1. A method, comprising: identifying a radio state of a mobile device, irrespective of whether a TCP connection is open between a server and the mobile device, wherein identifying the radio state of the mobile device includes receiving a packet having a header portion containing an attribute field added as an extension to the packet header, wherein the attribute field specifies a delay value indicating a radio timeout of the mobile device and includes a field ID and a field payload, wherein a highest order bit of the field ID indicates whether the attribute field is the last attribute field to be added to the packet header and the remaining bits of the field ID include a value defining a format of the field payload, wherein a highest order bit of the field payload indicates whether the remaining portion of the field payload is associated with the field ID, wherein the remaining bits of the field payload contain a numeric payload indicating a radio timeout of the mobile device; sending a server-generated message to the mobile device over either a TCP connection or short message service (SMS) based on the radio state.