Chapter 5 Cabling Topologies

Question 1

NAME THE 3 FUNDAMENTAL CABLING TOPOLOGIES?

Answer 1

1. STAR
2. RING
3. BUS

Question 2

NAME 5 TYPES OF HYBRID CABLING TOPOLOGIES?

Answer 2

1. HIERARCHICAL STAR
2. STAR-WIRED RING
3. CLUSTERED STAR
4. TREE AND BRANCH
5. MESH

Question 3

WHAT TOPOLOGY IS GENERALLY DEPLOYED FOR OSP CABLING?

Answer 3

STAR

Question 4

A star topology directly
links all buildings requiring
connection to the

Answer 4

(MC) MAIN CROSS-CONNECT (CD) CAMPUS DISTRIBUTOR

Question 5

What is the ideal location
for the MC (CD)?

Answer 5

1. CO-LOCATED WITH OR CLOSE TO THE PRIMARY ER.
2. AT THE CENTER OF THE BUIDLINGS BEING SERVED.
3. HAVE ADEQUATE SPACE FOR CORSS-CONNECT HARDWARE AND EQUIPMENT.
4. HAVE SUITABLE PATHWAYS LINING IT TO OTHER BUILDINGS.

Question 6

Name five advantages
associated with using a
star topology for campus
backbone cabling.

Answer 6

1. PROVIDES CENTRALIZED FACILITIES ADMINISTRATION.
2. ALLOWS TESTING AND RECONFIGURATION OF THE SYSTEMS TOPOLOGY AND APPLICATIONS FROM THE MC (CD)
3. ALLOWS EASY MAINTENENACE AND SECURITY AGAINST UNATHORIZED ACCESS.
4. PROVIDES INCREASED FLEXABILITY.
5. ALLOWS EASY ADDITION OF FUTURE CAMPUS BACKBONES.

Question 7

Name two disadvantages
associated with using a
star topology for campus
backbone cabling.

Answer 7

1. INTRODUCES SINGLE POINTS OF FAILURE.
2. INCREASES COST.

Question 8

What term is used to
describe the tree-like
structure where a trunk and
branch relationship exists
within a cabling topology?

Answer 8

HIERARCHICAL

Question 9

True or False
The link from the MC (CD)
to the IC (BD) may be an
interbuilding or an
intrabuilding link.

Answer 9

True. The link from the MC (CD)
to the IC (BD) may be an
interbuilding or an
intrabuilding link.

Question 10

IN TYPICAL APPLICATIONS, THE LINK FROM THE IC (BD) TO THE HC (FD) WILL BE OF WHICH TYPES?

Answer 10

AN INTRABUILIDING LINK

Question 11

What configuration should
the ICT designer consider
when the distance from the
switch to the last
workstation exceeds the
transmission limit?

Answer 11

Hierarchical star. In this
configuration, the first-level
backbone either cross-connects
or interconnects to the
second-level backbone via
active network equipment.

Question 12

What type of configuration
should the ICT designer
consider using when
available pathways do not
allow for all cables to be
routed to an MC (CD)?

Answer 12

Two-level hierarchical star. In
large networks, this allows
electronics (e.g., switches) to be
used more effectively to utilize
bandwidth and distance
capabilities of the cabling or to
segment the network physically.
TDMM: Page 5-8

Question 13

Why are ring topologies
increasingly becoming the
normal design architecture
for OSP operations?

Answer 13

Ring topologies can support
high-bandwidth transport
applications, sophisticated
routing schemes, and primary
and protection switching
capabilities.
TDMM: Page 5-9

Question 14

Name three benefits
associated with using a
ring topology.

Answer 14

1. FAULT-TOLERANT REDUNDANT ROUTING.
2. GREATER RELIABILITY AND SIGNIFICANTLY LESS CABLING SERVICE DOWNTIME.
3. FLEXIBLE ARCHITECTURE.

Question 15

What three conditions must
be met before a physical
ring topology can be
considered for connecting
the intrabuilding ICs (BDs)
and MCs (CDs)?

Answer 15

1. The existing pathways must
   support it.
2. The primary purpose of the
   network is optical fiber distributed
   data interface, SONET/ATM, or
   high-speed Gigabit Ethernet.
3. There is a redundant cable path.
   TDMM: Page 5-10

Question 16

When would a physical
star/logical ring be used?

Answer 16

• When ICT designer determines
  that a physical ring route is not
  possible
• When an existing cable will be
  used in a segment of the total
  project
  TDMM: Page 5-12

Question 17

Name three factors the ICT
designer will use to
determine if a clustered
star topology is an
appropriate solution.

Answer 17

1 .Electronics
2.Designer’s survivability plans
3. Transmission budget selected
at the MC (CD) and each node
site
TDMM: Page 5-13

Question 18

Name three advantages
associated with using a
clustered star topology.

Answer 18

1 . Allows for fault-tolerant redundant
routing at route locations
2. May reduce design costs for the
electronics and cables at the node sites
3. Takes advantage of the concentration
of electronic equipment in a common
location for network management
operations and efficiency
TDMM: Page 5-13

Question 19

What type of topology is a
linear configuration?

Answer 19

BUS TOPOLOGY

Question 20

What will happen if a break
occurs along the route of a
bus configuration?

Answer 20

All network communications
will be lost.
TDMM: Page 5-14

Question 21

What is a common
application of the tree and
branch topology?

Answer 21

Cable tv operations that use
coaxial cabling
TDMM: Page 5-15

Question 22

Name the two types of
mesh network topologies.

Answer 22

1 FULLY CONNECTED
2. PARTIALLY CONNECTED.

Question 23

Why are fully connected
mesh topologies not
adopted for most
networks?

Answer 23

1. Too expensive
2. Too complex
   TDMM: Page 5-16

Question 24

Where are fully connected
mesh topologies
commonly used?

Answer 24

In provider and enterprise
networks to connect their
routers when there are a limited
number of nodes and
redundancy is important.
TDMM: Page 5-16

Question 25

What formula is used to calculate the number of nodes required for a fully connected mesh topology?

Answer 25

N = x * (x-1)/2 N = Number of links X = Number of nodes TDMM: Page 5-17

Question 26

What is the minimum number of subscribers supported by the OLT?

Answer 26

Sixteen per port (utilizing a passive optical splitter) TDMM: Page 5-20

Question 27

Where is the optical network unit (ONU) assumed to be located?

Answer 27

The ONU is assumed to be on the outside the premise. TDMM: Page 5-22

Question 28

Name three locations where Ethernet over PTP balanced twisted-pair cable might be a good fit.

Answer 28

1. Established neighborhoods 2. Business parks 3. Multi-dwelling units (MDI-Js) TDMM: Page 5-26

Question 29

Why are load coils used?

Answer 29

To improve the (voice) transmission performance TDMM: Page 5-27

Question 30

How many levels of cross- connections are permitted in a backbone distribution system?

Answer 30

NO MORE THAN TWO.

Question 31

When are direct connections between T Rs permitted?

Answer 31

When the backbone distribution system is expected to meet the requirements for a bus or ring topology configuration TDMM: Page 5-35