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?

What does George Millers “magic number 7” refer to? (be specific)

A TCP sender cannot see packets being dropped inside the network. Instead, it infers loss from two signals: a retransmission timeout, and the arrival of three duplicate ACKs.Which statement about these two signals is correct?

A symbolic link points to another file or directory.