Patent Description:
<CIT> discloses an apparatus comprising a network interface and at least one processor to establish communication with a network terminal access point, TAP, of a first network, each node of the first network having an IP address; establish communication with at least one node of a second network, at least one node in the second network corresponding to a node in the first network; receive a first packet and a second packet from the network TAP of the first network, each packet comprising a source IP address, the source IP address indicating a respective node in the first network from where each packet originates; and launch the first packet and the second packet from a respective node in the second network that corresponds to the source IP address of each packet. <CIT> discloses in the same context of replaying captured network traffic, equal IP addresses of corresponding nodes in the first and second network nodes and the received packets comprising a timestamp to be launched in a sequence according to the timestamp. <CIT> discloses a time machine arrangement for performing health check on a network environment. The arrangement includes a set of network ports that that is configured for receiving and outputting network data traffic. The arrangement also includes a monitoring port for receiving at least a portion of the data traffic flowing through the network. The arrangement further includes a set of processors configured at least for managing and analyzing the data traffic. The set of processors includes a scheduler component for directing the data traffic, a filtering component for applying a set of filters on the set data traffic, an encryption component for encrypting the data traffic, and a trigger component for defining a set of conditions for storing the data traffic. The arrangement yet also includes a storage memory component for storing a copy of at least the portion of the data traffic flowing through the network environment. Finally, <CIT> discloses a network tap apparatus comprising a plurality of network interfaces, at least one processor to receive, via a network interface, a packet from a source device, the packet being bound for a destination device, the source device and the destination device being nodes of a first network, the source device and the destination device each being associated with a respective internet protocol, IP, address, generate a duplicate packet that is a copy of the packet, and forward, using another network interface, the duplicate packet to another destination device in a second network, the other destination device in the second network having an IP address that is identical to that of the destination device in the first network.

Accordingly computer networks heretofore may include a mesh of interconnected servers, hubs, routers, switches, and storage arrays carrying critical information. Such networks may be prone to infrastructure failures due to network hardware changes and network congestion.

The present invention is defined in the appended independent apparatus claim <NUM> to which reference should be made. Advantageous features are set out in the appended dependent claims <NUM>-<NUM>.

As noted above, networks may be prone to failures. In some networks, the sequence in which data packets are transmitted may be critical. For example, in video streaming networks, packets must typically arrive at the playback device in the correct sequence so that the video shows correctly. In a trading system, the correct sequence of the packets may be important so that the correct state of the order is reflected on a trader's workstation. Furthermore, packets may be lost during transmission. In this instance, a network administrator may attempt to recover the lost packets. However, an administrator troubleshooting lost or out-of-sequence data packets may disrupt the performance of a live production network. The administrator may need to execute trouble shooting software that may slow down a live data network being used by customers. Such a disruption may result in customer dissatisfaction, which in turn may lead to a loss of revenue.

In view of the foregoing, disclosed herein is an apparatus that monitors live production data packets and permits playback of these packets without disrupting a live production network.

The aspects, features, and advantages of the present disclosure will be appreciated when considered with reference to the following description of examples and accompanying figures.

<FIG> shows a schematic diagram of an illustrative computer apparatus <NUM> for executing some of the techniques disclosed herein. Computer apparatus <NUM> may comprise a device capable of processing instructions and transmitting data to and from other computers, including a laptop, a full-sized personal computer, a high-end server, or a network computer lacking local storage capability. Computer apparatus <NUM> may include all the components normally used in connection with a computer. For example, it may have a keyboard and mouse and/or various other types of input devices such as pen-inputs, joysticks, buttons, touch screens, etc., as well as a display, which could include, for instance, a CRT, LCD, plasma screen monitor, TV, projector, etc. Computer apparatus <NUM> may also comprise a network interface <NUM> to communicate with other devices over a network. As will be noted further below, computer apparatus <NUM> may be used to store and replay packets,.

The computer apparatus <NUM> may also contain at least one processor <NUM>, such as processors from Intel ® Corporation. In another example, processor <NUM> may be an application specific integrated circuit ("ASIC"). Memory <NUM> may store instructions that processor <NUM> may retrieve and execute. In one example, memory <NUM> may be used by or in connection with an instruction execution system that permits processor <NUM> to fetch or obtain the logic from memory <NUM> and execute the instructions contained therein.

Memory <NUM> may be a non-transitory computer readable medium ("CRM"), which may comprise any one of many physical media such as, for example, electronic, magnetic, optical, electromagnetic, or semiconductor media. Some examples of suitable non-transitory computer readable medium include, but are not limited to, a portable magnetic computer diskette such as floppy diskettes or hard drives, a read-only memory ("ROM"), an erasable programmable read-only memory, a portable compact disc or other storage devices that may be coupled to computer apparatus <NUM> directly or indirectly. The non-transitory CRM may also include any combination of one or more of the foregoing and/or other devices as well.

As noted above, computer instructions stored in memory <NUM> may cause processor <NUM> to carry out one or more of the techniques disclosed herein. These instructions may comprise any set of instructions to be executed directly (such as machine code) or indirectly (such as scripts) by processor <NUM>. In this regard, the terms "instructions," "scripts," or "modules" may be used interchangeably herein. The computer executable instructions may be stored in any computer language or format, such as in object code or modules of source code. Furthermore, it is understood that the instructions may be implemented in the form of hardware, software, or a combination of hardware and software and that the examples herein are merely illustrative.

As will also be discussed further below, computer apparatus <NUM> may store and sort data packets for replay in database <NUM>. These packets may be retrieved later for replay. Database <NUM> is not limited to any particular data structure. The data stored in database <NUM> may be formatted in any computer-readable format. Database <NUM> may comprise computer registers, a relational database with multiple tables arranged with fields and records, XML documents, or flat files. The stored data may comprise any information sufficient to identify the relevant information, such as numbers, descriptive text, proprietary codes, references to data stored in other areas of the same memory or different memories (including other network locations) or information that is used by a function to calculate the relevant data.

While <FIG> only depicts one processor, one memory, and one database, it is understood that computer apparatus <NUM> may actually comprise additional processors, memories, and databases working in tandem that may or may not be stored within the same physical housing or location. To wit, although all the components of computer apparatus <NUM> are functionally illustrated as being within the same block, it will be understood that the components may or may not be stored within the same physical housing.

One working example of the system, method, and non-transitory computer readable medium is shown in <FIG>. In particular, <FIG> illustrates a flow diagram of an example method <NUM> (embodiment not covered by the claimed invention) for monitoring and replaying packets. <FIG> show a working example in accordance with the techniques disclosed herein. The actions shown in <FIG> will be discussed below with regard to the flow diagram in <FIG>.

Referring to <FIG>, a processor (e.g., a processor <NUM> of computer apparatus <NUM>) may establish communication with a network TAP of a first network, as shown in block <NUM>. In block <NUM>, a processor may also establish communication with at least one node of a second network. Referring now to <FIG>, an example network topology in accordance with aspects of the disclosure is shown. <FIG> illustrates a network <NUM> and a network 301P. In the example of <FIG>, network <NUM> may be a production environment that includes workstations <NUM> and <NUM>; switches <NUM> and <NUM>; and, network TAPS <NUM> and <NUM>. Network 301P may be a packet monitoring environment that includes workstations 302P and 314P; switches 306P and 310P; hub <NUM>; computer apparatus <NUM>; and database <NUM>. In the example of <FIG>, at least one node in the second network 301P may correspond to a node in the first network <NUM> such that respective IP addresses of corresponding nodes are equal. For example, workstation <NUM> and 302P may have identical IP addresses. Furthermore, switches <NUM> and 306P and switches <NUM> and 310P may also have identical IP addresses. The advantage of having these identical IP addresses will be explained further below.

The workstations <NUM>, <NUM>, 302P, and 314P may also have at least one processor, at least one memory, and at least one network interface like computer apparatus <NUM> shown in <FIG>. Networks <NUM> and 301P may be local area networks ("LAN") or a wide area networks ("WAN"). A LAN may include, for example, an Ethernet <NUM>/<NUM> LAN or a gigabit Ethernet LAN. Networks <NUM> and 301P may be connected to a service provider via a cable network, a digital subscriber line (DSL) network, a T1 or T3 network, a microwave network, a WiMax (IEEE <NUM>) network, or the like. Furthermore, networks <NUM>, 301P, and the intervening nodes therein may use various protocols including virtual private networks, local Ethernet networks, and private networks using communication protocols proprietary to one or more companies, cellular and wireless networks, HTTP, and various combinations of the foregoing. In one example, networks <NUM> and 301P may be wireless networks that conform to standards including Bluetooth®, IEEE <NUM>. 11a, IEEE <NUM>. 11b, IEEE <NUM>, IEEE <NUM>, or the like. It is understood that the network topologies shown in <FIG> are merely illustrative and that many different topologies may be implemented. Furthermore, it is understood that a network topology may include many more workstations, hubs, switches, servers, and network TAPS and that the example of <FIG> shows a small number of nodes for ease of illustration only.

Network <NUM> is shown with a workstation <NUM> in communication with another workstation <NUM>. In between workstation <NUM> and workstation <NUM>, there are two network switches, switch <NUM> and switch <NUM>, and three network TAPS <NUM>, <NUM>, and <NUM>. As noted above, at least one device of network <NUM> may have a corresponding device in network 301P. These corresponding devices may have identical IP addresses. That is, if the IP address of switch <NUM> is <NUM>. <NUM>, <NUM>, the IP address of the corresponding switch 306P may be the same. By way of example, workstations <NUM> and <NUM> of network <NUM> correspond to workstations 302P and 314P of network 301P respectively. Switches <NUM> and <NUM> of network <NUM> correspond to switches 306P and 310P in network 301P respectively.

Each switch in the network shown in <FIG> may comprise a memory, and a processor. Further, each switch may include a number of data ports, such as uplink data ports and downlink data ports. One or more switches in the networks of <FIG> may also include data comprising flow tables. For example, each entry in a given flow table may include a key and an action. As a switch receives packets, header information in those packets may be matched against the keys of the flow table to determine a corresponding action such as a next hop. The entries in the flow table may be used directly or indirectly to forward packets. While each switch in <FIG> is depicted as hardware switches, a software based switch may be used in other examples. In this instance, the flow table may be accessed directly by a forwarding software module to alter the packet's header information and to forward the packet to an appropriate port. Alternatively, a processor of a switch may program hardware modules based on the flow table entries, and these hardware modules may forward packets based on each flow's match criteria, action, and priority. As noted above, network <NUM> may be a live or primary network where users are transferring real-time data between workstation <NUM> and workstation <NUM>. In contrast, network 301P may be used for capturing the packets and/or replaying the packets.

Each network TAP <NUM>, <NUM>, and <NUM> of network <NUM> comprises hardware that duplicates each packet flowing between a respective pair of network nodes (i.e., network TAP <NUM> mirrors bi-directional packets flowing between workstation <NUM> and switch <NUM>, network TAP <NUM> mirrors bi-directional packets flowing between switch <NUM> and switch <NUM>, and so on). The duplicated packet s forwarded to the device in network 301P that corresponds to the destination device in network <NUM>. By way of example, workstation <NUM> may transmit a packet destined for switch <NUM>. In this instance, network TAP <NUM> may create a duplicate of the packet and forward that duplicate to the corresponding switch 306P in network 30IP. By way of further example, if a packet is traveling from switch <NUM> to workstation <NUM>, network TAP <NUM> may create a duplicate and forward that duplicate to workstation 302P. As such, each network TAP may forward duplicates to the corresponding destination node in network 30IP depending on the direction of the packet.

As noted earlier, corresponding devices in networks <NUM> and 30IP have identical IP addresses. By using an identical IP address, the duplicate packet created by a network TAP would automatically route to the corresponding device in network 301P without needing additional logic in the network TAP to alter the destination address. For example, if a network TAP in the production environment forwarded all the duplicate packets to a monitoring device with a unique IP address, the destination IP address of each duplicate packet may need to be changed so that each packet routes accordingly. Changing the destination IP of each packet may be a burden on the production environment and may cause further delays.

The switches and workstations of network <NUM> and their counterparts in network <NUM>01P are time synchronized. By way of example, if network TAP <NUM> of <FIG> copies a packet and forwards the duplicate to switch 306P and the timestamp of the duplicate is not synchronized with the internal clock of switch 306P, switch 306P may reject the duplicate packet. Therefore, in one example, a timeserver (not shown) may be linked to the switches and workstations of network <NUM> and their counterparts in network 301P. The time server may include, for example, a GPS satellite antenna wired to a grandmaster precision time protocol (PTP) clock. Thus, the PTP protocol may be used to synchronize clocks throughout networks <NUM> and 301P. The PTP may be in accordance to the standards specified in IEEE <NUM>-<NUM> and IEEE <NUM>-<NUM>.

The network TAPS shown in <FIG> may be designed to mirror the traffic without impeding the flow of the production traffic flowing in network <NUM>. Referring now to <FIG>, a detailed illustration of a network TAP <NUM> in accordance with the present disclosure is shown. Each network TAP may also comprise a processor <NUM> and memory <NUM>. The first network interface <NUM> may be coupled to wired or wireless networks. In one example, the first network interface <NUM> may comprise a plurality of ports configured to permit bi-directional traffic to pass through network TAP <NUM>. The second network interface <NUM> may provide access to a device in second network 301P. That is, the duplicate packets may be forwarded via the second network interface <NUM>. However, in other examples, first network interface <NUM> may permit the bi-directional traffic as well as forward the duplicate packets to network 301P. Memory <NUM> of network TAP <NUM> may include network access instructions.

Each network TAP may be a switched port analyzer (SPAN) or remote switch port analyzer (RSPAN) TAP that makes copies of each packet passing between devices in the network. In one example, each network TAP shown in <FIG> may be an optical fiber TAP. An optical fiber TAP may provide the exact duplicate of the signal on the network link without any disruption to the network activity. Optical fiber TAPS may continually pass data on its ports, without either modifying or degrading the signal passing through. The Optical fiber TAP may provide a duplicate of each packet passing by splitting a small amount of light flowing on the tapped network link. In an example, the network TAPS shown in the figures may be active Optical fiber TAPS, which use electricity for operation, or passive Optical fiber TAPS that do not use electricity.

Referring back to the example of <FIG>, packets received by corresponding devices in network 301P (i.e., workstations 302P/314P and switches 306P/310P), may be forwarded to hub <NUM>. Hub <NUM> may be a series of packet handling switches that route all the packets to computer apparatus <NUM>. Hub <NUM> may insert other relevant information in the packet. By way of example, if network <NUM> is used for real-time trading of financial instruments, Hub <NUM> may ensure that all the relevant identifiers are included in the packet (e.g., order identifier, trade identifier, etc.).

All the packets received by computer apparatus <NUM> from Hub <NUM> may be stored in database <NUM> and the packets may be sorted by timestamp. That is, computer apparatus <NUM> may store all the packets transferred between the devices of network <NUM> in database <NUM> by way of network 301P. As noted above, the users of network <NUM> may be traders and the packets may represent orders for financial instruments or execution of trades for financial instruments. In this instance, a second packet may be associated with the first packet by way of an order identifier, execution identifier, etc. That is, the second packet may have an identifier that is identical to or related in some way with the first packet (e.g., each packet may be a different transaction on the same order). Referring now to <FIG>, an example packet representing a trade for a financial instrument is shown. The illustrative packet of <FIG> may comprise transport protocol details <NUM>, a source internet protocol ("IP") address <NUM>, and a user identifier field <NUM>. The illustrative packet may also comprise a financial instrument field <NUM> that may contain a symbol of a stock or bond, and a price field <NUM> that may represent a bid price, ask price, or execution price. The illustrative packet may also contain a size field <NUM> that may represent an amount of the instrument being bought, sold, or otherwise executed, and comprises a timestamp field <NUM> that represents the time in which a particular network node generated or forwarded the packet. The illustrative packet may also include a destination IP address field <NUM>. The precision of timestamp field <NUM> may be set to nanoseconds, however it is understood that different levels of precision may be used. As noted above the timestamps between networks <NUM> and 301P are synchronized.

Referring back to <FIG>, computer apparatus <NUM> may launch packets in the second network from a respective node in the second network that corresponds to the source IP address in each packet, as shown in block <NUM>. In one example, the monitoring network 301P shown in <FIG> may be used to replay the packets. However, a separate replay network may also be used. <FIG> illustrates a working example of a separate replay network. The network in <FIG> may be used for replay and analysis instead of the networks shown in <FIG> to further avoid any risk of disrupting the production environment of network <NUM>. A separate replay network may also be advantageous if disruption to the monitoring network 301P is also necessary. In this instance, network 301R shown in <FIG> may be used for replay in lieu of network 301P. However, it is understood that network 301P may still be used for replay and analysis. Network 301R of <FIG> may have workstations 302R and 314R and switches 306R and 310R. The workstations and switches shown in network 301R may also have identical IP addresses as their respective corresponding devices in network <NUM>. That is, the IP addresses of workstations 302R and 314R may be identical to the IP addresses of workstations <NUM> and <NUM> in network <NUM> of <FIG> respectively. Similarly, the IP addresses of switches 306R and 310R may have the identical IP addresses as switches <NUM> and <NUM> in network <NUM> respectively. While <FIG> shows computer apparatus <NUM> also used for replay, it is understood that a different computer apparatus may be used for replay. Each packet in database <NUM> may include a source IP address, an identifier, and a timestamp. In addition, the plurality of packets may be sorted in the database by timestamp and identifier. Also, in other implementations, the IP addresses of the replay devices in network 301R may be different from their counterparts in the production network. In this instance, the source and destination IP addresses of each packet may need to be altered before replay. This change of IP addresses may not disturb the production and mirror networks shown in <FIG>.

As noted above, each packet in database <NUM> may comprise a source IP address, an identifier, and a timestamp. Referring back to the working example of <FIG>, a packet travelling from workstation <NUM> to workstation <NUM> in network <NUM>, may have a total of three copies stored in database <NUM>. By way of example, a first copy is generated by network TAP <NUM>, a second copy is generated by network TAP <NUM>, and a third copy is generated by network TAP <NUM>. Thus, a snapshot of the packet as it travels through the network may be captured in database <NUM>. By way of further example, the first, second, and third copies may be associated with a particular order of a financial trade.

Referring back to <FIG>, computer apparatus <NUM> may launch the plurality of packets from the corresponding source IP address in the second network (e.g. , network 301R of <FIG>) in a sequence that is in accordance with the timestamp of each packet. This allows computer apparatus <NUM> to reproduce an initial route of each packet as it should have been in the first network (e.g. , network <NUM>). As noted above, at least one device in the network <NUM> has a corresponding device in network 301R.

As also noted above, three copies of a packet traveling from workstation <NUM> to workstation <NUM> in <FIG> may be stored in database <NUM>. Network TAPS <NUM>, <NUM>, and <NUM> generate each copy respectively. The first copy of the packet may have an earlier timestamp as the second packet, and the second packet may have an earlier timestamp than the third packet. The three packets may be sorted such that the packet with the earliest timestamp may be launched first, the packet with the second earliest timestamp may be launched second, and so on. In a trading system scenario, the packets may also be sorted by order identifier such that the packets of each order are grouped together in the database.

Referring back to <FIG>, computer apparatus <NUM> may retrieve the packets for a particular order, such as a first-in-first-out order based on the timestamp. In the event an administrator desires to launch a packet from workstation <NUM>, computer apparatus <NUM> may transmit the first copy to workstation 302R to permit workstation 302R to launch the packet to workstation 314R again. This allows the system to replay a packet from different points in the network to determine where the packet was lost or where the packet encountered network congestion. In the event an administrator would like to play the second packet produced by network TAP <NUM> as the packet travelled from switch <NUM> to switch <NUM>, computer apparatus <NUM> may retrieve and transmit the second packet to switch 306R and allow the packet to travel from switch 306R to workstation <NUM>. Since these packets already include a destination IP address, the packets would automatically route to the destination node.

Referring now to <FIG>, an example method <NUM> that is executed by a network TAP in network <NUM> is shown. In block <NUM>, a network TAP receives, via a network interface, a first packet from a source device, the first packet being bound for a destination device. As noted above, the source device and the destination device are nodes of a first network, such as switch <NUM> and switch <NUM> of network <NUM>. The source device and the destination device are each associated with a respective IP address. In block <NUM>, a network TAP generates a duplicate packet that is a copy of the first packet. The network TAP may further permit packets to proceed toward the destination device in the first network. For example, in <FIG>, network TAP <NUM> may permit a packet to flow between switch <NUM> and switch <NUM>. In block <NUM>, a network TAP forwards, using another network interface, the duplicate packet to another destination device having an IP address identical to that of the destination device in the first network. The other destination device may be a node in a second network different from the first network. For example, network TAP <NUM> in <FIG> may forward duplicate packets to either switch 306P or 310P depending on the direction in which the packet is traveling. As noted above, the switches and workstations in network 301P of <FIG> may have identical IP addresses as their counterparts in network <NUM> to reduce the burden on the production network.

Claim 1:
A network tap apparatus (<NUM>, <NUM>, <NUM>, <NUM>) comprising
a plurality of network interfaces (<NUM>, <NUM>, <NUM>);
at least one processor (<NUM>, <NUM>) to:
receive, via a network interface (<NUM>, <NUM>, <NUM>), a packet (<NUM>) from a source device, the packet (<NUM>) being bound for a destination device, the source device and the destination device being nodes of a first network (<NUM>), the source device and the destination device each being associated with a respective internet protocol, IP, address;
generate a duplicate packet (<NUM>) which comprises a timestamp and which duplicate packet (<NUM>) is a copy of the packet (<NUM>) comprising the timestamp, wherein the timestamp represents the time in which a network node in the first network (<NUM>) generated or forwarded the packet (<NUM>); and
forward, using another network interface (<NUM>, <NUM>, <NUM>), the duplicate packet (<NUM>) to another destination device in a second network (301P, 301R), the other destination device in the second network (301P, 301R) having an IP address that is identical to that of the destination device in the first network (<NUM>),
wherein
an internal clock of the destination device in the first network (<NUM>) is synchronized with an internal clock of the destination device in the second network (301P, 301R).