Session Initiation Protocol (SIP)

Session Initiation Protocol (SIP) Internet telephony Future


Emerging from Voice over the Internet, on the day of this evolution has reached Over the Internet Phone. Most of the Telephone Over the Internet relies on the H.323 protocol developed by the International Telecommunication Union (ITU) http://www.itu.int. Which essentially is a forcible process of signaling to the PSTN phone network Internet, of course, this process has not necessarily match the network is the Internet packet switching.

Therefore, the Internet Engineering Task Force (IETF) http://www.ietf.org which is the highest institution in engineering the Internet to develop all the standards used by the Internet is open to the evolution that has been added to make Internet telephony (not a telephony over the Internet ).

The concept of Internet telephony is very different with telephony over the Internet, which is currently making a lot of headache operators, government and the House of Representatives. How the phones, in simple language, when we are pressing our nelepon number and destination phone number after we are we will be talking to one another. So, here, the differences mendasarnya, the internet telephony goal is no longer in need of identification with phone numbers, such as, +62 21 123 4567, but the URL does not identify with the different Web! Phone number can remain in contact but a subset (small part) of the identification techniques internet telephony. In the political language, we no longer have to depend on Telkom, service, the government, even the House of Representatives to operate Internet telephony, is located on the absolute power of the people!

Some examples of forms of identification Internet telephony, are:

• sip: onno@indo.net.id - you will be dealing directly with the phone onno@indo.net.id.
• sip: djancoek@surabaya.com; transport = tcp - you will be dealing directly with the phone djancoek@surabaya.com with the TCP transport to be more reliable.
• sip: @ sipgate.jakarta.com +001-234-567 8967; user = phone - you will be dealing directly with your partners in the United States that use regular phone.

Clearly visible that the traditional phone numbers that we know is only a subset of Internet telephony. The few dependence to the power of our government that will take power numbers. Maybe will see the excruciating reality of the day it will move from the hands of the government to the people.

There are many operational scenarios, SIP will be difficult to explain in a brief article in this, most can take in a free from http://www.ietf.org, http://www.iptel.org and http://www. sipforum.org. Some software SIP open source can be taken from the site of Open Source as http://www.sourceforge.org. With the movement of open-source Internet telephony will be impossible not to encourage the formation of local industries in Indonesia for an independent pengembangkan Internet telephony.

In general, how to work the Internet telephony can be drawn as it appears in the picture I took of Dr. presentation. Andreas Steffen of Switzerland. Step by step standards / procedures interaction of normal Internet telephony, are:

1. The caller will send a signal INVITE to the proxy server.
2. Proxy server will ask the service to the directory where the URL of the destination. Directory services can be SQL, LDAP, etc..
3. Directory service will provide answers to the proxy server will actually be the location of the destination.
4. Proxy server will forward the INVITE message to the destination.
5. Bell will ring at the destination computer.
6. If the goal was willing to accept, the objectives will be OK to send message to the proxy server.
7. Proxy server will forward the message to the caller OK.
8. Telephone callers will give the message acknowledge (ACK) to the proxy server.
9. Proxy server will forward the engine to the correct destination.

After the establishment of a connection is established, the relationship voice communication will occur. The need to note here that the specifications and technology understand that the proxy is an Internet telephony in the development of a rapid and can be seen in http://www.ietf.org and http://www.iptel.org.




It is interesting to see, the SIP protocol, such as text-based HTML (Web), so very easy to perform debugging and programming. The shipment is similar to sending e-mail only, we will see the From field, To, Subject. In the field, which added some specific to Internet telephony, such as Call-ID, Via.

In the message body entries in the Session Description Protocol (SDP), which explains the ability of the terminal for Internet telephony deal.

Infrastructure provider infrastructure is perhaps the most serious will to adopt this technology. On this day in Indonesia, we are on the technology generation to the 2G or 2.5G two. Some countries have been developing in 3G. specification in the 4G mobile technology, the Internet will become the main base, not more ISDN. 4G will use SIP as the main focus of attention side by side with the V6 IP routing technology and the Internet are optimal. This means? Infrastructure & technology, Telkom will slowly leave the people!