Now, let's bring together what we know about networks and devices into a single network or single device. This is the idea behind telecommunications convergence. New networks carrying voice, video, and data over IP are beginning to emerge. The transition to a converged network will not be easy and will take many years before a full implementation is completed.
You may ask: Why do we need to converge in the first place? Well, a single network managing all telecommunications needs would be a cost-effective solution as we develop for the future. There are some new considerations like quality of service, lack of features and priority issues, but in general, a converged network using TCP/IP is a good idea.
Both H.323 and Session Initiation Protocol are used today for voice over IP (VOIP) solutions (Figure 10.7). We'll look at the similarities and differences of each of these protocols.
Figure 10.7 VOIP solution.
We'll also look at IPV6 and the ramifications of a completely networked environment for the future. Finally, we'll look at some converged devices that are gaining in popularity, specifically, a cellular phone that has audio and video capabilities and a personal digital assistant that functions as a PC and more.
H.323 is the voice over IP (VOIP) standard that has been recommended by the International Telecommunications Union (ITU). This recommendation provides the technical requirements for voice communications over data networks without any quality of service (QOS) provisions. The standard provides for both point-to-point and multipoint conferencing specifications. Calling features commonly associated with the PSTN (call forwarding and call waiting, for example) are not included with this specification.
The most common use of H.323 is for voice conversation with the Internet as its transmission path. PCs are equipped with microphones, speakers, and the appropriate software to run H.323 with a web browser. The voice quality associated with these calls is usually low, however. The cost for domestic voice services is usually free.
H.323 certainly has its limitations; however, newer VOIP protocols are emerging with even more features and enhancements.
Session Initiation Protocol
Session Initiation Protocol (SIP) is the future of voice telecommunications. Both H.323 and SIP are considered voice over IP (VOIP) solutions. SIP uses a single address for all necessary telecommunications. Computer, telephone, wireless telephone, and personal digital assistant (PDA) can all be used with SIP. SIP can also provide instant messaging, video conferencing, and gaming accessible as a group function.
SIP is a relatively new protocol that determines how voice and data are transported across data networks. It is designed to be integrated with IP services such as video, email, and the Internet, bringing all telecommunications services into one common, integrated platform.
A SIP telephone is sometimes referred to as an Ethernet telephone since the telephone connection is made to an Ethernet jack on a LAN. Each SIP telephone has a TCP/IP address, so you can change telephone device preferences.
Besides network connectivity, a SIP telephone is somewhat different from a traditional telephone. First of all, you must log in to the SIP telephone device much like you would log in for a networked PC desktop device. This login tells the SIP server that you are now available at the telephone you just logged in to. This provides security benefits and allows access to your telephone only to authorized users.
Other features such as call filtering can be used. For example, if you are in a special meeting, you can program your SIP phone to ring only when the call is from your manager. Another new feature is call presence. With call presence you can determine who is logged in on the network and available for voice/data calls. With this information, you can create an audio or video conference among your coworkers.
We already know that SIP services packetize voice for data transmission. If the local network is already heavily congested however, quality of service (QOS) issues may be a major factor. IP networks must be optimized to carry "real time" voice and data together, with minimal delay and errors.
Development of SIP and SIP telephone networks is still in its infancy. Much more study and SIP system implementation is needed before this technology can become a mainstream product. The cost for SIP equipment is still quite high. Cost savings will come from the elimination of PBXs, dedicated lines, and the administrative costs associated with traditional voice networks. Many companies are still reluctant to remove proven PSTN and PBX technologies and replace them with SIP technology. It is anticipated that both technologies will need to coexist for many years to come.
IPV6 and Future Applications
IPV6 is short for "Internet Protocol Version 6," which is a future generation protocol designed to replace the current standard IPV4. Today's IPV4 Internet is almost 20 years old and is having problems. The most serious problem is the growing shortage of IPV4 addresses needed to access the Internet.
IPV6 fixes the address shortage problem and adds many significant improvements to the protocol in areas such as automated network configuration and enhanced routing. With IPV6, some of the IPV4 header information was dropped, creating a simplified packet structure. The 16-byte, 128-bit IPV6 addresses are four times longer than the 4-byte IPV4 addresses. IPV6 is expected to eventually replace IPV4, with the two running together for several years during this transition phase.
One of the most intriguing ideas behind IPV6 is the prospect of assigning IP addresses to virtually everything. Yes. I mean everything! Devices, people, pets, appliances, machines...
People. An extremely small transmitting device can be implanted under your skin. This device would contain your IP address, enabling you to access certain rooms and office buildings without swiping a magnetic card or showing an ID. The IP address could also contain links to information regarding your medical history or financial status.
Pets. An extremely small transmitting device can be implanted under an animal's skin. This device would also contain an IP address for your pet. If the animal is lost, links to information regarding ownership and veterinary history can be obtained.
Appliances. An appliance would contain an IP address with a wired or wireless connection to a local area network in your home. If you are having trouble with the appliance, you would call a service technician who would then diagnose the appliance problem directly over the Internet. The diagnostic would determine whether the entire unit would need replacement or whether certain parts could be fixed and what the labor costs would be. This would all be done without a technician's visit.
Machines. An intelligent soda machine would contain an IP address with a wired or wireless connection to a local area network in an office complex. The intelligent soda machine would be connected to the Internet, and the price of the soda would be determined by answers to the following questions:
Is the weather hot or cold? In hotter weather, the price of soda would be higher. In colder weather, the price would be lower.
What is the current inventory of soda in the machine? A fully loaded soda machine would charge less for soda than an empty soda machine.
When is the next soda delivery date? If soda is to be delivered tomorrow, the price may be lower than if soda is to be delivered next week. An Internet link to the warehouse can determine delivery dates.
What is the current value of stock for the soda company? A higher value of stock may reflect a higher price for the can of soda. An Internet link to a stock ticker can be used to determine a company's value.
What are the age and the maintenance requirements for the soda machine? A new soda machine may cost more, raising the price for the can of soda. An older soda machine may require maintenance, which could also be reflected in a higher price for a can of soda.
Personal Digital Assistant
Shrink a laptop computer to the size of a large calculator and you have a personal digital assistant (PDA). PDAs have become quite prevalent in business applications. PDAs use the Windows CE operating system or the Palm OS (Figure 10.8).
Figure 10.8 Personal digital assistant.
Whichever device and operating system is chosen, PDAs have a portability advantage over traditional PCs and laptops. Software exclusively written for PDAs can be similar to software written for PCs. Wireless connectivity can be used to access the Internet or email, and a serial connection can be used to access a traditional PC or laptop.
With devices such as hard drives and memory growing smaller and smaller, it is expected that PDAs will eventually become predominant in the computing industry.
As with any important device as small as a PDA, special security considerations should be taken to safeguard data and passwords.
Mobile Multimedia Phone
The idea of one device for telecommunications voice, data, and video is not new. However, technology has increased so rapidly within the last few years that these concepts are beginning to become a reality.
Many cellular telephones in use today have limited access to the Internet with a micro-browser. Mini-browsers display data such as weather, news, sports, etc. However, today's Internet browsing features are usually very limited.
The widespread acceptance of cellular telephone technology is mainly due to its portability. Voice telecommunications anywhere at any time is truly appealing to both consumers and businesses alike. What about other telecommunications technologies besides voice? Wouldn't it be great to have a converged cellular device that could perform voice video and data services? Let's imagine some of the possibilities:
Video-conferencing with your coworkers at a bus stop.
Watching streaming video of a newscast before boarding a commuter train.
Sending images of a family vacation instantly.
Receiving MP3 audio of the latest popular music.
Checking your browser to find the closest fast-food restaurant.
The development of a converged cellular multimedia device will not happen all at once. Networks must be developed and retooled, and the appropriate bandwidth must be obtained. Most likely, a gradual conversion from the cellular voice networks of the present to the cellular multimedia networks of the future will happen during the next five years or more.
With a mobile multimedia phone, real-time voice, video, and data will be available to support the desire for any time, any place telecommunications (Figure 10.9).
Figure 10.9 Mobile multimedia phone.