Chapter 14: Remote Connectivity

Question 1

Describe SONET.

Answer 1

Makes up vast majority of long distance connections.

Question 2

What is a local exchange?

Answer 2

-defined grouping of individual phone circuits served by a single multiplexer.

Question 3

What is a central office:

Answer 3

handles one or more exchanges

Question 4

What is the last mile?

Answer 4

connection from central office to individual users.

Question 5

Describe DS0.

Answer 5

• digital signal rate

- 64 Kbps

Question 6

What is a T-carrier?

Answer 6

• digital trunk carrier.
• T1: high speed digital networking technology.
• line is shielded two-pair cabling that connects to ends of a T-1. Two send, two receive.
• CSU/DSU: Channel service unit/digital service unit.

Question 7

Describe DS1.

Answer 7

• digital signal one: special signaling.
• frame consists of 25 pieces; framing bit and 24 channels.
• channel: single 8 bit DS0 data sample. 193 bits per DS1 frame
• frame transmitted 8,000 ties per second for a throughput of 1.544 Mbps.
• TDM.

Question 8

Describe fractional t1 access.

Answer 8

where you just but some of the channels.

Question 9

Describe a t3

Answer 9

data rate of 45Mbps on dedicated telephone connection.

-672 individual DS0 channels. mainly used by regional telephone companies and ISPs.

Question 10

Describe an E1.

Answer 10

• similar to T1

- 2.048 Mbps(32 channels at 64 Kbps)

Question 11

Describe an E3.

Answer 11

16 E1 lines. 34 Mbps

Question 12

What does a CSU/DSU perform?

Answer 12

-performs line encoding and conditioning functions.

Question 13

What is the function of a CSU?

Answer 13

• protects t1/T3 line from lightening stikes and other electrical interference.
• stores statisticas and capabilities for loopback testing.

Question 14

What is the function of a DSU?

Answer 14

• supplies timing to each user port.

- converts user’s data signal and converts to specificed line code and framing format for transmission.

Question 15

Describe a T1.

Answer 15

24 channels, 1.544 Mbps

Question 16

Describe a T3,

Answer 16

672 channels, 44.736 Mbps

Question 17

Describe an E1.

Answer 17

32 channels 2.048 Mbps

Question 18

Describe an E3 line.

Answer 18

512 channels 34.368 Mbps

Question 19

What does SONET stand for?

Answer 19

Synchronous Optical Network (US)

Question 20

What does SDH stand for?

Answer 20

Synchronous Digital Hierarchy(europe)

Question 21

What does SONET do?

Answer 21

Defines inteface standard at physical and data link layers

-important standard for making WAN interconnections.

Question 22

What are OC standards?

Answer 22

Optical Carrier Standards.

• denote optical data-carrying capacity in bps of fiber optic cables.
• OC speeds from 51.8Mbps(OC-1) to 39.8 Gbps(OC-768).

Question 23

What is WDM?

Answer 23

Wavelength division multiplexing.

• newer version is Dense WDM
• can support approximately 150 signals. 7.7 gigabytes

Question 24

What is STS?

Answer 24

Synchronous Transport Signals.

• STS payload: data
• STS overhead: signaling and protocol info.

Question 25

What is X.25?

Answer 25

- First generation of packet switching. | - CCITT packet switching protocol.

Question 26

What is Frame Relay?

Answer 26

- used primarily with T-carrier lines. - no data integrity. - being replaced by ATM and MPLS

Question 27

What is ATM?

Answer 27

Asynchronous Transfer MOde - integrated voice, video and data on one connection. - short fixed length packets (cells) - 155.52 - 622.08 Mbps and beyond.

Question 28

Describe MPLS

Answer 28

Multiprotocol Label Switching - adds an MPLS label that sits between Layer 2 header and layer 3 info. - purpose: move traffic quickly by providing network-wide quality of service.

Question 29

What is a BERT?

Answer 29

Bit Error Rate Test: verifies T-carrier connection from end to end.

Question 30

Describe 802.16 wiMax

Answer 30

range up to 30 miles

Question 31

What is a b-channel?

Answer 31

- DS0 channel | - two b, one d.

Question 32

What is BPL

Answer 32

Broadband over PowerLine | -powerline communications

Question 33

What is citrix

Answer 33

- WinFrame/Metaframe | - independent computing architecture.

Question 34

Describe RTP

Answer 34

Real-Time Transport Protocol bedrock of VOIP standards.

Question 35

Describe SIP and H.323

Answer 35

- setup, delivery of VOIP sessions - use multicasting - run on top of RTP.

Question 36

Describe real time streaming protocol.

Answer 36

runs on TCP port 554.