TOPOLOGY

“The Topology is the geometric representation of the relationship  of the links and the linking devices (Nodes) in a Network” 
Or
“Topology defines the physical or the Logical Agreement of Links in a Network”

Topology of a Network is suggestive of how a network is laid out. It refers to the specific configuration and structure of the connections between the Links and the Nodes. Two or more devices connect to a Link and two or more Links form a Topology


  Question: What to consider when choosing a Topology????????
  Answer: Relative status of the devices to be linked.

Two relationships are possible in a network

  PEER-TO-PEER: Devices share the link equally

  PRIMARY-SECONDARY: One device controls traffic and the others must transmit through it


o  Every device has dedicated a point-to-point link to every other device
o  Dedicated: Means that the link carries traffic only between these two devices
Links to connect ‘n’ devices
o  Each device must have         
   I/O Ports

Example Mesh Topology
In figure above, we have 5 Nodes, therefore:

  No. of Links= 5(5-1)/2 = 10
  No. of I/O Ports= 5-1 = 4

  This increase exponentially with increase in No. of Nodes

  e.g. for 6 nodes = 15 Links 7 Nodes=21 Links 1 − n 2) 1 ( − n n