In a communication terminal implementing a radio link control (RLC) protocol, error propagation to higher layer protocols is mitigated by use of an additional length indicator, referred to herein as a new packet indicator, in the RLC data blocks to indicate the beginning of a new higher layer packet in addition to a conventional length indicator to indicate the last segment of a higher layer packet. The new packet indicator prevents the Logical Link Control (LLC) data segment at the beginning of an RLC data block from being concatenated with an LLC data segment in the previous data block even when length indicators in the previous data block are not received.