Computing – Communications and Networks - Protocol architecture

Protocol architecture


 Switches are layer 2 intermediate systems
 Transparent forwarding
 Management protocols (Spanning Tree, VLAN)


Interconnection at layer 3

 Routers
 interconnect subnetworks
 logically separate groups of hosts
 managed by one entity
 Forwarding based on IP address
 structured address space
 routing tables: aggregation of entries
 works if no loops - routing protocols (IGP - Internal Routing Protocols)
 scalable inside one administrative domain

Protocol architecture



 Routers are layer 3 intermediate systems
 Explicit forwarding
 host has to know the address of the first router
 Management protocols (control, routing, configuration)

Overlaid stacks? Long-haul links

 Fiber at physical layer (SONET/SDH)
 Dense Wave Division Multiplexing (DWDM)
 one color of the light λ
 Different technologies
 ATM
 Frame Relay
 POS (Packet over SONET/SDH)
 Type of the network
 NBMA (Non Broadcast Multiple Access) or point-to-point
 Complex protocol hierarchies
 IP over ATM