Deck 8: Layer 1 Networking Protocols

Question 1

The digital signal standard used in North America to define the bit-per-second rate is the North American Digital ________.

Answer 1

Hierarchy

Question 2

As defined by the North American Digital Hierarchy, the DS-0 channel has a rate of ________ kbps and is equivalent to one channel of information.

Answer 2

64kbps

Question 3

________ is the partitioning of a bit stream into definable patterns.

Answer 3

Framing

Question 4

The framing standard that improves the reliability of the circuit and extends the number of overhead bits available is called:

A) superframe
B) extended superframe
C) prolonged superframe
D) enhanced superframe

Question 5

Framing bits that synchronize the equipment are also called synchronization flags, or:

A) Fm bits
B) Fr bits
C) Fs bits
D) Ft bits

Question 6

Framing bits that are used for signaling are called:

A) Fm
B) Fr
C) Fs
D) Ft

Question 7

________ bit signaling occurs when the least significant bit is used to form a pattern that represents on-hook, off-hook, ringing, no ringing, busy, and so forth.

Question 8

A 64 kbps channel has an overall bit rate of ________ kbps.

Question 9

Clear channel signaling is used instead of robbed bit signaling to eliminate the loss of bits when ________ is being transported.

Question 10

The main difference between ESF (extended superframe) and SF (superframe) is the number of frames within the master frame.

Question 11

Cyclic redundancy check guarantees a 99.999% error-free circuit and is considered equally as efficient as SF error-checking.

Question 12

Part 15 of the FCC's Rules and Regulations docket states that no more than ________ consecutive zeros can be transmitted in a row so that the terminating equipment doesn't become confused.

A) 32
B) 26
C) 15
D) 13

Question 13

The keep alive signal is required when no signal is present in order to keep the end pieces of equipment ________.

Question 14

The most common line-coding scheme used today is:

A) B8ZS
B) Bit 7
C) AMI
D) ZBTSI

Question 15

The T1 circuit standard is built around a(n) ________-interleaved format.

Question 16

The DS-2 circuit uses a(n) ________-interleaved structure when multiplexing ones and zeros.

Question 17

How many 64 kbps can travel on one DS-1 circuit?

A) 16
B) 24
C) 64
D) 128

Question 18

The names DS-2 and T1 are used interchangeably

Question 19

The T1 circuit is able to carry ________ Mbps.

Question 20

The acronym used to describe the practice of breaking information into chunks and placing it in specific time slots is ________.

Question 21

Bits used to carry information about a signal, such as error rates, are called:

A) relative bits
B) conversion bits
C) overhead bits
D) underneath bits
E) information bits

Question 22

Although it is unlikely that the DS-2 signal will emerge as a popular transmission method, it will always be found embedded in the ________ signal.

Question 23

Which of the following is not a method used to define the structure of the DS-3 signal?

A) M23 framing format
B) C-bit parity format
C) clear channel
D) ESF

Question 24

The most common DS-3 framing format used today is:

A) M23
B) C-bit parity
C) clear channel
D) ESF

Question 25

In a(n) ________ signal, there is no timing source.

Question 26

In the DS-2 frame format, M bits are used to align the ________.

Question 27

In the DS-13 M13 frame format, the overhead bits used for messages are the:

A) F bits
B) M bits
C) P bits
D) X bits
E) C bits

Question 28

The C-bit parity frame structure differs from the M13 frame format, primarily in Blocks 3, 5, and 7.

Question 29

When a DS-3 is optioned for ________, there is no framing format attached.

A) M23
B) C-bit parity
C) M13
D) clear channel

Question 30

The purpose of the 560 Mbps system is to multiplex more information on one fiber-optic strand.

Question 31

A known advantage of SONET over the North American Digital standard is that it:

A) ensures equipment interoperability
B) allows smooth handoffs between the international standard and the North American standard networks
C) provides a flexible network topology
D) increases the transmission rate
E) introduces the ring architecture, thereby increasing the network's survivability
F) all of the above

Question 32

The seven interfaces commonly used in the SONET hierarchy are VT-1.5, VT-6, OC-1, OC-3, OC-12, OC-48, and ________.

Question 33

In the SONET hierarchy, the Term VT:

A) stands for video technology
B) is used to define the higher rate signals mapped into a SONET STS-1 frame
C) both a and b are true
D) neither a nor b is true

Question 34

The SONET level that carries 155 Mbps of information is the:

A) OC-1
B) OC-3
C) OC-12
D) OC-48

Question 35

The purpose of the SONET hierarchy is to simplify the way lower rate signals are multiplexed into higher rate signals.

Question 36

One OC-48 signal can carry as many as 32,000 simultaneous voice conversations.

Question 37

The portion of the circuit that connects one SONET fiber multiplexer to another is called the ________.

Question 38

The stratum clock hierarchy defines how ________ the timing source is.

Question 39

The highest clock level provided by GPS is stratum:

A) 4
B) 3
C) 2
D) 1

Question 40

In bidirectional line switched ring, protection switching occurs at the ________ level of the network.

Question 41

Which is not a type of ring architecture in SONET?

A) bilateral multidirectional switched ring (BMSR)
B) bidirectional line switched ring (BLSR)
C) unidirectional path switched ring (UPSR)
D) none of the above (all are ring architectures)

Question 42

A BLSR ring provides better bandwidth usage than the UPSR but is more complicated and has a slightly longer switch-to-protect time.