Combining the benefits ofmultilayer optimization andpacket-optical integration
Sandrine Pasqualini, Colby Barth, Cyril Margaria
MPLS Japan 2015, November 9th

1Copyright © 2015 Juniper Networks, Inc.

Introduction• Multi-Layer Optimization combined with packet-Optical Integration can leadto significant network CAPEX & OPEX savings• The following slides will discuss several network architectural options to help
determine the best long term packet-optical strategy• We will begin with a Baseline network & analyze several incrementaloptimizations
Op#miza#on	  'Savings'	  45%	  40%	  35%	  30%	  25%	  20%	  15%	  10%	  5%	  0%	  Baseline	  2Op2mized	  (bypass	  3)	  Op2mized	  (min	  bypass)	  PTX	  only	  Copyright © 2015 Juniper Networks, Inc.

Methodology• Create baseline using current network• Based on ‘fixing’ the links present in the current network (with a bit of cleaning up: aggregating parallellinks, getting rid of remote ASs, etc. …)• In the IP layer, model intra-PoP connectivity as well as inter-PoP connectivity (total of 92 nodes, 32 PoPs)• Count the number of ports in each layer & apply generic costs

PE-routerP-routerPE-routerP-routerInternal PoP structure3

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Transport network• ROADM network, 100G wavelengths• Point-to-point DWDM map (41 nodes, 60 links)

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Traffic matrix• The network provides reliable traffic data
• Full mesh of auto-bandwidth RSVP-TE LSPs
• Year1 traffic: 2.703T
5-­‐Year	  Traﬃc	  Growth	  Rate	  45%	  40%	  35%	  30%	  25%	  20%	  15%	  10%	  5%	  0%	  40%	  35%	  Year1	  5Year2	  30%	  30%	  30%	  Year3	  Year4	  Year5	  Copyright © 2015 Juniper Networks, Inc.

Cost	  model	  • Generic	  costs	  We	  want	  to	  look	  at	  what	  aspects	  of	  cost	  can	  be	  used	  to	  inﬂuence	  the	  model	  without	  having	  speciﬁc	  vendor	  discoun2ng	  interfering	  Coun2ng	  ports,	  when	  considering	  mul2ple	  dimensions,	  does	  not	  always	  reﬂect	  the	  best/lowest	  cost	  design	  • Other	  computa2on	  constraints	  250k iterations per design set
100% B/W protection via IP/MPLS
Never exceed 24T per PoP from Year-0 to 2
Never exceed 48T from Year-3 to 5	  6Example	  generic	  ‘costs’	  used	  in	  this	  exercise	  Pla2orm	  port	  types	  10G	  100G	  SR	  100G	  LR	  100G	  ITU	  Tunable	  Normalized	  cost	  1	  2	  3	  	  	  22	  Copyright © 2015 Juniper Networks, Inc.

Calculating a baseline model• Design rules••••

All core links are aggregated into Nx100G links
Connectivity (inter-PoP and intra-PoP) is ‘fixed’ and follows existing network
IP links routed on shortest transport path (or shortest diverse, for protecting traffic)
IP links dimensioned to carry all traffic, with 100% protection• Costing the result• Count the number of interfaces• Apply generic costs

7Copyright © 2015 Juniper Networks, Inc.

Cost benefits of packet-optical integration• The baseline network makes use of significant amounts of router
bypass• Up to 6 bypassed routers for some IP links• We want to show that
• Reducing router bypass to an optimum amount provides a more cost
efficient network• Improved latency without increasing hop count significantly• Improved link utilization while still guaranteeing 100% traffic protection• Leveraging packet-optical integration provides significant additional costsavings• Colored router ports• Scales well over a 5-year period with 30% to 40% traffic growth

8Copyright © 2015 Juniper Networks, Inc.

What is Packet Optical Integration?
Data	  Plane	  Integra#on	  Control Plane Integration

Colored	  op)cs	  in	  the	  router	  enable	  CAPEX	  savings	  by	  elimina)ng	  grey	  interfaces,	  transponder	  boards	  &	  shelves,	  and	  OPEX	  savings	  on	  power	  consump)on	  and	  footprint.	  

TE-controller and SDN for multi-layer, andapplication driven traffic engineering.	  Op)mizes	  QoS	  (latency,	  throughput),	  	  network	  availability	  and	  	  u)liza)on.

Management Plane Integration
End-to-end wavelength provisioning. Virtualtransponders allow management of router interface
through the transport NMS.

9Copyright © 2015 Juniper Networks, Inc.

Multilayer optimization scenarios• Evaluate multiple optimization scenarios based on ‘cost’ & ‘design-rules’• Maintain Intra-PoP structure• Fixed traffic matrix: 96k demands, 2.7Tb of total traffic & fixed transport layer• 100% protection for single link & SRLG failures• Optimized designs, comparing various levels of bypass• Bypass3: maximum allowed bypass between 2 remote sites = 3• BypassMin: maximum allowed bypass between 2 remote sites = 0• Some sites do not have a P-router and can still be bypassed (max bypass is 2)• PacketOptical: same design rule as bypassMin, but considering additional cost benefits ofpacket optical integration.

10Copyright © 2015 Juniper Networks, Inc.

Multilayer planning engine• MIND Optimization engine• Minimizes overall transmission and equipment costs whilesatisfying traffic, resiliency, and performance requirements
for multilayer networks• MIND Design Challenge• Create the optimal IP/MPLS (client-layer) design Given thePE-to-PE traffic matrix• Based on a known Transport (server layer) network CreateTransport ‘routes’ to satisfy client layer design• Or based on abstract server-layer plus associatedconstraints to define the server topology and the SRLG
information for the IP layer• The optimum solution is obtained by selectively pruning theIP topology from the set of possible links obtained from thetransport layer or abstract links plus constraints

Other	  planning	  	  Applica#ons	  MIND	  MLP	  Applica#on	  Candidate Links
Transport & IP
Nodes
Traffic Matrix

NorthStar	  Controller	  	  Mul2-­‐layer	  Network	  11Copyright © 2015 Juniper Networks, Inc.

Design parameters• Design inputs• Node groups• Candidate link definitions• To restrict intra- and inter-PoP connectivity• (e.g. no PE to remote P-router connectivity)• Node multilayer mappings• Between nodes in same site

• Project global design constraints• Maximum bypass• Cost inputs• Hardware types and costs• Link types and costs

12linkType LayerName carriedDemandType linkBandwidth
ET10G IP
Packets
10GET100G IPPackets
100G
ET100G Transport Packets
100GhardwareType LayerName baseCost portUnit
MXIP
1000 10G
PE_router
PTX_IP
IP
1000 100G
P_router
ROADM
Transport
1000 100G

linkType LayerName Section LinkCostFixed LinkCostperKM
ET10G IP
11100.01
ET100G IP
1500
0.01
ET100G Transport
15000.01

Copyright © 2015 Juniper Networks, Inc.

Optimized bypass3 model

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•••

All core links are aggregated into (Nx)100G links
Intra-PoP links are aggregated to 100G if the # of 10G > 5
Intra-PoP connectivity structure is maintained•

Set a maximum bypass rule of 3 (going down from 6 in Baseline)

Baseline

Bypass3Copyright © 2015 Juniper Networks, Inc.

Optimized bypassMin model• Same baseline rules as previous design• Notes• Bypass = 0 except in a few areas where bypass = 2 (going down from a max of 3 inbypass3 scenario)• Some sites do not have a local P-router to connect directly too thus we need totraverse multiple ROADMs to connect to the nearest P-router14Baseline

BypassMin

Copyright © 2015 Juniper Networks, Inc.

Optimized PacketOptical integration• Same design rules as BypassMin• Applying integrated packet-optical integrated architecture to count ports• Notes• Cost reduction is dominated by the removal of the back-to-back client interfaces
between P-routers and ROADMs

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Results
ROADM	  	  client	  side	  port	   line	  side	  port	  reduct	  reduct	  	  100G	  WAN	  port	  reduct	  	  Baseline	  	  Bypass3	  	  BypassMin	  -­‐	  12%	  -­‐12%	  -­‐	  26%	  36%	  -­‐	  100%	  99%	  -­‐	  1%	  9%	  -­‐	  15%	  -­‐11%	  	  PacketOp#cal	  89%	  75%	  99%	  9%	  -­‐65%	  ROADM	  Total	  	  Normalized	  total	  network	  cost	  	  Baseline	  	  Op#mized	  (bypass	  3)	  	  Op#mized	  (min	  bypass)	  	  PacketOp#cal	  1610G	  port	  reduct	  P-­‐router	  	  100G	  Local	  port	  reduct	  PE-­‐router	  888.00	  378.00	  352.00	  352.00	  P-­‐router	  1400.00	  808.00	  1008.00	  6029.00	  13908.00	  10368.00	  9168.00	  3398.00	  16196.00	  11554.00	  10528.00	  9779.00	  Savings	  -­‐	  29%	  35%	  40%	  Copyright © 2015 Juniper Networks, Inc.

RSVP reserved vs. unreserved B/W• Using the auto-bandwidth LSPs & IP/MPLSview CSPF
• More room to grow despite lower cost for Bypass3 & BypassMin
Average	  link	  u2liza2on	   Average	  peak	  link	  u2liza2on	  Baseline	  39.00%	  67.59%	  Bypass3	  BypassMin	  31.99%	  61.68%	  36.98%	  64.33%	  80%	  60%	  Avg	  LinkU2l	  40%	  Avg	  PeakU2l	  20%	  0%	  PMO	  17

ByPass3	  MinBypass	  Copyright © 2015 Juniper Networks, Inc.

Min/Max latency comparison• Hop count (steady-state & worst-case) increases while path distance (steadystate & worst-case) is reduced• Better performance characteristics!
Path distance (km)IP layer	  Baseline	  	  Op#mized	  (bypass	  3)	  	  Op#mized	  (min	  bypass)	  Hop countWorst case hop count

Avg

Max

Avg

MaxAvgMaxAvg

Max

1279

9213

3392

11279

3.9

9

5.67

12

1399

7456

2608

9184

4.01

13

6.04

181134

7399

3127

9459

4.57

14

7.42

194000	  12000	  3000	  9000	  2000	  PathDistAvg	  6000	  PathDistMax	  1000	  WCPathDistAvg	  3000	  WCPathDistMax	  0	  0	  Baseline	  18Worst case pathdistance (km)Bypass3	  minBypass	  Baseline	  Bypass3	   minBypass	  Copyright © 2015 Juniper Networks, Inc.

MLO trending
Long-­‐term	  trending	  results	  in	  an	  increasing	  year-­‐over-­‐year	  savings	  • Savings:	  ~40%	  in	  year-­‐1	  to	  ~90%	  in	  year-­‐5	  Analysis	  used	  a	  ﬁxed	  A-­‐>Z	  traﬃc	  matrix	  with	  incremental	  growth	  over	  a	  5-­‐year	  cycle	  •45%	  40%	  35%	  30%	  25%	  20%	  15%	  10%	  5%	  0%	  40%	  35%	  Year1	  Year2	  30%	  30%	  30%	  Year3	  Year4	  Year5	  5-­‐Year	  Total	  CAPEX	  Comparison	  MLO	  enables	  YoY	  adapta2on	  in	  the	  event	  the	  traﬃc	  changes	  100%	  B/W	  protec2on	  via	  IP/MPLS	  for	  PTX-­‐
only	  model	  System	  Capaci2es	  <	  24T	  WC	  per	  PoP	  from	  year-­‐0	  to	  2	  <	  48T	  WC	  per	  PoP	  from	  	  year-­‐3	  to	  5	  195-­‐Year	  Traﬃc	  Growth	  Rate	  90%40%

2014	  Year02015	  Year12016	  Year2

Baseline PTX	  only	  PMO	  Year32017	  Linear	  (PMO)	  PacketOptical2018	  Year4Year52019	  Linear	  (PTX	  only)	  Copyright © 2015 Juniper Networks, Inc.

MLO planning study highlights• Benefits of packet-optical integration• Significant cost savings given an optimium amount of bypass• More efficient network• Importance of taking all layers into account• Not only at planning stage, but operations as well

Operational challenges towards
multilayer optimized IP/MPLS networks

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Challenges for clients of transport networks
Clients	  of	  a	  Transport	  Network	  …	  	  § No	  visibility	  into	  the	  network’s	  	  actual	  topology	  	  § No	  resource	  availability	  informa2on	  § For	  good	  reason:	  ü Security	  Considera2ons	  ü Technology	  Considera2ons	  ü Scalability	  Considera2ons	  21However,	  Clients	  need	  to	  inﬂuence	  …	  § The	  way	  the	  services	  	   provided	  to	  them	  are	  routed	  	  across	  the	  transport	  network	  ü Some	  services	  need	  to	  be	  disjoint	  ü Some	  services	  need	  to	  be	  co-­‐routed	  	  ü Some	  services	  need	  to	  be	  op2mized	  based	  on	  lowest	  cost	  criteria,	  while	  	  ü Some	  services	  need	  to	  have	  the	  best	  delay	  characteris2cs	  Copyright © 2015 Juniper Networks, Inc.

WAN SDN controller with multilayer visibility• Compute ‘optimal’ paths for packet(client-layer) LSPs••••

Dynamic SRLGs from transport
Latency from transport
Optical protection in-use
Coordinated multilayer maintenanceOp#cal	  Controller	  Applica#on	  NorthStar	  REST/RESTCONF	  server	  REST/RESTCONF	  Mul2layer	  topology	  Path	  computa2on	  server	  • Facilitate multilayer planning &optimization

BGP-­‐LS	  • Populate planning tool server-layer
topology• Populate planning tool traffic-matrix

PCEP	  • Multi-layer provisioning
Server-­‐Layer	  22Client-­‐Layer	  Copyright © 2015 Juniper Networks, Inc.

Thanks