Any clues where I could start searching?

In the Xcode Hardware I/O Tools <https://developer.apple.com/downloads/>, you find the Apple PacketLogger which is very handy for Bluetooth Classic. Are you sure the RFComm channel is still 1? ConnectToServer extracts the channel ID via the Service-Discovery Profile (SDP) and an UUID. By the way, this opens a Bluetooth Baseband connection as well. But you saw that, I guess, because gExampleChatServiceClassUUID is a private UUID, not the one for the Serial-Port Profile (SSP) you are looking for. Mhm. _______________________________________________ Do not post admin requests to the list. They will be ignored. Bluetooth-dev mailing list (Bluetooth-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/bluetooth-dev/site_archiver%40lists.... This email sent to site_archiver@lists.apple.com