Aspects of the present disclosure provide techniques for compressing data packets for cellular internet of things (CIoT) communications. An example method generally includes establishing at least one prefill buffer common to one or more UEs, wherein the prefill buffer includes a plurality of common strings, generating a compressed packet by finding matches to the common strings in at least one of a header portion or payload portion of the packet and associating identifiers with the common strings, and transmitting the packet.