beacon data length

[Kuo]

Currently, I'm developing a beacon. We would like to employ a beacon to send a package including a IP address to other device for getting a new message from the website.

I've study the example of ble_app_beacon. In that one, the section "ble_advdata_manuf_data_t manuf_specific_data" is used to broadcast specific data and supports the data length up to 23 bytes.

Since this specification is unable to satisfy our requirement, could you tell me that the maximum length of package while the beacon is advertising or how to extend the length of advertising package?

[endnode]

You've read correctly, the maximum size of ADV packet in BT LE 4.0-4.2 is 31Bytes but in case your device is GAP&GATT (layers') compliant you need to cut some overhead (3Bytes for "Flags AD" object and 4Bytes of "Manufacturer Specific Data AD" header). So you have 24Bytes in maximum. Note that there is a way to send "another" 31Bytes in SCAN_RSP packet but that must be actively requested by Observer and again you need to count 4Bytes of GAP overhead so maximum 27Bytes. In addition active scanning won't have such frequency as ADVertising so total bandwidth will be lower... but for transporting quasi-static string in Broadcaster/Observer mode you can employ up to 24+27=51Bytes, you just need to split them (and Observer need to actively scan+reconstruct them back).

Read more in any BLE Advertising/Beacon tutorial on the internet.