UNIVERSITY OF BOLTON CREATIVE TECHNOLOGIES COMPUTING SEMESTER TWO EXAMINATION 2014/2015 NETWORK MANAGEMENT MODULE NO: CPU6009

Transcription

1 UNIVERSITY OF BOLTON [CRT09] CREATIVE TECHNOLOGIES COMPUTING SEMESTER TWO EXAMINATION 2014/2015 NETWORK MANAGEMENT MODULE NO: CPU6009 Date: Friday 29 th May 2015 Time: 14:00 16:00 Instructions to Candidates: There are SIX questions. Answer ANY FOUR questions. All questions carry equal marks. Marks for parts of questions are shown in brackets. Electronic calculators may be used provided that data and program storage memory is cleared prior to the examination.

2 Page 2 of 6 Question 1 1a) Discuss the concept of Flow Management used in data networks. Include a brief review of the different standards currently being used. Define the unique keys used in this technology. Describe how flow management can assist network managers to identify problems encountered in the network. [13 Marks] 1b) With regard to IPv4 traffic flows: explain the process of fragmentation. Use as an example a 4464 Byte (Token Ring) packet traversing a router link with MTU=508. Indicate how things would differ in an IPv6 environment. [8 Marks] 1c) How would you accommodate non-snmp and various versions of SNMP in a managed communications network. [4 Marks] Question 2 2a) Discuss the interaction of Structure of Management Information (SMI), Abstract Syntax Notation One (ASN.1) and Basic Encoding Rules (BER) used in a managed network managed scenario. [9 Marks] 2b) Using SNMP commands explain in detail how you would retrieve statistics from a managed device such as a Router or Ethernet Switch. If you wanted to traverse a group of OID s what command would you use? If you wanted to analyse utlisation of an Ethernet Switch port, how would you do it? [9 Marks] 2c) The Management Information Base (MIB) is one of the fundamental elements of systems. Give an descriptive account of the MIB structure, it s role and details about interface and RMON areas. Include the interaction of a MIB with a typical RDBMS residing in a System. [7 Marks] PLEASE TURN THE PAGE.

3 Page 3 of 6 Question 3 3a) Critically appraise how Systems have evolved, to incorporate standards based features such as the Telecommunications Management Network (TMN) and de facto SNMP elements. Include practical examples of management systems used at various TMN levels. [12 Marks] 3b) Given the command line shown below, explain what each of the components is used for: snmpwalk v1 u monitor c public [6 Marks] 3c) List the primitive commands used in SNMP versions 1 and 2 and explain what the following commands are used for: snmpdelta and snmptable [7 Marks] Question 4 4a) Critically appraise the major advantages a modern central core network based on IP-MPLS, such as BT s 21CN has, over traditional vertical based separate networks. What disadvantages do pure IP or ATM core networks have? Access to these modern networks may use GFP over SDH. Appraise the fundamental aspects of these two systems, essentially describing what they do. 4b) Using a combination of SNMP commands and Open Source networking analysis tools, give a detailed account of how would you manage point to point link performance in an network. The scope of this analysis covers both the link and end points. Include details of parameters measured and any Open Source tools, which are useful in achieving these measurements. 4c) Outline what is meant by the term PMTU Black Hole Router and hence describe the impact on managing such network connections. [5 Marks]

4 Page 4 of 6 PLEASE TURN THE PAGE. Question 5 5a) Critically appraise the latency factors involved when downloading a file across a network of interconnected LANs and WANs. Assess this scenario for both TCP and UDP transmissions. 5b) Show using BGP examples how a network manager can at least hint to external neighbours about the preferred path into an Autonomous System. It will be useful to include a diagram showing various traffic flows and choices. [7 Marks] 5c) Explain what issues and challenges a network manager has to address to implement a multi-vendor management system. [8 Marks] Question 6 6a) Discuss the issues surrounding the carrying of voice over IP. Include in your discussion how VoIP can effectively be carried across an IP core network. [9 Marks] 6b) i) Evaluate what is meant by 1 Erlang of traffic and hence define what an Erlang is. You must include in your discussion the term CCS Centrum Call Second. ii) Using Erlang to Packet conversion, what is the equivalent throughput in bytes of 8 Erlangs, based on 64kbps channels? iii) Using the table below, which is an extract from an Erlang B table, calculate the following: Scenario 1: If 4 Erlangs of VoIP traffic are required and the grade of service needed to overcome interference is to be P.015, how many trunks are required for this transmission?

5 Page 5 of 6 Question 6 continues over the page. Question 6 continued. PLEASE TURN THE PAGE. Scenario 2: Given 3 trunks and a probability of blocking GOS = 0.05, how many Erlangs of traffic can be carried by this network? Scenario 3: Given 4 Erlangs of traffic that utilise 7 trunks, what is the probability of blocking? No. of Traffic (A) in erlangs for P = Trunks (N) 0.1% 0.2% 0.5% 1% 1.2% 1.3% 1.5% 2% 3% 5% 7% 10% c) In a VoIP based network scenario, justify the rationale for using different traffic tables for different situations. You must specify the type of traffic and which tables are appropriate for that particular scenario. [6 Marks]

6 Page 6 of 6 END OF PAPER