Nlr.net © 2004 National LambdaRail, Inc 1 Capacity Planning At Layers 1 and 2 Quilt Meeting Oct 13, 2006

nlr.net© 2004 National LambdaRail, Inc

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Capacity PlanningAt Layers 1 and 2

Quilt MeetingOct 13, 2006


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Capacity Planning - Basic Issues

• At Layer3 • Measure and monitor traffic on the link• Upgrade or add links based on average or peak traffic

utilization• Overprovision when possible

• At Layer1 and Layer2• Traffic utilization

– Part but not all of the planning Layer2– Not an issue at all for Layer1

• Availability and use of resources– What exists– What is planned


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Example - NLR Layer1

• Allocation Map• Indicates capacity of each segment along the

backbone• Easy to tell what the busy paths are• But isn’t the whole story when doing capacity

planning

Allocated Waves - Layer1


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Layer1 - Adding a new Lambda

• Need to assess what resources are available between Point A and Point B

• For each segment in the path• Can it physically support a new wave ?• Do needed resources (hardware, cables) already exist ?• If additional resources are needed, are they available?

– Equipment– Space– Power

• A “no” for any of the questions can mean• Capacity is not available along that specific path• An alternate path might be available

– But does it meet the original requirements?• Long delay in getting wave implemented


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• Path between Starlight (STAR) and Los Angeles (LOSA)• One of the most popular NLR routes• At least 5 possible paths

• Two are equivalent– STAR-CHIC-KANS-DENV-ODGE-BOIS-SEAT-

SUNN-LOSA– STAR-CHIC-KANS-DENV-RATO-ALBU-ELPA-

PHOE-LOSA• Others sub-optimal

– More segments– Too long a path


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• Currently - • Capacity exists along all 5 paths,

• Implement requested lambda along the most efficient route• Resources

• Use spare/quickstart wave where possible– Already installed transponders

» Channel planning already done– Replace ASAP in order to be prepared for next request

• Use spare transponders where spare/quickstart does not exist– 80-channel transponder cards provide most flexibility

» Otherwise may end up with channel conflicts– Replenish stock of cards as necessary

• Order additional transponders if necessary– Typically 8-12 weeks to install if new transponder cards are

needed.


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• Constant planning at layer1 is needed• Identify congested segments

• STAR-CHIC - already at 80% capacity• Upgrade plan in progress

– Requires both new fiber and new equipment

• Other busy segments• CHIC-KANS (45%), SEAT-PORT (40%), KANS-DENV &

CHIC-CLEV (35%)– Not yet a problem, but consider alternative paths

when possible to best utilize infrastructure


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• Capacity exists, but need additional equipment• Front Ends for each segment along Northern route are at

75% or greater capacity. – Resources required

» Equipment - new or existing» Additional co-location space» Additional Racks, Power

• Trade off between cost and delivering services in timely manner• Core set of shared spares, cost effective way to reduce

deployment time– Chassis, transponders, cables, amplifiers, etc.

• Other resources more costly to have “on-hand”– Co-location space, racks, power, fiber

» Add as needed, prioritizes resources with known long-lead times.


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Capacity Planning at Layer2

• Layer2 Planning has attributes of both Layer1 and Layer3 networks

• Link Utilization - traffic monitoring is important, but not the whole story

• Link Allocation• VLANs with reserved bandwidth

– Need to include in link utilization estimates, even if the bandwidth isn’t actually used

• Link Utilization and Allocation don’t always correspond• Segments with the most VLANs with dedicated bandwidth don’t

necessarily have the most traffic• Dedicated VLANs as backup paths

– Typically no traffic over the path, but bandwidth needs to be available (and un-congested) on demand.


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Capacity Planning at Layer1

• VLANs with non-dedicated bandwidth– May be the busiest segments– Viewed as cheap bandwidth, thus may be used more

than a more expensive link– End user should expect congestion (but that’s not

always the case !!)


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Layer2 Traffic Map - Traffic over each segment


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FrameNet VLAN Allocation


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Layer2 Capacity Planning

• Adding Capacity• Dedicated bandwidth - add capacity once

dedicated bandwidth allocation reaches 75%. • Actual Link Utilization -

• Need to add capacity once actual use reaches 75%• Or need to remind those with non-dedicated bandwidth

VLANs that congestion is possible.

• Where a busy Layer2 segment corresponds to a busy Layer1 segment

• Need to reserve Layer1 segment sooner rather than later

Documents

Nlr.net © 2004 National LambdaRail, Inc 1 Capacity Planning At Layers 1 and 2 Quilt Meeting Oct 13, 2006