packet switched networks

pannupandit

I am little bit confused abt difference b/w packet switched networks and circuit switched networks.IF anybody have the link ...plz send it to me...

EdTheLad

Switched network generally refers to an ethernet ( fast,Giga etc) which uses layer 2 switches rather than having a layer 3 routing network.
Circuit switched refers to the setup of a dedicated path for a connection,,FR and ISDN are circuit switched.

Cauthon

Actually, Frame Relay is a packet switched network, as are X.25 and ATM. Ethernet is a LAN technology, and when we're talking packet vs. circuit switched we're working with the WAN space and dealing with telcos, not our local LAN.

The classic circuit switched network is the phone system. When data (in this case your voice) needs to be transmitted, a physical circuit is established between the two endpoints. When you hang up the phone, that circuit is disconnected and eliminated. In CISCO terms, circuit switched networks are great when you need guaranteed bandwidth over intermittent periods of time. Examples are: Telephone, 56k, ISDN.

Frame is the most popular packet switched network. It works by creating a virtual circuit between the two endpoints. What this means is that you only have a physical circuit between your router and the telco/isp. Once your packets arrive at the telco they are switched through various Frame Relay switches on-route to their destination. Advantages of packet switched networks are lower costs (for both the telco and for you). They're used in particular for point-to-multipoint links (branch offices to home office).

Mike

scharique

Cauthon wrote:

Actually, Frame Relay is a packet switched network, as are X.25 and ATM. Ethernet is a LAN technology, and when we're talking packet vs. circuit switched we're working with the WAN space and dealing with telcos, not our local LAN.

The classic circuit switched network is the phone system. When data (in this case your voice) needs to be transmitted, a physical circuit is established between the two endpoints. When you hang up the phone, that circuit is disconnected and eliminated. In CISCO terms, circuit switched networks are great when you need guaranteed bandwidth over intermittent periods of time. Examples are: Telephone, 56k, ISDN.

Frame is the most popular packet switched network. It works by creating a virtual circuit between the two endpoints. What this means is that you only have a physical circuit between your router and the telco/isp. Once your packets arrive at the telco they are switched through various Frame Relay switches on-route to their destination. Advantages of packet switched networks are lower costs (for both the telco and for you). They're used in particular for point-to-multipoint links (branch offices to home office).

Mike

This is a very good explanation. Thanks

dmaftei

There are two main differences between packet-switched and circuit-switched networks:

1. how the communication between endpoints starts. In circuit-switched networks a path between the endpoints is established beforehand, then data are sent along that path; the path exists until the communication ends. In packet-switched networks data are sent without first establishing a path.

2. how data are sent between the endpoints. In packet-switched networks the source splits the data in discreet fragmets (called, unsurprisingly, packets), then proceeds to send the packets; the packets may follow different paths between the source and destination, and may arrive out of order (and it's the destination's business to reorder the received packets.) In circuit-switched networks the source may or may not split the data (ATM, for example, does), then proceeds to send the data along, and only along, the established path.

EdTheLad

Ops did i really write FR , anyway ATM is cell switched.

pannupandit

thanks a lot Guys...now I got it....