CN110505137B

CN110505137B - Function expansion type wired network device

Info

Publication number: CN110505137B
Application number: CN201810470616.3A
Authority: CN
Inventors: 吕国正
Original assignee: Realtek Semiconductor Corp
Current assignee: Realtek Semiconductor Corp
Priority date: 2018-05-16
Filing date: 2018-05-16
Publication date: 2021-12-07
Anticipated expiration: 2038-05-16
Also published as: CN110505137A

Abstract

The invention discloses a function expansion type wired network device, which can utilize an external circuit to execute the operation that an Ethernet device does not support/stops supporting. One embodiment of the wired network device includes an ethernet switch and a Field Programmable Gate Array (FPGA). The switch comprises a plurality of Ethernet ports including a designated port and a first port, receives a first packet from the first port, and modifies the first packet to output a second packet to the designated port when the first packet meets a predetermined condition. The FPGA receives the second packet from the designated port, and processes the second packet to output a third packet to the designated port according to a first modification made by the switch in the second packet. The switch receives the third packet from the designated port, and processes the third packet to output a fourth packet to one of the plurality of Ethernet ports according to a second modification made by the FPGA in the third packet.

Description

Function expansion type wired network device

Technical Field

The present invention relates to a network device, and more particularly, to a wired network device having an expansion function.

Background

In the field of communications, tunneling (tunnel) technology can encapsulate (encapsulate) an original packet conforming to one communication protocol into a tunnel packet conforming to another communication protocol (i.e., a tunnel protocol), or decapsulate (decapsulate) a tunnel packet to obtain data of an original packet, and thus tunneling technology can be used for data transmission between incompatible network devices or for providing a secure path in an unsecured network.

In recent years many new tunneling protocols have been proposed to accommodate different needs. If a conventional ethernet device receives a tunneling protocol packet that it does not support, it will typically forward the packet to an internal processor at a higher layer (e.g., application layer) in the ethernet device for processing, or forward the packet to an external processor outside the ethernet device via a non-ethernet interface (e.g., Peripheral Component Interconnect Express (PCIe) interface) for processing in conjunction with suitable hardware and software; however, the above method has a problem of low effective performance.

In addition, some ethernet devices can add a private header (private header) to a packet to carry information related to the tunneling protocol, and transmit the packet to a processing circuit capable of recognizing and processing the private header for processing.

Furthermore, some solutions have been proposed to allow a general ethernet device to utilize the header of an ethernet packet to carry tunneling protocol related information, however, since the function of a general ethernet device (e.g., a switch) is usually not scalable, the ethernet device lacks sufficient programmability to transmit the ethernet packet with tunneling protocol information to a processing circuit for processing, and the ethernet device cannot further process the packet processed by the processing circuit.

Disclosure of Invention

An objective of the present invention is to provide a function-extended wired network device (function-extended wired network device) for performing an operation that is not supported/stopped by an ethernet device by using an external circuit.

The invention discloses a function expansion type wired network device, one embodiment of which comprises an Ethernet device and an external circuit. The Ethernet device comprises a plurality of Ethernet ports, the Ethernet ports comprise a designated port and a first port, and the Ethernet device is used for receiving a first packet from the first port and modifying the first packet to output a second packet to the designated port when the first packet meets a first preset condition. The external circuit is coupled to the designated port, and is configured to receive the second packet from the designated port, and process the second packet to output a third packet to the designated port according to a first modification made by the ethernet device in the second packet, wherein the ethernet device is further configured to receive the third packet from the designated port, and process the third packet to output a fourth packet to one of the ethernet ports according to a second modification made by the external circuit in the third packet. In one embodiment, the external circuit decapsulates (decapsulates) the second packet (i.e., the tunnel packet) according to the first modification to generate the third packet; or the external circuit encapsulates (encapsulates) the second packet based on information of a specific Tunnel Protocol (specific Tunnel Protocol) according to the first modification to generate the third packet, wherein the ethernet device does not support/stop supporting the decapsulation operation and the encapsulation operation.

The features, operation and effects of the present invention will be described in detail with reference to the drawings as preferred embodiments.

Drawings

FIG. 1 illustrates an embodiment of a functionally expanded wired network device of the present invention;

FIG. 2 illustrates one embodiment of the Ethernet network device of FIG. 1; and

fig. 3 shows an embodiment of an application of the function expanding wired network device of the present invention.

Detailed Description

The invention discloses a function expansion type wired network device, which can utilize an external circuit to execute the operation that an Ethernet device does not support/stops supporting, thereby achieving the application flexibility.

Fig. 1 shows an embodiment of the function expanding wired network device of the present invention. In the embodiment, the functionally-extended wired network device 100 includes an ethernet device 110 and an external circuit 120. One embodiment of Ethernet device 110 is an Ethernet switch (Ethernet switch) that supports or does not support an open flow Protocol (Openflow Protocol), depending on the needs of the implementing inventors. One embodiment of the external circuit 120 is a Field-Programmable Gate Array (FPGA) or equivalent; however, the external circuit 120 may also be one of the following: a Central Processing Unit (CPU) or equivalent; a Network Processing Unit (NPU) or its equivalent; and an Application-Specific Integrated Circuit (ASIC) or an equivalent thereof. The ethernet device 110 may operate without the external circuit 120; however, the cooperative operation of the ethernet device 110 and the external circuit 120 may achieve a preferred processing performance in terms of specific functions (e.g., functions supporting a tunnel protocol) compared to the independent operation of the ethernet device 110.

Please refer to fig. 1. The ethernet device 110 includes four ethernet ports P0, P1, P2 and P3, which include a designated port P0 and a first port P1, through which the ethernet device 110 receives and transmits packets via the transmission line 10. In one embodiment, the ethernet device 110 receives a first packet from the first port P1, modifies the header of the first packet to generate a second packet to be directed (directed to) the external circuit 120 when the first packet meets a first predetermined condition (or when the first packet carries specific information corresponding to pre-stored information of the ethernet device 100), and then the ethernet device 110 outputs the second packet to the external circuit 120 through the designated port P0; when the first packet does not meet the first predetermined condition, the ethernet device 110 modifies the header of the first packet to generate the second packet to be directed to another network device (e.g., another ethernet switch), and outputs the second packet to the another network device through one of the other ethernet ports P1, P2, and P3. One embodiment of the first predetermined condition includes one of a first condition and a second condition, the first condition requiring that the first packet is a Tunnel packet (e.g., a GPRS Tunnel Protocol (GTP) Tunnel packet), and when the first packet meets the first condition (the second packet is also a Tunnel packet), the external circuit 120 decapsulates the second packet; the second condition requires that the first packet is a native Ethernet packet (i.e., an Ethernet packet without tunneling encapsulation), and that the native Ethernet packet is a packet requiring tunneling encapsulation (i.e., encapsulation conforming to a specific tunneling protocol described below), and when the first packet meets the second condition (i.e., the second packet is an Ethernet packet requiring tunneling encapsulation), the external circuit 120 encapsulates the second packet according to information of a specific tunneling protocol (e.g., GTP or a known/self-developed tunneling protocol). It is noted that, in another embodiment, the ethernet device 110 includes one or more other designated ports (which function as the designated port P0), which may be selected from the ethernet ports P2 and P3 or from other ethernet ports (not shown in fig. 1) included in the ethernet device 110.

As mentioned earlier, the ethernet device 110 may determine whether the content of a/some fields (e.g., a Data Link Layer field and/or a Network Layer field) of the header of the first packet matches one of the first condition and the second condition by using a known table lookup method or other known methods, such as a comparison procedure, and an example of the content of the/these fields is at least one of the following information: a Destination Media Access Control Address (DMAC); a Source Media Access Control Address (SMAC); destination Internet Protocol Address (DIP); a Source Internet Protocol Address (SIP); a destination port (destination port) of a User Datagram Protocol (UDP); and Bearer (Bearer). For example, the ethernet device 110 is a switch supporting an open flow protocol (OpenFlow), and is configured by a user to execute a multi-channel determination procedure, as shown in tables 1 to 5(Table _1 to Table _5) of fig. 2, where tables 1 to 5 are as follows:

(1) table 1 represents that the ethernet device 110 determines whether the DMAC of the first packet is the MAC of the ethernet device 110 (i.e. the flag "Key: DMAC" in Table 1), if the determination result in Table 1 is yes, the ethernet device 110 executes the determination procedure in Table 2 (i.e. the flag "Hit: Goto Table _ 2" in Table 1), and if the determination result in Table 1 is no, the ethernet device 110 discards the first packet (i.e. the flag "Miss: Drop" in Table 1);

(2) table 2 represents that the ethernet device 110 determines whether the first packet is a tunnel packet according to at least one of the destination ports of the DIP, SIP and UDP of the first packet (i.e. the flag "Key: DIP, SIP, UDP _ DP" in Table 2), if the determination result in Table 2 is yes, the ethernet device 110 sets a parameter NHOP _ IDX, and executes the determination procedure in Table 5 (i.e. the flag "Hit: Set NHOP _ IDX; Go to Table 5" in Table 2), if the determination result in Table 2 is no, the ethernet device 110 executes the determination procedure in Table 3 (i.e. the flag "Miss: Go to Table 3" in Table 2);

(3) table 3 represents that the ethernet device 110 determines whether the first packet needs to be tunneled according to the SMAC of the first packet (i.e. the flag "Key: SMAC" in Table 3), if the determination result in Table 3 is yes, the ethernet device 110 sets a parameter BEARER and executes the determination procedure in Table 4 (i.e. the flag "Hit: Set BEARER; Go to Table _ 4" in Table 3), if the determination result in Table 1 is no, the ethernet device 110 sets the parameter BEARER to 0 and executes the determination procedure in Table 4 (i.e. the flag "Miss: Set BEARER ═ 0; Go to Table _ 4" in Table 3);

(4) table 4 represents that the ethernet device 110 determines how to forward the first packet according to at least one of the Bearer and the DIP of the first packet (i.e. the flag "Key: Bearer, DIP" in Table 4), if the determination result in Table 4 is the first determination result, the ethernet device 110 sets the parameter NHOP _ IDX and performs the determination procedure in Table 5 (i.e. the flag "Hit: Set NHOP _ IDX; Go to Table 5" in Table 4), if the determination result in Table 4 is the second determination result, the ethernet device 110 sets the parameter NHOP _ IDX and performs the determination procedure in Table 5 (i.e. the flag "Miss: Set NHOP _ IDX; Go to Table 5" in Table 4), wherein the setting of the parameter NHOP _ IDX of the first determination result is different from the setting of the parameter NHOP _ IDX of the second determination result; and

(5) table 5 represents that the ethernet device 110 refers to the parameter NHOP _ IDX (i.e. the flag "Key: NHOP _ IDX" in table 5) to Set at least one of DMAC, SMAC, output port, and Time To Live (TTL) of the first packet in decreasing order (i.e. the flag "Hit: Set DMAC/SMAC, output port, TTL-1" in table 5) when the parameter NHOP _ IDX matches one of a plurality of pre-stored parameter values, or to discard the first packet (i.e. the flag "Miss: Drop" in table 5) when the parameter NHOP _ IDX does not match the pre-stored parameter values.

Please refer to fig. 1. In one embodiment, the external circuit 120 is coupled to the designated port P0 for receiving the second packet, and processes the second packet to output a third packet to the designated port P0 according to a first modification made by the ethernet device 110 in the second packet, wherein the ethernet device 110 further receives the third packet from the designated port P0 and processes the third packet to output a fourth packet to one of the ethernet ports P0-P3 according to a second modification made by the external circuit 120 in the third packet. In one embodiment, the first modification includes a modification of the DMAC and/or SMAC of the first packet, such that the external circuit 120 may perform one of a decapsulation (decapsulation) operation or an encapsulation (encapsulation) operation according to a value of the DMAC and/or SMAC; more specifically, when the first packet satisfies the first condition (when the first packet is a Tunnel packet), the first modification causes the DMAC of the second packet to be a first value, and when the first packet satisfies the second condition (when the first packet is a native ethernet packet requiring Tunnel encapsulation), the first modification causes the DMAC of the second packet to be a second value, so that the external circuit 120 may decapsulate the second packet to generate the third packet when the DMAC of the second packet is the first value, and the external circuit 120 may encapsulate the second packet to generate the third packet based on the information of the specific Tunnel protocol (e.g., a table of GTP and a Tunnel Endpoint Identifier (TEID)) when the DMAC of the second packet is the second value. In one embodiment, the second modification includes a modification of the DMAC of the second packet (e.g., the DAMC is modified to the MAC of the Ethernet device 110) and a modification of the SMAC of the second packet (e.g., when the external circuit 120 encapsulates the second packet to generate the third packet, the SMAC is modified to carry tunnel protocol compliant information such as TEID), so that the Ethernet device 110 may receive the third packet for subsequent processing according to the value of the DMAC and modify the third packet to transmit the fourth packet to another network device (e.g., another Ethernet switch) according to the value of the SMAC, or transmit the fourth packet to the external circuit 120 for the encapsulation (in which case, the external circuit 120 previously decapsulates the second packet to generate the third packet). In one embodiment, the ethernet device 110 does not support/stop supporting the specific tunneling protocol (or the ethernet device 110 cannot process packets of the specific tunneling protocol without passing through the CPU/NPU), so the functionally-extended wired network device 100 is supported by the external circuit 120.

As mentioned above, the ethernet device 110 may determine whether the third packet meets a second predetermined condition to determine to transmit the fourth packet to the another network device or transmit the fourth packet to the external circuit 120. In detail, if the third packet meets the second predetermined condition, the ethernet device 110 modifies the third packet to output the fourth packet to the designated port P0, thereby allowing the external circuit 120 to receive and process the fourth packet; if the third packet does not satisfy the second predetermined condition, the ethernet device 110 modifies the third packet to output the fourth packet to one of the ethernet ports P1, P2, P3 other than the designated port P0, thereby forwarding the fourth packet to the other network device. In one embodiment, the second predetermined condition is similar to the second condition; in detail, the second predetermined condition requires that the third packet is an ethernet packet and that the ethernet packet is a packet requiring tunnel encapsulation (i.e. encapsulation conforming to the specific tunnel protocol). In one embodiment, when the third packet meets the second predetermined condition, the external circuit 120 processes the fourth packet according to a third modification made by the ethernet device 110 in the fourth packet to output a fifth packet to the designated port P0; thereafter, the ethernet device 110 receives the fifth packet from the designated port P0, and processes the fifth packet to output a sixth packet to one of the ethernet ports P1, P2, and P3 other than the designated port P0 according to a fourth modification made by the external circuit 120 in the fifth packet. In one embodiment, the third modification is similar to the first modification and includes a modification of the DMAC and/or SMAC of the third packet, and the fourth modification is similar to the second modification and includes a modification of the DMAC and SMAC of the fourth packet. In one embodiment, the external circuit 120 encapsulates the fourth packet according to the specific tunneling protocol to output the fifth packet to the designated port P0.

Please refer to fig. 1. Whether the first packet is a new tunnel packet (whose payload includes an ethernet header) or a native ethernet packet, the embodiment of fig. 1 can also be practiced without modifying the ethernet header of the first packet. In one embodiment, the ethernet device 110 supports a legacy tunneling Protocol (legacy tunneling Protocol), and therefore, the ethernet device 110 and the external circuit 120 utilize a legacy tunneling header (legacy tunneling header) conforming to the legacy tunneling Protocol to carry information of the tunneling Protocol that the ethernet device 110 does not support/stop supporting; in detail, when the first packet is a tunnel packet conforming to the legacy tunneling protocol, the ethernet device 110 modifies an existing (legacy) legacy tunnel header of the first packet (when the existing legacy tunnel header is used as the header of the second packet) or combines a new legacy tunnel header with the first packet (when the new legacy tunnel header is used as the header of the second packet) to generate the second packet; when the first packet is a native ethernet packet or a new tunneling packet does not conform to the legacy tunneling protocol, the ethernet device 110 combines a legacy tunneling header with the first packet to generate the second packet. In one embodiment, when the first packet does not include a legacy tunnel header, the first modification includes a combination of the legacy tunnel header and the first packet as the second packet, so that the external circuit 120 processes the second packet according to information carried by the legacy tunnel header to output the third packet to the designated port P0. In one embodiment, when the first packet includes an existing legacy tunnel header, the first modification includes a modification to the existing legacy tunnel header (e.g., a modification to the DMAC/SMAC of the existing legacy tunnel header or a modification to an unused field of the existing legacy tunnel header), such that the external circuit 120 processes the second packet according to information carried by the existing legacy tunnel header to output the third packet to the designated port P0. In one embodiment, when the first packet includes an existing legacy tunnel header, the first modification includes combining a new legacy tunnel header with the first packet to generate the second packet, such that the existing legacy tunnel header is not modified, and the external circuit 120 processes the second packet to output the third packet to the designated port P0 according to information carried by the new legacy tunnel header. In one embodiment, the second modification includes a modification of a legacy tunnel header (e.g., a modification of DMAC/SMAC of the legacy tunnel header) in the second packet, so that the ethernet device 110 modifies the third packet to output the fourth packet according to information carried by the legacy tunnel header. In summary, the embodiment of fig. 1 can utilize the old tunnel header to carry information required for subsequent processing (e.g., tunneling packets and decapsulating tunneled packets), and optionally avoid modifying the original header of the first packet.

Please refer to fig. 1. In one embodiment, at least one of the ethernet ports P0, P1, P2, and P3 is configured as at least one Link Aggregation (LAG) port including the designated port P0, the ethernet device 110 and the external circuit 120 form a bandwidth Aggregation connection via the at least one LAG port, wherein the bandwidth Aggregation connection complies with an IEEE 802.3ad standard specification, and a transmission rate of the bandwidth Aggregation connection is not less than 100 megabits per second (10 gigabits/s). In one embodiment, the transmission through the ethernet ports P0, P1, P2, and P3 is full-duplex (full-duplex) transmission. In one embodiment, as shown in fig. 3, the functional expansion wired network device 100 can be used as a Serving Gateway-User Plane (SGW-U) 312 of a User layer of a mobile core network (mobile core network) 310; the functionally-extended wired network device 100 can also be used as the SGW-U322 of the mobile network edge computing architecture 320, in which case the functionally-extended wired network device 100 is disposed between any two of: an evolved node b (enb)330 of Long Term Evolution (LTE) for communicating with the ue 340; a local server (local server)324 connected to the SGW-U322; and a packet data network Gateway (PDN Gateway-User Plane (PGW-U))314 at the User Plane, which is connected to the SGW-U312 and an internet 350. It is noted that the mobile core network 310 and the mobile edge computing architecture 320 may include other hardware and/or other connections as required, which are well known in the art and the related descriptions are omitted herein.

Although the modification of the packet header (e.g., the first modification, the second modification, the third modification, and the fourth modification) is mostly a modification of DMAC and/or SMAC, the present invention is not limited thereto, and other fields (e.g., ethertype (ETHER TYPE), virtual local area network TAG (VLAN TAG)) of the data link layer and/or the network layer may be modified to carry specific information (e.g., tunneling related information) for the ethernet device 110 and/or the external circuit 120 to recognize and take appropriate actions. It is noted that modifying the header of a packet is well known in the art, tunneling a packet and decapsulating a tunneled packet, and therefore the description of the prior art is omitted herein without affecting the understanding of those skilled in the art and practicing the present invention. It is to be noted that, when the implementation is possible, a person skilled in the art can selectively implement part or all of the technical features of any one of the foregoing embodiments/implementations, or selectively implement a combination of part or all of the technical features of the foregoing embodiments/implementations, thereby increasing the flexibility in implementing the invention.

In summary, the function-expanding wired network device of the present invention can utilize an external circuit to perform operations that an ethernet device does not support/stop supporting, thereby achieving application flexibility.

Although the embodiments of the present invention have been described above, these embodiments are not intended to limit the present invention, and those skilled in the art can make variations on the technical features of the present invention according to the explicit or implicit contents of the present invention, and all such variations may fall within the scope of the patent protection sought by the present invention.

Description of the symbols

10 transmission line

100 function expansion type wired network device

110 Ethernet network device

120 external circuit

Designated one of the P0 Ethernet ports

First port of P1 Ethernet network ports

P2, P3 Ethernet port

Judging program of Table _ 1-Table _5 Ethernet device

310 mobile core network

312. 322 SGW-U (service gateway of user layer)

314 PGW-U (packet data network gateway of user layer)

320 mobile network edge computing architecture

324 local server

330 evolved node B of long term evolution technology

340 client

350 the internet.

Claims

1. A function expanding wired network device, comprising:

an Ethernet device, comprising a plurality of Ethernet ports, wherein the plurality of Ethernet ports comprise a designated port and a first port, the Ethernet device is used for receiving a first packet from the first port and executing a first modification on the first packet to output a second packet to the designated port when the first packet meets a first predetermined condition, wherein the first predetermined condition comprises one of a first condition and a second condition; the first condition requires that the first packet is a tunnel packet; the second condition requires that the first packet is a native ethernet packet requiring tunneling; and

an external circuit, coupled to the designated port, for receiving the second packet and configured to:

when the first packet meets the first condition, the external circuit performs a second modification on the second packet according to the result of the first modification to decapsulate the second packet to generate and output a third packet, or

When the first packet meets the second condition, the external circuit performs the second modification to the second packet based on a specific tunneling protocol information according to the first modification result to encapsulate the second packet to generate and output the third packet,

wherein the Ethernet device processes the third packet to output a fourth packet to one of the Ethernet ports according to the second modification result after receiving the third packet,

wherein the first modification comprises at least one of the following modifications: modifying a destination mac address of the first packet; and a source MAC address of the first packet, and

the second modification comprises the following modifications: modifying a destination mac address of the second packet; and a modification to a source MAC address of the second packet.

2. The functionally expanded wired network device of claim 1, wherein the first modification comprises making a destination mac address of the second packet a first value when the first packet meets the first condition; and when the first packet meets the second condition, the first modification comprises making the destination MAC address of the second packet a second value.

3. The functionally expanded wired network device according to claim 1, wherein if the third packet meets a second predetermined condition, the ethernet device performs a third modification on the third packet to output the fourth packet to the designated port; and if the third packet does not meet the second predetermined condition, the Ethernet device modifies the third packet to output the fourth packet to one of the Ethernet ports,

wherein the second predetermined condition requires that the third packet is an ethernet packet requiring tunneling encapsulation.

4. The functionally expanded wired network device of claim 3, wherein the external circuit is configured to receive the fourth packet from the designated port when the third packet meets the second predetermined condition, and perform a fourth modification on the fourth packet to output a fifth packet according to the result of the third modification, the ethernet device is further configured to receive the fifth packet, and process the fifth packet to output a sixth packet to one of the ethernet ports according to the result of the fourth modification.

5. The functionally-extended wired network device of claim 1, wherein the ethernet network device supports a legacy tunneling protocol, and encapsulates the first packet according to the legacy tunneling protocol to generate the second packet; when the first packet does not include an existing legacy tunnel header, the first modification includes a combination of a legacy tunnel header and the first packet as the second packet, so that the external circuit processes the second packet according to the legacy tunnel header to output the third packet; and when the first packet includes the existing legacy tunnel header, the first modification includes a modification of the existing legacy tunnel header or includes a combination of a new legacy tunnel header and the first packet, such that the external circuitry processes the second packet to output the third packet according to the existing legacy tunnel header or the new legacy tunnel header.

6. The functionally-extended wired network device of claim 5, wherein the second modification comprises a modification of the legacy tunnel header of the second packet.