My friend suggested to remove the enhanced plan because most people don’t really need that; and possible to lower the procedural costs. I can’t wait to contact them back tomorrow to find out if it would be less to get the procedure done with less than $3,500.00.

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From My Ride, posted by Hank Görman on 2/27/2010 (15 items)

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Grady Green, grady.green@hickam.af.mil

Jason Weeks, jason.weeks-1@nasa.gov

Electrical Engineering Department

 Bobby Lyle School of Engineering

Southern Methodist University

6251 Airline Rd

Dallas, TX 75205

Abstract– IPv6 is an interesting topic for every single Telecommunication Engineer; which is designed for the next generation by the Internet Engineering Task Force (IETF). The emerged IPv6 to replace the IPv4 due to exhaustion; besides Internet Global communities require double number of IP addresses in the next 10 years. Therefore, IPv6 has the capability to provide up to number of IP addresses that can use for billion years. Other beneficial features include: stateless address auto-configuration, multicast, security implementation, simplified processing, jumbo grams, mobility, and extensive options.

Keywords:  Internet Protocol Version 6 (IPv6), DHCPv6, ICMPv6, Voice-Over-IP (VoIP), Name Resolutions, Routing Functions, Mobility.

1. INTRODUCTION

The Internet Protocol version 6, or IPv6 for short is known for the next generation Internet protocol to replace the limited Internet Protocol version 4 (IPv4).  Because of the limitation of the IPv4 with 32-bit is not suitable for future expansion of Internet usage; especially more Internet users in the dense populated nations like China, India, United States, Indonesia, and etc.  The Internet Engineering Task Force had great vision in predicting IPv6 is needed to overcome the expansion; therefore, in the early 1994, IETF drafted up documents to support new development.  It is documented under RFC (Request for Comment) 2460. Other benefits of IPv6 include more features, functionalities, and especially higher security enforcement (Hagen, 4).  The IPv6 uses 128-bit in its address compares to 32-bit in IPv4, which would allow approximate 3.4 x 10³⁸ addresses.  In addition to the larger number IPv6 addresses can eliminate from using network translation addresses.  One of the most important about improving the features is quality of service (QoS); especially most telephony has been migrating to digital by using voice-over-Internet Protocol (VoIP).  In other words, IPv6 has 8-bits traffic-class to provide the better quality of service and avoid data loss, and jitter (latency).  The domain name resolution has benefit from the IPv6 in improvement.  The multicast listener discovery is embedding into ICMPv6 to provide better routing function.  Although there are many benefits of IPv6 for current and future usages, what has been developed to devote the telecommunication communities?    

- Complete Research Article in PDF format

     The developed country Governments should consider carefully in make any decision to deal with foreign investment and trades.  Perhaps, they should use their past experiences to assist the developing countries, and possible considering the future outcome not the present.  In contrast developing countries should be modernized to accept foreign relations and adopt capitalism.  In the recent report shows most of developing countries are usually historical Socialist or Monarchy type of Government.  Obviously, there is nothing wrong with being non-capitalism, but they should to choose what had been proven that work best for the economies.  Obviously, some studies show there are downturns of globalization with negative impacts.  In order to prevent the future negative impact and financial crisis, the Government should analysis the weakness that cause problem. 

    Before the World Trade Center was attacked by Terrorists in September 2001, the globalization was the main subject for discussion in increasingly international economies.  It plays the major role in intellectual and political divides; in order to be well developed nations must undergo through many phrases, and many positive and negative impacts as the results.  There is always tough decision on Government because some problems arise from globalization such as job loss, immigration issues, national boarder protection, and etc.  Sometimes private sectors have problem making decision due to economies downturn.  But mostly the trend in decision making is always to the Government.   In the recent interview President Obama’s Senior Economic Advisor, Mr. Larry Summers by Harold Myerson; who stated, ‘”those who, just as in the 1930s, tried to learn the lesson that market capitalism didn’t work and needed to be replaced with an entirely different model.” He believes in the past capitalism did not work well as it should; therefore, suggesting the Government should take different approaches on capitalism to aim for positive result.  That could be a tough decision on Politian enough because the Government controls regulations and foreign policies.  Since September 11, 2001 incident with terrorism, many developed countries are protested and debated against globalization.  However, the debated issues are much stronger due to the essential of how economies are structured and especially individual governments deal with each others.  In the recent years, it has been increasing interaction of Governmental agencies in globalization because of their federal economic systems.  Moreover, the developed countries should make the market leaning forward to world economies, or maybe at least some essential aspect.  Mr. Alan Greenspan of Bank for International Settlements believes that developing countries must strive to have more globalization.

     The globalization could be beneficial depends on how individual national government dealing with international relations with other countries.  It gives opportunities for developing countries to improve benefit consumers and proficient producers, but it requires more challenges.  Furthermore, providing free trade between nations and link countries to peace likes United Nations.  In modern economies, marketing and trading play major key in national wealth.  Therefore, globalization is the opening for countries to access large markets, and beneficial capital flows.  Perhaps increasing the imports and exports of goods and services would be the factor of its benefits.   In other words, more investment would boost better living standards within the developing country, meaning it is force for long term economy stabilities.  For certain countries specialize at different products, for example, Japan is known well in the electronic and automobile productions, China is known for cheap labor in goods, so India in customer services.  Per Mr. Palmer’s research shows free trade is the greatest path to eliminated child labor.  “Around the world approximately 250 million children labor,” this number has been dropped dramatically when globalization is implemented.  It also improve their education opportunities because with better living condition would be an open door.

     Although globalization brings many benefits to the world, but always there are people fears of international financial market crises; besides, the benefits for invested countries would be unbalanced.  In this case, the Government would be the central regulation for limited trades leading to imports issue to become dangerous.  This is possible to become more broken economic systems around the world.   Last year, the world economies were suddenly shifted to unexpected direction, many countries poverty had risen up to high percentages.  The national average income had dropped across the developing countries include:  17% in Indonesia, 40% in China, 32% in South Africa, 40% in China, 40% in India, 24% in Argentina, and etc.  In the article, “Why Globalization Is in Trouble,” by Mr. Branko Milanovic, he emphasizes that more developed countries fear with globalization due to job loss because of outsourcing to developing countries.  Today with modern technologies have shifted the jobs outsourcing to low-wage countries, which give the countries like United States and Canada financial crisis.  Maybe the benefit of job outsourcing would help the price on production cheaper for consumers; however, imagine million jobs are sent to over-sea that means million people lose their jobs.   Another fear is increasing immigration, which possible lead to culture intensity issue.  The immigration has been the most important agenda in the United States for the past decade; especially during the recent presidential election.  Whether the there are methods to control immigration problem in this country.  Both job loss and immigration problems are brought by globalization, which is harmful to developed countries.

     In order to minimize the negative impact on globalization, every country should attempt to stop terrorism.   Mr. Alan Greenspan’s research shows terrorism is number one concern in globalization on economy downturns. “Terrorism poses a challenge to the remarkable record of globalization.  A global society reflects an ever more open economic environment…” There are several ways that the Government and Central Bank can do to minimize the negative impact on globalization such as changing policies on foreign affairs, trading, or lowering interest rates.  

       In brief, globalization is the central key to world economies; however, not every single participated country would be beneficial.  Some countries might suffer serious crisis due to terrorism, job loss, market downturns, and even national debts.  In the opposite side, new age of globalization has brought to high standard and most of developing countries are up to the speed.  Improving the marketing trades and living condition standard are most influences.

REFERENCES

• Faiola, Anthony. “A Global Retreat As Economies Dry Up.”  Washington Post, March 5, 2009.
• Gjelten, Tom. “Economic Crisis Poses Threat to Global Stability.” National Public Radio, February 18, 2009.
• Greenspan, Alan. “Globalization.” Bank for International Settlements.  October 24, 2001.  Retrieved on July 5, 2009. URL: http://www.bis.org/
• Milanovic, Branko. “Developing Countries Worse Off Than Once Thought.” Yale Global Online. Carnegie Endowment. February 11, 2008.  URL: http://www.carnegieendowment.org
• Milanovic, Branko.”Why Globalization Is in Trouble.” Yale Global Online. Carnegie Endowment. August 29, 2006. URL: http://www.carnegieendowment.org
• Palmer, Tom G. “Globalization is Great.”  Cato Institute. October 2002. Retrieved on July 7, 2009.
• Beneficial trend: The globalization of well-being”. Growth Strategies. FindArticles.com. 02 Aug, 2009. http://findarticles.com/p/articles/mi_qa3908/is_200301/ai_n9208283/

Abstract - This paper describes the most common vulnerabilities on organizational computer system that often most users never thought about.  These vulnerabilities can take place both in the commercial environment as well as in the home use.   They can be used as an attack surface to hackers and thieves.  There are two easiest ways that could allow an intruder to compromise workstation and servers are through the use of their services and/or physically attack the hardware equipments.  In fact, the main focus on this topic is the recent security experimentation at work and how overcome the obstacle of the attack.

I.  The Easiest Attack Surface

        There are many studies have been done on the issues such as network exploitations, hackings, spywares, viruses, ID thefts, worms, Trojans, and physical network security.  According to Kaspersky.com, in December 2008, there had been 38,190 of different malicious (spywares, viruses, and Trojans).  45% are viruses, 45% are Trojans, and 10% are malicious wares [2]. 

       In the work environment, to power on the workstation without thinking what are the things going on behind the pictures of computer’s desktop.  I later have Outlook open and start to do my day-to-day email tasks.  Workstation’s security normally doesn’t come to mind; especially I’m in the Networking field.  My day-to-day main tasks are to fix big network issues, deploy and manage projects to meet IT department’s objectives.  I relied on our Cisco networking and security devices to protect against information security threats. 

       Sometimes I have to travel on business’ needs, which I normally carry a laptop that synced up to all of my files, emails, and settings.  My usual expectation is that this laptop will allow me to do the work that I would normally do on my desktop.  It has Symantec Endpoint Protection system installed to prevent viruses, spywares, Trojan, and network tampering just as my workstation.  It has “Auto Protect” turned on with the capability of Network Proactive Detection and Tampering Prevention.  When an unusual packets arrived or when it detects so, it will drop that specific connection and alerts me.  Another security mechanism is in order to use my laptop; I will have to authenticate myself by providing a valid username and password.  The probability of having someone to steal my laptop, or authorize using is so low that I don’t consider that even a possibility.  If it is ever stolen, nothing can get out because the entire hard drive is encrypted with 128 bits of Advance Encryption System (AES).

There are many computer services that are running in conjunction to the Windows Operation System services utilize somewhere in the 65,535 ports.  Some of these are essential to the operations of both Windows and third party software.  However, unless you have spent a great amount to research on each and every service running inside of Windows otherwise you wouldn’t know.  A few examples of the services running both on XP, Vista and Windows 2003 servers are:  MSTSC (Microsoft Terminal Service), Computer Browser (allow to browse other computers), Server (allows to share files), Network Location Awareness, Live Update, and Net Logon [3].

II. Security Issues at Work

From my work experience, one morning, I noticed my workstation was running a lot slower compared to a few days ago.  I looked at my workstation’s system performance and noticed that it had used up on average more than 70% of CPU and 80% of memory resources.  I immediately suspected something was running in the background that consuming a huge amount of system resources.  I looked up the Event Logs and saw many application errors and failure audits in the firewall logs.  I checked the Symantec Endpoint Protection and it was out of date more than a month ago. I looked up the MSCONFIG startup, there were many weird automatic startup programs and services which will run after the Windows operating system finished loading.  I immediately disconnected my workstation from the network, migrated all the files to an external hard drive and wiped the whole workstation with the new Windows XP on it.  The cost for this was I lost nearly a day of work.  I learned one of the most important lessons:  I should at least check my workstation running services once a month.  I can’t really trust the free wares, and open sources.  In the proactive to this problem, I learned to copy my system registries and perform full system backup once awhile.  If my workstation runs abnormally, I can just restore the registries to undo the changes or I can just restore the entire system to minimize the downtime.   Also, turn off any unused services to prevent holes in the computer and this will minimize the risks of exposures.

III. Security Solution

         In order to overcome with the recent attacks, a research was conducted.  According to WindowsSecurity.com, secure baseline is the suite security settings that are created to meet each the organization, department or different entity’s requirements [3].  For instance, in the organization I am working for right now, we have security baseline just about for all workstation and server applications, services and network security.  However, according to this article, many other organizations create their own security baseline based on:  account policies, user rights, event log settings, restricted groups, system services, file permissions, and registry permissions. These entire security baselines can be established using Microsoft Windows Active Directory policies.  In the organization I am working with now we only apply some of these security baselines.  They are set using templates so we don’t have to change on every single item when there is a change needs to be made.  Our security baselines are:

1. Microsoft Exchange (Email server)
   1. Maximum attachment to send: 10MB
   2. Maximum attachment to receive: 10MB
   3. All emails to be scanned for any possible threats such as viruses, spam, spywares or Trojan horses before coming into our internal network.
   4. Everyone’s mailboxes capacity no bigger than 1 GB
   5. SSL is used when access emails from the outside
   6. All mails are fully backed up once a week
   7. Mail servers are scanned nightly for threats
   8. Microsoft updates are verified before patched
   9. Antivirus definitions are pushed nightly
   10. Network Security
       1. All network traffics are scanned using Cisco SSM for possible security threats
       2. All wireless access points are located on a different network segment and all using 128bit AES encryption
       3. All MAC addresses are verified before they put on the network
       4. User rights
          1. Resources are managed based on different groups/ departments
          2. Users’ access privileges are based on their job based role
          3. Account Policies
             1. All users’ passwords expired every 90 days
             2. Passwords must be longer than 8 characters with the use at least one special character
             3. Passwords can’t be words contain in dictionary
             4. Users can only access computers which they are assigned to (except for IT administrators)
             5. Users can only logon their machines from 6 AM to 10 PM

      The ways to implement these security baselines are through the use of the two most popular mechanisms:  Cisco policies and Microsoft group policy templates.

Cisco policies:  There are templates inside of the Cisco firewalls or ASA that allow a network administrator to set single or group policies that can be used to examine all the incoming or outgoing traffic.  For instance, the web filter template can be used to filter and record URL (Universal Resource Locator) for all the incoming or outgoing port 80 (HTTP).  In fact, most of the ASA these days have the capabilities to scan all traffic for threat detection and they will block traffic automatically.  Another way of controlling network security is to create a universal template from scratch to fit an organization’s needs.  It can be set to map different ports, traffic, protocols and MAC addresses.

        Microsoft group policy templates:  Group Policy Organization (GPO) – This feature allows network administrator to set rules, permissions using templates.  These templates can be used in multiple servers or groups.  For example, Microsoft Management Console (MMC) can be used to establish many of these settings.  An administrator can perform all these tasks by using graphical interfaces on the Windows Domain Controller (DC) through the use of Active Directory (AD).

In conclusion, security baseline is the suite of security settings that are created to meet each the organization, department or different entity’s requirements.  They are just like templates that allow quickly and convenience ways to deploy security settings in the network.  Any users, computers, network servers can have the same security settings throughout the organization.

IV. Physical Security

       Physical security comes in many parts.  Some people think of having multiple backups, lock their computers, lock the room and use surveillance cameras to monitor, or hide the access to their computers as much as possible are safe.  In the best practice, physical security is the combination all the above [1].  I learned it the hard way.  I once had a friend visited me.  When he came, I was working on a few things for the company I used to work for.  I asked him to sit for a few minutes while I was going upstairs to prepare some drinks.  After I was gone for about 5-7 minutes, I suddenly remembered that I forgot to bring up a few papers.  I ran down and there he was having his USB flash drive sticking in my desktop and copying files from my old work place.  Another accidental that I experienced was my project files.  I spent many days working on this project and right before the due date, the hard drive crashed.  I lost all my work, and worse of all, I lost all my favorite Mp3, old pictures and documents. 

        Servers are the primary targets to many hackers, and organized crimes.  They contain concentrated databases and files which are like jackpots to these criminals.  However, in today network technologies and defense mechanisms are detected abnormal behaviors.  Therefore, corporate workstations are a lot easier targets because they are low profiled machines and have most of the running services just as same as the servers.  They can be used as the stepping stones for the criminals to escalate their privileges and/or to use them to attack servers or services.  Therefore, the best practice is turn off any services that I don’t use to minimize the risks.

V. Conclusion          

        In brief, physical security just as important as the workstation (client software) security because if someone has access to my machine, they can carry out criminal acts however they want.  Therefore, if I don’t use my workstation, the least I can do is to lock up the screen to prevent authorized access to my profiles.  The best way is to setup a multiple defense mechanisms such as office lock, keyboard lock, computer lock, and account lock.  Also, to be more secured a surveillance camera will be used to monitor.

References

[1] Bogue, Robert L. “Lock IT Down:  Don’t Overlook Physical Security on Your Network.”

      August 11, 2003, Tech Republic, Retrieved on March 25, 2009 from

      [http://articles.techrepublic.com.com/5100-10878_11-5054057.html]

[2] Monthly Malware Statistics:  December 2008. Retrieved March 23, 2009 from

      [http://www.kaspersky.com/news?id=207575722]

[3] Windows Security. Retrieved on April 15, 2009 from [http://www.windowsecurity.com]

        The Wi-Fi is an IEEE 802.11b; a simple wireless network likes radio technology.  Today, this type of network is very popular in telecommunication simply low cost.  And especially the absence of cellular network in certain airspace area such as hospitals, government, hotels, airports, and etc; therefore, the wireless IEEE 802.11b plays an important role in mobile communication.  The introduction to dual-mode cell phone with capability of voice-over-wireless network or better known as (VoIP) has certain ultimate goals in mobile communication.  In the recent years, the voice-over Wi-Fi software and hardware development have implemented the mobile communication.  This factor promotes a huge market benefit in deploying five hundred million cellular handsets to the market.  According to Phil Solis, a Senior Wi-Fi Analyst at ABI Research says, “Many enterprises now have established Wi-Fi networks and integrating voice-over-Wi-Fi functionality is a natural progression.  As Wi-Fi network proliferate, it only makes sense to give users the ability to switch from a cellular carrier’s network to the enterprise Wi-Fi network.”  The improvement of technology tailors the way of operating telecommunication with several factors.  The first factor is coming to the reduction costs secure the high performance services.  Secondly, network has improved yearly in upgrading the enhanced voice and data services to the cellular phone.  This factor includes the 3G data network, which was introduced to the mobile communication in the past five years.  Third factor is the augmentation of Wi-Fi technology to where is lacking cellular coverage.  For example, certain building in the urban area location cellular networks from towers are blocked by airspace.  Therefore, the Wi-Fi technology would provide more benefits through broadband networks.  Fourth factor is resources and bandwidth; a typical voice channel takes only 64 kilobit per second, and with the modern broadband network can provide plenty of voice channels.  The final factor is the telephony communication evolution from using the SIP-based signaling protocol, which known as Internet Protocol Multimedia Subsystems or IMS (for short).  The usage is simple and easy in handing-offs cellular and Wi-Fi infrastructure.

       The Unlicensed Mobile Access is a convergence network by using Wi-Fi standard network.  According to UMA Architecture define it as, “an extension of GSM/GPRS mobile service into the customer’s premises that is achieved by tunneling certain GSM/GPRS protocols between the customer’s premises and the Core Network over a broadband IP network, and replaying them through an unlicensed radio link inside the customer’s premises.”  The network delivers low cost with high performance in mobile communication at the office and public wireless network.  There are certain companies provide the low-cost UMA deployment likes T-Mobile IPAccess and HotSpot.  T-Mobile provides over millions HotSpot and IP Access at the Airliners lounges, private sectors, public sectors, Starbuck stores, and the mall kiosks within the United States.  The company also introduces T-Mobile at Home services, which the subscribers can use their broadband networks and SIM (Subscriber Identify Module) card to make the calls.  There are millions growth of mobile communication substitution in yearly, but the performance in maintaining the network is very challenges in delivering the services. The dual-mode Wi-Fi and GSM handset can be accessed through the Unlicensed Mobile Access router network.  Most of these devices are available usage at the home, company office, local libraries, and even convenient public places like shopping malls, airports, and hospitals.  With the Universal Mobile Access network, the operators and subscribers would save lot of money in operating and communicating.  Especially it is very convenient for the subscribers, which they could use their mobile services at anytime and anywhere within the operated locations.  The way of Universal Mobile Access work is starting from the mobile provider through their Mobile Core Network such as circuit packet, IMS services, and etc.  The UMA Network Controller (UNC) delivers these services over the broadband networks, and manages mobile services as well as the mobility access between works. The UMA Enabled Femtocells device can provide the UMT and GSM networks that work for most of the standard mobile cellular phone.  From there, cellular phone can access through the UMA device to the Mobile Core Network through VoIP.

          What are the issues that dual-mode Wi-Fi and GSM handset involve, and how these involvements become realities?  The most complicated one is the handoff situation between two networks; in particularly the problem with existed signaling while the device is in-used.  For example, a subscriber is GSM network for having a conversation with someone; however, the call must be interrupted before switching to the Wi-Fi network.  Perhaps, it is not allowing switchover while the call is in progress, unless the call is terminated due to no reception from the GSM network.  The second complication is the billing system; especially the Wi-Fi network is cheaper but not one hundred percents free.  Maybe, customers must subscribe for both networks in their service package plan, so it is more convenient for both subscriber and operator.  Other issues are the phone integration, device power management, and codec usage.  The phone can stay on the GSM network with the device on sleeping mode; however, in contrast Wi-Fi requires the phone to be on in order to scan for signaling.  Sometimes calls are affected by the latency and packet loss.

        When comes to dual-mode Wi-Fi and GSM handset devices, the mobile communication companies fears to lose their revenue due to low-cost in the Wi-Fi network.  Today there are many technology companies produce cellular phone with embed Wi-Fi capabilities.  According to Phil Solis, “but long term, as with most new developments, carriers will likely see dual mode cellular / voice-over-Wi-Fi handsets as a means to differentiate their offerings.”  The mobile communication companies have to accept the realities of changing the way of communication.  Therefore, T-Mobile was the first carrier to provide easy ways to communicate between cellular and Wi-Fi networks by using the same device.  So, what are the devices have capability to handle both Wi-Fi and GSM network out in the current market?  There are devices such as Nokia 9500 Communicator, Motorola MPx, HP 6300 Series, D-Link’s V-Click, and etc.  These handset devices are operated by Microsoft Windows Mobile, Symbian, Blackberry, and etc.

       The Nokia 9500 Communicator has capability to handle Wi-Fi, GSM/GPRS and EDGE networks.  It integrates with Wi-Fi 802.11b, which has the abilities to support 64 and 128 bit WEP data encryption.  It uses the latest Symbian operating system that is usually for the Smartphone.  It displays a high revolution graphic in color, and has large keyboard for text messaging.  The user can customize the setting such as profile, ringtones, speed dials, and much more in this application.  The calendar, personal contacts, message and personal folder are also including in the handset application.  Furthermore, the handset also supports SMTP, IMP4, and POP3 mail protocols; which user can have multiple email accounts in one devices.  

          The Motorola MPx is built similar to the Nokia 9500 Communicator, but the handset has unique QWERTY keyboard.  It has the tri-band services are built in the device such as capabilities to handle infrared, Bluetooth 1.1, IEE 802.11b, GSM 900, GSM 1800, GSM 1900, and GPRS networks.  The applications are including Pocket Outlook, MSN Messenger, Pocket Internet Explorer, Windows Media Player, Voice Recorder, Calculator, Calendar, Terminal Services, Excel, Word, and etc.  It able to handle 200 MHz, and has the Secured Digital and MMC memory expansion slot. 

       The D-Link’s V-CLICK phone has the dual-mode Wi-Fi and GSM capacity.  The company released the handset into the market in 2009 with full features like tri-band GSM.  Also, has the ability to handle Wi-Fi 802.11b with a speed of 2.4 GHz access.  The handset phone book is operated from the Subscriber Identification Module card.  The handset is built with a click of button can switch from cellular mode to Wi-Fi mode; however, the user must configure the wireless SIP profile.  This handset has strong security such as WEP, WPA, and WPA2 for data and voice encryptions.

         In brief, the dual-mode Wi-Fi and GSM networks availability would enhance the mobile communication network to the next generation.  The Unlicensed Mobile Access is getting more popular because of low-cost service with minimal maintenance.  The dual-mode issues are complicated; however, they will not stop in populating new services.  Due to improvement of technology yearly, the dual-mode handset device is getting more affordable to the customers.  With capabilities of new application features, the device can handle most of the user’s task and security to the high standard. 

References

• Chandra, Praphul & Lide, David. “Wi-Fi Telephony: Challenges and Solutions for Voice over WLANs.”  Elsevier Inc. Burlington, MA. 2007.
• Heine, Gunnar. “GSM Networks: Protocols, Terminology, and Implementation.”  Artech House Inc, Norwood, MA 1999.
• “White Paper on Dual-Mode Phone (GSM & Wi-Fi).” N Group.
• “Dual Mode Mobile”.  The Wikipedia. November 27, 2008.  <http://en.wikipedia.org/wiki/Dual_mode_mobile>
• McZeal, Al. “World’s First Dual-Mode Unlocked GSM/Wi-Fi Phone to Offer Free Calling Over World-Wide Network.” Free Press Release. November 30, 2008. <http://www.free-press-release.com/news/print-1186247150.html>
• Universal Mobile Access.  UMA Today. 2007. <http://www.umatoday.com>
• T-Mobile. The Wikipedia. November 29, 2008. < http://en.wikipedia.org/wiki/T-Mobile>
• “D-Link Introduces V-CLICK Dual-Mode GSM / Wi-Fi Phone.” Geekzone.com. October 4, 2006. <http://www.geekzone.co.nz/content.asp?contentid=6731>
• “Nokia 9500 Communicator” CNET Asia Reviews. <http://asia.cnet.com/reviews/handphones/0,39001713,39018327p,00.htm>
• “Motorola MPx.” Motorola . <http://www.motorola.com/mediacenter/news/detail.jsp?globalObjectId=3869_3244_23>
• ABI Search. December 1, 2008.  <http://www.abiresearch.com/home.jsp>

       The SS7 protocol stack is similar to the Open System Interconnection or known as the OSI model.  However, there are only four levels are considered to be similar with the OSI layers.  The SS7 protocol stacks are identified at the Message Transfer Part (MTP) level 1, level 2, level 3, and the top level.  These are the same as the physical layer, data link layer, network layer, and the application layer.  The top level consists of TUP, TCAP, ISUP, and SSCP; each section of this level is important to the protocol stack.  The Message Transfer Part (MTP) level 1 is defined in the physical and electrical characteristics in providing the signaling; which include the E-1 network which has 2048 kb/s with providing 30 voice channels with a synchronizing channel and a common signal channel, and the DS-1 network has 1544 kb/s with providing 24 voice channels, or 23 voice channels and one common signaling channel.  The message Transfer Part (MTP) level 2 provides the accurate data transmission during the call including the call initiation and termination.  In this transmission, the layer implements sequence validation, error protection, and flow control.  If the error is detected during the signal transmission, the message will be retransmitted.  The MTP level 3 offers the routing function between the signal points, which avoids failure connection transmission when the signals are congested.  The ISDN User Part distinct the protocol is initiating the call, managing the call, and terminating the circuits to end the call.  Perhaps, if the call is made within the switch system network, it does not require using ISUP signaling.  The Telephone User Part is simpler than ISUP, example is no caller ID; however, TUP is used more in handling analog circuits.  Certain parts of the world still use TUP for setting up the call and terminating the call processes.  The majority networks in the globe replaced TUP by the ISUP, especially in the European Union Nations and North America.  The Signaling Connection Control Part (SSCP); is a connection-oriented and connectionless network.  Its functions are controlling the toll free number, calling card number, and customer identification number; therefore, it is easy to track the billing usage.  The SSCP would translate these numbers into the subsystem number to identify the destination signal to the Transaction Capabilities Application Part.  The TCAP provides information between non-circuits data across the SS7 by using SSCP services.  Its functions are authentication, personal identification number validation, equipment identification, and roaming services.

       The Signaling Links is known to transmit both directions between 56 to 64 kilobits per section.  These signals are transmitted on an out-of-band channel, separate from voice channel because they are Intelligent Network to separate these two types of signals.  It also prevents fraudulent network service usage, such as stealing network for commercial purposes and reselling the calling cards.  The Signaling Point are unique because the point codes.  Point codes are addresses in the SS7 network and identify the destination and source.  The Signaling points use routing table rule for the path of individual messages.  There are three types of Signaling Point in SS7:  Service Switching Point (SSP), Signal Transfer Point (STP), and Service Control Point (SCP).  The SSP’s are performing as switches that initiating and terminating the call.  The Signaling messages are being setup, manage and terminate in the voice circuits for every single call.  The STP provides signaling points by routing new message for every incoming message to the specific SSP.  It also acts as a firewall to ensure exchanged manages are secured.  The SCPs provide the configuration service in the event of signaling failure, or for special services like “800” numbers.  If the transmission failed, the SCP re-route the signaling messages to a different base links, or remove the call to a different destination for 800 services.

     There are six different Signaling Link types; these are from A to F, in respect to the SS7 protocol.  The A link is connecting between the signaling end points for message from or to the destination sources.  The B link is connecting between STP’s to provide signaling message transmission.  The C link is connecting between STP’s; however, it pairs up the signal point for reliability if a link fails.  The D link provides secondary connection in STP’s unless there is a problem with the primary, and then the D link temporarily replaces the B link connection.  The E link is connecting between SSP and STP, it is an alternating path in the event that the A link is not reachable.  The F link is connecting between the two end points likes the A link.  Normally, it is not used in STPs, unless there is a problem with STP’s, and not being used; therefore, the F link is replaced for straight connection.

      The typical call process in the SS7 involves two phone switches; one is as a sender “A” and the other one is a recipient “B.”   During the initial calling process, the sender signaling message goes through a switch “A” to determine the destination number and linking itself to the switch “B.”   The trunk voice routing would be setup in response to address message to define the destination source.  Therefore, from the switch “A” routing the message to the switch “B,” and determine whether the call is signaling or busy due to the recipient engaged in calls.  Once the setup is done, the switch “B” would start to formulate the answer message to identify the connection.  The answer message indicates if the destination reason has gone “off-hook.”  This leads to a voice channel connection.  If the sender hangs up the phone first, then the switch “A” would generate a release message (REL) to the recipient or switch “B.”  The opposite happens when a user hangs up.  In either this case, the other party receives a release complete message (RLC).

         In brief the SS7 is a global standard protocol defined by the ITU for telecommunication, and especially for wireless networks.  It consists of 4 different levels and similar to the Open System Interconnection Model.  It has three different signaling Point types and sign different link types.

References:

. Bates, Regis J. “Broadband Telecommunications Handbook.” McGraw-Hill Companies Inc, United States. 2002

. Heine, Gunnar.  “GSM Networks: Protocols, Terminology, and Implementation.” Artech House Inc., Norwood, MA. 1999.

. “SS7 Tutorial” International Engineering Consortium.  November 27, 2008.  <http://www.iec.org/online/tutorials/ss7>