ring topology - a network topology in which network nodes are connected in a circular configuration. each node examines the data sent through the ring and passes on data not address to it.
star topology - a network topology in which network nodes connect to a central hub through which all data is routed.

Answered by Nishu's , an ibibo Master, at 9:52 AM on October 14, 2008

Ring
The type of network topology in which each of the nodes of the network is connected to two other nodes in the network and with the first and last nodes being connected to each other, forming a ring – all data that is transmitted between nodes in the network travels from one node to the next node in a circular manner and the data generally flows in a single direction only.
Dual-ring
The type of network topology in which each of the nodes of the network is connected to two other nodes in the network, with two connections to each of these nodes, and with the first and last nodes being connected to each other with two connections, forming a double ring – the data flows in opposite directions around the two rings, although, generally, only one of the rings carries data during normal operation, and the two rings are independent unless there is a failure or break in one of the rings, at which time the two rings are joined (by the stations on either side of the fault) to enable the flow of data to continue using a segment of the second ring to bypass the fault in the primary ring.

Star
The type of network topology in which each of the nodes of the network is connected to a central node with a point-to-point link in a 'hub' and 'spoke' fashion, the central node being the 'hub' and the nodes that are attached to the central node being the 'spokes' (e.g., a collection of point-to-point links from the peripheral nodes that converge at a central node) – all data that is transmitted between nodes in the network is transmitted to this central node, which is usually some type of device that then retransmits the data to some or all of the other nodes in the network, although the central node may also be a simple common connection point (such as a 'punch-down' block) without any active device to repeat the signals.

Source Site:
http://en.wikipedia.org/wiki /Network_topology#Star

Answered by Mohd Saqib , an ibibo Master, at 1:06 AM on October 14, 2008

Star

The type of network topology in which each of the nodes of the network is connected to a central node with a point-to-point link in a 'hub' and 'spoke' fashion, the central node being the 'hub' and the nodes that are attached to the central node being the 'spokes' (e.g., a collection of point-to-point links from the peripheral nodes that converge at a central node) – all data that is transmitted between nodes in the network is transmitted to this central node, which is usually some type of device that then retransmits the data to some or all of the other nodes in the network, although the central node may also be a simple common connection point (such as a 'punch-down' block) without any active device to repeat the signals.

Notes:

1.) A point-to-point link (described above) is sometimes categorized as a special instance of the physical star topology – therefore, the simplest type of network that is based upon the physical star topology would consist of one node with a single point-to-point link to a second node, the choice of which node is the 'hub' and which node is the 'spoke' being arbitrary[1].

2.) After the special case of the point-to-point link, as in note 1.) above, the next simplest type of network that is based upon the physical star topology would consist of one central node – the 'hub' – with two separate point-to-point links to two peripheral nodes – the 'spokes'.

3.) Although most networks that are based upon the physical star topology are commonly implemented using a special device such as a hub or switch as the central node (i.e., the 'hub' of the star), it is also possible to implement a network that is based upon the physical star topology using a computer or even a simple common connection point as the 'hub' or central node – however, since many illustrations of the physical star network topology depict the central node as one of these special devices, some confusion is possible, since this practice may lead to the misconception that a physical star network requires the central node to be one of these special devices, which is not true because a simple network consisting of three computers connected as in note 2.) above also has the topology of the physical star.

4.) Star networks may also be described as either broadcast multi-access or nonbroadcast multi-access (NBMA), depending on whether the technology of the network either automatically propagates a signal at the hub to all spokes, or only addresses individual spokes with each communication.

Ring

The type of network topology in which each of the nodes of the network is connected to two other nodes in the network and with the first and last nodes being connected to each other, forming a ring – all data that is transmitted between nodes in the network travels from one node to the next node in a circular manner and the data generally flows in a single direction only.

Dual-ring

The type of network topology in which each of the nodes of the network is connected to two other nodes in the network, with two connections to each of these nodes, and with the first and last nodes being connected to each other with two connections, forming a double ring – the data flows in opposite directions around the two rings, although, generally, only one of the rings carries data during normal operation, and the two rings are independent unless there is a failure or break in one of the rings, at which time the two rings are joined (by the stations on either side of the fault) to enable the flow of data to continue using a segment of the second ring to bypass the fault in the primary ring.

Answered by jaivir , an ibibo Master, at 7:41 PM on October 13, 2008

Simply put, a topology is the layout of a network. In 'Star' topology, all computers and devices are connected to a centrally located hub or switch. The hub or switch collects and distributes the flow of data within the network. It’s better to use a switch than a hub because a switch transmits the data to the intended recipient rather than to all hosts on a network.

Whereas in 'Ring' topology, all computers and devices are connected to cable that forms a closed loop. Each computer on this type of topology acts like a repeater and boosts the signal before sending it to the next computer. It transmits data by passing a “token” around the network. Hence this type of network is commonly called a token ring network. Similar to the Bus topology, if one computer fails, the entire network goes down. Of these two (along with the third, 'Bus' topology), network topologies, the Star topology is the best network type and is based on the Ethernet standard.

For additional information on all of these topologies, please visit the Cisco Internetworking handbook - topologies section at: http://tinyurl.com/ccnatop

Answered by A.R. , an ibibo Master, at 6:37 PM on October 13, 2008

Manish its star and not satr topology but anyway......

Comparing star and ring topologies....

The re-routing of data around a fiber cut must be accomplished within the standard of 50-msec set by SONET/SDH. With equal recovery and monitoring features, how then does a star-based system compare with a ring-based system?

In the case of a ring where the line rate is shared among all the users of the ring, the throughput per node is twice the line rate, divided by the number of nodes on the ring multiplied by the bandwidth re-use factor. For analysis, assume that, on average, a packet travels halfway around the ring, giving a bandwidth re-use factor of 2 and a throughput per node of 2 x 2B/N, where B is the line rate and N is the number of nodes.

Key to this comparison of the different topologies is the cost associated with a given throughput. The characteristic parameter for this analysis is the number of router ports used for interconnection. If DWDM transceivers are used, the router port count is equal to the number of transceivers. If non-DWDM techniques are used, the number of router ports equals the number of fiber spans.

Answered by Keshto Patel , an ibibo Master, at 6:36 PM on October 13, 2008

Ring topology will have one computer connected to another as a loop like A-> B-> C->D->E->A
If there is any disconnection between these link, the communication would go in anti-clock wise.
The is no one-to-one connectivity ...

Start Topology, each computer would be connected to each other individually. Any computer can communicate with the other one directlly, just try to see the screen shots of these topologies in google.

Answered by Kamal Teja , an ibibo Citizen, at 6:28 PM on October 13, 2008

Ring Topology
In a ring network, every device has exactly two neighbors for communication purposes. All messages travel through a ring in the same direction (either "clockwise" or "counterclockwise"). A failure in any cable or device breaks the loop and can take down the entire network.

To implement a ring network, one typically uses FDDI, SONET, or Token Ring technology. Ring topologies are found in some office buildings or school campuses.

Star Topology
Many home networks use the star topology. A star network features a central connection point called a "hub" that may be a hub, switch or router. Devices typically connect to the hub with Unshielded Twisted Pair (UTP) Ethernet.

Compared to the bus topology, a star network generally requires more cable, but a failure in any star network cable will only take down one computer's network access and not the entire LAN. (If the hub fails, however, the entire network also fails.)

Answered by Sharad Singh , an ibibo Master, at 6:05 PM on October 13, 2008

Well Manish , both are totally different type of Topology in terms of design.

In a ring network / topology every device has exactly two neighbors for communication purposes. All messages travel through a ring in the same direction (either "clockwise" or "counterclockwise").
A failure in any cable or device breaks the loop and can take down the entire network.


On the other hand , A star network features a central connection point called a "hub" that may be a hub, switch or router. Devices typically connect to the hub with Unshielded Twisted Pair (UTP) Ethernet.

Compared to other topologies , a star network generally requires more cable, but a failure in any star network cable will only take down one computer's network access and not the entire LAN. (If the hub fails, however, the entire network also fails.)

For more details , Please visit the source site :

http://compnetworking.about.co m/od/networkdesign/a/topologies.htm

Answered by Alok Gupta , an ibibo Guru, at 6:01 PM on October 13, 2008