Exchange & Cabinet Tour
19th November 2009
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• Traditional fixed telephony is based around a central office or exchange that serves customers with an urban planning limit of 3.6km. Note that this was often exceeded, using multiple cable gauges, especially in Auckland,
• The outside plant, typically consists of three main components; the feeder, the distribution and the drop. The main distribution frame (MDF), copper cross connect cabinet and the distribution pillar serve as the termination points between the three main components.
Customer’sHome
MD
F
Connectivity toNational
Network
FeederCable
DistributionPillar
DistributionCable
ET
P*ETP -ExternalTest Point
MDF - MainDistribution Frame
AccessNetwork
Equipment
200+pairs50+ pairs
DropLead
2 Pair
Copper CrossConnect Cabinet
130,000 km of distribution cable
Nationwide
Typically direct buried
9,000 km of feeder cable nationwide
Typically in ducts
Traditional Copper Network
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• A copper network is capable of very high speeds (towards 100Mbps). However this is only attained by using very high frequencies which drop away with length. The higher bandwidth means the higher the frequencies that need to be used.
• This is why a network that is designed for the low frequencies of voice (300-3400Hz) does not carry the high frequencies (up to 30MHz for VDSL2) for broadband the same distances.
• Improving the performance of the network therefore comes not from fundamentally changing it, just from shortening the length of copper between the customer and the equipment generating the high frequencies.
• Essentially shortening the loop is replacing the copper cross connect cabinet with a new active cabinet that houses a DSLAM and is connected by fibre back to the network.
• Telecom has been doing this for new build and lifecycle replacement since 1996.
Customer’sHome
DistributionPillar
New Active Cabinet
DistributionCable
50+ pairs
DropLead
2 Pair
ET
P
NewFibre
Feeder
MD
F
AccessNetwork
Equipment
Connectivity toNational
Network
The Exchange Equipment and MDF isshifted into the cabinet
The bulk of theaccess network isuntouched by the
transition
Cabinetisation means moving fibre closer to the customer
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ISAM EthernetTo IPCore
Fibre Feeder
VoiceBroadband
10M on CopperTDM Data
100M & 1000MFibre
Cabinet Local Exchange Aggregation Networks
The basic building blocks
DSLAM or Ethernet Switch
AggregationSwitch
Edge
Telecom IP Core Network
Application Edge
Local Loop / Access Network
Core TransportNetwork
Core Transport Network
AggregationTransport Network
AggregationTransport Network
Customer
DSLAM
Voice Mux
SDH Transport SDH Transport
NEC DTLM
Host DSLAM
ATM
Ethernet
PSTNVoice onCopper
Fibre Feeder
Fibre Feeder
To rest ofPSTN
To IPCore
To IPCore
Fibre direct to the customer 10M / 100M / 1000M
DSL onCopper
TDM DataCopper
Cabinet Local Exchange Aggregation Networks
OLD
NEW
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• Size of cabinets
- Single bay cabinet 1660w x 1500h x 600d - Double bay cabinet 2250w x 1500h x 600d - Mostly single bay cabinets will be deployed (some double bays required)
Single and Double Bay Whisper Cabinets
On the outsideOn the inside
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Typical cabinets that will be replaced
USC(PCM) & PedestalNokia 480 PCM
BPO Cross-connect
Nokia 240 PCM
Krone Cross-connect Nokia 60 PCM