Connections, Switching, Routing

Front 1

Connection-oriented Networking

Back 1

Requires up-front signaling
• Very little signaling during the connection, possibly none
• Connection is usually torn down after the “call” is done

Front 2

Connectionless Networking

Back 2

Requires packets
• Every packet moves through the network independent of the
other ones

Front 3

Circuit switching

Back 3

Sets up a fixed, exclusive path through the network
• Can be switched (per call) or permanent
• Fixed timing (delay), no jitter

Front 4

Packet Switching

Back 4

Circuits are always shared
• Performance is variable
• Variable delay=jitter

Front 5

Switching

Back 5

Usually refers to a process inside a network
node
• Many circuits come in, many go out
• The switch creates (on demand) a
connection between one input and one
output
• Used in circuit switching in each node that is
on the (pre-determined) path of the data

Front 6

Routing

Back 6

A packet is received on one interface
• Router stores the packet in its entirety
• Router consults a local table to decide where the packet
needs to go
• Router now sends the packet out on the selected port

Front 7

Connectionless Routing

Back 7

Routing decisions are made based on an address
contained in the packet itself

Front 8

Connection Oriented Routing

Back 8

During connection setup, a routing decision is associated
with a short label
• Packets carry this label
• Forwarding is done based on the label

Front 9

static routing

Back 9

Forwarding decisions are built into the router by hand
and changed by hand

Front 10

Dynamic routing

Back 10

Routers communicate with each other and build
decision (routing) tables based on what they learn
from the other routers