CN116455818A - Network tap and method for copying and obtaining data streams therein - Google Patents

Abstract

The invention discloses a network splitter and a method for duplicating and acquiring data streams therein, which can be used for 10G 10Gbps network links. The network splitter includes: four serial transceivers, the differential of the first serial transceiver The differential signal output by the signal output interface is connected to the differential signal input interface of the second serial transceiver and the third serial transceiver respectively as two single-ended signals, and the differential signal output by the differential signal output interface of the second serial transceiver The two single-ended signals are respectively connected to the differential signal input interfaces of the first serial transceiver and the fourth serial transceiver.

Description

Network tap and method of copying and retrieving data streams therein

technical field

The invention relates to the field of network communication, in particular to a network splitter and a method for copying and acquiring data streams therein.

Background technique

A network tap (Network TAP, TAP=Test Access Point) is a network device used to obtain data streams on a network link (network link) in a data communication network, and is usually used for network fault diagnosis. Network performance analysis, network security or network data storage and other fields. Generally, a network tap has two network ports and at least one split port. The two network ports of the network splitter are respectively connected to two network communication devices, such as computers, network switches or routers, etc. After the two network devices are connected to the network splitter, the data stream transmitted between them will not be shunted by the network At the same time, the network splitter sends the data flow transmitted between the two network devices to the data stream receiving device connected to the split port through the split port.

At present, the data communication network technology mainly adopts the Ethernet (Ethernet) technology, and the Ethernet technology has been standardized by the IEEE international organization as the IEEE 802.3 standard. The IEEE 802.3 standard formulates various Ethernet protocols based on different transmission media and different speeds of network links. The transmission medium of the Ethernet network link can be a network cable composed of 4 pairs of twisted pairs, or an optical cable composed of optical fibers. The speed of network links in Ethernet includes 10Mbps, 100Mbps (100M Ethernet), 1Gbps (Gigabit Ethernet), 10Gbps (10 Gigabit Ethernet) and other higher rates, such as 28Gbps, 40Gbps and 100Gbps.

Therefore, different network splitters need to be used for Ethernet network links using different transmission media or rates. Fig. 1 shows a system diagram of a network splitter 10 based on the prior art. The network splitter 10 has two network ports, a first network port 21 and a second network port 22 , and a splitting port 23 . The first network port 21 is connected to the first network device 11 , the second network port 22 is connected to the second network device 12 , and the distribution port 23 is connected to a data flow receiving device 13 . The network splitter 10 also includes a splitter circuit 20 , which connects the two network ports 21 and 22 and the splitter port 23 inside the network splitter 10 . The function of the shunt circuit 20 is to obtain the data stream without affecting the data stream transmitted between the first network device 11 and the second network device 12 and send the acquired data stream to the data stream receiver through the shunt port 23 device13.

The shunt circuit 20 shown in FIG. 1 is an Ethernet switch IC (Integrated Circuit) chip, such as the RTL8367 5-port 10/100/1000Base-T Gigabit Ethernet switch IC chip of Realtek Company. The method is to select three ports of the Ethernet switch integrated circuit chip as the first network port 21, the second network port 22 and the shunt port 23, and the Ethernet switch integrated circuit chip is set to a port mirroring function, and the port mirroring function is fixed. The data flow through the network ports 21 and 22 is copied and forwarded to the distribution port 23. In this way, the first network device 11 and the second network 12 can mutually send and receive data flows through the two network ports 21 and 22 of the network splitter 10, and at the same time, the data flows transmitted between the two network devices 11 and 12 are copied and forwarded to the distribution port 23, and transmitted to the data flow receiving device 13 through the distribution port 23.

For a network splitter used for a 100M (100Mbps)/1 Gigabit (1Gbps) network link, using a 100M/1000M Ethernet switch integrated circuit chip as the shunt circuit 20 is considered to be a very economical circuit method, This is because 100M/Gigabit Ethernet switch integrated circuit chips are widely used in Ethernet switch equipment in the home and small business markets, making the price of 100M/Gigabit Ethernet switch IC chips very low.

However, for a network tap for a 10Gbps network link, using a 10GbE switch IC may not be the way to go. First of all, because 10 Gigabit Ethernet switch IC chips are mainly used to manufacture high-end Ethernet switches for large enterprises (such as data centers and large companies), their market demand is higher than that of 100M/Gigabit Ethernet switch IC chips. It is much smaller, so the price of 10G switch IC chips is much higher than that of 100M/Gigabit Ethernet switch IC chips. Second, due to the high operating frequency of the 10 Gigabit Ethernet switch integrated circuit chip, the heat generated is higher, and more complex heat dissipation measures are required, such as the use of cooling fans, to ensure that the 10 Gigabit Ethernet switch integrated circuit chip does not overheat. The corresponding heat dissipation treatment measures will inevitably increase the product cost. In addition, due to the long-term high-temperature operation of the 10-Gigabit Ethernet switch IC chip, its working reliability will be reduced accordingly, especially the use of a cooling fan with lower reliability, which may reduce the use of the 10-Gigabit Ethernet switch IC chip. Product reliability of the chip as a network shunt of the shunt circuit 20 .

Another disadvantage of using Ethernet switch IC chips to implement network splitters is that the product life cycle of Ethernet switch IC chips is usually relatively short, and will often be discontinued by chip manufacturers within a few years and replaced by a new generation with more advanced features. It is replaced by Ethernet switch integrated circuit chips with better performance or more advanced functions. Because the pins of the new generation of Ethernet switch ICs are usually not compatible with the pins of the previous generation of Ethernet switch ICs, network tap manufacturers have to redesign the network tap using the new Ethernet switch ICs circuit. This will increase the additional burden and cost of product design and production.

Contents of the invention

In view of the above situation, the present invention proposes a new network shunt circuit structure and implementation method. The advantages of the network splitter based on the present invention include not relying on the use of a specific Ethernet switch integrated circuit chip, high reliability, low manufacturing cost, flexible configuration, and can work at 10Gbps (10Gbps) rate.

According to one aspect of the present invention, a network splitter is provided, which is used to copy and obtain the data flow of the network link between the first network device and the second network device and send the data flow to the data flow receiving device , which includes:

A first serial transceiver, the first serial transceiver includes a network port connectable to the first network device, a differential signal input interface and a differential signal output interface;

A second serial transceiver, the second serial transceiver includes a network port connectable to the second network device, a differential signal input interface and a differential signal output interface;

A third serial transceiver, the third serial transceiver includes a network port and a differential signal input interface connectable to the data stream receiving device;

A fourth serial transceiver, the fourth serial transceiver includes a network port and a differential signal input interface connectable to the data stream receiving device;

The differential signal output interface of the first serial transceiver includes a first signal output terminal and a second signal output terminal, the signal output by the first signal output terminal and the signal output by the second signal output terminal have the same amplitude but The polarity is opposite, the differential signal input interface of the second serial transceiver is set to use the first single-ended signal connection wire to connect to the first signal output end, the differential signal of the third serial transceiver The input interface is configured to be connected to the second signal output terminal by using a second single-ended signal connection wire;

The differential signal output interface of the second serial transceiver includes a third signal output terminal and a fourth signal output terminal, the signal output by the third signal output terminal and the signal output by the fourth signal output terminal have the same amplitude but The polarity is opposite, the differential signal input interface of the first serial transceiver is set to use the third single-ended signal connection wire to connect to the third signal output end, the differential signal of the fourth serial transceiver The input interface is configured to be connected to the fourth signal output terminal by using a fourth single-ended signal connection wire.

According to another aspect of the present invention, there is provided a method for duplicating and acquiring data streams in a network splitter, wherein the network splitter includes a first network port, a second network port, a first split port and a second split port, The network splitter receives the data flow in the first direction from the first network port, and outputs the data flow in the first direction from the second network port and the first splitting port, and the network splitter receives the data flow in the first direction from the first network port. The second network port receives the data flow in the second direction, and outputs the data flow in the second direction from the first network port and the second distribution port, characterized in that it includes:

Converting the data flow in the first direction into a differential signal through a first serial transceiver, the differential signal includes a first single-ended signal and a second single-ended signal, and the first single-ended signal and the second single-ended signal The terminal signals have the same amplitude but opposite polarity;

converting the first single-ended signal into a first output signal through a second serial transceiver, the first output signal fully represents the data flow in the first direction, and the first output signal is received from the second network port output;

converting the second single-ended signal into a second output signal through a third serial transceiver, the second output signal fully represents the data flow in the first direction, and the second output signal is split from the first port output.

converting the data flow in the second direction into a differential signal through a second serial transceiver, the differential signal includes a third single-ended signal and a fourth single-ended signal, and the third single-ended signal and the fourth single-ended signal The terminal signals have the same amplitude but opposite polarity;

converting the third single-ended signal into a third output signal through the first serial transceiver, the third output signal fully represents the data stream in the second direction, and the third output signal is obtained from the first A network port output;

converting the fourth single-ended signal into a fourth output signal through a fourth serial transceiver, the fourth output signal fully represents the data flow in the second direction, and the fourth output signal is split from the second port output.

Description of drawings

The accompanying drawings of the present invention are used to provide further understanding and explanation of the present application, and do not constitute an improper limitation of the present invention.

Fig. 1 is a system diagram of a network splitter according to the prior art.

Fig. 2 is a schematic circuit diagram of a network splitter according to the present invention.

FIG. 3 is a schematic diagram of a circuit according to an embodiment of the present invention. In this embodiment, the network splitter is a PCI Express bus computer add-in card.

Detailed ways

The device structure and implementation method of the present invention will be described and illustrated below in conjunction with several aspects and several embodiments of the present invention. It should be understood that these descriptions and illustrations are only used to explain the present invention, not to limit the present invention. In some instances, well-known structures or methods are not described in detail in order not to obscure the present invention.

Referring to FIG. 2, it shows a schematic circuit diagram of a network splitter 100 according to the present invention. The network splitter 100 includes four serial transceivers (transceivers) 101-104, which are placed on a printed circuit board (PCB). Each serial transceiver 101-104 has a network port 110 and a serial differential signal interface, which includes a positive polarity signal input terminal TD+ and a negative polarity signal input terminal TD- differential signal input Interface 124 and a differential signal output interface 128 of a positive polarity signal output terminal RD+ and a negative polarity signal output terminal RD−. The function of the serial transceiver is to convert the data stream electrical signal or optical signal received from the network port 110 into a differential electrical signal, and output it from the differential signal output interface 128 . On the other hand, it converts a differential electrical signal representing the network data flow received by the differential signal input interface 124 into a corresponding electrical or optical signal representing the data flow, and outputs it from the network port 110 .

In the network splitter 100, the first serial transceiver 101 and the second serial transceiver 102 are connected to each other in such a manner that the positive polarity signal output terminal RD+ of the differential signal output interface 128 of the first serial transceiver 101 passes through The PCB connection wire 152 is connected to the positive polarity signal input terminal TD+ of the differential signal input interface 124 of the second serial transceiver 102, and the positive polarity signal output terminal RD+ of the differential signal output interface 128 of the second serial transceiver 102 passes through the PCB The connecting wire 153 is connected to the positive polarity signal input terminal TD+ of the differential signal input interface 124 of the first serial transceiver 101; the negative pole of the differential signal input interface 124 of the first serial transceiver 101 and the second serial transceiver 102 The sex signal input terminals TD- are respectively grounded. In addition, the negative polarity signal output terminal RD- of the differential signal output interface 128 of the first serial transceiver 101 is connected to the negative polarity signal input terminal TD- of the differential signal input interface 124 of the third serial transceiver 103 through the PCB connection wire 151 Connected, the negative polarity signal output terminal RD of the differential signal output interface 128 of the second serial transceiver 102-pass the negative polarity signal input terminal TD of the differential signal input interface 124 of the fourth serial transceiver 104 through the PCB connection wire 154 - connected; the positive polarity signal input terminal TD+ of the differential signal input interface 124 of the third serial transceiver 103 and the fourth serial transceiver 104 is grounded. The respective differential signal output interfaces 128 of the third serial transceiver 103 and the fourth serial transceiver 104 are not used, and can be terminated with a matching resistor (not shown), whose resistance value is equal to the output impedance of the corresponding differential output 128 . Typically, the value of this matching resistor is 100 ohms.

As can be seen from FIG. 2, in the network splitter 100, the differential signal output from the differential signal output interface 128 of the first serial transceiver 101 is configured or "separated" into two single-ended signals (single-ended signal ), the two single-ended signals are respectively output from the positive polarity signal output terminal RD+ and the negative polarity signal output terminal RD− of the differential signal output interface 128 . The signal amplitudes output by the two signal outputs are the same, but the polarity of the signals is opposite. Here, the positive polarity signal output terminal RD+ and the negative polarity signal output terminal RD- of the differential signal output interface 128 are respectively connected to the second serial transceiver 102 and the third serial transceiver 102 and the third serial transceiver 102 by PCB connection wires 152 and 151 in a "point-to-point" connection mode. The differential signal input interfaces 124 of the transceivers 103 are connected to each other. For those skilled in this professional field, they are easy to understand, because the negative polarity signal input terminal TD- of the differential input interface 124 of the second serial transceiver 102 and the positive polarity of the differential input interface 124 of the third serial transceiver 103 The polarity signal input terminals TD+ are respectively grounded, which will ensure that the respective differential signal input interfaces 124 of the second serial transceiver 102 and the third serial transceiver 102 can correctly receive corresponding single-ended input signals. In particular, although the signal amplitude of each single-ended signal is halved relative to the amplitude (voltage) of the differential signal, as long as the signal amplitude of the single-ended signal is greater than the minimum input signal amplitude required by the differential signal input interface 124, the single-ended input signal can still be received normally. On the other hand, because the signal amplitudes of the two single-ended signals output from the differential signal output interface 128 of the first serial transceiver 101 are the same but opposite in polarity, the connection method shown in FIG. 2 ensures that the second serial The input signals received by the respective differential signal input interfaces 124 of the transceiver 102 and the third serial transceiver 102 are the same, so the respective corresponding signals output from the network port 110 are also the same, which is equivalent to the third serial The data stream output from the network port 110 of the transceiver 103 duplicates the data stream output from the network port 110 of the second serial transceiver 102 . Similarly, it can be known that the data stream output from the network port 110 of the fourth serial transceiver 104 duplicates the data stream output from the network port 110 of the first serial transceiver 101 .

In other words, after four serial Ethernet transceivers 101-104 are connected according to FIG. 2 and the method described above, the data flow received by the network port 110 of the first serial The network port 110 of the transceiver 102 is transmitted, and another same or copied data stream is also transmitted from the network port of the third serial transceiver 103 . Similarly, the data stream received by the network port 110 of the second serial transceiver 102 will be transmitted from the network port 110 of the first serial transceiver 101, and another same or copied data stream will also be transmitted from the network port 110 of the first serial transceiver 101. The network port of the fourth serial transceiver 103 transmits out. Therefore, the network port 110 of the first serial transceiver 101 and the second serial transceiver 102 corresponds to the two network ports 21 and 22 of the network splitter 10 shown in FIG. 1 , and the combined third serial transceiver The respective network ports 110 of 103 and the fourth serial transceiver 104 correspond to the split port 23 in the network splitter 10 shown in FIG. 1 . In addition, it can be clearly seen that the data flow through the network splitter 100 is bidirectional.

It should be noted that the serial Ethernet transceivers 101-104 in the network tap 100 must work at the same rate. This same rate depends on the rate of the network link accessed by the network tap 100 . For example, when the rate of the network link is 10Gbps, the rate of the serial Ethernet transceivers 101-104 in the network splitter 100 must also be 10Gbps.

As shown in FIG. 2, four serial Ethernet transceivers 101-104 are connected to each other by PCB connection wires 151-154. These PCB connection wires constitute a passive shunt circuit, that is, no active device is used in the circuit and the function of the data flow shunt circuit is realized. According to the present invention, the four serial transceivers 101-104 are placed on the printed circuit board close enough to each other so that the four PCB connecting wires 151-154 are short enough. In addition, for the two PCB connection wires 152-153 connecting the first and second serial Ethernet transceivers, it is further considered to match the length of the wires. These measures will enable the passive shunt circuit to work at a rate of 10Gbps or higher, so that the network splitter 100 can be used for a 10Gbps (10Gbps) network link, that is, the network splitter 100 can be used in 10Gbps Serial transceivers 101-104 at megabit (10Gbps) or higher rates can still work normally. Here, normal operation means that when the network splitter 100 is connected to a 10Gbps network link, it will not affect the transmission of data streams on the 10Gbps network link, and the network splitter 100 can correctly Copy and fetch data streams.

According to the present invention, a clock and data recovery (CDR) circuit can also be provided in the first serial transceiver 101 and the second serial transceiver 102 respectively, and the clock and data recovery circuit acts on the corresponding serial transceiver network The data flow signal received by the port 110 . This clock and data recovery circuit is not necessary, but after a very long cable or optical cable transmission, the data stream signal received by the network port 110 will be very weak, this clock and data recovery circuit is conducive to correctly receive Transmission is attenuated so that it becomes very weak signal.

It can be seen that the network splitter 100 according to the present invention has many advantages, including not needing to use an Ethernet switch integrated circuit chip, nor needing to use other active high-speed integrated circuit devices, as in some prior art network splitters A fan-out buffer integrated circuit chip (1-to-2 fanout buffer IC Chip) that may be used in two outputs for splitting data streams, etc. Therefore, the network splitter 100 according to the present invention can not only be used for 10 Gigabit (10Gbps) network links, but also avoid some major engineering and manufacturing problems faced by the aforementioned prior art network splitters and difficult.

The structure and method of the network splitter 100 according to the present invention shown in FIG. 2 are described and disclosed in detail above. The following describes three embodiments according to the present invention to further explain the present invention.

Embodiment 1: In this embodiment, the four serial transceivers 101-104 in FIG. 2 adopt standardized small form-factor pluggable SFP or SFP+ Ethernet transceiver modules (Small Form-Factor Pluggable Ethernet Transceiver). The SFP (Small Form-factor Pluggable) and SFP+ standards are formulated by the Multi-Source Agreement (MSA). MSA is an alliance formed by optoelectronic equipment manufacturers and system integrators, aiming to promote the development of optoelectronic equipment by formulating a series of communication protocols and standards. The SFP and SFP+ standards define an interchangeable optical module and the corresponding interface specifications, so that devices produced by different manufacturers can interoperate. SFP is the earliest standard for Gigabit Ethernet 1GbE (Gigabit Ethernet) connections, while SFP+ is an upgraded version for 10 Gigabit Ethernet 10GbE connections. Since the mechanical dimensions and pin definitions of SFP and SFP+ are the same, they are collectively referred to as SFP/SFP+ in the following description.

In this embodiment, the four SFP/SFP+ Ethernet transceiver modules in the network tap 100 must be able to work at the same rate. The same rate depends on the rate of the network link to which the network tap 100 is connected.

In addition, in this embodiment, a clock can be respectively set in the SFP/SFP+ Ethernet transceiver module as the first serial transceiver 101 and the SFP/SFP+ Ethernet transceiver module as the second serial transceiver 102 and a data recovery (CDR) circuit, the clock and data recovery circuit acts on the data stream received by the network port 110 of the corresponding SFP/SFP+ Ethernet transceiver module. This clock and data recovery circuit is not necessary, but after a very long cable or optical cable transmission, the data stream signal received by the network port 110 will be very weak, this clock and data recovery circuit is conducive to correctly receive Transmission is attenuated so that it becomes very weak signal.

In this embodiment, only four fixed metal frames (SFP Cage) with SFP/SFP+ sockets need to be soldered on the circuit board PCB of the network splitter 100, for connecting four pluggable SFP/SFP+ Ethernet transceivers device module. Because the circuit of the network splitter 100 itself does not need to include a physical layer PHYIC chip for implementing four serial transceivers, the circuit complexity and cost of the network splitter 100 itself are greatly reduced.

Another advantage of the network splitter 100 in this embodiment is that it can be flexibly configured using SFP/SFP+ Ethernet transceiver modules supporting Ethernet standards, so that the same network splitter 100 can be used for 100M (100Mbps) Ethernet network link, Gigabit (1Gbps) Ethernet link or 10 Gigabit (10Gbps) or even more than 10 Gigabit Ethernet network link, and these Ethernet network links can be electrical signal network links or optical signal network links .

For example, the network splitter 100 can be configured with four SFP+ 10 Gigabit (10Gbps) Ethernet transceiver modules, of which two SFP+ 10 Gigabit Ethernet transceiver modules are transceiver modules that support the 10GBase-SR 10Gbps optical Ethernet protocol in IEEE 802.3 , as the first and second serial Ethernet transceivers 101 and 102, their respective fiber optic network ports are connected to two 10 Gigabit fiber optic network devices. The other two SFP+ 10 Gigabit Ethernet transceiver modules are transceiver modules that support the 10GBase-T10Gbps twisted pair cable Ethernet protocol in IEEE 802.3, as the third and fourth serial Ethernet transceivers 103 and 104, their respective The twisted-pair cable network port (RJ45) is connected to two 10GBase-T RJ45 ports on the data stream receiver device through two network cables respectively. Here, 10GBase-SR and 10GBase-T are Ethernet protocols specified by IEEE802.3 to transmit 10 Gigabit (10Gbps) rate using short-distance multimode fiber and network cables (such as CAT6) composed of four pairs of twisted pairs.

In addition, another advantage of the network splitter 100 in this embodiment is that the same network splitter 100 can be used for both Ethernet network links and non-Ethernet network links. For example, when the network tap 100 is used with four SFP/SFP+ Ethernet transceiver modules, the network tap 100 can be used for an Ethernet link. When the network splitter 100 is used together with four SFP/SFP+ transceiver modules supporting the Fiber Channel (FC) standard, the network splitter 100 can be used for a Fiber Channel FC link. Fiber Channel FC protocol is a high-speed data transmission protocol to connect data storage and host computing servers.

Embodiment 2: see FIG. 3 . In this embodiment, the network splitter 200 is a PCI Express bus computer card. PCI Express (Peripheral Component InterconnectExpress) bus is a standard computer expansion bus used to connect various hardware devices inside the computer, such as Ethernet network cards and so on. It is a high-speed, low-latency serial bus that can provide higher data transfer rates and reliability than traditional PCI buses. In this embodiment, the network splitter 200 as a computer card includes a dual-port network interface controller NIC (Network Interface Controller) integrated circuit chip 210 and two fixed metal frames with SFP/SFP+ sockets. These two fixed metal frames with SFP/SFP+ sockets are respectively used to connect two pluggable SFP/SFP+ Ethernet transceiver modules, which serve as the first serial transceiver 101 and the second serial transceiver 102 respectively , while the third serial transceiver 103 and the fourth serial transceiver 104 are part of the dual-port network interface controller NIC integrated circuit chip 210, and are located inside the integrated circuit chip. The serial differential signal interfaces of these four serial transceivers are connected to each other in the manner shown in Figure 2; the network ports of the third and fourth serial transceivers are respectively PCI Express bus interfaces, and they are respectively connected to the two-port network interface The PCI Express bus switch circuit module 240 in the controller NIC integrated circuit chip 210 is also connected to the PCI Express edge slot connector (Edge Connector) 220 of the computer card through the PCI Express bus 230 . It can be seen that the PCIExpress edge slot connector 220 of the computer card is equivalent to the physical interface of the distribution port of the network splitter 200 .

Embodiment 3: In this embodiment, the network splitter is configured with two fixed metal frames with SFP/SFP+ sockets for connecting two pluggable SFP/SFP+ Ethernet transceiver modules, which are respectively shown in Figure 2 The first serial transceiver 101 and the second serial transceiver 102 shown, and the third serial transceiver 103 and the fourth serial transceiver 104 shown in FIG. 2 are an Ethernet network switch integrated circuit chip A portion, located inside the integrated circuit chip. The serial differential signal interfaces of these four serial transceivers are connected to each other in the manner shown in Figure 2; the differential signal input interface 124 of the third serial transceiver 103 and the fourth serial transceiver 104 is the Ethernet network switch The two ports of the integrated circuit chip, the network port of the third serial transceiver 103 and the fourth serial transceiver 104 are "mapped" to another port of the Ethernet network switch integrated circuit chip inside the Ethernet network switch integrated circuit chip. 1 or 2 ports, as the diversion port of the network splitter.

The above descriptions are only some embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement or improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. A network splitter, for duplicating and acquiring the data stream of the network link between the first network device and the second network device and sending the data stream to the data stream receiving device, characterized in that it comprises : A first serial transceiver, the first serial transceiver includes a network port connectable to the first network device, a differential signal input interface and a differential signal output interface; A second serial transceiver, the second serial transceiver includes a network port connectable to the second network device, a differential signal input interface and a differential signal output interface; A third serial transceiver, the third serial transceiver includes a network port and a differential signal input interface connectable to the data stream receiving device; A fourth serial transceiver, the fourth serial transceiver includes a network port and a differential signal input interface connectable to the data stream receiving device; The differential signal output interface of the first serial transceiver includes a first signal output terminal and a second signal output terminal, the signal output by the first signal output terminal and the signal output by the second signal output terminal have the same amplitude but The polarity is opposite, the differential signal input interface of the second serial transceiver is set to use the first single-ended signal connection wire to connect to the first signal output end, the differential signal of the third serial transceiver The input interface is configured to be connected to the second signal output terminal by using a second single-ended signal connection wire; The differential signal output interface of the second serial transceiver includes a third signal output terminal and a fourth signal output terminal, the signal output by the third signal output terminal and the signal output by the fourth signal output terminal have the same amplitude but The polarity is opposite, the differential signal input interface of the first serial transceiver is set to use the third single-ended signal connection wire to connect to the third signal output end, the differential signal of the fourth serial transceiver The input interface is configured to be connected to the fourth signal output terminal by using a fourth single-ended signal connection wire. 2. The network splitter as claimed in claim 1, wherein the four serial transceivers are pluggable SFP/SFP+ transceiver modules, and the four SFP/SFP+ transceiver modules are in Working at the same rate, the same rate matches the rate of the data flow on the network link. 3. The network splitter according to claim 1, characterized in that, the first single-ended signal connecting wire, the second single-ended signal connecting wire, the third single-ended signal connecting wire and the first single-ended signal connecting wire The four single-ended signal connection wires are part of the passive shunt circuit, and the passive shunt circuit is configured to support the network shunt to work at a rate of at least 10Gbps. 4. network splitter as claimed in claim 1, is characterized in that, described first serial transceiver and the second serial transceiver each have a clock and data recovery circuit, and described clock and data recovery circuit Act on the data stream signal received by the corresponding network port of the serial transceiver. 5. The network splitter according to claim 1, wherein the network splitter can be used for both Ethernet network links and non-Ethernet network links. 6. network splitter as claimed in claim 1, is characterized in that, described network splitter is the computer plug-in card of PCI Express bus, and the computer plug-in card of described PCI Express bus comprises dual-port Ethernet network interface controller An integrated circuit chip, the third serial transceiver and the fourth serial transceiver are located inside the dual-port network interface controller integrated circuit chip, and the first serial transceiver and the second serial transceiver are Pluggable SFP/SFP+ Ethernet transceiver modules. 7. A method for duplicating and acquiring data streams in a network splitter, said network splitter comprising a first network port, a second network port, a first split port and a second split port, said network splitter from The first network port receives the data flow in the first direction, and outputs the data flow in the first direction from the second network port and the first split port, and the network splitter receives from the second network port The data flow in the second direction, and outputting the data flow in the second direction from the first network port and the second distribution port, is characterized in that it includes: Converting the data flow in the first direction into a differential signal through a first serial transceiver, the differential signal includes a first single-ended signal and a second single-ended signal, and the first single-ended signal and the second single-ended signal The terminal signals have the same amplitude but opposite polarity; converting the first single-ended signal into a first output signal through a second serial transceiver, the first output signal fully represents the data flow in the first direction, and the first output signal is received from the second network port output; converting the second single-ended signal into a second output signal through a third serial transceiver, the second output signal fully represents the data flow in the first direction, and the second output signal is split from the first port output; converting the data flow in the second direction into a differential signal through a second serial transceiver, the differential signal includes a third single-ended signal and a fourth single-ended signal, and the third single-ended signal and the fourth single-ended signal The terminal signals have the same amplitude but opposite polarity; converting the third single-ended signal into a third output signal through the first serial transceiver, the third output signal fully represents the data stream in the second direction, and the third output signal is obtained from the first A network port output; converting the fourth single-ended signal into a fourth output signal through a fourth serial transceiver, the fourth output signal fully represents the data flow in the second direction, and the fourth output signal is split from the second port output. 8. the method for duplicating and obtaining data flow in network splitter as claimed in claim 7, is characterized in that, described four serial transceivers are pluggable SFP/SFP+ transceiver modules, and described four The two pluggable SFP/SFP+ transceiver modules work at the same rate, and the same rate matches the data flow. 9. The method for duplicating and obtaining data streams in a network splitter as claimed in claim 7, wherein the four serial transceivers are connected to each other in a passive shunt circuit mode, and the passive shunt circuit It is set to be able to support the network splitter to work at a rate of at least 10Gbps. 10. the method for duplicating and obtaining data flow in network splitter as claimed in claim 7, is characterized in that, described network splitter is the computer plug-in card of PCI Express bus, and the computer plug-in card of described PCI Express bus comprises A dual-port Ethernet network interface controller integrated circuit chip, the third serial transceiver and the fourth serial transceiver are located inside the dual-port Ethernet network interface controller integrated circuit chip, the first and the first Two serial transceivers are pluggable SFP/SFP+ Ethernet transceiver modules.