Recently, we implemented an

integration with Free Mobile

, the French mobile operator, for one of our clients. Free Mobile communicates with its partners through the SMPP protocol, which is widely used in telecom for exchanging SMS messages.

This wasn’t our first experience working with SMPP. We had already completed several similar integrations in the past - including projects with other operators and aggregators such as HighCo - so the team was able to move quickly and anticipate most of the tricky parts of the protocol.

Ever wondered what a real mobile message to Orange, Vodafone, or O2 looks like under the hood?

0000003F00000004000000000000000100010153656E64657249440001013338

336313237363530350000000100000000000D48656C6C6F20416E6472697921

This line is what actually travels over the wire when you integrate with mobile operators using SMPP (Short Message Peer-to-Peer protocol).

Implementing SMPP in Java was one of the first challenging yet exciting tasks we tackled while building a new platform for

Echovox, more than 12 years ago. It's a hidden engine behind every "ping" and "buzz" you get from businesses worldwide.

Back then, mastering SMPP felt like unlocking a secret language of the telecom world — and it still powers the mobile messaging ecosystem today.