An integrated firewall policy validation tool.

Security policies are increasingly being implemented by organisations. Policies are mapped to device configurations to enforce the policies. This is typically performed manually by network administrators. The development and management of these enforcement policies is a difficult and error prone task. This thesis describes the development and evaluation of an off-line firewall policy parser and validation tool. This provides the system administrator with a textual interface and the vendor specific low level languages they trust and are familiar with, but the support of an off-line compiler tool. The tool was created using the Microsoft C#.NET language, and the Microsoft Visual Studio Integrated Development Environment (IDE). This provided an object environment to create a flexible and extensible system, as well as simple Web and Windows prototyping facilities to create GUI front-end applications for testing and evaluation. A CLI was provided with the tool, for more experienced users, but it was also designed to be easily integrated into GUI based applications for non-expert users. The evaluation of the system was performed from a custom built GUI application, which can create test firewall rule sets containing synthetic rules, to supply a variety of experimental conditions, as well as record various performance metrics. The validation tool was created, based around a pragmatic outlook, with regard to the needs of the network administrator. The modularity of the design was important, due to the fast changing nature of the network device languages being processed. An object oriented approach was taken, for maximum changeability and extensibility, and a flexible tool was developed, due to the possible needs of different types users. System administrators desire, low level, CLI-based tools that they can trust, and use easily from scripting languages. Inexperienced users may prefer a more abstract, high level, GUI or Wizard that has an easier to learn process. Built around these ideas, the tool was implemented, and proved to be a usable, and complimentary addition to the many network policy-based systems currently available. The tool has a flexible design and contains comprehensive functionality. As opposed to some of the other tools which perform across multiple vendor languages, but do not implement a deep range of options for any of the languages. It compliments existing systems, such as policy compliance tools, and abstract policy analysis systems. Its validation algorithms were evaluated for both completeness, and performance. The tool was found to correctly process large firewall policies in just a few seconds. A framework for a policy-based management system, with which the tool would integrate, is also proposed. This is based around a vendor independent XML-based repository of device configurations, which could be used to bring together existing policy management and analysis systems.

English: its role as the language of comity in an employment programme for Canadian immigrants.

This study explores the experiences of a culturally and linguistically diverse group of immigrant adult students as they attended a 12-week employment preparation course for newcomers to Canada. The main aim of the course was to equip the immigrants with knowledge and skills, including English for employment purposes, which are necessary to be competitive in the labour market. Using ethnographic methods, mainly participant observation with audio recording, to collect data, this paper analyses the communicative strategies that this group of multilingual speakers and their Canadian teachers deployed to discursively construct a ‘heterotopia’ defined here as ‘intensely affective spaces that redefine the experiential feeling of being and becoming’. Analysis of transcribed audio recordings reveals that despite differences in communication conventions and sociocultural backgrounds, the research participants from Congo, Haiti, India, Bangladesh, Jordan and the Philippines managed to establish a socially cohesive team that emphasises shared relational identity and in-group membership. The findings show how they creatively mobilised previously acquired pragmatic strategies and resources from their L1 to suit the demands of the ongoing interaction in English. It is suggested that language teaching in the context of preparing immigrants for labour market integration entails a pedagogical approach that foregrounds the affordances of English not only as the language of employment but perhaps more importantly as the ‘language of comity’. It is therefore suggested that the teaching of the host country’s language should focus less on grammatical correctness and focus more on providing the adult learners with opportunities to activate existing pragmatic resources and strategies which have to do with establishing rapport and friendly relations.