22-Elec-B4 Information Technology Networks: December 2017

Paper format. Engineers Canada / Professional Engineers of Ontario, National Examinations — December 2017, 16-Elec-B4 Information Technology Networks. Three hours, closed book, a PEO-approved non-programmable calculator permitted. Five questions of 25 marks each; any four constitute a complete paper worth 100 marks, and the marks are printed in the left margin against every sub-part. All five questions are solved here, because this set is a study resource rather than an exam attempt.

Reference texts.

• A. Leon-Garcia and I. Widjaja, Communication Networks: Fundamental Concepts and Key Architectures, 2nd ed., McGraw-Hill — the syllabus text for this paper (layering, transport, routing, switching).
• J. F. Kurose and K. W. Ross, Computer Networking: A Top-Down Approach, 8th ed., Pearson — IP forwarding tables, TCP congestion control, packet versus circuit switching.
• A. S. Tanenbaum and D. J. Wetherall, Computer Networks, 5th ed., Pearson — the OSI reference model and the TCP/IP layer stack.
• D. Bertsekas and R. Gallager, Data Networks, 2nd ed., Prentice-Hall — shortest-path routing and Dijkstra's algorithm.
• RFC 791 (Internet Protocol), RFC 950 (subnetting), RFC 1918 (private address space), RFC 3022 (NAT), RFC 4632 (CIDR), RFC 8200 (IPv6), RFC 5681 (TCP congestion control), ISO/IEC 7498-1 (OSI basic reference model).

Canadian context. The addressing and numbering practice assumed throughout is the Canadian one: IPv4 and IPv6 blocks used by Canadian networks are allocated by ARIN, of which Canada is part, and the national research network CANARIE has run production IPv6 since the mid-2000s, which is why the IPv6 answer in Question 1(c) is the operational rather than the theoretical response. Circuit-switched telephony in Question 5 refers to the Canadian PSTN as regulated by the CRTC.