IS 3413 Telecom Huddleston Exam 2 Latest 2023 with
complete solution
Transport Layer (Layer 4)
Links application and network layers
Responsible for segmentation & reassembly
Session management
Network Layer (Layer 3)
Responsible for addressing & routing
Transmission Control Protocol (TCP)
Most common transport layer protocol
Used for reliable transmission of data
Connection-oriented
User Datagram Protocol (UDP)
Used in time-sensitive situations, for control messages, when reliability less critical or
handled by application layer
Connectionless
Linking to the Application Layer
Ports used to identify application (2-byte numbers, 0 to 1)
Client ports are usually high-numbered ephemeral ports (>1024)
HTTP: TCP port 80
SMTP: TCP port 25
POP3: TCP port 110
Segmenting
Breaking up large files into smaller segments (and putting back together)
Session Management
Using a session: connection-oriented messaging (TCP)
three-way handshake: SYN, SYN-ACK, ACK
Sending messages w/o a session: connectionless messaging (UDP)
Internet Protocol (IP)
IPv4: 32-bit addresses (232 or ~4.29 billion possible)
IPv6:128-bit addresses (2128 or ~3.4 × 1038 possible)
Routing
Identifying what path to have a packet take through a network from sender to receive
, Routing Tables
Used to make routing decisions
Shows path to use to reach given destination
Kept by computers making routing decisions
Centralized Routing
(host-based networks, uncommon)
Routing decisions made by one computer
Decentralized Routing
(used by the Internet)
Decisions made by each node independently, with data exchange
Static Routing
Fixed routing tables, manually configured
Dynamic Routing
(sometimes called adaptive routing) Routers exchange data using protocols to update
tables
Distance Vector
based on the number of "hops" between two devices
Link State
based on number of hops, circuit speed & traffic congestion
Routing Information Protocol (RIP)
Dynamic distance vector protocol
Useful in smaller, less complex networks
Open Shortest Path First (OSPF)
Dynamic link state protocol
Most widely used on large enterprise networks
EIGRP
Enhanced Interior Gateway Routing Protocol
IS-IS
Intermediate System to Intermediate System
ICMP
Internet Control Message Protocol
Simplest possible interior routing protocol, Limited ability to update routing tables (ping
command)
BGP
Border Gateway Protocol
Exterior routing.
Used to exchange information between autonomous systems
Unicast
one computer to another computer (default)
Broadcast
one computer to all computers in subnet
complete solution
Transport Layer (Layer 4)
Links application and network layers
Responsible for segmentation & reassembly
Session management
Network Layer (Layer 3)
Responsible for addressing & routing
Transmission Control Protocol (TCP)
Most common transport layer protocol
Used for reliable transmission of data
Connection-oriented
User Datagram Protocol (UDP)
Used in time-sensitive situations, for control messages, when reliability less critical or
handled by application layer
Connectionless
Linking to the Application Layer
Ports used to identify application (2-byte numbers, 0 to 1)
Client ports are usually high-numbered ephemeral ports (>1024)
HTTP: TCP port 80
SMTP: TCP port 25
POP3: TCP port 110
Segmenting
Breaking up large files into smaller segments (and putting back together)
Session Management
Using a session: connection-oriented messaging (TCP)
three-way handshake: SYN, SYN-ACK, ACK
Sending messages w/o a session: connectionless messaging (UDP)
Internet Protocol (IP)
IPv4: 32-bit addresses (232 or ~4.29 billion possible)
IPv6:128-bit addresses (2128 or ~3.4 × 1038 possible)
Routing
Identifying what path to have a packet take through a network from sender to receive
, Routing Tables
Used to make routing decisions
Shows path to use to reach given destination
Kept by computers making routing decisions
Centralized Routing
(host-based networks, uncommon)
Routing decisions made by one computer
Decentralized Routing
(used by the Internet)
Decisions made by each node independently, with data exchange
Static Routing
Fixed routing tables, manually configured
Dynamic Routing
(sometimes called adaptive routing) Routers exchange data using protocols to update
tables
Distance Vector
based on the number of "hops" between two devices
Link State
based on number of hops, circuit speed & traffic congestion
Routing Information Protocol (RIP)
Dynamic distance vector protocol
Useful in smaller, less complex networks
Open Shortest Path First (OSPF)
Dynamic link state protocol
Most widely used on large enterprise networks
EIGRP
Enhanced Interior Gateway Routing Protocol
IS-IS
Intermediate System to Intermediate System
ICMP
Internet Control Message Protocol
Simplest possible interior routing protocol, Limited ability to update routing tables (ping
command)
BGP
Border Gateway Protocol
Exterior routing.
Used to exchange information between autonomous systems
Unicast
one computer to another computer (default)
Broadcast
one computer to all computers in subnet
