Abstract: A packet scheduler controls dispatch of packets containing constant bit rate (CBR) or real time variable bit rate (rt-VBR) at an ingress operation of multiplexing the packets into payloads of an asynchronous transfer mode (ATM) bearer virtual circuit connection. Packets can be queued in one of a number of queues according to priority. The scheduler controls assembly of common part sublayer payload data units (CPS-PDU) comprising any unused octets from a previous packet partially dispatched, and whole packets in order of priority. If a holdover timer period expires before a common part sublayer payload data unit is completed, the payload of that data unit is packed with null data; and dispatched. The packet dispatch is controlled so as to match the traffic characteristics of an underlying bearer channel.

Abstract: In a Quality of Service system, segments in a TCP session are assigned a priority level. A segment may contain an acknowledgement and data. The system determines if network congestion is detected or anticipated in the segment's priority band or in a higher priority band. When the TCP segment arrives at a network point, the segment is split into an acknowledgement segment and a data segment. The acknowledgement segment is scheduled at a higher QoS priority than the data segment.

Abstract: A method and apparatus for detecting compromised host computers (e.g., Bots) are disclosed. For example, the method identifies a plurality of suspicious hosts. Once identified, the method analyzes network traffic of the plurality suspicious hosts to identify a plurality suspicious hub-servers. The method then classifies the plurality of candidate Bots into at least one group. The method then identifies members of each of the at least one group that are connected to a same controller from the plurality suspicious controllers, where the members are identified to be part of a Botnet.

Abstract: A method and system for sharing over-allocated bandwidth between different classes of service in a wireless network. Traffic is transmitted for a first service class in excess of bandwidth allocated to the first service class using unused bandwidth allocated to a second class. After transmitting traffic for the first service class in excess of bandwidth allocated to the first service class using unused bandwidth allocated to a second class, traffic for a third service class is transmitted in unused bandwidth remaining in the second service class.

Abstract: A method and apparatus are provided for performing a virtual network connection merge. In one example, the method assembles at least one data unit from data traffic of at least one network connection. A credit is calculated for each network connection. A chosen data unit to be transmitted to an output channel is determined based on the credits of the network connections. The chosen data unit is then transmitted to the output channel.

Abstract: A method for indicating the priority of a Voice Over Internet Protocol (VoIP) call includes receiving a dialed number for a connection, generating a call set up request including the dialed number, receiving a priority for the call based on user input provided contemporaneously with the dialed number, generating a priority indicator based on the priority, and transmitting the call setup request and priority indicator to a destination device.

Abstract: A method (200) for communicating messages (170, 175). A priority level can be associated with a message, and a time in which to communicate the message can be automatically selected based on the associated priority level and a communication rate plan (165). The message can be automatically communicated at the selected time. A subscriber communication rate plan can be queried to determine when there is a discounted communication rate or when free communications are available. The message can be communicated immediately if the priority that is associated with the message is high. The present invention also relates to a method (500) for processing calls. An inbound call (405) can be received and a priority level can be associated with the call. The call can be automatically sent to voice mail if the priority level is low or a call session can be established if the priority level is high.

Abstract: A method for operating a server having a maximum capacity for servicing requests comprises the following steps: receiving a plurality of requests; classifying each request according to a value; determining a priority for handling the request according to the value, such that requests with higher values are assigned higher priorities; placing each request in one of multiple queues according to its priority value; and dropping the requests with the lowest priority when the plurality of requests are received at a rate that exceeds the maximum capacity. The server operates according to a session initiation protocol. Classifying each request comprises running a classification algorithm.

Abstract: An apparatus for classifying data packet protocol values in a packet architecture comprising a packet header and a packet payload including an extension header is described. The apparatus comprises a processor configured to specify a packet protocol value in an extension header of a type requiring mandatory examination by at least one device receiving a packet. For example, an apparatus comprises a packet processor unit configured to generate a data packet comprising the extension header, wherein the extension header specifies a packet protocol value, wherein the extension header is a mandatory extension requiring examination by a receiving apparatus to which the packet may be sent, wherein the packet protocol value is also carried in one or more additional headers in the packet, and wherein the extension header enables classifying the packet based on the packet protocol value and without traversing the additional headers in the packet.

Abstract: In a communication system, a first communication apparatus includes: an application data generating unit for generating application data including data at an application level and a priority at the application level; and a lower-level packet generating unit disposed therein for generating a packet by adding to the application data a header including a destination address and a source address at a level lower than the application level. A first relay apparatus includes: a priority identifying unit disposed therein for determining whether or not a priority is set in the application data of the packet received by the first relay apparatus, and thereby identifying a first priority at the application level; and a priority control unit disposed therein for renewing a TOS field value in the header of the packet, the header being at the level lower than the application level, on the basis of the first priority.

Abstract: A system and method for transmitting and bundling network packets is provided. The incoming network packet size is determined and if the remote buffer space is sufficient to hold the network packet it is transmitted to the destination port. If the remote buffer space is not enough to hold the network packet it is discarded. The system includes an arbitration module that receives remote buffer space information and transmits the network packet if the remote buffer space has enough space to hold the packet. The arbitration module also determines if a second network packet is from a same source port having a same source virtual lane, and has the same destination virtual lane (bundling conditions). If the second network packet meets the bundling conditions, then it is transmitted after the first network packet, even if other packets were received before the second network packet.

Abstract: A system and method of moving information units from a network processor toward a data transmission network in a prioritized sequence which accommodates several different levels of service. The present invention includes a method and system for scheduling the egress of processed information units (or frames) from a network processing unit according to stored priorities associated with the various sources of the information units. A system for allowing peak bursts based on a system of credits and charges is taught along limits on such peak bursts. Also taught is a system for preventing a flow's disconnection and reconnection to the queues from allowing it to unfairly achieve an improved position.

Abstract: A method and apparatus for enhancing performance of a packet service of a mobile communication terminal is disclosed. When the mobile communication terminal uses a packet service, an RAB set between the mobile communication terminal and a base station is compared to a reference value and the priority level of a packet service task processed in the mobile communication terminal is raised only when the mobile communication terminal is connected to the base station at or above the reference value. When the packet service is terminated, the priority level of the packet service task is returned to an original low priority level. The mobile communication terminal uses a maximum transmission speed for the packet service and when the mobile communication terminal uses a concurrent service requiring both real time service and packet service, packet service performance may be improved without affecting the real time service.

Abstract: There is disclosed an QoS-oriented burstification method supporting various grades of burstification delay guarantee. For the arrival packets, the packets are sequentially inserted in a sequence of windows on weight basis, thereby forming a queue. The window size together with the weight of each flow determines a maximum number of packets of each flow in a window. For the departure packets, there is generated a burst consisting of a plurality of packets from the head of the queue when either a total number of packets reaches a maximum burst size or a burst assembly timer expires.

Abstract: A method and system for completion coalescing by a Transmission Control Protocol (TCP) receiver (e.g., in a TCP/IP offload engine (TOE)). The method comprises: processing inbound TCP segments; and performing completion processing of received TCP ACKS and/or RDMA Read Requests independently of the processing of the inbound TCP segments.

Abstract: Label contention in a label switched network is resolved by applying a contention resolution scheme that reconciles policies for handling unidirectional and bidirectional label switched path setup.

Abstract: A system and method for sharing a resource (e.g., buffers) among multiple queues (e.g., InfiniBand send queues). Each queue has a local context indicating the Current amount of the resource allocated to the queue, the Minimum it is guaranteed, and a Maximum amount. A context may also include one or more pointers for managing the queue. Global Available and Reserve values indicate, respectively, the amount of the resource not currently allocated and the amount of the resource being reserved to guarantee each queue its Minimum. When an element is posted to a queue, a Full signal is raised for every queue to prevent further activity while the global values and the affected queue's context are updated. Then, if Available>0, the signal is de-asserted for any queue for which Current<Minimum or, if Available>Reserve, for any queue for which Current<Maximum.

Abstract: A method of routing packets includes receiving a first packet, where the first packet has a first ordering requirement with respect to a prior packet that was received before the first packet, allocating a first entry that corresponds to the first packet in a scheduler, where the first entry includes a first indication of the first ordering requirement, and in response to the first indication, selecting the first entry corresponding to the first packet if one or more first resources used by the first packet and one or more second resources that are used by the prior packet but not by the first packet are available. As long as older entries whose resources are available are selected before newer entries, the first entry will be selected after the prior packet's entry due to the inclusion of the first indication in the first entry.

Abstract: Data cells of plural classes are transferred from input ports to output ports through a switch by storing the cells at each input port in class-specific virtual output queues (VOQ) within sets of VOQs associated with output ports, and providing credits to VOQs according to class-associated guaranteed bandwidths. When a cell is received at a VOQ having credits, a high-priority request for transfer is generated. If a cell is received at a VOQ that does not have any available credits, a low-priority request for transfer is generated. In response to requests, grants are issued to VOQ sets without regard to class, high-priority requests being favored over low-priority requests. When a grant is received for a particular VOQ set, an arbitrator selects a VOQ from the set, giving priority to VOQs having credits over VOQs without credits, and a cell from the selected VOQ is transferred.

Abstract: A hierarchical scheduler architecture for use with an access node terminal disposed in an access network portion. Ingress flows aggregated via a plurality of aggregation layers are switched through an ATM fabric that segregates flow cells based on service priority categories (planes). Thus, a two-dimensional scheduler employs arbitration on a per-aggregation layer, per-service priority basis, wherein each layer is responsible for selecting the most eligible flow from the constituent flows of that layer, which is forwarded to the next layer for arbitration. A service-based arbiter selects overall winner cells for emission through the fabric from winner cells generated for each service plane.

Abstract: A method and apparatus for packet scheduling using a virtual time stamp for a high capacity combined input and output queued switching system. A network employs a virtual time reference system (VTRS) to generate packet virtual time stamps associated with each packet traversing the network. The VTRS includes edge conditioners located at the edge of the network that receive unregulated packet traffic and generate regulated packet traffic for a given flow. The edge conditioners also add a packet virtual time stamp to each incoming packet. Core routers within a network core reference the packet virtual time stamps to schedule packet flow. The core routers also update the packet virtual time stamps using virtual delays. The packet virtual time stamps are removed from the packets when the packets leave the network core through an edge conditioner.

Abstract: Various aspects of apparatuses and methods for enabling a subscriber premise network interface device (NID) to facilitate communication services including digitally derived voice services to be facilitated between a central office and a subscriber premise are disclosed herein. In accordance with one embodiment of the disclosures herein, such a method includes facilitating a downstream DSL voice channel transmission process at a subscriber premise Network Interface Device (NID) and facilitating an upstream DSL voice channel transmission process at the subscriber premise NID. The downstream DSL voice channel transmission process facilitates converting a voice component of a downstream DSL data stream to a corresponding downstream analog voice signal. The upstream DSL voice channel transmission process facilitates converting an upstream analog voice signal to an upstream voice component of an upstream DSL data stream.

Abstract: In a data system, such as a cable modem termination system, different-priority flows are scheduled to be routed to their logical destinations by factoring both the priority level and the time spent in queue. The time that each packet of each flow spends waiting for transmission is normalized such that the waiting times of all flows are equalized with respect to each other. A latency scaling parameter is calculated.

Abstract: The invention relates to arranging data flow control in a data transfer system comprising a sender and at least two protocol entities serving the transmission of data from the sender. The originating protocol entity of a suspension request primitive is checked. Suspension is set as the data transmission status for the protocol entity that has originated a suspension request primitive. The originating protocol entity of a resume request primitive is checked before sending it to the sender. Also the status information is checked. Transmission of the resume request primitive to the sender is prevented if suspension is set for any other protocol entity than the originating protocol entity of the resume request primitive.

Abstract: A system (10) for communicating information associated with one or more subscribers includes a connecting link (50). A first switching system (14) coupled to the connecting link (50) communicates remote voice signals (60) and remote data signals (62) using the connecting link (50). A second switching system (14) coupled to the connecting link (50) includes an interface (56) to receive the remote voice signals (60) and the remote data signals (62) using the connecting link (50). The second switching system (14) also includes subscriber line ports (17) for receiving local voice signals (52) and local data signals (54) from subscribers. The interface (56) of the second switching system (14) selectively communicates the highest priority available signals using an outgoing link, voice signals (52, 54) having higher priority than data signals (60, 62). In a more particular embodiment, the remote voice signals (60) may have higher priority than the local voice signals (52).

Abstract: The present invention provides a method and a communications system for the exchange of data between at least two users who are in contact with one another using a bus system. The data are included in messages which are transmitted by users over the bus system. A specifiable priority is assigned to each message. In order to achieve, in the normal case, a high probability of a short latency period (t) of a message to be transmitted, and to be able to guarantee, in the worst case, a maximum latency period (tmax), it is provided that the priorities assigned to the messages be dynamically modified during the operation of bus system. Preferably, the set of all messages is subdivided into equivalence classes, and a priority is assigned to each equivalence class. During the operation of the bus system, the priorities of the messages are dynamically modified within an equivalence class, and the priorities of the equivalence classes are dynamically modified.

Abstract: A bandwidth allocation method used in a point-to-multipoint communication system, for efficiently using the bandwidth while shortening delay time. A central unit quantizes round-trip propagation delay times of subsidiary units, groups the subsidiary units, assigns the same quantized round-trip delay time to the same group, and allocates allocation request signal bandwidths to the subsidiary units of the same group when receiving allocation requests within a predetermined period. Based on the quantized round-trip delay time, the bandwidths are located as close as possible while the bandwidths do not temporally overlap with each other and as temporally ahead as possible. Data signal bandwidths are also allocated to the subsidiary units of the same group, based on the quantized round-trip delay time and requested amounts of data, in a manner such that the bandwidths are located as temporally ahead as possible but temporally behind in comparison with the allocation request signal bandwidths.

Abstract: A packet sending apparatus that improves packet transmission quality by preventing loss of packet information, while minimizing a reduction in transmission rate. A clock frequency deviation correction calculation section calculates a valid packet sending period in which valid packets packet information of which is not lost due to clock frequency deviation between the packet sending apparatus and a packet receiving apparatus are included and the number of valid packets included in the valid packet sending period.

Abstract: A communication system includes a cell site router that receives a voice traffic stream in a layer two based protocol. The cell site router removes redundant information to generate a compressed stream of payloads from the layer two based protocol voice traffic stream. The cell site router sorts each payload of the compressed stream according to its intended destination and generates a layer two packet for each group of payloads of the compressed stream having a same intended destination. The cell site router prioritizes for transmission each layer two packet with other packets not carrying the voice traffic stream and having the same intended destination The communication system also includes an aggregation node that receives packets from the cell site router. The aggregation node separates layer two packets from the other packets and extracts each payload from each of the layer two packets.

Abstract: For an electronic apparatus in which data is transferred between a plurality of processing devices and a memory, a technique is provided which prevents the data transfer from being restricted and allows the processing devices to operate efficiently. The order of priorities of data transfer operations through channels is changed on the basis of a relation between thresholds and the amounts of data remaining respectively in FIFO buffers. This prevents the FIFO buffers from becoming empty of data, or from being filled up with data, which allows the devices to operate efficiently.

Abstract: A method, apparatus, and article of manufacture for retaining packet order in multiprocessor systems utilizing multiple transmit queues while minimizing spinlocks are disclosed herein. Embodiments of the present invention define multiple transmit queues for a given priority level of packets to allow parallel processing and queuing of packets having equal priority in different transmit queues. Queuing packets of equal priority in different transmit queues minimizes processor time spent attempting to acquire queue-specific resources associated with one particular transmit queue. In addition, embodiments of the present invention provide an assignment mechanism to maximize utilization of the multiple transmit queues by queuing packets corresponding to each transmit request in a next available transmit queue defined for a given priority level. Coordination between hardware and software allows the order of the queued packets to be maintained in the transmission process.

Abstract: A method for coordinating packet transmission order for a plurality of registers of different priority levels is disclosed. Packets are transmitted from the registers according to the priority levels in a normal condition. A count value is generated in response to the transmitted packets. A particular priority level of one of the registers, from which a packet is being transmitted out, is recorded when the count value is larger than a predetermined threshold. Then the normal condition switches into a cleaning condition, and one packet is transmitted from each of the registers which are not empty and have priority levels lower than the particular priority level according to priority. Finally, reset the count value, and return to the normal condition. A device for coordinating packet transmission order for a plurality of registers of different priority levels is also disclosed.

Abstract: A method and apparatus are provided for establishing a network using a WZCSVC program without any collision. The method includes connecting to one of a plurality of wireless networks according to a predetermined order using information on the plurality of wireless networks; receiving a request for a connection to a new wireless network; suspending a wireless service in response to the request; and processing the request upon the suspension of the wireless service.

Abstract: The invention provides a method and system for fast scheduling using a work-conserving Round Robin strategy. The method and system select one of a plurality of queues of data packets for switching it to an output port in a current timeslot, for achieving work-conserving Round Robin scheduling. The method is based on a consideration range for each queue that is a set of queues having priority over the given queue. The method comprises the steps of generating a mask for a given queue for masking all queues outside a consideration range of the given queue and applying the mask and a queue ready flag for the given queue for determining if the given queue is to be selected in the current time slot.

Abstract: A virtual LAN (VLAN) has a number of segments connected by a connection-based network. A method for providing differentiated service to frames having different user priorities in a VLAN carries frames associated with different user priorities over different channels in the connection-based network. The connection-based network may be an ATM network in which channels are specified by a connection identifier which may comprise a VPI/VCI pair. A bridge according to the invention has one or more bridge ports. Each of the bridge ports may be associated with a VPI. The bridge ports may each be associated with a plurality of service interfaces each capable of terminating a connection in the connection-based network. The service interfaces may each be associated with a VCI. Priority tagged frames received at the bridge port are mapped to service interfaces on the basis of their user priorities.

Abstract: A method and apparatus for allocating access to a scarce resource. A load of each flow on the resource is calculated. The aggregate load is compared to a maximum steady state load. A drop policy is established responsive to the comparison. The drop policy is applied to the flows at an input interface of the device.

Abstract: A method for routing data packets in a network analyzes data packets in the network with a selected network node. The path of the data packets to a destination address is manipulated in accordance with certain requirements. Information contained in the data packets as well as further information which is available to the network node is used for a routing. The further information can either be called up from a database of the network node or from a plurality of tables, which may be distributed in the network. A transfer node, such as a switching service, which is suitable for the requirements is determined. An apparatus for routing data packets in a network is also provided.

Abstract: Control of the transmission of streaming data between a first data processing system and a second data processing system in a packet network is provided. Priorities are assigned to packets of the streaming data based on characteristics of the packets of streaming data. Performance of transmission of the packets from the first data processing system to the second data processing system is monitored and retransmission of selected ones of the packets from the first data processing system to the second data processing system is terminated based on the assigned priority of the selected ones of the packets and the monitored performance of transmission. The streaming data may be progressively encoded. Furthermore, the priorities assigned to the packets of streaming data may be based on the level of progressive coding associated with a packet of data.

Abstract: The present invention is directed to a method and apparatus for scheduling a resource to meet quality of service guarantees. In one embodiment of three levels of priority, if a channel of a first priority level is within its bandwidth allocation, then a request is issued from that channel. If there are no requests in channels at the first priority level that are within the allocation, requests from channels at the second priority level that are within their bandwidth allocation are chosen. If there are no requests of this type, requests from channels at the third priority level or requests from channels at the first and second levels that are outside of their bandwidth allocation are issued. The system may be implemented using rate-based scheduling.

Abstract: A system and method for prioritizing the transmission of packets in a wireless local area network. A station selects a packet from local priority queuing and identifies the priority bits of the packet. The station declares the priority of the selected packet based on the binary value of the priority bits. If the station detects that another station has selected a packet with a higher priority, then the station ceases to contend for transmission during the current transmission cycle.

Abstract: A method and system for converting a plurality of ranges of values for a plurality of packet classification rules in a computer system is disclosed. The plurality of ranges exists in at least one dimension. The method and system include mapping each of the plurality of ranges to a plurality of nonoverlapping prefixes. The method and system also include mapping the plurality of nonoverlapping prefixes to a plurality of overlapping prefixes corresponding to the plurality of ranges. The plurality of overlapping prefixes include a plurality of shorter matching overlapping prefixes for a plurality of nonconflicting ranges.

Abstract: Systems and techniques for scheduling of data transmission to remote mobile units so as to provide at least an acceptably low level of delay. A scheduler computes an urgency value for each data stream serving a mobile unit and sets the urgency value equal to the highest urgency value of a data stream serving the mobile unit. The scheduler computes a scheduling priority for each mobile unit based on a computation that takes into account the urgency value of the mobile unit and schedules the highest priority mobile unit for service, selecting the highest priority data stream serving the mobile unit scheduled for transmission. The urgency value for a data stream depends on the sensitivity of the data stream to delay and the delay experienced by the data stream. Computation of the urgency value may take into account a delay limit associated with the data stream.

Abstract: A network system for carrying out communication between a control station and a plurality of devices connected to a network. The communication includes data communication which requires real-time attributes and message communication which does not require real-time attributes. The data communication includes a first data communication, and a second data communication. The system includes a plurality of transmission queues for temporarily storing transmission data provided in the control station, wherein one of the queues holds transmission data for the second communication. After the first data communication is carried out in accordance with a predetermined cycle time, an appropriate switching between the message communication and the second communication is carried out in the remaining time of the cycle time to complete one cycle, whereafter the cycle is repeatedly carried out.

Abstract: Techniques are disclosed for flexible allocation of address pins of an interface bus to particular sub-buses of the interface bus. The interface bus is between at least one physical layer device and a link layer device in a communication system. Each of the sub-buses has an interface block of the link layer device associated therewith, the interface bus being configurable to carry a composite address signal having a plurality of portions each associated with one of the address pins of the interface bus. The interface blocks of the link layer device are controlled such that each of at least a subset of the interface blocks utilizes only particular ones of the address pins that are controllably allocated to the associated sub-bus in accordance with configuration information stored in the link layer device. The composite address signal is generated as a combination of address outputs of the interface blocks.

Abstract: A system and method for performing forward channel scheduling for an HDR system includes collecting status information of connected terminals, calculating a predetermined weight (?(n)), calculating priority values of respective terminals based on the collected status information and the weight (?(n)), and selecting a terminal having the highest priority value and providing the selected terminal with the service. By considering the number of connected mobile terminals, disadvantages of other proposed scheduling algorithms are overcome. Also, the entire throughput of the HDR system is improved by maintaining Quality of Service (QoS) of the mobile terminals that require the real-time service.

Abstract: A sender transmits performance monitoring packets to a receiver via a network either prior to or in the midst of transmission appropriately, for monitoring communication quality (a communication delay, for example) of the network. A result of the monitoring is judged from returned performance monitoring result packets, whereby priority classes of communication packets are decided to perform subsequent transmission.

Abstract: In an ATM communication system or communication terminal the cell loss priority information (CLP) in operation, maintenance, administration and resource-management cells (OAM) that are inserted between cells (DP1, DP2) of a virtual connection (GFR-Vx) with a guaranteed frame rate, is detected by determining the cell loss priority information (CLP) of the cell (DP1) of the respective virtual connection (GFR-Vx) which is actually to be transmitted and by inserting said information in the operation, maintenance, administration and resource-management cells (OAM).

Abstract: Packets being transmitted through a communication network are recognized as belonging to various individual flows. A property of each individual flow is measured by adding a value, such as a unity value or a packet length value, to a cumulative sum when each packet in the individual flow is recognized, and subtracting a fixed value from the cumulative sum at unit time intervals. The packets are prioritized according to the cumulative sum. This scheme enables network resources to be used preferentially for individual flows that do not cause congestion.

Abstract: Dynamic adaptation of connection-oriented networks is introduced wherein, once congestion is encountered, dynamic adaptation steps may be performed. Four adaptation steps are proposed for reacting to various network congestion scenarios. It is further recommended that the steps are performed in a particular order such that the higher severity and longer sustentation of the network congestion the more strict step is performed to alleviate the network congestion. At a switch in the connection-oriented network, utilization of a trunk carried on a link connected to the switch is monitored and, if said utilization of said trunk exceeds a first threshold, a first degree of adaptation is initialized wherein use of the trunk by further connections is prevented. Subsequent degrees of adaptation are triggered when high utilization continues and surpasses higher thresholds. The subsequent degrees of adaptation involve rerouting connections that make use of the trunk.

Abstract: Methods for sequencing datagram transmissions are disclosed, including, receiving an unqueued segment to be enqueued in a queue. The queue comprises at least one segment. Determining a priority level and a number of attempted transmissions for the unqueued segment (100). If the unqueued segment is enqueued in front of a segment belonging to a datagram in the queue, and at least one segment belonging to the datagram has been transmitted before all the segments belonging to the datagram have been transmitted, at least one of the following functions is performed: discarding any remaining segments belonging to the datagram in the queue, transmitting any remaining segments belonging to the datagram in the queue, and re-enqueuing segments belonging to the datagram at the same location in the queue as the partially transmitted datagram, but with a different identifier.