test 1 Flashcards
Define circuit switching
Circuit Switching is the process of setting up and keeping open a physical circuit between two or more users until the connection is terminated.
ID the advantages of circuit switching
- The users have exclusive use of that specific circuit’s entire bandwidth.
- No congestion
- No channel access delay
- Low variance and end to end delay
ID the disadvantages of circuit switching
- Due to dedicated channels, circuit switching networks can be expensive
- Slight delay in establishing a connection due to overhead required to make a connection through numerous switchboards
- Inefficient use of bandwidth
ID the purpose of a switchboard
Provide capability to connect one telephone line to any other within a network, alleviating the need for multiple point-to-point circuits
Define Trunk Circuit
- Trunk is a communication line between two switching systems
- Trunked circuit is when a call is placed across a trunk
Define Point-to-Point Circuit
Dedicated connection directly between two telephones without the aid of a switchboard
(PIC)
Define Loop Circuit
Loop circuit connects a telephone to a switchboard
PIC
Define Long Local
Telephone set residing at a different site than the switchboard
Define Switchboard Code
Uniquely identify each switchboard within a circuit switching network
ID the purpose of Global Block Numbering Plan (GBNP)
- Incorporates all services into a joint network
- IDs a unique service-managed block of unit and subscriber numbers for each military branch
- IDs databases and sub-networks within the blocks of numbers
- Simplifies network management through the standardization of assignable NATO codes, area codes, and switchboard codes
ID the structure of the Global Block Numbering Plan
3 digit area code
4 digit switch code
3 digit subscriber code
Define Call Routing
Call routing is the method by which a switchboard routes traffic across trunks to other switchboards
Define Deterministic Routing
Traffic is sent to one route at a time via programmed routing tables
Define Alternate Routing
Provide a path for calls to travel through should the primary route fail
Define Switching Office
Central location that provides communication service to subscribers with the same office code (switch code)
Define signaling
Information exchange governing the establishment and control of a telecommunications connection and the management of the network
Define Analog In-Band signaling
- Signals that use audio tone frequencies within the human speech/hearing range
- Examples are Dial Pulsing and Dual Tone Multi-Frequency (DTMF)
- _______D in____________________ occurs when signaling bits travel along the same channel as traffic. It is often referred to as “Channel Associated Signaling” (CAS).
- _________D out_______________________ is a signaling method in which signaling bits travel in a separate channel from the associated traffic. It is often referred to as “Common Channel Signaling” (CCS).
- Dial Pulsing and Dual Tone Multi-Frequency (DTMF) are examples of
________A in____________________. - _________A out________________________ is a signaling method which uses a portion of the channel bandwidth provided by the transmission medium (the carrier channel).
Define Digital In-Band Signaling
- Signaling bits travel along the same channel as traffic
- Also called “robbed bit” signaling because it will “rob” the least significant bits of the user traffic to convey line state information
Define Analog Out-of-Band Signaling
- Uses a portion of the channel bandwidth provided by the transmission medium
- Portion utilized is above the highest frequency used by voice
Define Digital Out-of-Band Signaling
- Signaling bits travel in a separate channel from the user generated traffic
- PRI is the form of digital out-of-band signaling most prevalent in the Marine Corps
Define encoding
Encoding is the process by which information (data) is impressed onto an analog or digital waveform for the purpose of transmission and utilization at a destination.
ID the two steps of the waveform coding process
- Sampling (analog measured at regular intervals)
- Quantizing (conversion of sample analog wave voltage through assigning the sampled voltage discrete digital values typically 8 bits
Define digital line coding
Method by which a digital bit stream (data) is represented on a transmission link
Define Integrated Services Digital Network
The Integrated Services Digital Network (ISDN) is a circuit switched telephone network system designed to allow digital transmission of voice, video, and data over ordinary copper telephone lines.
Define Trunk Level One (T1)
Signaling method based on the T-carrier scheme developed by Bell Laboratories to improve commercial telephone service
standard telecommunications carrier system utilized in North America
24 channel 1.544Mbps
ID the data rate associated with Digital Signal Level Zero (DS-0)
- DS0 has a transmission rate of 64 kbps
- T-1 is comprised of 24 DS0s giving total transmission rate of 1544 kbps (1.544 Mbps)
ID the structure of a Channel Associated Signaling (CAS) T-1
- All 24 channels can be used for user traffic
- Least significant bit used at the 6th and 12th frame
- Each channel is responsible for its own signaling
ID the advantages of a CAS T-1
All 24 channels are available for user traffic
ID the structure of a Primary Rate Interface T-1
-24th channel is utilized solely to send circuit maintenance data (Data Channel)
ID the advantages of a Primary Rate Interface T-1
-Calls setup much faster -DS0 channels within the PRI can be bonded together to form larger channels
Define Compression
The process of encoding information using fewer bits
ID the audio codec used to prepare a signal for transmission over a LAN connection within the Marines Corps
G.711
ID the audio codec used to prepare a signal for transmission over a WAN connection with the Marine Corps
G.729
Define Fractional T-1
Any T-carrier data transmission rate between 64 kbps and 1544 kbps
ID the structure of the BRI configuration
- Two 64 kbps B channels
- One 16 kbps D channel
- One 48 kbps framing and synchronization
Define Digital Subscriber Line
Service designed to digitally extend a high speed data circuit over ordinary copper telephone lines
Define voice packetization
Exact length of time a CODEC is applied to an analog voice stream to construct a single digital packet
ID the purpose of a digital signal processor (DSP)
DSP is a chip that performs all the sampling, encoding and compression functions on analog audio coming into a router or media gateway device on a packet switching network
convert an analog audio signal into a digital bit stream
ID the purpose of a Voice Port
Voice ports enable a T-1 trunk coming from a circuit switchboard to be terminated at a packet switching network router for the purpose of either using the IP network to extend a T-1 trunk to another distant circuit switchboard or to integrate your circuit switching network with a separate VoIP network
Define Transcoding
- Direct conversion from one codec to another
- Eg Using G.729 to compress a signal that was encoded with G.711
ID the purpose of a media gateway device
- Allow PSTN (Public Switched Telephone Network) or DSN (Defense Switched Network) to use the packet switching network to extend telephone trunks (T-1’s) long distance
- Enable interoperability between VoIP phones and POTS phones
look at powerpoint D5
Define network convergence as it applies to communications networks
Network convergence is the combination of voice, video and data services across the same network infrastructure
Define IP trunking
A method of trunk extension where two circuit switchboards are logically connected together by a T-1 that traverses the packet switching network
ID the bandwidth planning factor associated to the given cable
WD-1 (Slashwire)
Limited transmission capability -narrowband applications
WF-16
Limited transmission capability -narrowband applications
CX-4566 (26-Pair)
??
Coaxial Cable
Greater bandwidth system wide, greater bandwidth for each channel compared to twisted pair, supports mixed range of services
Fiber Optic
Extremely high bandwidth
Twisted Pair Cat 1 10 Mbps Cat 2 4 Mbps Cat 3 10 Mbps Cat 4 16 Mbps Cat 5 100 Mbps Cat 6 1000 Mbps Cat 7 10 Gigabit
ID the maximum planning range for the given cable
CX-11230 (Coax)
1.6km
TFOCA
8km
Cat3/4/5
100m
Single Mode Fiber
Up to 500 miles
Multimode Fiber
8-64km
ID the primary function of a Voice Distribution System
Provide a point where individual telephone lines can be tied into the network
Given a list of interfacing standards, ID the appropriate connector used to terminate the corresponding interfacing standard
EIA-232D Standard (RS-232C):
DB-25
EIA-530 Standard (RS-530):
DB-25
Registered Jack:
RJ-11 (6 pins) Phones
RJ-45 (8 pins) Ethernet
RJ48 (8 pins) ISND/T1
Category of twisted pair and bandwidth capacities
Different types of Marine Corps nomenclature cables
-CX etc,
-Planning ranges
Interfacing standards and what types of cables they terminate
ID the telephony capabilities of the Secure Terminal Equipment (STE)
- Secure calls
- Transferring data at up to 128 kbps using ISDN over tactical/DSNcommercial/foreign networks
- Facilitates multimedia applications such as VTC, digital faxing, data file transfer
- Receive cryptographic keys over phone, including re-key of STE terminal itself
ID the purpose of the KSV-21 (Fortezza Card)
Gives the STEthe ability to process securecalls
ID the safeguarding requirements of the Secure Terminal Equipment (STE) telephone set
STE itself is unclassified equipment and does NOT require accountability within the COMSEC material control system
ID the safeguarding requirements of the KSV-21 (Fortezza Card)
- When issued, card must be kept on person or stored in manner that will minimize loss, unauthorized use, substitution, tampering or breakage
- User who accepts responsibility is solely responsible and cannot transfer the card without the knowledge of the COMSEC manager
- Other users may use the card as long as that person is cleared to the security level of the keys programmed on the card
- Authorized person must supervise access by a person not having an appropriate clearance to a STE with a KSV-21 inserted
- Card can be transported without written courier authorization
- Card can be sent through x-ray machines without harmful effects
ID the purpose of the OMNItelephone system
Marine Corps uses OMNI only to encrypt an unsecure phone network
ID the characteristics of International Maritime Satellite (INMARSAT) wireless telephone systems
Marine Corps uses INMARSAT systems to provide:
- Rapid response, man portable
- Secure voice, fax and data using STE terminals
- Secure, high-speed data transmission with interfaces to KIV-7 and KG-84 series encryption devices
ID the characteristics of Iridiumwireless satellite telephone systems
- Provides constant, mobile on-the-move telephones and other services (paging, messaging, fax, low data rate) to small handsets nearly anywhere in the world
- Consists of 66 operational satellites and 7 spares
- Data from handset is cross-linked to adjacent satellites before being down-linked to gateways in Arizona or Hawaii
ID the characteristics of Thurayawireless satellite telephone systems
- Regional satellite telephone service provider based in United Arab Emirates
- Provides coverage throughout most of Europe, Middle East, North/Central/East Africa, Asia and Australia
- Two operational satellites
- Not a program of record
