{"id":34183,"date":"2019-10-31T21:56:52","date_gmt":"2019-10-31T18:56:52","guid":{"rendered":"https:\/\/prohoster.info\/blog\/smpp-odnorangovyj-protokol-korotkih-soobshhenij\/"},"modified":"2019-10-31T21:56:52","modified_gmt":"2019-10-31T18:56:52","slug":"smpp-odnorangovyj-protokol-korotkih-soobshhenij","status":"publish","type":"post","link":"https:\/\/prohoster.info\/en\/blog\/administrirovanie\/smpp-odnorangovyj-protokol-korotkih-soobshhenij","title":{"rendered":"SMPP is a peer-to-peer short message protocol.","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Hello! Although messengers and social networks are displacing traditional means of communication every day, the popularity of SMS remains unaffected. Verification on a popular website, or notification about a transaction, they repeat and will continue to live on. Have you ever wondered how it all works? Very often, the SMPP protocol is used for sending bulk messages, which is what this article will cover.
\n<\/a><\/noindex>
\nThere have already been articles about SMPP on Habr, 1<\/a><\/noindex>,2<\/a><\/noindex>, but their purpose was not to describe the protocol itself. Of course, you can start directly with the original source \u2014 the specification<\/a><\/noindex>, but I think it would be good to have a brief overview as well. I will explain using version 3.4. I welcome your objective criticism.<\/p>\n

The SMPP protocol is a peer-to-peer messaging protocol. This means that each peer\/hub server is equal. In its simplest form, the SMS messaging exchange scheme looks like this:<\/p>\n

\"SMPP
\n
\nHowever, if the national operator does not have a route to a remote region, they request a middleware\u2014an SMS hub. Sometimes, to send one SMS, a chain must be built between several countries, or even continents.<\/p>\n

About the protocol<\/h4>\n

\nSMPP is an application-level protocol based on PDU exchange and transmitted over TCP\/IP or X.25 sessions for sending SMS and USSD messages. Typically, SMPP is used in a persistent connection mode, which helps save time. SMPP uses a client-server communication model.<\/p>\n

Communication mode<\/h4>\n

\n\"SMPP
\n
\nMessage exchange between the sender and the SMS center via SMPP can be conducted in the following modes:<\/p>\n

Transmitter \u2014 message transmission in one direction, sequentially
\nReceiver \u2014 only receiving messages from the SMS center.
\nTransreceiver \u2014 message exchange between the SMS center and the user<\/p>\n

Structure<\/h3>\n

\n\"SMPP
\n<\/p>\n

Message length<\/h3>\n

\nOne SMS message can contain 70 characters when typed in Cyrillic and no more than 157 Latin characters + 3 UDH. If an SMS exceeds the character limit, it will be split into several segments and recombined on the receiving device. In case of segmentation, the number of characters decreases due to message headers indicating the part of the message. Therefore, when sending a large SMS message, it contains a maximum of 153 Latin characters or 67 non-typical characters.<\/p>\n

Data Coding Scheme<\/h3>\n

\nHowever, characters require encoding for message transmission. In the SMPP protocol, a special field\u2014the Data Coding Scheme, or DCS\u2014handles encoding. This field indicates how messages should be recognized. Additionally, the DCS field includes:<\/p>\n