Can You Tell Me Something About Mesh Topology?

The physical or logical layout of the cables and devices that connect the nodes of a network is called topology. There are three basic topologies: Bus , star and ring. Another  less commonly used physical topology is mesh topology.    The mesh topology is most expensive to implement. In a mesh environment, a cable runs from every computer to every other computer. If  you have four computers , you must have six cables i.e three coming from each computer to the other computers.The big advantage to this arrangement is that data can never fail to be delivered. If one connection goes down, there are other ways to route the data to the destination .The mesh topology is ideal for connecting routers on the internet to make sure that data always get through.      Mesh topology is applied in two ways which is    -Full mesh  -Partial mesh    In full meshed topology, each node in a network is connected to every other node. It is completely fault tolerant. In partially meshed topology , a node is connected to some of other nodes in the network which are most related to it.

A mesh network is the local area network where each of the computer and network devices are connected with many redundant interconnections between network nodes. Mesh topology is not commonly used topology because it is very expensive to implement. Mesh topology is classified in to two categories; full mesh and partial mesh. In full mesh topology all nodes are connected to every other node in a network. In full mesh topology point to point link is establish between all nodes that make it possible for data transmitted from one node to all other nodes in a network. It is used where reliability is required or small numbers of nodes are connected. It is very much expensive and difficult to implement. It is reliable and has a good performance. As compare to full mesh topology partial mesh topology is less expensive and has less redundancy. In partial mesh topology some nodes are connected with all other nodes present in network and some nodes are connected to one or two node in the network. Mesh topology is mostly used in Wide area network (WAN) and wireless networks. Mesh topology is not preferred in Local area networks (LAN).

In the mesh topology every device has always a dedicated point to point link to every other device. This term dedicated can be explained as a link which is carrying the traffic only and only between the two devices it connects. A "fully connected mesh" network has n (n-1)/2 physical channels to link and associate 'n' devices.

To handle that many links, every device on the network must have (n-1) I/O ports. A mesh has so many advantages over other network topologies. first is the use of dedicated links always guarantees that every connection can carry its own data load, so in this way the traffic troubles are eliminated, that can take place when links are being shared by multiple devices. the other advantage is that a mesh topology is robust in nature. It means that if one link destroys it does not incapacitate the entire system. Another major advantage is the security and privacy. When each message moves and travels along a dedicated path, only the intended recipient sees it.

Physical boundaries are helpful in preventing other users from gaining an access to the messages. Finally, point to point links make fault identification and fault isolation very simple and easy. So that, traffic can be routed to avoid links with supposed cause problems.

Mesh Topology: Before going to the Mesh topology details first I would like to define what topology means? The topology in simple words can be defined as the network layout that connects different computers for the transfer of information. The Network Geometry can be categorized in to
(1) Physical Topology: which can be defined as the physical layout of the network e.g. how the computers are physically connected.
(2) Logical Topology: The Logical topology can be defined as how the Signals from Generator reach to its Destination, but in many cases the logical topology is same as the physical but in many cases there are networks that are configured as Star but logically they work as ring or bus networks.
Regarding the Mesh topology which employs two schemes.

(1) Full Mesh: In full Mesh topology scheme each node (workstation) is connected to the others for data transfer, sharing etc.
(2) Partial Mesh: As far as the Partial Mesh topology scheme is concerned it is just like the Full Mesh topology scheme but in this topology scheme some workstations are connected only to those workstations to which they are more concerned for information and resource sharing, and some workstations are connected to whole of other workstations.

The Mesh networks are usually ad-hoc based. The main advantage with the Mesh networks is that it can even operate in case of any breakdown in one of the nodes or they loose connectivity with the network.

Mesh topology is most common topology used today. It is highly fault tolerant. Mesh topology may b 'Hybrid' or 'True'. In a true mesh topology each device or network node is connected through a separate cable to every other device on the network.
While hybrid meshes topology mostly uses star. Ring or bus topology with some redundant links to provide additional fault tolerance.
Mesh topology is expensive because a dedicated link is used between each pair of nodes on network.
But it is mostly used topology because of ease of troubleshooting. If some node or some connection to a node creates a problem then it will not disturb the communication link of other nodes because each node is separately connected with other nodes. Thus, we can easily detect the connection that creates some problem. If cable breaks at some point in the network then it will affect only two devices that are connected to that cable.
No guess work is required to troubleshoot this network. Routing is not used in mesh topology because sender sends the message/data directly to recipient.
But there are some disadvantages associated with this topology. It is difficult to install and maintain and very costly.

But there is something I don't understand how NIC (Network Information Center) OR  network card can handle more than one cabe because I think it only have one port  and you said that all pc is connecting together by using more than one cable
can any body explain to  me please.