

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