How to clean your Mother Board
by: Ray Geide
If you have not done the inspection mentioned in the previous article - How to Clean your Case, now is the time to do so. Look at the blades of the fan in the back of the computer. Also look at any vents. Is there clusters of dust there? Is there grime caked on to it? If so, the inside needs to be cleaned. If the fan blades are clean but it has been several years since you have cleaned the motherboard or if the computer is around cigarette smoke, it probably should be cleaned anyway. Dust and particles in the air (like cigarette smoke) can build up on the circuitry of the motherboard and cause it to heat up and/or corrode. The first thing that you need to do is unplug your computer. Then open up the case to get access to the motherboard. Cases open differently. If you don't know how to open your case, look on the back of your computer along the edge for some screws. These screws may hold on side panels or an upside down U shaped panel that covers the sides and top. Removing the screws will allow you to take off the cover. Other cases have the screws on the front of the computer. To get access to these screws, you must first remove the front panel by pressing a hidden latch. The cover is there to give easy access to the inside of your computer, so if you look hard enough, you should be able to figure out how to remove it. Remember that if you touch anything on the motherboard, you should be grounded by either touching the metal frame of the computer with your other hand or by wearing a special grounding device. The goal of cleaning the motherboard is to remove all dust and debris from the motherboard and all components inside of the case. This can be done using one of three methods. The preferred method is to use a can of compressed air to blow it out. Always hold the can in an up-right position to prevent the propellent chemicals which can damage or corrode components from coming out. Dust and dirt should be blown away from the motherboard and out of the case. Another way to remove dust is to use a vacuum. The common advice is to only use a battery operated vacuum because an AC powered vacuum causes static and static can ruin the motherboard. I have used an AC powered vacuum (before I knew that it was not recommended) to clean my motherboard many times and it has never caused any problems, but I may have just been lucky. When using the vacuum, keep the nozzle a couple of inches away from the motherboard or any other components so that it does not come in contact with them and so that any small parts are not sucked into the vacuum. If you do not have a can of compressed air or a vacuum, you can use a dry cloth and brush to clean the motherboard. Be careful not to dislodge or break anything using this method. While cleaning the motherboard, be careful not to unplug any cables or connections or to dislodge any loose components, such as, jumpers. Methodically clean the whole inside of the case going over all of the motherboard from one end to the other and all other components. Don't forget to clean the fans and heat sinks. Do not open up the power supply box or stick anything in it beyond the fan. If you do, you could get a shocking surprise and ruin your computer. If your computer does not work when you put it back together, something was obviously dislodged during the cleaning. Open the case back up and push all connections and cards into their slots. Look for anything that may have become disconnected. Cleaning the motherboard is probably the most dangerous form of cleaning but it is necessary to prevent an early death of your computer.
About The Author
Ray Geide writes a free weekly newsletter called Ray's Computer Tips and moderates a discussion board answering computer questions called Computer Q&A. He is an experienced computer programmer who has been writing top-rated software for over a decade. Though he has written for some big-name companies, he prefers to write for his own company, Super Win Software, Inc. http://www.superwin.com/
Saturday, July 5, 2008
Clean Your Case
How To clean your Case
by: Ray Geide
There is nothing wrong with leaving spills, dirt, and stains on your computer case. After all isn't that what the case is for, to protect the electronic components inside from spills and dirt? This is true, but there are still parts of the case that need to be cleaned and checked if you want your computer to live a long and prosperous life. Unless you like looking at dirt everytime you look at your computer, you should go ahead and clean those spills, stains, and dust off of the case. You can do this with just about any cloth and cleaner. Do not use highly abrasive cleaners that might ruin or mar the surface and do not use solvents on plastic. A wet sponge will even work. Just make sure that the cleaner or any liquid does not seep into the inside through cracks and vents. If there is any possibility that you are going to get that messy, turn off and unplug the computer first and wait to turn it back on until any liquid has had a chance to fully dry. After you have wiped off the outside, it is time for a little inspection. Look at the blades of the fan in the back of the computer. Also look at any vents. Is there dust there? Is there a lot of dust and grime caked on to it? If so, that is an indicator that the inside also needs to be cleaned (I will tell you how to do that in next week's article - How to Clean your Motherboard). Some clean environments never have to have the inside cleaned. Some need it cleaned monthly. When I lived in Russia, even though I didn't notice it, the air was not clean. The fan on the computer would cake up with dirt and grime after about a month of use. And so I would have to clean the fan, vents, and inside monthly. If I had let it go for several months without cleaning, the fan would have stopped working and the computer would have overheated. Where I now live in the US, the air is clean and I have gone years without having to clean it. Again, the indicator of this is the blades of the fan and the vents. If they are dirty, they need to be cleaned. You can do some of the cleaning from the outside. First, turn off the computer. Then get out the vacuum sweeper and using the hose, vacuum out the vents and the fan(s). If you have compressed air (you can purchase compressed air from your computer store), you may want to blow air in through the vents (or intake fan if you have one) to loosen the dust and suck it out using the vacuum. If there is still dust or dirt in the vents or on the blades of the fan, you can use a Q-tip to clean them. If you do not have a vaccum, you can use compressed air alone. Always use short bursts to avoid moisture buildup. Start with the computer off and blow into every hole and vent. Then turn the computer on and blow everything except for the exhaust fan once again. With the case clean, your computer will look nicer and with the fan and vents cleaned out it will breathe easier and run cooler.
About The Author
Ray Geide writes a free weekly newsletter called Ray's Computer Tips and moderates a discussion board answering computer questions called Computer Q&A. He is an experienced computer programmer who has been writing top-rated software for over a decade. Though he has written for some big-name companies, he prefers to write for his own company, Super Win Software, Inc. http://www.superwin.com/
by: Ray Geide
There is nothing wrong with leaving spills, dirt, and stains on your computer case. After all isn't that what the case is for, to protect the electronic components inside from spills and dirt? This is true, but there are still parts of the case that need to be cleaned and checked if you want your computer to live a long and prosperous life. Unless you like looking at dirt everytime you look at your computer, you should go ahead and clean those spills, stains, and dust off of the case. You can do this with just about any cloth and cleaner. Do not use highly abrasive cleaners that might ruin or mar the surface and do not use solvents on plastic. A wet sponge will even work. Just make sure that the cleaner or any liquid does not seep into the inside through cracks and vents. If there is any possibility that you are going to get that messy, turn off and unplug the computer first and wait to turn it back on until any liquid has had a chance to fully dry. After you have wiped off the outside, it is time for a little inspection. Look at the blades of the fan in the back of the computer. Also look at any vents. Is there dust there? Is there a lot of dust and grime caked on to it? If so, that is an indicator that the inside also needs to be cleaned (I will tell you how to do that in next week's article - How to Clean your Motherboard). Some clean environments never have to have the inside cleaned. Some need it cleaned monthly. When I lived in Russia, even though I didn't notice it, the air was not clean. The fan on the computer would cake up with dirt and grime after about a month of use. And so I would have to clean the fan, vents, and inside monthly. If I had let it go for several months without cleaning, the fan would have stopped working and the computer would have overheated. Where I now live in the US, the air is clean and I have gone years without having to clean it. Again, the indicator of this is the blades of the fan and the vents. If they are dirty, they need to be cleaned. You can do some of the cleaning from the outside. First, turn off the computer. Then get out the vacuum sweeper and using the hose, vacuum out the vents and the fan(s). If you have compressed air (you can purchase compressed air from your computer store), you may want to blow air in through the vents (or intake fan if you have one) to loosen the dust and suck it out using the vacuum. If there is still dust or dirt in the vents or on the blades of the fan, you can use a Q-tip to clean them. If you do not have a vaccum, you can use compressed air alone. Always use short bursts to avoid moisture buildup. Start with the computer off and blow into every hole and vent. Then turn the computer on and blow everything except for the exhaust fan once again. With the case clean, your computer will look nicer and with the fan and vents cleaned out it will breathe easier and run cooler.
About The Author
Ray Geide writes a free weekly newsletter called Ray's Computer Tips and moderates a discussion board answering computer questions called Computer Q&A. He is an experienced computer programmer who has been writing top-rated software for over a decade. Though he has written for some big-name companies, he prefers to write for his own company, Super Win Software, Inc. http://www.superwin.com/
Friday, July 4, 2008
web Development
Web Development And The Big Time Out
by: Scott Lindsay
One of the great debilitators in online business is simply the perceived (or real) lack of time. Business owners are used to moving forward. An online web presence can make them feel tied to an office chair learning skills they aren’t sure they want to know. It’s not uncommon for those who deal in full time web design to have individuals contact them for a site design, but have absolutely no idea what they want. Furthermore when the designer questions them the response might be, “I don’t know, just make it look nice.” Let’s not forget the core values or mission of the business. Many business owners have no idea how to answer those kinds of questions. They may stare blankly for a moment or two and there’s no more time for further deep thought so they go back to action – without answers. In many cases it is possible to answer some of the questions needed, but it may require taking time away from a familiar setting. It may also require more time than you think you want to give. If you can get to a place of concentrated contemplation you are likely to find yourself stripping ideas to their core to find out what your business is trying to accomplish and what your ultimate goals might be. As with almost any project you can turn frustration around if you will just take the time to come to terms with your vision. Sometimes we spend so much time ‘doing’ we never stop to ask the question, “Why?” This process can be a bit like taking a bus that drives around the park. You keep looking at the flowers and the park bench and long to sit in the quiet shade of a tree and just absorb the calming atmosphere. You know they will have a positive effect on you, but for some reason you just can’t seem to find the energy to get off the bus. It seems to me there are some sites that are misguided or rarely guided that could benefit from the process of self-evaluation. These sites may look nice, but there is a sense of disconnection that may not be easy to identify, but it’s fairly obvious to visitors. Creative energy is at a minimum while business owners simply tackle what seem to be the most urgent details. As more people gravitate to online business there needs to be a shift in the thinking of how one goes about doing business online. In many ways it can’t be approached in the same way a traditional business is developed, yet that is typically the way many new web commerce ventures choose to tackle the subject. You may discover your business will be more successful if you take some time for rigorous reflection. The time set aside can be a bit like an architect that takes the time to develop plans for a new building. You wouldn’t expect the architect to simply tell a construction crew to, “Go out there and build – something.” Work at ‘building’ your online business in a comprehensive way. Your effort can develop a firm foundation for long-term success.
About The Author
Scott Lindsay is a web developer and entrepreneur. Make your own website in just 5 minutes with HighPowerSites at: http://www.highpowersites.com or Build A Website at: http://www.buildagreatsite.com. Start your own ebook business with BooksWealth at: http://www.bookswealth.com
by: Scott Lindsay
One of the great debilitators in online business is simply the perceived (or real) lack of time. Business owners are used to moving forward. An online web presence can make them feel tied to an office chair learning skills they aren’t sure they want to know. It’s not uncommon for those who deal in full time web design to have individuals contact them for a site design, but have absolutely no idea what they want. Furthermore when the designer questions them the response might be, “I don’t know, just make it look nice.” Let’s not forget the core values or mission of the business. Many business owners have no idea how to answer those kinds of questions. They may stare blankly for a moment or two and there’s no more time for further deep thought so they go back to action – without answers. In many cases it is possible to answer some of the questions needed, but it may require taking time away from a familiar setting. It may also require more time than you think you want to give. If you can get to a place of concentrated contemplation you are likely to find yourself stripping ideas to their core to find out what your business is trying to accomplish and what your ultimate goals might be. As with almost any project you can turn frustration around if you will just take the time to come to terms with your vision. Sometimes we spend so much time ‘doing’ we never stop to ask the question, “Why?” This process can be a bit like taking a bus that drives around the park. You keep looking at the flowers and the park bench and long to sit in the quiet shade of a tree and just absorb the calming atmosphere. You know they will have a positive effect on you, but for some reason you just can’t seem to find the energy to get off the bus. It seems to me there are some sites that are misguided or rarely guided that could benefit from the process of self-evaluation. These sites may look nice, but there is a sense of disconnection that may not be easy to identify, but it’s fairly obvious to visitors. Creative energy is at a minimum while business owners simply tackle what seem to be the most urgent details. As more people gravitate to online business there needs to be a shift in the thinking of how one goes about doing business online. In many ways it can’t be approached in the same way a traditional business is developed, yet that is typically the way many new web commerce ventures choose to tackle the subject. You may discover your business will be more successful if you take some time for rigorous reflection. The time set aside can be a bit like an architect that takes the time to develop plans for a new building. You wouldn’t expect the architect to simply tell a construction crew to, “Go out there and build – something.” Work at ‘building’ your online business in a comprehensive way. Your effort can develop a firm foundation for long-term success.
About The Author
Scott Lindsay is a web developer and entrepreneur. Make your own website in just 5 minutes with HighPowerSites at: http://www.highpowersites.com or Build A Website at: http://www.buildagreatsite.com. Start your own ebook business with BooksWealth at: http://www.bookswealth.com
Back User Agents
Back to Back User Agents for Telecommunications
by: Danny Loeb
Today’s telecommunications networks are a delicate blend of clients and servers that together offer virtually endless possibilities when it comes to services and applications. For every new client developed, there seems to be a score more on the way — from mobile handsets, PDAs, terminals, telephones, video phones, IP set-top-boxes, and so on. There are essentially two types of servers that connect between clients on large networks: Proxy servers and Back-to-Back User Agent (B2BUA) servers. The more prevalent Proxy servers feature predictable behavior — simply connecting between clients. Effectively, B2BUA servers are much stronger and intelligent entities that perform actions which Proxy servers cannot. Moreover, B2BUA servers provide a flexible solution for a wide range of applications and services and are becoming the primary engine for more and more SIP servers in NGN and IMS networks. The difference between Proxy servers and B2BUA servers is sometimes not fully understood. In this article, we will explore what makes B2BUA servers such an appealing alternative to standard Proxy servers. Better understanding of B2BUA servers can help managers understand the value, and the tradeoffs, of choosing a B2BUA server, as well as the frameworks needed to develop a wide range of SIP applications and SIP services using it. Figure 1 - Architectural difference between Proxy servers and B2BUA servers B2BUA Server Defined B2BUA servers are used to provide value added features for point-to-point calls and manage multi-point calls. The power behind a B2BUA server is derived mostly from the fact that it has a very generic definition, which gives it almost unlimited power. However, this same characteristic is the root of the controversy surrounding it. IETF standard (RFC 3261) defines a back-to-back user agent as “a logical entity that receives a request and processes it as a user agent server (UAS). In order to determine how the request should be answered, it acts as a user agent client (UAC) and generates requests. Unlike a Proxy server, it maintains a dialogue state and must participate in all requests sent on the dialogues it has established.” B2BUA servers have capabilities that far exceed those of other types of SIP servers, and answer the need for developing sophisticated value added SIP applications that cannot be implemented as Proxy applications. Some of these capabilities, which are unique to B2BUA servers, are outlined below: 3rd Party Call Control (3PCC) Features 3rd Party Call Control (3PCC) is the ability of an entity (usually a controller) to set up and manage communication between two or more parties. 3PCC is often used for operator services and conferencing. 3PCC actions are important capabilities, exclusive to B2BUA servers since “passive” non call-stateful elements, such as Proxy servers, cannot initiate these types of activities. Some examples of 3PCC services are online billing, QoS, resource prioritization, call transfer, click-to-dial, mid-call announcement and more. 3PCC actions can be initiated automatically by B2BUA server applications, like disconnecting a call following credit expiration in an online-billing system. Or they can be initiated by remote administrative control (OSS), e.g. invite parties to a multi-point conferencing session. Figure 2 - Schematic outline of B2BUA server offering 3PCC functionality Inter-working Function (IWF) for Interoperability SIP was designed as a highly flexible and extendible protocol. The very strength of this flexibility is also an inherent weakness, since the vast array of client types in the market still need to connect. B2BUA Inter-working Functions (IWF) defines a wide range of powerful SIP servers that connect SIP clients that “speak” in different protocol dialects, or support different capabilities. This Inter-working function is very important in enabling connectivity between clients with different capabilities and/or protocol dialects. Or even between clients and networks – where the B2BUA server actually acts as an access device. Examples of what IWF can do include: • Connecting SIP clients to IMS networks by adding and removing IMS SIP protocol extensions (AKA P-Headers) that are essential for connecting to the IMS network • Connecting clients with different Session Timers settings • Connecting clients with different media capabilities and with distinct Session Description Protocol (SDP) messages by relaying between the two types of control sessions • Connecting to different types of networks (e.g. IPv4, IPv6) and support for different transport types, such as TCP/UDP/SCTP/TLS Figure 3 - Schematic outline of a B2BUA Inter-Working Function Multi-point Call Management B2BUA servers an also implement multi-point call scenarios where multiple CPE devices connect to the B2BUA, and the B2BUA provides services to all CPE. Due to these unique capabilities, B2BUA servers are widely used in the communications industry. A few examples are listed below: • Online-billing/prepaid functions • Servers supporting Resource Prioritization (RP) and/or Quality of Service (QoS) features • Multi Point Conferencing servers • IVR servers • PBX Applications and Softswitches • Application Layer Gateways (ALG) • FW/NAT Traversal applications • Privacy servers • 3rd-Party Call Control Applications (3PCC) • Service Creation Environment (SCE) runtime engines • Session Boarder Controller (SBC) • IMS S-CSCF, P-CSCF, I-CSCF • SIP Inter-work Function (IWF) Gateway • Security Gateway (SEG) • Voice Call Continuity (VCC) servers In addition, B2BUA servers play an important role in emerging IMS networks. Recent releases of 3GPP IMS specifications (3GPP TS 24.229 V8.0.0) indicate that an increasing number of IMS network element servers, such as P-CSCF, IBCF,SBC etc., are B2BUA servers. The reason for this is that value added services are usually session stateful, and feature capabilities that go beyond basic call proxying. Applications written on top of B2BUA Application servers fulfill several roles, such as SIP User Agents, SIP Proxy servers and SIP Registrars. B2BUA Server Challenges B2BUA application developers face many challenges, such as achieving rapid time-to-market, conformance and interoperability, offering customization for proprietary services and support for High Availability (HA) and redundancy. A comprehensive B2BUA framework can help developers overcome these challenges. A solid B2BUA framework should have modular application building block architecture for increased flexibility, abstraction and short delivery time. Traditional architecture, which features a single configurable state machine, is not flexible enough. Also, a B2BUA framework should facilitate developing B2BUA applications by flexibly linking “pluggable” high-level Modular Application Building Blocks (MABB). Developers should have the ability to combine these MABBs and they should be designed in a way that allows developers to further customize their behavior if needed. This type of architecture complies with contemporary Service Oriented Architecture (SOA) concepts, and is suitable for powering flexible business communication platforms. This modular architecture can save months of work. With a set of MABBs in hand, developing the application is a matter of combining existing MABBs to produce the required business logic. In addition, this architecture enhances efficiency; development of new MABBs can be done concurrently. A B2BUA framework should facilitate developing applications that fully conform to standards and are interoperable; without restricting developers from customizing protocol behavior for special cases. Moreover, it should conform for non-standard implementations, as well as to mediate between two versions of the same standard. This type of framework allows developers to focus on their proprietary application with the confidence that their final application will be fully interoperable. And finally, a B2BUA framework should provide the ability to configure, amend and replace application building blocks to create proprietary features. With this ability, developers can maximize existing code – significantly reducing development time, shortening testing cycles, and reducing overall time-to-market. Figure 4 - Traditional architecture of a B2BUA framework RADVISION’s B2BUA Application Framework http://www.radvision.com/Products/Developer/SIPServer delivers these capabilities and more. The B2BUA Application Framework module is a part of the RADVISION SIP server Platform, a software framework that offers the essential building blocks for the development of a wide variety of high performance SIP and IMS servers. The rich set of components and modules can be flexibly combined to match customers’ requirements for developing SIP servers that offer both standard and advanced SIP services. Applications written on top of RADVISION’s B2BUA framework are developed by combining customizable modular application building blocks. This is effectively large chunks of functionality that can be strung together to form ad-hoc applications, enabling developers to focus on the high-level business logic and use building blocks that hide low-level details. As one of the most popular IM applications, Yahoo! Messenger was the first large consumer player that adopted B2B UA. Yahoo! Messenger combined its backend scalable platform with RADVISION’s B2B UA to serve millions of monthly unique messaging users around the world. Yahoo selected RADVISION’s B2BUA due to its robust performance and scalability features. Figure 5 - The architecture of RADVISION B2BUA Application Framework RADVISION also offers automatic High Availability (HA) and Redundancy support. The B2BUA framework automatically replicates the run-time state of the different Services and B2BUA framework core. In the event of a server outage, a redundant server takes over seamlessly and provides uninterrupted service continuity. B2BUA framework benefits in a nutshell • Significantly reduces time to market developing proprietary B2B applications and services. • Allows adding advanced services easily to retain competitive advantage and evolve to meet growing customer demands. • Focuses on the business logic and hides low level operator communication intricacies. • Delivers off-the-shelf conformance and interoperability. • Enables rapid development of applications that can interoperate with different vendors. • Enables adding high-availability features easily. Click here http://www.radvision.com/Resources/WhitePapers/b2bua.htm for more extensive information on B2BUA Servers. By Danny Loeb, RADVISION http://www.radvision.com Product Manager
About The Author
Danny Loeb is a seasoned Product Manager at RADVISION, leading RADVISION’s SIP Server Platform and Server Solutions product family. With over ten years of experience Danny has vast multidisciplinary knowledge in product management, system architecture, integration and development of servers for data communication and voice communication networks. Prior to joining RADVISION, he served as System Integration Manager and System Architect at Charlotte’s Web Networks, a developer of core-IP Terabit Routers, where he lead the foundation of the company’s Remote Presence Solutions Division. Previously, Mr. Loeb served in several positions at Microsoft as part of the Internet Security and Acceleration Development Team.
by: Danny Loeb
Today’s telecommunications networks are a delicate blend of clients and servers that together offer virtually endless possibilities when it comes to services and applications. For every new client developed, there seems to be a score more on the way — from mobile handsets, PDAs, terminals, telephones, video phones, IP set-top-boxes, and so on. There are essentially two types of servers that connect between clients on large networks: Proxy servers and Back-to-Back User Agent (B2BUA) servers. The more prevalent Proxy servers feature predictable behavior — simply connecting between clients. Effectively, B2BUA servers are much stronger and intelligent entities that perform actions which Proxy servers cannot. Moreover, B2BUA servers provide a flexible solution for a wide range of applications and services and are becoming the primary engine for more and more SIP servers in NGN and IMS networks. The difference between Proxy servers and B2BUA servers is sometimes not fully understood. In this article, we will explore what makes B2BUA servers such an appealing alternative to standard Proxy servers. Better understanding of B2BUA servers can help managers understand the value, and the tradeoffs, of choosing a B2BUA server, as well as the frameworks needed to develop a wide range of SIP applications and SIP services using it. Figure 1 - Architectural difference between Proxy servers and B2BUA servers B2BUA Server Defined B2BUA servers are used to provide value added features for point-to-point calls and manage multi-point calls. The power behind a B2BUA server is derived mostly from the fact that it has a very generic definition, which gives it almost unlimited power. However, this same characteristic is the root of the controversy surrounding it. IETF standard (RFC 3261) defines a back-to-back user agent as “a logical entity that receives a request and processes it as a user agent server (UAS). In order to determine how the request should be answered, it acts as a user agent client (UAC) and generates requests. Unlike a Proxy server, it maintains a dialogue state and must participate in all requests sent on the dialogues it has established.” B2BUA servers have capabilities that far exceed those of other types of SIP servers, and answer the need for developing sophisticated value added SIP applications that cannot be implemented as Proxy applications. Some of these capabilities, which are unique to B2BUA servers, are outlined below: 3rd Party Call Control (3PCC) Features 3rd Party Call Control (3PCC) is the ability of an entity (usually a controller) to set up and manage communication between two or more parties. 3PCC is often used for operator services and conferencing. 3PCC actions are important capabilities, exclusive to B2BUA servers since “passive” non call-stateful elements, such as Proxy servers, cannot initiate these types of activities. Some examples of 3PCC services are online billing, QoS, resource prioritization, call transfer, click-to-dial, mid-call announcement and more. 3PCC actions can be initiated automatically by B2BUA server applications, like disconnecting a call following credit expiration in an online-billing system. Or they can be initiated by remote administrative control (OSS), e.g. invite parties to a multi-point conferencing session. Figure 2 - Schematic outline of B2BUA server offering 3PCC functionality Inter-working Function (IWF) for Interoperability SIP was designed as a highly flexible and extendible protocol. The very strength of this flexibility is also an inherent weakness, since the vast array of client types in the market still need to connect. B2BUA Inter-working Functions (IWF) defines a wide range of powerful SIP servers that connect SIP clients that “speak” in different protocol dialects, or support different capabilities. This Inter-working function is very important in enabling connectivity between clients with different capabilities and/or protocol dialects. Or even between clients and networks – where the B2BUA server actually acts as an access device. Examples of what IWF can do include: • Connecting SIP clients to IMS networks by adding and removing IMS SIP protocol extensions (AKA P-Headers) that are essential for connecting to the IMS network • Connecting clients with different Session Timers settings • Connecting clients with different media capabilities and with distinct Session Description Protocol (SDP) messages by relaying between the two types of control sessions • Connecting to different types of networks (e.g. IPv4, IPv6) and support for different transport types, such as TCP/UDP/SCTP/TLS Figure 3 - Schematic outline of a B2BUA Inter-Working Function Multi-point Call Management B2BUA servers an also implement multi-point call scenarios where multiple CPE devices connect to the B2BUA, and the B2BUA provides services to all CPE. Due to these unique capabilities, B2BUA servers are widely used in the communications industry. A few examples are listed below: • Online-billing/prepaid functions • Servers supporting Resource Prioritization (RP) and/or Quality of Service (QoS) features • Multi Point Conferencing servers • IVR servers • PBX Applications and Softswitches • Application Layer Gateways (ALG) • FW/NAT Traversal applications • Privacy servers • 3rd-Party Call Control Applications (3PCC) • Service Creation Environment (SCE) runtime engines • Session Boarder Controller (SBC) • IMS S-CSCF, P-CSCF, I-CSCF • SIP Inter-work Function (IWF) Gateway • Security Gateway (SEG) • Voice Call Continuity (VCC) servers In addition, B2BUA servers play an important role in emerging IMS networks. Recent releases of 3GPP IMS specifications (3GPP TS 24.229 V8.0.0) indicate that an increasing number of IMS network element servers, such as P-CSCF, IBCF,SBC etc., are B2BUA servers. The reason for this is that value added services are usually session stateful, and feature capabilities that go beyond basic call proxying. Applications written on top of B2BUA Application servers fulfill several roles, such as SIP User Agents, SIP Proxy servers and SIP Registrars. B2BUA Server Challenges B2BUA application developers face many challenges, such as achieving rapid time-to-market, conformance and interoperability, offering customization for proprietary services and support for High Availability (HA) and redundancy. A comprehensive B2BUA framework can help developers overcome these challenges. A solid B2BUA framework should have modular application building block architecture for increased flexibility, abstraction and short delivery time. Traditional architecture, which features a single configurable state machine, is not flexible enough. Also, a B2BUA framework should facilitate developing B2BUA applications by flexibly linking “pluggable” high-level Modular Application Building Blocks (MABB). Developers should have the ability to combine these MABBs and they should be designed in a way that allows developers to further customize their behavior if needed. This type of architecture complies with contemporary Service Oriented Architecture (SOA) concepts, and is suitable for powering flexible business communication platforms. This modular architecture can save months of work. With a set of MABBs in hand, developing the application is a matter of combining existing MABBs to produce the required business logic. In addition, this architecture enhances efficiency; development of new MABBs can be done concurrently. A B2BUA framework should facilitate developing applications that fully conform to standards and are interoperable; without restricting developers from customizing protocol behavior for special cases. Moreover, it should conform for non-standard implementations, as well as to mediate between two versions of the same standard. This type of framework allows developers to focus on their proprietary application with the confidence that their final application will be fully interoperable. And finally, a B2BUA framework should provide the ability to configure, amend and replace application building blocks to create proprietary features. With this ability, developers can maximize existing code – significantly reducing development time, shortening testing cycles, and reducing overall time-to-market. Figure 4 - Traditional architecture of a B2BUA framework RADVISION’s B2BUA Application Framework http://www.radvision.com/Products/Developer/SIPServer delivers these capabilities and more. The B2BUA Application Framework module is a part of the RADVISION SIP server Platform, a software framework that offers the essential building blocks for the development of a wide variety of high performance SIP and IMS servers. The rich set of components and modules can be flexibly combined to match customers’ requirements for developing SIP servers that offer both standard and advanced SIP services. Applications written on top of RADVISION’s B2BUA framework are developed by combining customizable modular application building blocks. This is effectively large chunks of functionality that can be strung together to form ad-hoc applications, enabling developers to focus on the high-level business logic and use building blocks that hide low-level details. As one of the most popular IM applications, Yahoo! Messenger was the first large consumer player that adopted B2B UA. Yahoo! Messenger combined its backend scalable platform with RADVISION’s B2B UA to serve millions of monthly unique messaging users around the world. Yahoo selected RADVISION’s B2BUA due to its robust performance and scalability features. Figure 5 - The architecture of RADVISION B2BUA Application Framework RADVISION also offers automatic High Availability (HA) and Redundancy support. The B2BUA framework automatically replicates the run-time state of the different Services and B2BUA framework core. In the event of a server outage, a redundant server takes over seamlessly and provides uninterrupted service continuity. B2BUA framework benefits in a nutshell • Significantly reduces time to market developing proprietary B2B applications and services. • Allows adding advanced services easily to retain competitive advantage and evolve to meet growing customer demands. • Focuses on the business logic and hides low level operator communication intricacies. • Delivers off-the-shelf conformance and interoperability. • Enables rapid development of applications that can interoperate with different vendors. • Enables adding high-availability features easily. Click here http://www.radvision.com/Resources/WhitePapers/b2bua.htm for more extensive information on B2BUA Servers. By Danny Loeb, RADVISION http://www.radvision.com Product Manager
About The Author
Danny Loeb is a seasoned Product Manager at RADVISION, leading RADVISION’s SIP Server Platform and Server Solutions product family. With over ten years of experience Danny has vast multidisciplinary knowledge in product management, system architecture, integration and development of servers for data communication and voice communication networks. Prior to joining RADVISION, he served as System Integration Manager and System Architect at Charlotte’s Web Networks, a developer of core-IP Terabit Routers, where he lead the foundation of the company’s Remote Presence Solutions Division. Previously, Mr. Loeb served in several positions at Microsoft as part of the Internet Security and Acceleration Development Team.
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