What is IP telephony? '
The term IP telephony can be divided into two parts. One is IP and the other is telephony. IP here refers to the Internet Protocol. And we all know what telephony or telephone is. If you have an internet connection, we can use a telephony system based on the internet. This is the IP telephony system. We don't need a new internet connection to get IP telephony. You can turn on this telephony system using the internet connection that you have at home, office or mobile.
'How can I get an IP telephony connection?'
If you have an internet connection, we can get IP telephony connection from those who provide IP telephony with previous internet connection. There are 29 such companies approved by the Bangladesh government that provide IP telephony. There are some rules to follow to make this connection-
1. Must have internet connection.
2. It will take 2 copies of the picture.
3. Photocopy of National / Voter ID Card.
4. Registration form needs to be filled (a form similar to the one we fill in when buying a mobile SIM)
IP Telephony Category:
1. IP telephony solution for Corporate. (IP telephony is currently being used at the corporate level as a means of communication between the various organizations themselves as well as a means of public relations between the various service providers. IP telephony is being used by various banks, corporate offices and providing services using this telephony system. Through various hospitals e-medical service. Call centers have also introduced this system.)
From the picture below we can learn how to set up a corporate call center IP. Will work by phone:

From the picture below we can understand how to use IP in their own offices. The phone can be used where there is no cost other than the set-up cost.

2. IP telephony solution for retails. (Individual usage purpose, but this service is not currently offered in Bangladesh) 3. Hosted solution. (IP phones are used here only for internet use, no infrastructure is required here. This system is usually used by organizations that do not have their own network system and their network settings and maintenance are done by IP telephony providers.) And they only use the IP telephony system over the phone.)
Benefits & Uses of IP Telephony:
1. Customized solution (meaning you can use your telephone system the way you want to use it)
2. Flexible system (many lines can be used with one phone)
3. Full control access (This system has its own Administrative control panel. As a result, all types of services can be nicely controlled from there.)
4. Easy maintenance (If you have your own network system, you can do maintenance of this service. And if the service is a Hosted solution, then maintenance is not required.)
5. More Secured system (The security of your own internet network and the security of the operator are the same as its security. So this security is more secure than any telephone system)
6 . VAS (value added service) availability & accessibility. (Apart from talking on mobile, we can also avail the services that we get at the time of IP telephony set-up. As a result, we can get these services at the cost of set-up for which we do not have to incur any additional cost later.)
7. Low cost & cost effective (IP telephony is the lowest cost of all means of communication. There is no cost to make calls from one IP phone to another IP phone, only another phone i.e. mobile, Calls to land phones, etc. cost less than the normal charge of those phones. Here the line rate is also lower.)
From the picture below we can see how to use IP in an office. Telephony in use:
From the picture above we can understand how we can deliver voice messages from the server to many different people at once.
8 . Voice call:
IP telephony can be used in the same set as talking at home using BTCL. Can also be used in traditional PABX. Video calls can be made as easily as 3G if you have an IP telephone. For all these reasons, this service is very popular in the field of e-medical service and video conferencing.
9. Conferencing system:
IP The conference capacity of the phone is more than any other phone. For example: 10,000 people can hold a conference at a time using this telephony system.
10. Communication from anywhere within your own network is much easier and it's a lot like quick dialing. This service can be much more controlled such as internal communication records that can be used for future official purposes and this record is only with you and there is no chance of information being smuggled because it is in your own network.
11. We can receive fax as email via IP phone. In this case we do not need to have a fax machine.
12. One can be kept in call waiting only on mobile but unlimited person can be kept in call waiting together in IP phone. Moreover, many calls can be received at once. Even a list can be called at once where everyone does not need to call separately. This makes it much easier to communicate in this system.
13. The kind of SMS on mobile. IP can be sent as well. We can record a voice over the phone and send many at once, which saves time and increases the acceptability of the message. Finally the IP. Telephony is a beautiful advancement of current technology. After all, this system has made communication much easier and safer at a much lower cost.
Nice info.. thanks