CSE 486 Midterm Questions with
complete solution 2025/2026
What is IP's place in the network stack? - correct answer ✔On top of other networks (IP makes very
few assumptions, in turn makes very few guarantees )
IP datagrams are small, self-contained packets that contain what? - correct answer ✔A source host
A destination host
Minimal other metadata
Uninterpreted data
What is Best Effort Delivery? - correct answer ✔Datagrams are delivered if possible but are dropped if
they cannot be delivered. They can be queued indefinitely meaning they can arrive:
late
out of order
not at all
How are IP datagrams routed? - correct answer ✔Individually from network to network. internet paths
can be different but tend to be the same over and over.
What are the two most common Internet transport protocols and what do they provide? - correct
answer ✔UDP for unreliable, low-latency communication, best effort delivery
TCP for reliable, congestion-aware communication
Provide:
Multiple endpoints per host
Protection from corruption (optional for UDP)
, What is a distributed system? - correct answer ✔Multiple computer programs, possibly spread out over
different networked components, communication by passing messages.
What is a synchronous system? - correct answer ✔A system where all actions take predictable time;
doing an action and predicting how long it will take
What is an asynchronous system? - correct answer ✔A system where all actions take unpredictable
time; Messages may be arbitrarily delayed
What happens if TCP loses a segment? - correct answer ✔Next data cannot be delivered at the receiver
Eventually the sender retransmits
The data is delivered at the receiver later than expected
What is a Race or Race Condition? - correct answer ✔Two or more events are dependent upon each
other; some events may happen in more than one order
What is a happens before relationship? - correct answer ✔Ensures a particular outcome
One step happens before another step preventing a race
What is a Communicating sequential process? - correct answer ✔A program model built on message
passing
Distributed systems communicate by message passing
Message exchanges create happens before relationships
Why is failure detection difficult for Asynchronous systems? - correct answer ✔Async systems may
have unpredictable delays; Not able to tell if a process has failed or has been delayed
What is a Fail-stop? - correct answer ✔Process halts and never takes another action
complete solution 2025/2026
What is IP's place in the network stack? - correct answer ✔On top of other networks (IP makes very
few assumptions, in turn makes very few guarantees )
IP datagrams are small, self-contained packets that contain what? - correct answer ✔A source host
A destination host
Minimal other metadata
Uninterpreted data
What is Best Effort Delivery? - correct answer ✔Datagrams are delivered if possible but are dropped if
they cannot be delivered. They can be queued indefinitely meaning they can arrive:
late
out of order
not at all
How are IP datagrams routed? - correct answer ✔Individually from network to network. internet paths
can be different but tend to be the same over and over.
What are the two most common Internet transport protocols and what do they provide? - correct
answer ✔UDP for unreliable, low-latency communication, best effort delivery
TCP for reliable, congestion-aware communication
Provide:
Multiple endpoints per host
Protection from corruption (optional for UDP)
, What is a distributed system? - correct answer ✔Multiple computer programs, possibly spread out over
different networked components, communication by passing messages.
What is a synchronous system? - correct answer ✔A system where all actions take predictable time;
doing an action and predicting how long it will take
What is an asynchronous system? - correct answer ✔A system where all actions take unpredictable
time; Messages may be arbitrarily delayed
What happens if TCP loses a segment? - correct answer ✔Next data cannot be delivered at the receiver
Eventually the sender retransmits
The data is delivered at the receiver later than expected
What is a Race or Race Condition? - correct answer ✔Two or more events are dependent upon each
other; some events may happen in more than one order
What is a happens before relationship? - correct answer ✔Ensures a particular outcome
One step happens before another step preventing a race
What is a Communicating sequential process? - correct answer ✔A program model built on message
passing
Distributed systems communicate by message passing
Message exchanges create happens before relationships
Why is failure detection difficult for Asynchronous systems? - correct answer ✔Async systems may
have unpredictable delays; Not able to tell if a process has failed or has been delayed
What is a Fail-stop? - correct answer ✔Process halts and never takes another action
