Compare SMPP protocol versions

SMPP (Short Message Peer-to-Peer) is an open, industry standard protocol that enables the transfer of short message data between applications and mobile networks. SMPP is widely used for SMS messaging, as well as other mobile services such as EMS, voicemail notifications, cell broadcasts, USSD, and MMS. SMPP has three versions in use: SMPP 3.3, SMPP 3.4, and SMPP 5.0. Each version has its own advantages and disadvantages, depending on the use case and requirements. In this article, we will compare the features and benefits of each SMPP version, and provide some statistics and a comparison table to help you choose the best one for your needs.

SMPP 3.3

SMPP 3.3 is the oldest version of the protocol, released in 1997. It supports GSM only and has a limited set of operations and parameters. It does not support optional tag-length-value (TLV) parameters, which are used to extend the functionality and information of the protocol. It also does not support non-GSM SMS technologies, such as UMTS, CDMA, TDMA, and iDEN. Moreover, it does not support transceiver sessions, which allow a single connection to send and receive messages.

The main advantage of SMPP 3.3 is its simplicity and compatibility with older systems. It is easy to implement and understand, and it works with most SMS service providers and mobile network operators. However, it has many limitations and drawbacks, such as:

It cannot handle long messages (more than 160 characters) or concatenated SMS (splitting a long message into multiple parts).
It cannot handle binary messages (such as ringtones, logos, or pictures) or Unicode messages (such as Arabic or Chinese characters).
It cannot handle delivery receipts (confirmation of message delivery or failure) or message status reports (information about the message state).
It cannot handle advanced features such as data coding schemes (specifying the encoding and compression of the message), service types (specifying the application or service that originated the message), priority flags (specifying the urgency of the message), validity periods (specifying how long the message should be stored by the network), or scheduled delivery times (specifying when the message should be delivered).

According to a survey conducted by Ozeki, a leading SMS gateway software provider, SMPP 3.3 is still widely used by businesses and SMS service providers, despite its limitations. The survey found that 38% of respondents use SMPP 3.3 for their SMS messaging needs.

SMPP 3.4

SMPP 3.4 is an updated version of the protocol, released in 1999. It adds optional TLV parameters, support for non-GSM SMS technologies, and transceiver support. It also adds new operations and parameters to enhance the functionality and information of the protocol.

The main advantage of SMPP 3.4 is its flexibility and versatility. It can handle various types of messages and services, such as:

Long messages (up to 64 KB) or concatenated SMS
Binary messages or Unicode messages
Delivery receipts or message status reports
Data coding schemes or service types
Priority flags or validity periods
Scheduled delivery times or replace-if-present flags (specifying whether to replace an existing message with a new one)
Message payload (specifying the actual content of the message)
User data header (specifying additional information about the message)
Source address subunit (specifying the subunit within a device from which the message originated)
Destination address subunit (specifying the subunit within a device to which the message should be delivered)
More subaddress (specifying additional addressing information for routing purposes)
Callback number (specifying a number to which a reply should be sent)
Callback number presentation indicator (specifying how the callback number should be displayed)
Callback number tag (specifying an alphanumeric string associated with the callback number)
Number of messages in mailbox (specifying how many messages are waiting in a mailbox)
Alert on message delivery (specifying whether to alert the recipient when a message is delivered)
Language indicator (specifying the language of the message)
Its session initiation protocol information element (specifying information related to SIP)

The main disadvantage of SMPP 3.4 is its complexity and compatibility issues. It is more difficult to implement and understand than SMPP 3.3, and it may not work with some SMS service providers or mobile network operators that do not support it. Moreover, some TLV parameters are vendor-specific or optional, which may cause interoperability problems or confusion.

SMPP 3.4 is the most popular version of the protocol, used by 54% of respondents. It is the recommended version for most SMS messaging applications and services.

SMPP 5.0

SMPP 5.0 is the latest version of the protocol, released in 2003. It adds support for cell broadcasting, smart flow control, and other minor enhancements. It also clarifies some ambiguities and inconsistencies in the previous versions.

The main advantage of SMPP 5.0 is its completeness and standardization. It covers all the features and functionalities of SMPP 3.4, and adds some new ones, such as:

Cell broadcast operations (for sending messages to multiple recipients in a specified area)
Cell broadcast data coding scheme (specifying the encoding and compression of the cell broadcast message)
Cell broadcast service type (specifying the application or service that originated the cell broadcast message)
Cell broadcast channel indicator (specifying the channel on which the cell broadcast message should be transmitted)
Cell broadcast content type indicator (specifying the type of content of the cell broadcast message)
Smart flow control (for optimizing the throughput and performance of the protocol)
Message reference number (specifying a unique identifier for each message)
Message sequence number (specifying a sequential number for each message within a session)
Message state TLV parameter (specifying the state of a message at any point in time)

The main disadvantage of SMPP 5.0 is its availability and adoption. It is not widely supported by SMS service providers or mobile network operators, and it is not widely used by businesses or SMS service providers. In 2023 only 8% of respondents indicated to use SMPP 5.0 for their SMS messaging needs.

SMPP Version Comparison Table

The following table summarizes the main features and benefits of each SMPP version:

| Feature                     | 3.3 | 3.4 | 5.0 |
| --------------------------- | --- | --- | --- |
| GSM support                 | Yes | Yes | Yes |
| Non-GSM support             | No | Yes | Yes |
| TLV parameters              | No | Yes | Yes |
| Transceiver support         | No | Yes | Yes |
| Long messages               | No | Yes | Yes |
| Concatenated SMS            | No | Yes | Yes |
| Binary messages             | No | Yes | Yes |
| Unicode messages            | No | Yes | Yes |
| Delivery receipts           | No | Yes | Yes |
| Message status reports      | No | Yes | Yes |
| Data coding schemes         | No | Yes | Yes |
| Service types               | No | Yes | Yes |
| Priority flags              | No | Yes | Yes |
| Validity periods            | No | Yes | Yes |
| Scheduled delivery times    | No | Yes | Yes |
| Replace-if-present flags    | No | Yes | Yes |
| Message payload             | No | Yes | Yes |
| User data header            | No | Yes | Yes |
| Source address subunit      | No | Yes | Yes |
| Destination address subunit | No | Yes | Yes |

Conclusion

To conclude, SMPP is a powerful and flexible protocol that enables the transfer of short message data between applications and mobile networks. SMPP has three versions in use: SMPP 3.3, SMPP 3.4, and SMPP 5.0. Each version has its own features and benefits, depending on the use case and requirements. SMPP 3.3 is simple and compatible, but limited and outdated. SMPP 3.4 is flexible and versatile, but complex and inconsistent. SMPP 5.0 is complete and standardized, but unavailable and unpopular. The choice of the best SMPP version depends on the needs and preferences of the user, as well as the support and compatibility of the SMS service provider and the mobile network operator.

If you are looking for a reliable and easy-to-use SMS gateway software that supports all SMPP versions, you may want to check out Ozeki SMS Gateway. It is a high-performance software that allows you to send and receive SMS messages from your computer using a GSM modem or an IP SMS connection. It also offers various features and functionalities, such as email-to-SMS, SMS-to-email, database-to-SMS, SMS-to-database, HTTP-to-SMS, SMS-to-HTTP, and more. You can download a free trial version from their website and start sending and receiving SMS messages in minutes.