type modifier description data(0) data(0) The packet is one that contains user information. Only the process possessing a transmit token is permitted to send data unless specifically requested to retransmit previously transmitted data. All packets of type data are multicast to the entire web. eow(1) A data packet with the eow (end of window) modifier set indicates that the transmitter intends to send no more packets in this heartbeat either because it has sent as many as permitted given the window parameter or simply has no more data to send during the current heartbeat. This is not client information but rather a hint to be used by transport providers to synchronize the computation and transmission of naks. eom(2) Data[eom] marks the end of the message to the consumers, and the surrendering of the transmit token to the master. And like a data[eow] a data[eom] packet implies the end of window. nak(1) request(0) A nak[request] packet is a consumer requesting a retransmission of one or more data packets. The data field contains an ordered list of packet sequence numbers that are being requested. Naks of any form are always unicast. deny(1) A nak[deny] message indicates that the producer source of the nak[deny]) cannot retransmit one or more of the packets requested. The process receiving the nak[deny] must report the failure to its client. empty(2) dally(0) An empty[dally] packet is multicast to maintain synchronization when no client data is available. cancel(1) If a producer finds itself in possession of a transmit token and has no data to send, it may cancel the token[request] by multicasting an empty[cancel] message. hibernate(2) If the master possesses all of the web's transmit tokens and all outstanding messages have been accepted or rejected, the master may transmit empty[hibernate] packets at a rate significantly slower than indicated by the web's value of heartbeat. join(3) request(0) A join[request] packet is sent by a process wishing to join a web to the web's unknown TSAP (see section 2.2.5). confirm(1) The join[confirm] packet is the master's confirmation of the destination's request to join the web. It will be unicast by the master (and only the master) to the station that sent the join[request]. deny(2) A join[deny] packet indicates permission to join the web was denied. It may only be transmitted by the master and will be unicast to the member that sent the join[request]. quit(4) request(0) A quit[request] may be unicast to the master by any member of the web at any time to indicate the sending process wishes to withdraw from the web. Any member may unicast a quit to another member requesting that the destination member quit the web due to intolerable behavior. The master may multicast a quit[request] requiring that the entire web disband. The request will be multicast at regular heartbeat intervals until there are no responses to retention requests. confirm(1) The quit[confirm] packet is the indication that a quit[request] has been observed and appropriate local action has been taken. Quit[confirm] are always unicast. token(5) request(0) A token[request] is a producing member requesting a transmit token from the master. Such packets are unicast to the master. confirm(1) The token[confirm] packet is sent by the master to assign the transmit token to a member that has requested it. token[confirm] will be unicast to the member being granted the token. isMember(6) request(0) An isMember[request] is soliciting verification that the target member is a recognized member of the web. All forms of the isMember packet are unicast to a specific member. confirm(1) IsMember[confirm] packets are positive responses to isMember[requests]. deny(2) If the member receiving the isMember[request] cannot confirm the target's membership in the web, it responds with a isMember[deny].