In a method and a medical telemetry system for communication between an external monitoring device and an implantable medical device of the medical telemetry system at a transmitting end, an implantable medical device frame layer packet is segmented into one or more data blocks of a radio packet. The data blocks are transmitted in the communication between the external monitoring device and the implantable medical device. A start of the implantable medical device is indicated in the frame layer packet by including in a first data block of the radio packet a segmentation and reassembly indicator having a first value. At the transmitting end, the data blocks are transmitted over a short-range medical radio link. At the receiving end, the data blocks are reassembled into the originally transmitted implantable medical device frame layer packet.