Service provisioning in two open-source SIP implementation, cinema and vocal
- Authors: Hsieh, Ming Chih
- Date: 2013-06-18
- Subjects: Real-time data processing , Computer network protocols , Internet telephony , Digital telephone systems , Communication -- Technological innovations
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4687 , http://hdl.handle.net/10962/d1008195 , Real-time data processing , Computer network protocols , Internet telephony , Digital telephone systems , Communication -- Technological innovations
- Description: The distribution of real-time multimedia streams is seen nowadays as the next step forward for the Internet. One of the most obvious uses of such streams is to support telephony over the Internet, replacing and improving traditional telephony. This thesis investigates the development and deployment of services in two Internet telephony environments, namely CINEMA (Columbia InterNet Extensible Multimedia Architecture) and VOCAL (Vovida Open Communication Application Library), both based on the Session Initiation Protocol (SIP) and open-sourced. A classification of services is proposed, which divides services into two large groups: basic and advanced services. Basic services are services such as making point-to-point calls, registering with the server and making calls via the server. Any other service is considered an advanced service. Advanced services are defined by four categories: Call Related, Interactive, Internetworking and Hybrid. New services were implemented for the Call Related, Interactive and Internetworking categories. First, features involving call blocking, call screening and missed calls were implemented in the two environments in order to investigate Call-related services. Next, a notification feature was implemented in both environments in order to investigate Interactive services. Finally, a translator between MGCP and SIP was developed to investigate an Internetworking service in the VOCAL environment. The practical implementation of the new features just described was used to answer questions about the location of the services, as well as the level of required expertise and the ease or difficulty experienced in creating services in each of the two environments. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: Hsieh, Ming Chih
- Date: 2013-06-18
- Subjects: Real-time data processing , Computer network protocols , Internet telephony , Digital telephone systems , Communication -- Technological innovations
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4687 , http://hdl.handle.net/10962/d1008195 , Real-time data processing , Computer network protocols , Internet telephony , Digital telephone systems , Communication -- Technological innovations
- Description: The distribution of real-time multimedia streams is seen nowadays as the next step forward for the Internet. One of the most obvious uses of such streams is to support telephony over the Internet, replacing and improving traditional telephony. This thesis investigates the development and deployment of services in two Internet telephony environments, namely CINEMA (Columbia InterNet Extensible Multimedia Architecture) and VOCAL (Vovida Open Communication Application Library), both based on the Session Initiation Protocol (SIP) and open-sourced. A classification of services is proposed, which divides services into two large groups: basic and advanced services. Basic services are services such as making point-to-point calls, registering with the server and making calls via the server. Any other service is considered an advanced service. Advanced services are defined by four categories: Call Related, Interactive, Internetworking and Hybrid. New services were implemented for the Call Related, Interactive and Internetworking categories. First, features involving call blocking, call screening and missed calls were implemented in the two environments in order to investigate Call-related services. Next, a notification feature was implemented in both environments in order to investigate Interactive services. Finally, a translator between MGCP and SIP was developed to investigate an Internetworking service in the VOCAL environment. The practical implementation of the new features just described was used to answer questions about the location of the services, as well as the level of required expertise and the ease or difficulty experienced in creating services in each of the two environments. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
ICT and education in a less privileged school of NMBA
- Authors: Mahleza, Nomfundo
- Date: 2013
- Subjects: Educational technology -- South Africa -- Eastern Cape , Educational innovations -- Technological innovations -- South Africa -- Eastern Cape , Communication -- Technological innovations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/6237 , vital:21058
- Description: Today’s society requires citizens to have a greater knowledge of information technology (IT) than in previous decades. Strategy programs at a national level define the skill needed in an information society and encourage people to learn these skills (Ministry of Education, 2004). In order for everybody to have the opportunity to learn the basics of the new technology, computer science should be included in general education. The development of technology, like Information and Communication Technology (ICT) has turned the world into a global village (Hashem, 2006). The key instrument in this globalisation is the personal computer. Computer–mediated communication is increasingly becoming the dominant means of communication, particularly in the developed and in some developing countries (Adebisi, 2008). In a developing country, ICT is one of the prime ingredients for development. This generally means improvement of people’s lifestyle through improved education, income, skills development and employment. Development should now also be viewed as a multidimensional process involving major changes in social structures, popular attitudes and a national progression of life from unsatisfactory to satisfactory (Servaes, 1999). Since one of the goals of education is to prepare students for work and citizenship, schools are attempting to change their policies, practices and a curriculum to meet the challenge of making pupils ready for a future quite different than the immediate past (Turker & Codding, 1998). The integration of ICT into the teaching and learning environment in secondary education in Port Elizabeth could change learning and teaching attitudes of learners and teachers and help to prepare them for future challenges. However, the success of this integration will depend on how the learners and teachers adapt to the changes and whether they can make ICT technologies part of their daily life. As it is, there is little or no information available regarding the extent of current ICT usage and access in these secondary schools. The research focuses on the availability, usage and the impact of ICT in education, particularly at a secondary school in the poverty-stricken area of Zwide in Port Elizabeth.
- Full Text:
- Date Issued: 2013
- Authors: Mahleza, Nomfundo
- Date: 2013
- Subjects: Educational technology -- South Africa -- Eastern Cape , Educational innovations -- Technological innovations -- South Africa -- Eastern Cape , Communication -- Technological innovations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/6237 , vital:21058
- Description: Today’s society requires citizens to have a greater knowledge of information technology (IT) than in previous decades. Strategy programs at a national level define the skill needed in an information society and encourage people to learn these skills (Ministry of Education, 2004). In order for everybody to have the opportunity to learn the basics of the new technology, computer science should be included in general education. The development of technology, like Information and Communication Technology (ICT) has turned the world into a global village (Hashem, 2006). The key instrument in this globalisation is the personal computer. Computer–mediated communication is increasingly becoming the dominant means of communication, particularly in the developed and in some developing countries (Adebisi, 2008). In a developing country, ICT is one of the prime ingredients for development. This generally means improvement of people’s lifestyle through improved education, income, skills development and employment. Development should now also be viewed as a multidimensional process involving major changes in social structures, popular attitudes and a national progression of life from unsatisfactory to satisfactory (Servaes, 1999). Since one of the goals of education is to prepare students for work and citizenship, schools are attempting to change their policies, practices and a curriculum to meet the challenge of making pupils ready for a future quite different than the immediate past (Turker & Codding, 1998). The integration of ICT into the teaching and learning environment in secondary education in Port Elizabeth could change learning and teaching attitudes of learners and teachers and help to prepare them for future challenges. However, the success of this integration will depend on how the learners and teachers adapt to the changes and whether they can make ICT technologies part of their daily life. As it is, there is little or no information available regarding the extent of current ICT usage and access in these secondary schools. The research focuses on the availability, usage and the impact of ICT in education, particularly at a secondary school in the poverty-stricken area of Zwide in Port Elizabeth.
- Full Text:
- Date Issued: 2013
Bluetooth audio and video streaming on the J2ME platform
- Authors: Sahd, Curtis Lee
- Date: 2011 , 2010-09-09
- Subjects: Bluetooth technology , Mobile communication systems , Communication -- Technological innovations , Communication -- Network analysis , Wireless communication systems , L2TP (Computer network protocol) , Computer network protocols , Streaming audio , Streaming video
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4633 , http://hdl.handle.net/10962/d1006521 , Bluetooth technology , Mobile communication systems , Communication -- Technological innovations , Communication -- Network analysis , Wireless communication systems , L2TP (Computer network protocol) , Computer network protocols , Streaming audio , Streaming video
- Description: With the increase in bandwidth, more widespread distribution of media, and increased capability of mobile devices, multimedia streaming has not only become feasible, but more economical in terms of space occupied by the media file and the costs involved in attaining it. Although much attention has been paid to peer to peer media streaming over the Internet using HTTP and RTSP, little research has focussed on the use of the Bluetooth protocol for streaming audio and video between mobile devices. This project investigates the feasibility of Bluetooth as a protocol for audio and video streaming between mobile phones using the J2ME platform, through the analysis of Bluetooth protocols, media formats, optimum packet sizes, and the effects of distance on transfer speed. A comparison was made between RFCOMM and L2CAP to determine which protocol could support the fastest transfer speed between two mobile devices. The L2CAP protocol proved to be the most suitable, providing average transfer rates of 136.17 KBps. Using this protocol a second experiment was undertaken to determine the most suitable media format for streaming in terms of: file size, bandwidth usage, quality, and ease of implementation. Out of the eight media formats investigated, the MP3 format provided the smallest file size, smallest bandwidth usage, best quality and highest ease of implementation. Another experiment was conducted to determine the optimum packet size for transfer between devices. A tradeoff was found between packet size and the quality of the sound file, with highest transfer rates being recorded with the MTU size of 668 bytes (136.58 KBps). The class of Bluetooth transmitter typically used in mobile devices (class 2) is considered a weak signal and is adversely affected by distance. As such, the final investigation that was undertaken was aimed at determining the effects of distance on audio streaming and playback. As can be expected, when devices were situated close to each other, the transfer speeds obtained were higher than when devices were far apart. Readings were taken at varying distances (1-15 metres), with erratic transfer speeds observed from 7 metres onwards. This research showed that audio streaming on the J2ME platform is feasible, however using the currently available class of Bluetooth transmitter, video streaming is not feasible. Video files were only playable once the entire media file had been transferred.
- Full Text:
- Date Issued: 2011
- Authors: Sahd, Curtis Lee
- Date: 2011 , 2010-09-09
- Subjects: Bluetooth technology , Mobile communication systems , Communication -- Technological innovations , Communication -- Network analysis , Wireless communication systems , L2TP (Computer network protocol) , Computer network protocols , Streaming audio , Streaming video
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4633 , http://hdl.handle.net/10962/d1006521 , Bluetooth technology , Mobile communication systems , Communication -- Technological innovations , Communication -- Network analysis , Wireless communication systems , L2TP (Computer network protocol) , Computer network protocols , Streaming audio , Streaming video
- Description: With the increase in bandwidth, more widespread distribution of media, and increased capability of mobile devices, multimedia streaming has not only become feasible, but more economical in terms of space occupied by the media file and the costs involved in attaining it. Although much attention has been paid to peer to peer media streaming over the Internet using HTTP and RTSP, little research has focussed on the use of the Bluetooth protocol for streaming audio and video between mobile devices. This project investigates the feasibility of Bluetooth as a protocol for audio and video streaming between mobile phones using the J2ME platform, through the analysis of Bluetooth protocols, media formats, optimum packet sizes, and the effects of distance on transfer speed. A comparison was made between RFCOMM and L2CAP to determine which protocol could support the fastest transfer speed between two mobile devices. The L2CAP protocol proved to be the most suitable, providing average transfer rates of 136.17 KBps. Using this protocol a second experiment was undertaken to determine the most suitable media format for streaming in terms of: file size, bandwidth usage, quality, and ease of implementation. Out of the eight media formats investigated, the MP3 format provided the smallest file size, smallest bandwidth usage, best quality and highest ease of implementation. Another experiment was conducted to determine the optimum packet size for transfer between devices. A tradeoff was found between packet size and the quality of the sound file, with highest transfer rates being recorded with the MTU size of 668 bytes (136.58 KBps). The class of Bluetooth transmitter typically used in mobile devices (class 2) is considered a weak signal and is adversely affected by distance. As such, the final investigation that was undertaken was aimed at determining the effects of distance on audio streaming and playback. As can be expected, when devices were situated close to each other, the transfer speeds obtained were higher than when devices were far apart. Readings were taken at varying distances (1-15 metres), with erratic transfer speeds observed from 7 metres onwards. This research showed that audio streaming on the J2ME platform is feasible, however using the currently available class of Bluetooth transmitter, video streaming is not feasible. Video files were only playable once the entire media file had been transferred.
- Full Text:
- Date Issued: 2011
Effectiveness of ICT education in the Northern school area of Port Elizabeth
- Authors: Mooi, Alicia Tenjiswa
- Date: 2011
- Subjects: Educational technology -- South Africa -- Eastern Cape , Computer-assisted instruction -- South Africa -- Eastern Cape , Educational innovations -- Technological innovations -- South Africa -- Eastern Cape , Communication -- Technological innovations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9049 , http://hdl.handle.net/10948/1605 , Educational technology -- South Africa -- Eastern Cape , Computer-assisted instruction -- South Africa -- Eastern Cape , Educational innovations -- Technological innovations -- South Africa -- Eastern Cape , Communication -- Technological innovations
- Description: The use of information communication technology in the 21st Century is very important. The skills and knowledge of using these technologies should start at high school level, as it is at this stage where learners are equipped for tertiary education and the business world. This study seeks to answer how much ICT is used at the average school in Port Elizabeth and how effective such use is. South Africa is one of the countries in the whole world that is still behind in using the new technology. Learners from high school still enter university with no knowledge of how to use a computer. This becomes a problem in the world of technology as almost everything is done using technology. It also becomes a big problem when learners look for jobs in the business world. An active learning theory has been used on the study because, if learners can learn and have access computer at school, life will be easy for both learners and teachers, there would be co-operation and discussion and the fast way of doing school work. For the purpose of the study a qualitative research method has been used to ensure that answers are received straight from, teachers and learners for evidence. It is therefore clear that there are schools in South Africa that still needs the attention of the government in terms of getting access to computers and to have professional teachers for teaching the subject. The government has a responsibility of making sure that all learners and teachers in high schools have access to computers and internet. This will improve the working and learning conditions of both parties involved.
- Full Text:
- Date Issued: 2011
- Authors: Mooi, Alicia Tenjiswa
- Date: 2011
- Subjects: Educational technology -- South Africa -- Eastern Cape , Computer-assisted instruction -- South Africa -- Eastern Cape , Educational innovations -- Technological innovations -- South Africa -- Eastern Cape , Communication -- Technological innovations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9049 , http://hdl.handle.net/10948/1605 , Educational technology -- South Africa -- Eastern Cape , Computer-assisted instruction -- South Africa -- Eastern Cape , Educational innovations -- Technological innovations -- South Africa -- Eastern Cape , Communication -- Technological innovations
- Description: The use of information communication technology in the 21st Century is very important. The skills and knowledge of using these technologies should start at high school level, as it is at this stage where learners are equipped for tertiary education and the business world. This study seeks to answer how much ICT is used at the average school in Port Elizabeth and how effective such use is. South Africa is one of the countries in the whole world that is still behind in using the new technology. Learners from high school still enter university with no knowledge of how to use a computer. This becomes a problem in the world of technology as almost everything is done using technology. It also becomes a big problem when learners look for jobs in the business world. An active learning theory has been used on the study because, if learners can learn and have access computer at school, life will be easy for both learners and teachers, there would be co-operation and discussion and the fast way of doing school work. For the purpose of the study a qualitative research method has been used to ensure that answers are received straight from, teachers and learners for evidence. It is therefore clear that there are schools in South Africa that still needs the attention of the government in terms of getting access to computers and to have professional teachers for teaching the subject. The government has a responsibility of making sure that all learners and teachers in high schools have access to computers and internet. This will improve the working and learning conditions of both parties involved.
- Full Text:
- Date Issued: 2011
Extending the reach of personal area networks by transporting Bluetooth communications over IP networks
- Authors: Mackie, David Sean
- Date: 2007 , 2007-03-29
- Subjects: Bluetooth technology , Communication -- Technological innovations , Communication -- Network analysis , TCP/IP (Computer network protocol) , Computer networks , Computer network protocols , Wireless communication systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4637 , http://hdl.handle.net/10962/d1006551 , Bluetooth technology , Communication -- Technological innovations , Communication -- Network analysis , TCP/IP (Computer network protocol) , Computer networks , Computer network protocols , Wireless communication systems
- Description: This thesis presents an investigation of how to extend the reach of a Bluetooth personal area network by introducing the concept of Bluetooth Hotspots. Currently two Bluetooth devices cannot communicate with each other unless they are within radio range, since Bluetooth is designed as a cable-replacement technology for wireless communications over short ranges. An investigation was done into the feasibility of creating Bluetooth hotspots that allow distant Bluetooth devices to communicate with each other by transporting their communications between these hotspots via an alternative network infrastructure such as an IP network. Two approaches were investigated, masquerading of remote devices by the local hotspot to allow seamless communications and proxying services on remote devices by providing them on a local hotspot using a distributed service discovery database. The latter approach was used to develop applications capable of transporting Bluetooth’s RFCOMM and L2CAP protocols. Quantitative tests were performed to establish the throughput performance and latency of these transport applications. Furthermore, a number of selected Bluetooth services were tested which lead us to conclude that most data-based protocols can be transported by the system.
- Full Text:
- Date Issued: 2007
- Authors: Mackie, David Sean
- Date: 2007 , 2007-03-29
- Subjects: Bluetooth technology , Communication -- Technological innovations , Communication -- Network analysis , TCP/IP (Computer network protocol) , Computer networks , Computer network protocols , Wireless communication systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4637 , http://hdl.handle.net/10962/d1006551 , Bluetooth technology , Communication -- Technological innovations , Communication -- Network analysis , TCP/IP (Computer network protocol) , Computer networks , Computer network protocols , Wireless communication systems
- Description: This thesis presents an investigation of how to extend the reach of a Bluetooth personal area network by introducing the concept of Bluetooth Hotspots. Currently two Bluetooth devices cannot communicate with each other unless they are within radio range, since Bluetooth is designed as a cable-replacement technology for wireless communications over short ranges. An investigation was done into the feasibility of creating Bluetooth hotspots that allow distant Bluetooth devices to communicate with each other by transporting their communications between these hotspots via an alternative network infrastructure such as an IP network. Two approaches were investigated, masquerading of remote devices by the local hotspot to allow seamless communications and proxying services on remote devices by providing them on a local hotspot using a distributed service discovery database. The latter approach was used to develop applications capable of transporting Bluetooth’s RFCOMM and L2CAP protocols. Quantitative tests were performed to establish the throughput performance and latency of these transport applications. Furthermore, a number of selected Bluetooth services were tested which lead us to conclude that most data-based protocols can be transported by the system.
- Full Text:
- Date Issued: 2007
Securing softswitches from malicious attacks
- Authors: Opie, Jake Weyman
- Date: 2007
- Subjects: Internet telephony -- Security measures , Computer networks -- Security measures , Digital telephone systems , Communication -- Technological innovations , Computer network protocols , TCP/IP (Computer network protocol) , Switching theory
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4683 , http://hdl.handle.net/10962/d1007714 , Internet telephony -- Security measures , Computer networks -- Security measures , Digital telephone systems , Communication -- Technological innovations , Computer network protocols , TCP/IP (Computer network protocol) , Switching theory
- Description: Traditionally, real-time communication, such as voice calls, has run on separate, closed networks. Of all the limitations that these networks had, the ability of malicious attacks to cripple communication was not a crucial one. This situation has changed radically now that real-time communication and data have merged to share the same network. The objective of this project is to investigate the securing of softswitches with functionality similar to Private Branch Exchanges (PBX) from malicious attacks. The focus of the project will be a practical investigation of how to secure ILANGA, an ASTERISK-based system under development at Rhodes University. The practical investigation that focuses on ILANGA is based on performing six varied experiments on the different components of ILANGA. Before the six experiments are performed, basic preliminary security measures and the restrictions placed on the access to the database are discussed. The outcomes of these experiments are discussed and the precise reasons why these attacks were either successful or unsuccessful are given. Suggestions of a theoretical nature on how to defend against the successful attacks are also presented.
- Full Text:
- Date Issued: 2007
- Authors: Opie, Jake Weyman
- Date: 2007
- Subjects: Internet telephony -- Security measures , Computer networks -- Security measures , Digital telephone systems , Communication -- Technological innovations , Computer network protocols , TCP/IP (Computer network protocol) , Switching theory
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4683 , http://hdl.handle.net/10962/d1007714 , Internet telephony -- Security measures , Computer networks -- Security measures , Digital telephone systems , Communication -- Technological innovations , Computer network protocols , TCP/IP (Computer network protocol) , Switching theory
- Description: Traditionally, real-time communication, such as voice calls, has run on separate, closed networks. Of all the limitations that these networks had, the ability of malicious attacks to cripple communication was not a crucial one. This situation has changed radically now that real-time communication and data have merged to share the same network. The objective of this project is to investigate the securing of softswitches with functionality similar to Private Branch Exchanges (PBX) from malicious attacks. The focus of the project will be a practical investigation of how to secure ILANGA, an ASTERISK-based system under development at Rhodes University. The practical investigation that focuses on ILANGA is based on performing six varied experiments on the different components of ILANGA. Before the six experiments are performed, basic preliminary security measures and the restrictions placed on the access to the database are discussed. The outcomes of these experiments are discussed and the precise reasons why these attacks were either successful or unsuccessful are given. Suggestions of a theoretical nature on how to defend against the successful attacks are also presented.
- Full Text:
- Date Issued: 2007
A model for the development of service agreements in the Information and Communication Technology sector
- Authors: Johnston, Robert
- Date: 2006
- Subjects: Information technology , Communication -- Technological innovations , Service industries -- Management , Service -- Level agreements
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1143 , http://hdl.handle.net/10962/d1002772 , Information technology , Communication -- Technological innovations , Service industries -- Management , Service -- Level agreements
- Description: SAs are documents that specify the business relationship between stakeholders to an outsourcing agreement. SAs specify this relationship in a legally binding manner that assists in managing expectations of the stakeholders about the service provision. According to Verma (1999), an SA is a precise statement of the expectations and obligations that exist in a business relationship between two organisation: the service provider and the client. In order for organizations to have successful outsourcing partnerships, they need well crafted methods of developing Service Agreements (SAs). Successful methods will produce a conclusive contract that will act as a working document that details the spirit of cooperation between the service provider and the service recipient. This research investigates the development of SAs in the Information and Communication Technology (ICT) sector, and proposes a model for their development. A number of models for SA development have been analysed. Models are analysed from leading researchers in the area, from software houses such as Microsoft and from international standards organisations such as the BS15000 which stipulates the ITIL framework. Eight development principles are identified and explored. An investigation into SAs and their development is conducted. A model is proposed that is composed of the development principles. The development of SAs was explored in an empirical study by means of a survey administered to industry practitioners and a series of interviews with managers in the ICT industry. The results of the study indicate varying levels of support for the development principles and limited relationship between the development principles and the success of the SA, as defined by the number of changes made to the SA after it is completed.
- Full Text:
- Date Issued: 2006
- Authors: Johnston, Robert
- Date: 2006
- Subjects: Information technology , Communication -- Technological innovations , Service industries -- Management , Service -- Level agreements
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1143 , http://hdl.handle.net/10962/d1002772 , Information technology , Communication -- Technological innovations , Service industries -- Management , Service -- Level agreements
- Description: SAs are documents that specify the business relationship between stakeholders to an outsourcing agreement. SAs specify this relationship in a legally binding manner that assists in managing expectations of the stakeholders about the service provision. According to Verma (1999), an SA is a precise statement of the expectations and obligations that exist in a business relationship between two organisation: the service provider and the client. In order for organizations to have successful outsourcing partnerships, they need well crafted methods of developing Service Agreements (SAs). Successful methods will produce a conclusive contract that will act as a working document that details the spirit of cooperation between the service provider and the service recipient. This research investigates the development of SAs in the Information and Communication Technology (ICT) sector, and proposes a model for their development. A number of models for SA development have been analysed. Models are analysed from leading researchers in the area, from software houses such as Microsoft and from international standards organisations such as the BS15000 which stipulates the ITIL framework. Eight development principles are identified and explored. An investigation into SAs and their development is conducted. A model is proposed that is composed of the development principles. The development of SAs was explored in an empirical study by means of a survey administered to industry practitioners and a series of interviews with managers in the ICT industry. The results of the study indicate varying levels of support for the development principles and limited relationship between the development principles and the success of the SA, as defined by the number of changes made to the SA after it is completed.
- Full Text:
- Date Issued: 2006
Investigating call control using MGCP in conjuction with SIP and H.323
- Authors: Jacobs, Ashley
- Date: 2005 , 2005-03-14
- Subjects: Communication -- Technological innovations , Digital telephone systems , Computer networks , Computer network protocols , Internet telephony
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4631 , http://hdl.handle.net/10962/d1006516 , Communication -- Technological innovations , Digital telephone systems , Computer networks , Computer network protocols , Internet telephony
- Description: Telephony used to mean using a telephone to call another telephone on the Public Switched Telephone Network (PSTN), and data networks were used purely to allow computers to communicate. However, with the advent of the Internet, telephony services have been extended to run on data networks. Telephone calls within the IP network are known as Voice over IP. These calls are carried by a number of protocols, with the most popular ones currently being Session Initiation Protocol (SIP) and H.323. Calls can be made from the IP network to the PSTN and vice versa through the use of a gateway. The gateway translates the packets from the IP network to circuits on the PSTN and vice versa to facilitate calls between the two networks. Gateways have evolved and are now split into two entities using the master/slave architecture. The master is an intelligent Media Gateway Controller (MGC) that handles the call control and signalling. The slave is a "dumb" Media Gateway (MG) that handles the translation of the media. The current gateway control protocols in use are Megaco/H.248, MGCP and Skinny. These protocols have proved themselves on the edge of the network. Furthermore, since they communicate with the call signalling VoIP protocols as well as the PSTN, they have to be the lingua franca between the two networks. Within the VoIP network, the numbers of call signalling protocols make it difficult to communicate with each other and to create services. This research investigates the use of Gateway Control Protocols as the lowest common denominator between the call signalling protocols SIP and H.323. More specifically, it uses MGCP to investigate service creation. It also considers the use of MGCP as a protocol translator between SIP and H.323. A service was created using MGCP to allow H.323 endpoints to send Short Message Service (SMS) messages. This service was then extended with minimal effort to SIP endpoints. This service investigated MGCP’s ability to handle call control from the H.323 and SIP endpoints. An MGC was then successfully used to perform as a protocol translator between SIP and H.323.
- Full Text:
- Date Issued: 2005
- Authors: Jacobs, Ashley
- Date: 2005 , 2005-03-14
- Subjects: Communication -- Technological innovations , Digital telephone systems , Computer networks , Computer network protocols , Internet telephony
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4631 , http://hdl.handle.net/10962/d1006516 , Communication -- Technological innovations , Digital telephone systems , Computer networks , Computer network protocols , Internet telephony
- Description: Telephony used to mean using a telephone to call another telephone on the Public Switched Telephone Network (PSTN), and data networks were used purely to allow computers to communicate. However, with the advent of the Internet, telephony services have been extended to run on data networks. Telephone calls within the IP network are known as Voice over IP. These calls are carried by a number of protocols, with the most popular ones currently being Session Initiation Protocol (SIP) and H.323. Calls can be made from the IP network to the PSTN and vice versa through the use of a gateway. The gateway translates the packets from the IP network to circuits on the PSTN and vice versa to facilitate calls between the two networks. Gateways have evolved and are now split into two entities using the master/slave architecture. The master is an intelligent Media Gateway Controller (MGC) that handles the call control and signalling. The slave is a "dumb" Media Gateway (MG) that handles the translation of the media. The current gateway control protocols in use are Megaco/H.248, MGCP and Skinny. These protocols have proved themselves on the edge of the network. Furthermore, since they communicate with the call signalling VoIP protocols as well as the PSTN, they have to be the lingua franca between the two networks. Within the VoIP network, the numbers of call signalling protocols make it difficult to communicate with each other and to create services. This research investigates the use of Gateway Control Protocols as the lowest common denominator between the call signalling protocols SIP and H.323. More specifically, it uses MGCP to investigate service creation. It also considers the use of MGCP as a protocol translator between SIP and H.323. A service was created using MGCP to allow H.323 endpoints to send Short Message Service (SMS) messages. This service was then extended with minimal effort to SIP endpoints. This service investigated MGCP’s ability to handle call control from the H.323 and SIP endpoints. An MGC was then successfully used to perform as a protocol translator between SIP and H.323.
- Full Text:
- Date Issued: 2005
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