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.


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.


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.


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.


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


Circuit switching The call

1 Early telephone exchanges are a suitable example of circuit

switching


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.


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.


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


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


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


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.


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


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.


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


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.


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


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


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.


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.


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


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


Computer networking - Asynchronous Transfer Mode

1 ATM has similarity with both Circuit switching|circuit and Packet switching|packet switched

networking


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


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.


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


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.


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.


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.


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:


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:


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


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


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.


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


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


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)


Packet-switched - Connectionless and connection-oriented packet switching

1 # Connection-oriented communication|connection-oriented

packet switching, also known as virtual circuit switching.


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


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.


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.


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.


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


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


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.


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


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.


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.


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


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.


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.


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


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.


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:


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.


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.


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


Point-to-point (network topology) - Point-to-point

1 ::Within many Circuit switching|switched telecommunications

systems, it is possible to establish a permanent circuit


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


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.



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.



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.


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).


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)


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.


Decoupling capacitor - Switching subcircuits

1 In a switching subcircuit switching noise must be

suppressed


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:


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.


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.


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


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


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.


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


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)


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.


Optical burst switching - Advantages of OBS over OPS and OCS

1 This is similar to the advantage offered by packet switching over circuit switching.


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.


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


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

Signal 1|DS1 bit streamshttps://store.theartofservice.com/the-circuit-switching-toolkit.html

Narrowband ISDN

1 It has a circuit switching orientation.


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.


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


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.


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.


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


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.


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)


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.


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


For More Information, Visit:

• https://store.theartofservice.com/the-circuit-switching-toolkit.html

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