Post on 17-Dec-2015
transcript
Copyright VersaTel Telecom 2000Marc Teichtahl
Part One: The Design Brief
“effect the migration from traditional
transmission technologies to a next
generation platform optimized for the
transmission of purely packetized data”
Copyright VersaTel Telecom 2000Marc Teichtahl
The General Business Drivers
• Provide all services over IP based infrastructure
• Reducing costs & Increasing revenues = $PROFIT$
• Single management platform
• Ease of on-going operations and support
• Lower maintenance costs
• Lead the technology push into IP optics
• Influence the early adopters
Copyright VersaTel Telecom 2000Marc Teichtahl
Our Specific Business Drivers
• Utilize “owned” fiber network
• Match fiber topology against network architecture
• Decrease $/Mbps
• Shorten provisioning lead-time
• Shorten product time to market
• Provide “endless” scalability
• Allow for DWDM “plug & play”
• Provide forward consideration to MPLS and MPλS
Copyright VersaTel Telecom 2000Marc Teichtahl
50155 CAPEX(USD Millions)
PRODUCTS
IP Circuits
WAN Services
MPLS Services
Streaming Media
TECHNOLOGY
SDH/DPT
DPT
x4
x8
0Note: Revenues in millions USD
VOIP
WAN Carriage
????
The Business Drivers
Copyright VersaTel Telecom 2000Marc Teichtahl
Our Choices and Decisions
Key Challenges-:
• Mapping the topologies
• Matching segment parameters
• Designing optical regeneration
• SRP overhead considerations
• PoP Selection
• Fitting the rings together
Copyright VersaTel Telecom 2000Marc Teichtahl
To SDH or not to SDH ?
• SDH provides circuit capabilities
• DPT does not offer circuit capacity but pure IP
Does this impact our business model ?
• Lower unit revenue from IP sales – IP is cheaper
• Cheaper to implement DPT
Key factor to financial success
• Must yield high volume sales to be more profitable
Copyright VersaTel Telecom 2000Marc Teichtahl
To SDH or not to SDH ?
• SDH will always have a higher incremental cost
• You still have to add the router
• SDH will yield a broader range of more profitable products
• DPT will offer pure optimised IP capacity
Copyright VersaTel Telecom 2000Marc Teichtahl
To SDH or not to SDH ?
• Some segments may utilize SDH due to
• Optical Length or path loss
• Fibre requirements to close the ring
Copyright VersaTel Telecom 2000Marc Teichtahl
The Problems
• 9 Fiber Rings
• 35 PoP
• 3 Countries
• Geographical distances and optical limitations
• Traffic distribution
• Line card limitations
The Solutions
• International Core ring
• Local distribution rings
• Optical Regeneration
Mapping The Topologies
Copyright VersaTel Telecom 2000Marc Teichtahl
Mapping The Topologies - Logical
M ons
RotterdamDen Haag Alkmaar
S loterd ijkHaarlem
VersaTower Kru islaan
Breda Utrecht
Antwerpen
Luik
Hasselt
Leuven
Brussel
Charlero i
Kortrijk
G ent
Amersfoort
Zwolle
Deventer
Arnhem
Nijmegen
Leeuwarden
G roningen
Enschede
Den Bosch
M aastricht
Heerlen
Venlo
Eindhoven
ring A
ring B
ring Cring E
ring D
ring F
core ring
Antwerpen
R otterdam Slo terd ijk
D en Bosch
VenloBrusse l
Copyright VersaTel Telecom 2000Marc Teichtahl
Mapping The Topologies - Logical
Versatel F iber Distance and Attenuation
Design by: René Koning
Ow ner: Data Netw ork Developm ent
Revis ion Date: M arch 20 2000
Vers ion Agreed by:
65.2km14.0 dB
33.0km7.6 dB
58.0km12.5 dB
21.0km4.2 dB
53.0km12.2 dB
29.0km6.7 dB
57.8km12.3 dB
78.0km17.4 dB
35.5km8.9 dB
51.0km11.7 dB
64.8km13.1 dB
64.5km14.8 dB
30.0km6.9 dB
96.0km19.5 dB
31.0km7.1 dB
24.8km4.8 dB
85.7km18.7 dB
63.9km13.3 dB
80.0km18.4 dB
36.0km8.3 dB
61.0km14.0 dB
38.0km8.7 dB
79.0km18.1 dB
41.0km9.4 dB
31 km7.1 dB
Dist. and Attenuation(@ 1550nm)
52.0km9.5 dB
104.0km23.9 dB
105.0km24.2 dB
71.0km16.3 dB
Mons
Charleroi
75.0km17.3 dB
41.0km9.4 dB
61.0km14.0 dB
Luxembourg
150.0km34.5 dB
Namur
157.0km36.1 dB
42.0km9.7 dB
105.0km23.4 dB
56.0km12.9 dB
Kortrijk
30.2km6.9 dB
31.0km7.1 dB
Alkmaar
HaarlemSloterdijk
Kruislaan
VersaTower
Utrecht
Den Bosch
BredaRoosendaal
Rotterdam
Den Haag
Antwerpen
Gent
BrusselLeuven
Hasselt
Luik
Maastricht
Heerlen
VenloEindhoven
Nijmegen
Arnhem
Deventer
Enschede
Groningen
Leeuwarden
Zwolle
Amersfoort
11.0km2.5 dB
22.9km5.9 dB
Copyright VersaTel Telecom 2000Marc Teichtahl
Line Card Limitations
• Proprietary to Cisco
• Currently in IETF for standards ratification
• Optical path loss limitations of 25dB
• Currently limited to OC-48
• Maximum 32 SRP nodes per ring
• Slot capacity for OC-48 and OC-192
Copyright VersaTel Telecom 2000Marc Teichtahl
Matching Segment Parameters
• Each optical segment must be within the optical tolerance for all components
• Achieved by the use of optical regenerators
• On some paths consideration was given to using SDH
• Not used due to capacity constraints
• Unable to scale as quickly as a purely optical solution “plug&play”
Copyright VersaTel Telecom 2000Marc Teichtahl
Optical Regenerations
• Based upon tolerances of SRP line cards
• Maximum loss 25dB
• Maximum optical path length 80Km
• This was achievable due to the physical fibre paths and ability to easily splice where needed
Copyright VersaTel Telecom 2000Marc Teichtahl
Overhead Considerations
• SRP enforces additional overhead to SDH
• IPS only travels between adjacent nodes
• Topology discovery messages
• natively 32 bytes + 8 bytes per node
• sent every 5 seconds
• 10 node ring provides ~1.5Kbps for IPS
• This is negligible
• Total overhead = IPS+Topology Disc+Usage control
• For 10 nodes ~2Mbps
• On a OC-12 Ring overhead is ~0.31%
Copyright VersaTel Telecom 2000Marc Teichtahl
Overhead Considerations
Inter-node SRP Overhead
0102030405060708090
100
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31
Number of Nodes
Ove
r H
ea
d (
byt
es/
s)
Copyright VersaTel Telecom 2000Marc Teichtahl
PoP Selection
• PoPs selected on two criteria
• Commercial – ROI
• Technical
• Optical distances
• Proximity to IP interesting sites such as exchange points.
Copyright VersaTel Telecom 2000Marc Teichtahl
International Core Ring
OC-48 International core ring
• Based on Cisco 12016
• Covering route 1001.4Kms / 625.875Miles
• Utilizing 5 optical regenerators
• Optical loss tolerance 4.2dB<<OL<<24.2dB
Copyright VersaTel Telecom 2000Marc Teichtahl
Local Distribution rings
OC-12 Local distribution rings
• 8 Distribution rings
• Based on Cisco 12008
• Covering route > 3000Kms / 1875M
• Utilizing 19 optical regenerators
Copyright VersaTel Telecom 2000Marc Teichtahl
SRP Interconnect Issues
We require a ring interconnect methodology that allows for the overlay of a complex routing architecture.
Core R ing Core R ing
D istribution R ing
Local PoP
Copyright VersaTel Telecom 2000Marc Teichtahl
SRP Interconnect Issues
Unknown inter ring SRP issues.
• Statistical possibility of run away restore conditions
• Both Rings wrapping at same time
• Inter-Ring IPS over-head
• OC-48 -> OC-12 serialization issues
Copyright VersaTel Telecom 2000Marc Teichtahl
Routing Issues
• Use of a per PoP border router
• Utilizes ISIS and BGP
• DPT Overhead issues
• SDH comparisons
Copyright VersaTel Telecom 2000Marc Teichtahl
PoP Router Designations
• Each PoP has a border router.
• Connected to distribution routers
–Speed of transport between PoPs in event of failure
–Lower costs
• Multiple full tables
Copyright VersaTel Telecom 2000Marc Teichtahl
• Each PoP has a designated “net” identifier
• All inter-PoP routes are kept as level-1
• All intra-PoP, core and distribution routes are summarized on the PoP border routers into level-2
• Dial supernets are summarized at the dial aggragation router into level-2
• Core only carries level-2 summary routes.
ISIS Configuration
Copyright VersaTel Telecom 2000Marc Teichtahl
• Summarization is only allowed at level borders
• Causes internal PoP summarization issues
• Maintainence of huge topology tables.
• Integration with legacy OSPF networks may still prove to be an issue in the future
• Lack of flexibility in route selection and metric preferences
ISIS Issues
Copyright VersaTel Telecom 2000Marc Teichtahl
• Ease of configuration
• Simple adaptation for MPLS
• Via ISIS-extensions for MPLS
• Convergence speeds
• Flexibility in PoP and “net” naming schemes
ISIS Benefits
Copyright VersaTel Telecom 2000Marc Teichtahl
• All PoP border and customer aggragation routers are bgp speakers
• Utilization of full mesh between the PoP
• Utilization of confederations on a per PoP basis
• Use of route reflectors in the PoP
BGP Design
Copyright VersaTel Telecom 2000Marc Teichtahl
• Optically aware IP
– Utilizing both IP layer and optical layer MPLS signaling we aim to provide intelligent IP lambda capacity
– Allowing the IP layer to request further capacity from the optical.
– Allowing the optical layer to request a layer three re-route to avoid optical “congestion”
The Future Vision