December 12, 2012 at 11:20Allow direct SIP calls
Not so long ago, we launched the Online PBX service , designed for small companies from two people. The main objective of the service is the organization of internal office telephony via SIP.
In the process of developing the service, we came to an interesting conclusion - employees of different companies can make direct calls to each other, bypassing PSTN, just like they send emails to each other from different servers, just dial the SIP address of the interlocutor. But, as happens in fairy tales, there is a certain villain who spoils everything. Such villains can be called the installers of SIP-servers in the local network (for NAT), which exclude the ability to call them from the outside. This is the same as placing an e-mail server on the local network, which downloads letters from the mailbox to Gmail and transfers them according to certain rules to local mailboxes, and outgoing messages outside the company are also sent via Gmail, and you pay for every kilobyte of outgoing mail.
That is why our company did not become a telephone service provider, but relied on an open service.
This is my business card.
The most important thing on it is my email address, where you can send a letter, write a quick message and call. From it it is also easy to understand where I work and find all the necessary information about our company.
One of the reasons that we started a blog on Habré is to convey to the understanding of the people in whose hands the very SIP-servers the need to provide the ability to call your users for free, the need to take this into account in the dialplan of your configuration files, and not block everything, referring for safety. And also encourage you to talk about the benefits of such calls.
Perhaps then, in the future, you do not have to look for another cheap trunk.
In the process of developing the service, we came to an interesting conclusion - employees of different companies can make direct calls to each other, bypassing PSTN, just like they send emails to each other from different servers, just dial the SIP address of the interlocutor. But, as happens in fairy tales, there is a certain villain who spoils everything. Such villains can be called the installers of SIP-servers in the local network (for NAT), which exclude the ability to call them from the outside. This is the same as placing an e-mail server on the local network, which downloads letters from the mailbox to Gmail and transfers them according to certain rules to local mailboxes, and outgoing messages outside the company are also sent via Gmail, and you pay for every kilobyte of outgoing mail.
That is why our company did not become a telephone service provider, but relied on an open service.
This is my business card.
The most important thing on it is my email address, where you can send a letter, write a quick message and call. From it it is also easy to understand where I work and find all the necessary information about our company.
One of the reasons that we started a blog on Habré is to convey to the understanding of the people in whose hands the very SIP-servers the need to provide the ability to call your users for free, the need to take this into account in the dialplan of your configuration files, and not block everything, referring for safety. And also encourage you to talk about the benefits of such calls.
Perhaps then, in the future, you do not have to look for another cheap trunk.