Circuit Switched vs. Packet Circuit Switched vs. Packet Switched TechnologySwitched Technology

Old Technology vs. New Old Technology vs. New TechnologyTechnology

Circuit Switched TechnologyCircuit Switched Technology

Connection is established between 2 devices on a Connection is established between 2 devices on a network before they begin transmittingnetwork before they begin transmitting

Bandwidth is dedicated to this connection and Bandwidth is dedicated to this connection and remains available only to the source and remains available only to the source and destination devices until the connection is destination devices until the connection is terminatedterminated

During connection all data follows the same path 1During connection all data follows the same path 1stst selected by the switch or other connectivity deviceselected by the switch or other connectivity device

Packet Switched TechnologyPacket Switched Technology

Form of switching that breaks data into packets Form of switching that breaks data into packets or small groups of data before they are or small groups of data before they are transportedtransported

Size and content of each packet conform to Size and content of each packet conform to some predefined standardsome predefined standard

Each packet contains a destination address Each packet contains a destination address information about how to combine it with other information about how to combine it with other packets to recreate the original transmission packets to recreate the original transmission once the packets reach their destinationonce the packets reach their destination

AdvantagesAdvantages

Circuit SwitchedCircuit Switched

Ensures 2 devices exclusive Ensures 2 devices exclusive use of a communication use of a communication channelchannel

Transmissions between the 2 Transmissions between the 2 devices does not compete with devices does not compete with other devices on the networkother devices on the network

Well suited for applications of Well suited for applications of live radio and video live radio and video conferencingconferencing

Is used for modem Is used for modem connections across PSTN, connections across PSTN, ISDN, and T-carriersISDN, and T-carriers

Packet SwitchedPacket SwitchedPackets are free to travel any Packets are free to travel any path on the network to their path on the network to their destinationdestination

Makes it possible to find the Makes it possible to find the fastest circuit available at any fastest circuit available at any instanceinstance

Much faster and efficient Much faster and efficient technique than circuit or technique than circuit or message switchingmessage switching

Enables Service Providers to Enables Service Providers to integrate 3integrate 3rdrd party applications party applications with capabilities to interface with capabilities to interface signaling between IP and PSTN signaling between IP and PSTN networksnetworks

DisadvantagesDisadvantages

Circuit SwitchedCircuit Switched

Monopolizes a piece of the Monopolizes a piece of the bandwidth which is not an bandwidth which is not an efficient technologyefficient technology

Can become overwhelmed by Can become overwhelmed by continuous heavy trafficcontinuous heavy traffic

In heavy traffic cannot prevent In heavy traffic cannot prevent data lossdata loss

This technology has been This technology has been defined as being defined as being geographically limitinggeographically limiting

Packet SwitchedPacket SwitchedReplacement of the “Class-ful” Replacement of the “Class-ful” switches makes for concerns switches makes for concerns because of E911 and CALEA because of E911 and CALEA

Cost of replacement of some Cost of replacement of some circuit switched equipmentcircuit switched equipment

Problems with latency when Problems with latency when data packets are jumping and data packets are jumping and become scattered between become scattered between

transmissions.transmissions. In case of power outages uIn case of power outages u

Next GenerationNext Generation

With growth it was soon discovered that the media gateways were not With growth it was soon discovered that the media gateways were not dense enough for the levels of traffic they were handlingdense enough for the levels of traffic they were handling

Estimates suggest that half of all traffic today on core networks is comprised Estimates suggest that half of all traffic today on core networks is comprised of data and within 5 yrs 90% of that traffic WILL be dataof data and within 5 yrs 90% of that traffic WILL be data

New demands for email, instant messaging, video conf and World Wide New demands for email, instant messaging, video conf and World Wide Web applications were indicators of a growing demand for IP data based Web applications were indicators of a growing demand for IP data based communications as opposed to circuit switched communicationscommunications as opposed to circuit switched communications

Evolution to IP alternatives for the PSTN would not have happened without Evolution to IP alternatives for the PSTN would not have happened without the softswitch technologythe softswitch technology

Necessity, high reliability, scalability and intelligence in the bypass network Necessity, high reliability, scalability and intelligence in the bypass network became the mother of invention which came in the form of the softswitchesbecame the mother of invention which came in the form of the softswitches

Next Gen ‘ContNext Gen ‘Cont

When economics of legacy equipment begin to favor the next generation of When economics of legacy equipment begin to favor the next generation of technology the legacy equipment will be replaced by softswitch technology the legacy equipment will be replaced by softswitch architecturesarchitectures

New installations will have the advantage by purchasing and deploying New installations will have the advantage by purchasing and deploying softswitch solutions from the beginning without the burden of integration of softswitch solutions from the beginning without the burden of integration of older technologyolder technology

Migration to softswitch can however be accomplished gradually since the Migration to softswitch can however be accomplished gradually since the softswitch has also been designed to easily integrate with the legacy PSTNsoftswitch has also been designed to easily integrate with the legacy PSTN

SummarySummary

Those who are deep into the old technology will be fractured by an Those who are deep into the old technology will be fractured by an

architecture that is cheaper, simpler, smaller and more convenient toarchitecture that is cheaper, simpler, smaller and more convenient to

to use. They will not be quick to change until the economics show to use. They will not be quick to change until the economics show

acceptable cost savings. Most importantly, we don’t really know what acceptable cost savings. Most importantly, we don’t really know what

the applications are that customers will demand in the future. We dothe applications are that customers will demand in the future. We do

know however that current voice-centric infrastructure of “class-full”know however that current voice-centric infrastructure of “class-full”

switches will not be able to support these converged voice/data/videoswitches will not be able to support these converged voice/data/video

applications. This belief that customers will demand new services that applications. This belief that customers will demand new services that

require a new infrastructure is widespread and I strongly believe thatrequire a new infrastructure is widespread and I strongly believe that

it is an accurate belief! So the need to continually meet customerit is an accurate belief! So the need to continually meet customer

expectations of quality over a network built from new technology expectations of quality over a network built from new technology

IS THE FUTURE!IS THE FUTURE!

What happens when old & new What happens when old & new technology are not converged?technology are not converged?

ANY CARRIER THAT FAILS TO MOVE FORWARD ANY CARRIER THAT FAILS TO MOVE FORWARD WITH NEW GENERATION IN THE NEXT 3 YEARS WITH NEW GENERATION IN THE NEXT 3 YEARS WILL BE A GOOD CANDIDATE TO BE THE SUBJECT WILL BE A GOOD CANDIDATE TO BE THE SUBJECT OF A QUIZ SHOW QUESTION,…. WHAT COMPANY OF A QUIZ SHOW QUESTION,…. WHAT COMPANY USED TO BE A COMMUNICATIONS COMPANY BUT USED TO BE A COMMUNICATIONS COMPANY BUT NO LONGER EXIST???????NO LONGER EXIST???????