Download - Circuit switching
• circuit switching
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Best-effort delivery
1 Conventional telephone networks are not based on best-effort communication, but on
circuit switching. During the connection phase of a new call, resources are reserved
in the telephone exchanges, or a busy signal informs the user that the call is
blocked due to lack of free capacity. An ongoing phone call can never be
interrupted due to overloading of the network, and is guaranteed constant
bandwidth.https://store.theartofservice.com/the-circuit-switching-toolkit.html
Circuit switching
1 Circuit switching is a methodology of implementing a telecommunications network
in which two network nodes establish a dedicated communications channel (circuit) through the network before the nodes may
communicate. The circuit guarantees the full bandwidth of the channel and remains
connected for the duration of the communication session. The circuit functions as if the nodes were physically connected as
with an electrical circuit.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Circuit switching
1 Circuit switching contrasts with packet switching which divides the data to be
transmitted into packets transmitted through the network independently. In packet
switching, instead of being dedicated to one communication session at a time, network links are shared by packets from multiple
competing communication sessions, resulting in the loss of the quality of service
guarantees that are provided by circuit switching.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Circuit switching
1 In circuit switching, the bit delay is constant during a connection, as opposed to packet switching, where packet queues may cause
varying and potentially indefinitely long packet transfer delays. No circuit can be
degraded by competing users because it is protected from use by other callers until the
circuit is released and a new connection is set up. Even if no actual communication is taking
place, the channel remains reserved and protected from competing users.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Circuit switching
1 Virtual circuit switching is a packet switching technology that emulates circuit switching, in the sense that
the connection is established before any packets are transferred, and packets are delivered in order.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Circuit switching
1 While circuit switching is commonly used for connecting voice circuits, the concept of a dedicated path
persisting between two communicating parties or nodes can be extended to signal content other
than voice
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Circuit switching The call
1 Early telephone exchanges are a suitable example of circuit
switching
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Circuit switching Compared to datagram packet switching
1 Circuit switching contrasts with packet switching which divides the data to be transmitted into small units, called packets, transmitted
through the network independently. Packet switching shares available
network bandwidth between multiple communication sessions.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Circuit switching Compared to datagram packet switching
1 In circuit switching, and virtual circuit switching, a route and bandwidth is reserved from source to destination.
Circuit switching can be relatively inefficient because capacity is
guaranteed on connections which are set up but are not in continuous use, but rather momentarily. However, the connection is immediately available
while established.https://store.theartofservice.com/the-circuit-switching-toolkit.html
Computer network Routing
1 Routing is the process of selecting paths in a network along which to
send network traffic. Routing is performed for many kinds of
networks, including circuit switching networks and packet switched
networks.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
2G 2.5G (GPRS)
1 GPRS data transfer is typically charged per megabyte of traffic
transferred, while data communication via traditional circuit
switching is billed per minute of connection time, independent of
whether the user actually is utilizing the capacity or is in an idle state
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Digital subscriber line - History
1 Consumer-oriented ADSL was designed to operate on existing lines already
conditioned for Basic Rate Interface ISDN services, which itself is a digital circuit switching service (non-IP), though most
incumbent local exchange carriers (ILECs) provision Rate-Adaptive Digital
Subscriber Line (RADSL) to work on virtually any available copper pair facility
—whether conditioned for BRI or not
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Routing
1 Routing is performed for many kinds of networks, including the telephone network (circuit switching), electronic data networks (such as the Internet),
and transportation networks
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Public switched telephone network - Digital channels
1 The call is carried over the PSTN using a 64 kbit/s channel, originally designed by
Bell Labs. The name given to this channel is Digital Signal 0 (DS0). The DS0 circuit
is the basic granularity of circuit switching in a telephone exchange. A
DS0 is also known as a timeslot because DS0s are aggregated in time-division
multiplexing (TDM) equipment to form higher capacity communication links.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
General Packet Radio Service
1 GPRS is a best-effort service, implying variable throughput and
latency that depend on the number of other users sharing the service concurrently, as opposed to circuit
switching, where a certain quality of service (QoS) is guaranteed during
the connection
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Overlay network - In telecommunication
1 Overlay networks are used in telecommunication because of the
availability of digital circuit switching equipment and optical fiber. Telecommunication transport
networks and IP networks (that combined make up the broader
Internet) are all overlaid with at least an optical layer, a transport layer and an IP or circuit layers (in the
case of the PSTN).https://store.theartofservice.com/the-circuit-switching-toolkit.html
Packet switching - Overview
1 In cases where traffic fees are charged (as opposed to flat rate), for example in cellular communication
services, circuit switching is characterized by a fee per unit of
connection time, even when no data is transferred, while packet switching is characterized by a fee per unit of information transmitted (characters,
packets, messages, …).https://store.theartofservice.com/the-circuit-switching-toolkit.html
Packet switching - Connectionless and connection-oriented packet switching
1 connection-oriented packet switching, also known as virtual circuit switching.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Packet switching - X.25 vs. Frame Relay packet switching
1 Both X.25 and Frame Relay provide connection-oriented packet
switching, also known as virtual circuit switching
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Packet switching - DDX-1
1 This was an experimental network from Nippon PTT. It mixed circuit
switching and packet switching. It was succeeded by DDX-2.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Packet switching - Internet era
1 When Internet connectivity was made available to anyone who could pay for an ISP
subscription, the distinctions between national networks blurred. The user no
longer saw network identifiers such as the DNIC. Some older technologies such as
circuit switching have resurfaced with new names such as fast packet switching.
Researchers have created some experimental networks to complement the
existing Internet.https://store.theartofservice.com/the-circuit-switching-toolkit.html
Asynchronous Transfer Mode
1 ATM provides functionality that is similar to both circuit switching and
packet switching networks: ATM uses asynchronous time-division
multiplexing, and encodes data into small, fixed-sized packets (ISO-OSI
frames) called cells
https://store.theartofservice.com/the-circuit-switching-toolkit.html
History of mobile phones - Mobile broadband data – 3G
1 The main technological difference that distinguishes 3G technology from 2G technology is the use of
packet switching rather than circuit switching for data transmission
https://store.theartofservice.com/the-circuit-switching-toolkit.html
History of mobile phones - Native IP networks – 4G
1 One of the main ways in which 4G differed technologically from 3G was in its elimination of circuit switching, instead employing an all-IP network. Thus, 4G ushered in a treatment of
voice calls just like any other type of streaming audio media, utilizing
packet switching over internet, LAN or WAN networks via VoIP.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Statistical time division multiplexing - Comparison with static TDM
1 Static TDM and other circuit switching is carried out at the
physical layer in the OSI model and TCP/IP model, while statistical
multiplexing is carried out at the data link layer and above.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Telephone exchange - Historic perspective
1 On March 10, 1891, Almon Brown Strowger, an undertaker in Kansas
City, Missouri, patented the stepping switch, a device which led to the automation of telephone circuit
switching
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Computer networking - SONET/SDH
1 They were originally designed to transport circuit mode
communications from a variety of different sources, primarily to
support real-time, uncompressed, Circuit switching|circuit-switched
voice encoded in Pulse code modulation|PCM (Pulse-Code
Modulation) format
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Computer networking - Asynchronous Transfer Mode
1 ATM has similarity with both Circuit switching|circuit and Packet switching|packet switched
networking
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Wide area network - Design options
1 Instead of using leased lines, WANs can also be built using less costly
circuit switching or packet switching methods
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Telecommunications network
1 The Transmission (telecommunications)|transmission
links connect the nodes together. The nodes use circuit switching, message switching or packet switching to pass the signal through the correct links
and nodes to reach the correct destination terminal.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
PSTN
1 The 'public switched telephone network' ('PSTN') is the aggregate of the world's circuit switching|circuit-switched telephone networks that
are operated by national, regional, or local telephony operators, providing infrastructure and services for public
telecommunication
https://store.theartofservice.com/the-circuit-switching-toolkit.html
PSTN - Digital channels
1 The call is carried over the PSTN using a 64 kbit/s channel, originally designed by Bell Labs. The name
given to this channel is Digital Signal 0 (DS0). The DS0 circuit is the basic granularity of circuit switching in a telephone exchange. A DS0 is also known as a timeslot because DS0s
are aggregated in time-division multiplexing (TDM) equipment to
form higher capacity communication links.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Packet (information technology)
1 A 'network packet' is a formatted unit of data carried by a packet-switched network. Computer communications links that do not support packets, such as traditional Point-to-point link|point-to-point telecommunications links, simply transmit data as a bit stream. When data is formatted into packets, the Bandwidth (computing)|bandwidth of the
communication medium can be better shared among users than if the network were circuit
switching|circuit switched.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Private branch exchange
1 Initially, the primary advantage of PBXs was cost savings on internal phone calls: handling the circuit
switching locally reduced charges for local phone service. As PBXs gained
popularity, they started offering services that were not available in
the operator network, such as hunting (telephony)|hunt groups, call forwarding, and extension dialing. In the 1960s a simulated PBX known as
Centrex provided similar features from the central telephone exchange.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
LTE (telecommunication) - Features
1 Much of the LTE standard addresses the upgrading of 3G UMTS to what will
eventually be 4G mobile communications technology. A large amount of the work is aimed at simplifying the architecture of
the system, as it transits from the existing UMTS Circuit switching|circuit + packet
switching combined network, to an all-IP flat architecture system. E-UTRA is the air
interface of LTE. Its main features are:
https://store.theartofservice.com/the-circuit-switching-toolkit.html
LTE (telecommunication) - Voice calls
1 The LTE standard supports only packet switching with its all-IP
network. Voice calls in GSM, UMTS and CDMA2000 are Circuit switching|circuit switched, so with the adoption
of LTE, carriers will have to re-engineer their voice call network.
[ http://www.rohde-schwarz.com/appnote/1MA197.pdf Voice and SMS in LTE
Technology White Paper, Rohde Schwarz, 2011] Three different
approaches sprang up:
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Global IP Solutions - History
1 The founders recognized that, at the time, most VoIP solutions were using
existing technology developed for Circuit switching|circuit switched networks, and were therefore not
properly suited to handle the Network delay|delay, jitter and
packet loss presented by IP networks
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Optical switch - Terminology
1 In commercial terms (such as the telecom optical switch market size) it
refers to any piece of circuit switching equipment between fibers
https://store.theartofservice.com/the-circuit-switching-toolkit.html
IP Multimedia Subsystem - History
1 Also added voice call continuity between circuit switching and packet
switching domain (Voice call continuity|VCC), fixed broadband
connection to the IMS, interworking with non-IMS networks, policy and
charging control (policy and charging control|PCC), emergency sessions.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
IP Multimedia Subsystem - PSTN Gateways
1 A PSTN/CS gateway interfaces with PSTN Circuit switching|circuit switched (CS) networks. For
signalling, CS networks use ISDN User Part (ISUP) (or Bearer
Independent Call Control|BICC) over Message Transfer Part (MTP), while IMS uses SIP over IP. For media, CS
networks use Pulse-code modulation (PCM), while IMS uses Real-time
Transport Protocol (RTP).https://store.theartofservice.com/the-circuit-switching-toolkit.html
IS-136
1 IS-136 added a number of features to the original IS-54 specification,
including Short message service|text messaging, Circuit switching|circuit
switched data (CSD), and an improved compression protocol. SMS and CSD were both available as part
of the GSM protocol, and IS-136 implemented them in a nearly
identical fashion.https://store.theartofservice.com/the-circuit-switching-toolkit.html
UMTS-TDD - Competing Standards
1 UMTS-TDD has the advantages of being able to use an operator's
existing UMTS/Global System for Mobile Communications|GSM
infrastructure, should it have one, and that it includes UMTS modes
optimized for circuit switching should, for example, the operator want to offer telephone service
https://store.theartofservice.com/the-circuit-switching-toolkit.html
ISDN
1 ISDN is a Circuit switching|circuit-switched telephone network system, which also provides access to packet switched networks, designed to allow digital transmission of voice and data over ordinary Twisted pair|telephone copper wires, resulting in potentially better voice quality than an analog
phone can provide
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Femtocell - Standardised architectures
1 Each femtocell talks to the femtocell gateway and femtocell gateways talk to the CNE (MSC for Circuit switching|
circuit-switched calls, SGSN for Packet switching|packet-switched
calls)
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Packet-switched - Connectionless and connection-oriented packet switching
1 # Connection-oriented communication|connection-oriented
packet switching, also known as virtual circuit switching.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Packet-switched - X.25 vs. Frame Relay packet switching
1 Both X.25 and Frame Relay provide connection-oriented packet
switching, also known as virtual circuit switching
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Packet-switched - Internet era
1 When Internet connectivity was made available to anyone who could pay for an Internet Service Provider|
ISP subscription, the distinctions between national networks blurred.
The user no longer saw network identifiers such as the DNIC. Some older technologies such as circuit
switching have resurfaced with new names such as fast packet switching.
Researchers have created some experimental networks to
complement the existing Internet.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
High-Speed Circuit-Switched Data
1 Channel allocation is done in circuit switching|circuit-switched mode, as with CSD. This contrasts with the
more widely adopted General Packet Radio Service| GPRS. Higher speeds are achieved as a result of superior coding methods, and the ability to
use multiple Time-division multiplexing|time slots to increase
data throughput.https://store.theartofservice.com/the-circuit-switching-toolkit.html
H.263
1 The codec was first designed to be utilized in H.324 based systems
(Public Switched Telephone Network|PSTN and other Circuit switching|
circuit-switched network videoconferencing and
videotelephony), but has since also found use in H.323 (Real-time
Transport Protocol|RTP/IP-based videoconferencing), H.320
(Integrated Services Digital Network|ISDN-based videoconferencing), RTSP
(streaming media) and Session Initiation Protocol|SIP (IP-based videoconferencing) solutions.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
GPRS
1 GPRS usage is typically charged based on volume of data transferred,
contrasting with circuit switching|circuit switched data, which is usually billed per minute of connection time. Usage above the bundle cap is either charged per megabyte or disallowed.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
GPRS
1 GPRS is a best-effort service, implying variable throughput and latency (engineering)|latency that
depend on the number of other users sharing the service concurrently, as
opposed to circuit switching, where a certain quality of service (QoS) is guaranteed during the connection
https://store.theartofservice.com/the-circuit-switching-toolkit.html
UTRAN
1 This communications network, commonly referred to as 3G (for 3rd
Generation Wireless Mobile Communication Technology), can carry many traffic types from real-
time circuit switching|Circuit Switched to Internet Protocol|IP based packet switching|Packet
Switched
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Evolved Packet Core - Support of voice services and SMS
1 The EPC is a packet-only core network. It does not have a circuit switching|circuit-switched domain,
which is traditionally used for phone calls and SMS.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Rich Communication Services
1 Marketed by the GSMA under the brand name joyn™, RCS is an
upgrade that marks the transition of messaging and voice capabilities
from circuit switching technology to an all-IP world
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Telegraph - Teleprinters
1 By 1935, message routing was the last great barrier to full automation. Large telegraphy providers began to develop systems that used telephone
exchange|telephone-like rotary dialling to connect teletypewriters. These machines were called Telex
(TELegraph EXchange). Telex machines first performed rotary-telephone-style pulse dialling for
circuit switching, and then sent data by Baudot code. This type A Telex
routing functionally automated message routing.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Softswitch
1 A softswitch is typically used to control connections at the junction point between
circuit switching|circuit-switched and packet network|packet-switched networks.
A single device containing both the switching logic and the switched fabric can be used for this purpose; however, modern
technology has led to a preference for decomposing this device into a Call Agent
and a Media gateway|Media Gateway.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Optical mesh network - Optical mesh networks
1 Optical mesh networks refer to transport networks that are built directly off the
mesh-like fiber infrastructure deployed in metropolitan, regional, national, or
international (e.g., trans-oceanic) areas by deploying optical transport equipment
that are capable of Circuit switching|switching traffic (at the wavelength or
sub-wavelength level) from an incoming fiber to an outgoing fiber
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Packet radio
1 'Packet radio' is a form of packet switching technology used to
transmit Digital data|digital data via radio or wireless communications Data link|links. It uses the same concepts of data transmission via Datagram that are fundamental to
communications via the Internet, as opposed to the older techniques
used by dedicated or Circuit switching|switched circuits.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
5ESS switch
1 The '5ESS Switch' is a Class 5 telephone switch|Class 5 telephone
electronic switching system developed by Western Electric and
now sold by Western Electric's descendant, Alcatel-Lucent. This
Digital data|digital telephone exchange|central office telephone circuit switching system is used by many telecommunications service
providers.https://store.theartofservice.com/the-circuit-switching-toolkit.html
Crossbar switch - Applications
1 Crossbar switches are most famously used in information processing
applications such as telephony and circuit switching, but they are also
used in applications such as mechanical sorting machines.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Intel i860 - Versions and applications
1 From 2 to 360 compute nodes would reside in a circuit switching|circuit
switched fat tree network, with each node having local memory that could
be mapped by any other node
https://store.theartofservice.com/the-circuit-switching-toolkit.html
FDDI - Description
1 FDDI-II, a version of FDDI described in 1989, added circuit switching|
circuit-switched service capability to the network so that it could also
handle voice and video signals. Work started to connect FDDI networks to
synchronous optical networking (SONET) technology.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Virtual circuit
1 Virtual circuit communication resembles circuit switching, since
both are connection oriented, meaning that in both cases data is
delivered in correct order, and signalling overhead is required
during a connection establishment phase. However, circuit switching
provides constant bit rate and latency, while these may vary in a virtual circuit service due to factors
such as:
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Virtual circuit - Layer 2/3 virtual circuits
1 * Bandwidth reservation during the connection establishment phase is
supported, making guaranteed Quality of Service (QoS) possible. For
example, a constant bit rate QoS class may be provided, resulting in
emulation of circuit switching.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Teletraffic engineering
1 The field was created by the work of Agner Krarup Erlang|A. K. Erlang for
circuit switching|circuit-switched networks but is applicable to packet-
switched networks, as they both exhibit Markov property|Markovian
properties, and can hence be modeled by e.g. a Poisson process|
Poisson arrival process.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Advanced Research Projects Agency Network - History
1 Prior to the advent of packet switching, both voice and data
communications had been based on the idea of circuit switching, as in the traditional telephone circuit, wherein
each telephone call is allocated a dedicated, end to end, electronic
connection between the two communicating stations
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Point-to-point (network topology) - Point-to-point
1 ::Within many Circuit switching|switched telecommunications
systems, it is possible to establish a permanent circuit
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Network on a chip - Paradigm
1 Although Packet switching|packet-switching is sometimes claimed as
necessity for a NoC, there are several NoC proposals utilizing Circuit
switching|circuit-switching techniques
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Circuit-switched network
1 'Circuit switching' is a methodology of implementing a
telecommunications network in which two network nodes establish a dedicated communications channel (telecommunication circuit|circuit)
through the network before the nodes may communicate. The circuit guarantees the full bandwidth of the channel and remains connected for the duration of the communication
session. The circuit functions as if the nodes were physically connected as
with an electrical circuit.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Circuit-switched network
1 Circuit switching contrasts with packet switching which divides the data to be transmitted into Network packet|packets transmitted through
the network independently. In packet switching, instead of being dedicated to one communication session at a time, network links are shared by packets from multiple competing
communication sessions, resulting in the loss of the quality of service guarantees that are provided by
circuit switching.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Circuit-switched network
1 In circuit switching, the bit delay is constant during a connection, as opposed to packet switching, where packet queues may cause
varying and potentially indefinitely long packet transfer delays. No circuit can be
degraded by competing users because it is protected from use by other callers until the
circuit is released and a new connection is set up. Even if no actual communication is taking
place, the channel remains reserved and protected from competing users.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Media Gateway Control Protocol (Megaco) - Protocol Overview
1 In IP Multimedia Subsystem|IP Multimedia Subsystem (IMS), Media Gateway Control Function (MGCF) control Media Gateways (MGW)s to send
and receive call to / from the PSTN Circuit switching|circuit switched (CS) networks using. H.248. The
MGCF uses SIP messages to interact with IP_Multimedia_Subsystem#CSCF_.E2.80.93_Call_Session_Control_Function|Call Session Control Function
(CSCF) and IP_Multimedia_Subsystem#CSCF_.E2.80.93_Call_Ses
sion_Control_Function|Breakout Gateway Control Function (BGCF).
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Public land mobile network - Public switched telephone network
1 This aggregation of Circuit switching|circuit-switching telephone networks has evolved greatly from the days of Alexander Graham Bell, and in the late 20th century became almost
Signaling System 7|entirely digital in nature mdash; except for the final link from the telephone exchange|
central (local) telephone office to the user (the local loop)
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Shared medium
1 In circuit switching, each user typically gets a fixed share of the channel
capacity. A multiplexing scheme divides up the channel capacity|capacity of the
medium. Common multiplexing schemes include time-division multiplexing and
frequency-division multiplexing. Channel access methods for circuit switching include time division multiple access,
frequency-division multiple access, etc.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Decoupling capacitor - Switching subcircuits
1 In a switching subcircuit switching noise must be
suppressed
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Virtual connection
1 Virtual circuit communication resembles circuit switching, since
both are connection oriented, meaning that in both cases data is
delivered in correct order, and signalling overhead is required
during a connection establishment phase. However, circuit switching provides a constant bit rate and
latency, while these may vary in a virtual circuit service due to factors
such as:
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Broadband Integrated Services Digital Network
1 In the 1980s the telecommunications industry
expected that digital services would follow much the same pattern as voice services did on the public
switched telephone network, and conceived an end-to-end circuit
switching|circuit switched services, known as 'Broadband Integrated
Services Digital Network' ('B-ISDN').https://store.theartofservice.com/the-circuit-switching-toolkit.html
Best effort
1 It can be contrasted with reliable delivery, which can be built on top of best-effort delivery (possibly without latency and throughput guarantees),
or with circuit switching schemes which maintain a defined, continuous
quality of service.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Cell relay - How Cell Relay Works
1 At any time there is information to be transmitted; the switch basically
sends the data units. Connections don’t have to be negotiated like circuit switching. Channels don’t
have to be allocated because channels do not exist in ATM, and on condition that there is an adequate amount of bandwidth to maintain it, there can be indefinite transmissions
over the same facility.https://store.theartofservice.com/the-circuit-switching-toolkit.html
PABX - Private branch exchange
1 Initially, the primary advantage of a PBX was the cost savings for internal phone calls:
handling the circuit switching locally reduced charges for telephone service via the central
office lines. As PBX systems gained popularity, they were equipped with services that were not available in the public network, such as hunting
(telephony)|hunt groups, call forwarding, and extension dialing. In the 1960s a simulated PBX known as Centrex provided similar features from
the central telephone exchange.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Comverse Technology - Subsidiaries
1 Comverse's solutions support flexible deployment models, including in-
network, hosted and managed services, and can run on Circuit
switching|circuit-switched, Internet Protocol|IP, IP Multimedia Subsystem|
IMS, and Convergence (telecommunications)|converged
network environments
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Packet Switch Stream
1 Only after BT changed its most senior management who were fixated on
circuit switching/ISDN based on System X/Y telephone exchanges and embracing broadband/internet lock stock and barrel has this changed
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Defense Satellite Communications System - DSCS II
1 DSCS II provided secure circuit switching|voice and data
communications for the Military of the United States|U.S. military. The
program was managed by the Defense Communications Agency
(DCA), now the Defense Information Systems Agency.
https://store.theartofservice.com/the-circuit-switching-toolkit.html
Switch (disambiguation) - Information technology
1 *Circuit switch, for example a telephone switch or exchange, is a
device that forwards digital bit-streams or analog signals in a circuit
switching|circuit switched telecommunications network
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Optical burst switching
1 OBS is viewed as a compromise between the yet unfeasible full
optical packet switching (OPS) and the mostly static optical circuit
switching (OCS)
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Optical burst switching - Purpose
1 The purpose of optical burst switching (OBS) is to dynamically provision sub-wavelength
granularity by optimally combining electronics and optics. OBS considers sets of packets with similar properties called bursts. Therefore, OBS granularity is finer than optical circuit switching (OCS). OBS provides more bandwidth flexibility
than wavelength routing but requires faster switching and control technology. OBS can be
used for realizing dynamic end-to-end all optical communications.
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Optical burst switching - Advantages of OBS over OPS and OCS
1 This is similar to the advantage offered by packet switching over circuit switching.
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Public switched data network
1 Whilst there are several technologies that are superficially similar to the PSDN, such as Integrated Services
Digital Network (ISDN) and the Digital Subscriber Line (DSL)
technologies, they are not examples of it. ISDN utilizes the PSTN circuit-
switched network, and DSL uses point-to-point circuit switching
communications overlaid on the PSTN local loop (copper wires), usually utilized for access to a packet-switched broadband IP
network.
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Public switched data network
1 Short for packet-switched data network, a data communications
network that is based on the principles of packet switching, as
opposed to circuit switching that is used in public telephone networks
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Digital cross connect system
1 A 'digital cross-connect system' (DCS or DXC) is a piece of Circuit
switching|circuit-switched network equipment, used in
telecommunications networks, that allows lower-level Time-division
multiplexing|TDM bit streams, such as DS0 bit streams, to be rearranged and interconnected among higher-level TDM signals, such as Digital
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Narrowband ISDN
1 It has a circuit switching orientation.
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X.21
1 This includes specifications for Data terminal equipment|DTE/Data circuit-terminating equipment|DCE physical interface elements, alignment of call control characters and error control|error checking, elements of the call control phase for circuit switched|circuit switching services, and test
loops.
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Fat tree - Uses
1 From 2 to 360 compute nodes would reside in a circuit switching|circuit
switched fat tree network, with each node having local memory that could
be mapped by any other node
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Information network - Network packet
1 A network packet is a formatted unit of data (a list of bits or bytes) carried by a packet-
switched network. Computer communications links that do not support packets, such as traditional Point-to-point link|point-to-point telecommunications links, simply transmit
data as a bit stream. When data is formatted into packets, the Bandwidth (computing)|
bandwidth of the communication medium can be better shared among users than if the
network were circuit switching|circuit switched.
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Information network - Routing
1 Routing is the process of selecting network paths to carry network
traffic. Routing is performed for many kinds of networks, including circuit
switching networks and packet switched networks.
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Virtual Path Identifier
1 ATM provides functionality that is similar to both circuit switching and
packet switching networks: ATM uses Asynchrony|asynchronous time-division multiplexing,McDysan
(1999), p
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Long distance carrier - How it works
1 IXCs originally carried Circuit switching|voice traffic on analog lines, but voice traffic has since
become largely digitized. Therefore, voice traffic is more typically a data stream and can be intermixed with data traffic such as uplinks for DSL. Most commonly, links between an IXCs and COs are Asynchronous
Transfer Mode|ATM links carried on optical fiber.
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Access point base station - Standardised architectures
1 Each femtocell talks to the femtocell gateway and femtocell gateways talk to the Core Network Elements (CNE)
(MSC for Circuit switching|circuit-switched calls, SGSN for Packet switching|packet-switched calls)
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Nokia 5210
1 The 'Nokia 5210' is a mobile phone manufactured by Nokia. The
5210 features rubber Xpress-On shells, Wireless Application Protocol|
WAP over Circuit switching|CSD and a built in thermometer. The
thermometer displays the internal temperature of the phone's battery. This feature is also present on other
phones that have netmonitor enabled.
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GSM-R - History
1 In areas where the European Train Control System (ETCS) Level 2 or 3 is
used, the train maintains a circuit switching|circuit switched digital modem connection to the train
control centre at all times
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