Saltzer, Reed, and Clark asked where a network should place functions such as reliable delivery. Their answer is the end-to-end principle.Which statement describes the core claim of the end-to-end principle?

Figure: AS1, AS2 and AS3 (Module 4)Consider three ASes, AS1, AS2 and AS3, connected in a line. AS2 has two border routers, L and R. Router L connects to AS1, and router R connects to AS3. Router L learns a route to prefix p from AS1 over eBGP.How does router R learn the route to prefix p?

Figure: TCP cwnd over time (Module 2)The figure shows the congestion window, cwnd, of a TCP sender over time. A timeout occurs near the right edge of the plot.Which rule decides when TCP uses slow start and when it uses congestion avoidance?

Figure: A token bucket policer and a burst (Module 6)Consider a router that polices a flow with a token bucket. Tokens arrive at 1 token per second, and the bucket holds at most 50 tokens. Each packet needs one token.The flow has been idle, so the bucket is full. Then a burst of 80 packets arrives within 10 milliseconds, too fast for any new token to arrive.How does the policer handle the 80 packets?

The Linux kernel is the core component of the operating system.

The man command is used to view Linux documentation.

A sender and a receiver use the Go-back-N protocol. The sender transmits packets 1 to 10. Packets 1 to 6 arrive at the receiver in order. Packet 7 is lost in the network. Packets 8, 9 and 10 then arrive at the receiver.What does the receiver do with packets 8, 9 and 10?

Figure: Unibit trie (Module 5)Consider a unibit trie for the prefix database P1 to P9. A destination address begins with the bits 11001. The search starts at the root of the trie.Which prefix does the search return?

Figure: The token buckets of flows F1 and F2 (Module 6)Consider a router that polices flows F1 and F2, each with its own token bucket. Both buckets receive r = 100 tokens per second. F1’s bucket holds at most b = 10 tokens, and F2’s holds at most b = 100. Each packet needs one token.Both flows have been idle, so both buckets are full.How do the traffic agreements for F1 and F2 differ?

Figure: Fixed-stride trie with a stride of 3 (Module 5)Consider a fixed-stride trie with a stride of 3. Each step of a search reads 3 bits of the address, so a search can stop only after 3, 6 or 9 bits, and so on. For this reason, every prefix stored in the trie must have a length of 3, 6, 9 and so on. The prefix database holds P3 = 11001*, which is 5 bits long. P3 ends in the middle of a step, so the trie cannot store it as it is.Which prefixes replace P3 in the trie?