{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/9773"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/9773","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"AAL2 switching node to support voice services in 3rd and 4th generation networks","abstract":"The research community and industry alike have, over the past decade, been showing considerable interest in packet-switching networks to support voice services as well as data services. A technology that was standardised to accommodate these delay-sensitive requirements is Asynchronous Transfer Mode (ATM), which deals particularly well at transporting uncompressed voice and data. However, due to the exponential increase in wireless applications and their supporting access technologies, a need has arisen for an infrastructure in the wide area network to support and maintain the QoS requirements of low-bit rate, compressed voice. An adaptation layer known as AAL2 was re-standardised to support these specialised voice services. However, a severe side-effect of using AAL2 with traditional ATM switches results in inefficient routing and waste-age of resources. In this study, a design for an AAL2 switching node will be proposed to address the above-mentioned issues. The design is comprised of modules that perform the following functions: Buffering, payload interrogation, protocol translations, packet classification, packet re- routing, timing, scheduling and support for signalling and management interfacing. The supporting architecture is targeted towards an embedded >286-based computing system, which itself is overlaid upon one or several ports of a high-speed, research-oriented ATM switch, known as the Washington University Gigabit Switch (WUGS). In order to evaluate the operation and performance of the AAL2 switch architecture, a testbed is proposed and implemented, comprising the AAL2 switch at the core, with a supporting infrastructure to emulate the generation and analysis of low bit-rate voice traffic over an AAL2 connection. By conducting a set of experiments, a series of operational and performance results will be presented. Particular focus will be placed on the performance and efficiency of the AAL2 layer over ATM, as well as the ability of the switch to route packets from multiple sources to a set of output connections in the correct manner.","abstract_html":"The research community and industry alike have, over the past decade, been showing considerable interest in packet-switching networks to support voice services as well as data services. A technology that was standardised to accommodate these delay-sensitive requirements is Asynchronous Transfer Mode (ATM), which deals particularly well at transporting uncompressed voice and data. However, due to the exponential increase in wireless applications and their supporting access technologies, a need has arisen for an infrastructure in the wide area network to support and maintain the QoS requirements of low-bit rate, compressed voice. An adaptation layer known as AAL2 was re-standardised to support these specialised voice services. However, a severe side-effect of using AAL2 with traditional ATM switches results in inefficient routing and waste-age of resources. In this study, a design for an AAL2 switching node will be proposed to address the above-mentioned issues. The design is comprised of modules that perform the following functions: Buffering, payload interrogation, protocol translations, packet classification, packet re- routing, timing, scheduling and support for signalling and management interfacing. The supporting architecture is targeted towards an embedded >286-based computing system, which itself is overlaid upon one or several ports of a high-speed, research-oriented ATM switch, known as the Washington University Gigabit Switch (WUGS). In order to evaluate the operation and performance of the AAL2 switch architecture, a testbed is proposed and implemented, comprising the AAL2 switch at the core, with a supporting infrastructure to emulate the generation and analysis of low bit-rate voice traffic over an AAL2 connection. By conducting a set of experiments, a series of operational and performance results will be presented. Particular focus will be placed on the performance and efficiency of the AAL2 layer over ATM, as well as the ability of the switch to route packets from multiple sources to a set of output connections in the correct manner.","abstract_has_math":false,"creators":["Shepstone, Sven E"],"institution":"Department of Electrical Engineering","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Ventura, Neco"],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002","date_published":"2002","updated_at":"2026-07-22T22:23:33Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/9773","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Ventura, Neco"]},{"key":"dc:creator","label":"Author","values":["Shepstone, Sven E"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-11-22T05:41:14Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-11-22T05:41:14Z"]},{"key":"dc:date.issued","label":"Date","values":["2002"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Electrical Engineering"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/9773"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Includes bibliographical references."]},{"key":"dc:description.abstract","label":"Abstract","values":["The research community and industry alike have, over the past decade, been showing considerable interest in packet-switching networks to support voice services as well as data services. A technology that was standardised to accommodate these delay-sensitive requirements is Asynchronous Transfer Mode (ATM), which deals particularly well at transporting uncompressed voice and data. However, due to the exponential increase in wireless applications and their supporting access technologies, a need has arisen for an infrastructure in the wide area network to support and maintain the QoS requirements of low-bit rate, compressed voice. An adaptation layer known as AAL2 was re-standardised to support these specialised voice services. However, a severe side-effect of using AAL2 with traditional ATM switches results in inefficient routing and waste-age of resources. In this study, a design for an AAL2 switching node will be proposed to address the above-mentioned issues. The design is comprised of modules that perform the following functions: Buffering, payload interrogation, protocol translations, packet classification, packet re- routing, timing, scheduling and support for signalling and management interfacing. The supporting architecture is targeted towards an embedded >286-based computing system, which itself is overlaid upon one or several ports of a high-speed, research-oriented ATM switch, known as the Washington University Gigabit Switch (WUGS). In order to evaluate the operation and performance of the AAL2 switch architecture, a testbed is proposed and implemented, comprising the AAL2 switch at the core, with a supporting infrastructure to emulate the generation and analysis of low bit-rate voice traffic over an AAL2 connection. By conducting a set of experiments, a series of operational and performance results will be presented. Particular focus will be placed on the performance and efficiency of the AAL2 layer over ATM, as well as the ability of the switch to route packets from multiple sources to a set of output connections in the correct manner."]},{"key":"dc:title","label":"Title","values":["AAL2 switching node to support voice services in 3rd and 4th generation networks"]}]}],"canonical_facts":{"dc:contributor.advisor":["Ventura, Neco"],"dc:creator":["Shepstone, Sven E"],"dc:date.accessioned":["2014-11-22T05:41:14Z"],"dc:date.available":["2014-11-22T05:41:14Z"],"dc:date.issued":["2002"],"dc:description":["Includes bibliographical references."],"dc:description.abstract":["The research community and industry alike have, over the past decade, been showing considerable interest in packet-switching networks to support voice services as well as data services. A technology that was standardised to accommodate these delay-sensitive requirements is Asynchronous Transfer Mode (ATM), which deals particularly well at transporting uncompressed voice and data. However, due to the exponential increase in wireless applications and their supporting access technologies, a need has arisen for an infrastructure in the wide area network to support and maintain the QoS requirements of low-bit rate, compressed voice. An adaptation layer known as AAL2 was re-standardised to support these specialised voice services. However, a severe side-effect of using AAL2 with traditional ATM switches results in inefficient routing and waste-age of resources. In this study, a design for an AAL2 switching node will be proposed to address the above-mentioned issues. The design is comprised of modules that perform the following functions: Buffering, payload interrogation, protocol translations, packet classification, packet re- routing, timing, scheduling and support for signalling and management interfacing. The supporting architecture is targeted towards an embedded >286-based computing system, which itself is overlaid upon one or several ports of a high-speed, research-oriented ATM switch, known as the Washington University Gigabit Switch (WUGS). In order to evaluate the operation and performance of the AAL2 switch architecture, a testbed is proposed and implemented, comprising the AAL2 switch at the core, with a supporting infrastructure to emulate the generation and analysis of low bit-rate voice traffic over an AAL2 connection. By conducting a set of experiments, a series of operational and performance results will be presented. Particular focus will be placed on the performance and efficiency of the AAL2 layer over ATM, as well as the ability of the switch to route packets from multiple sources to a set of output connections in the correct manner."],"dc:identifier.uri":["http://hdl.handle.net/11427/9773"],"dc:language.iso":["eng"],"dc:publisher.department":["Department of Electrical Engineering"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["AAL2 switching node to support voice services in 3rd and 4th generation networks"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc"]},"updated_at":"2026-07-22T22:23:33Z"}