This article is a continuation of the previous article entitled “Understanding How to Work SMS”, here will be explained on how the SMS Gateway. When we hear the term SMS Gateway then we would imagine a system application that can receive and sending sms, and usually the system consists of a receiver, eg GSM modem or HP that is connected to a PC / computer and the applications that run within it. However, the explanation in this article will be a little different, here will be explained about the operation of the SMS Gateway is used side telecommunications providers (carriers), such as Telkomsel, XL, Indosat, etc.. You will also know how to process that occurs at polling service, premium sms, sms banking, sms etc Broadcast Operator.
What is an SMS Gateway?
SMS gateway is a device offering SMS transit, transforming messages to mobile network from other media, or vice versa, allowing transmission or receipt of SMS messages with or without using a mobile phone. (Wikipedia).
As explained above, the SMS Gateway can connect to other media such as the SMSC and the Content Provider’s server through an IP link to process an SMS service.
An SMS Gateway system, generally comprises hardware components (servers / computers equipped with network devices) and software (applications used for processing of the message). And for a large systems generally use the Database for data storage.
Position in Network GSM SMS Gateway.
Here is an example of the position of SMS Gateway in the operator’s network and its communication protocol used.
From the figure above shows that SMS Gateway serves as a liaison between Esme did sms relay (External Short Message entitiy) and SMSC and vice versa. Communication between Esme and SMS Gateway can be used with HTTP or SMPP protocols, while the SMSC using SMPP.
Esme is outside entities that can be either a server application service provider (Application Service Provider), which is owned by Content Providers, Banking applications, server polling, and others that can receive the message, process the message and send a response to incoming messages, as well as other devices such as e-mail gateway, WAP proxy server, Voice mail server.
Protocol SMPP (Short Message Peer to Peer)
SMPP protocol is quite popular the open, industry-standard protocol that is designed to provide a flexible data communications interface for data transfer short messages between SMS entities, such as Esme and SMSC. SMPP are widely used today is SMPP v3.4. SMPP is quite popular used because it provides a large capacity and fast transfer speeds sms.
In communication using the SMPP protocol, some functioning as SMPP server and the other as an SMPP client. As the diagram above in addition to functioning as an SMS Gateway SMPP server can also function as an SMPP client.
[Esme] —–> [SMSGW]
Esme = SMPP Client, SMSGW = SMPP Server
[SMPP] —–> [SMSC]
Client SMSGW = SMPP, SMSC = SMPP Server
An SMPP Client requires at least 4 pieces of the parameters to be able to communicate with the SMPP server, such as SMPP Server IP Address, Port Number, User Name and Password.
Protocol HTTP (Hypertext Transfer Protocol)
HTTP is an application layer network protocol used for distributed information systems, collaborative, and using hypermedia. We are all quite familiar with this protocol, the protocol used for web applications. As SMPP, the communication is client-server, eg: Web Browser as a client and a Web server.
There are two methods in the HTTP protocol, the GET and POST methods. Two methods can be selected according to needs.
Sample Flow SMS
From the above description we can imagine how the plot goes a sms based services, eg premium SMS.
1) Customer / Mobile Station (MS) sending a message.
2) go to SMSC SMS over a mobile network.
3) From the SMSC, the message will be transferred to the Content Provider through SMS Gateway.
4) Incoming messages to the Content Provider will be processed by the application, then the response is sent to the MS.