CN112887921B

CN112887921B - Method and equipment for reducing packet loss during switching of WAPI CPE (wireless local area network interface) equipment between APs (access points)

Info

Publication number: CN112887921B
Application number: CN202110091748.7A
Authority: CN
Inventors: 刘高锦
Original assignee: Shenzhen Zhikai Technology Co ltd
Current assignee: Shenzhen Zhikai Technology Co ltd
Priority date: 2021-01-23
Filing date: 2021-01-23
Publication date: 2022-02-01
Anticipated expiration: 2041-01-23
Also published as: CN112887921A

Abstract

The invention discloses a method and equipment for reducing packet loss when WAPI CPE equipment is switched among APs, wherein the method comprises the steps of the WAPI CPE equipment based on a wireless network; the WAPI CPE equipment is provided with two wireless radio frequency interfaces A and B, and initially the WAPI CPE equipment is simultaneously connected with a first AP to establish a first main wireless connection M and a first standby wireless connection S and transmits wireless flow by using the first main wireless connection M; when the wireless connection is switched to a second AP in the moving process by the WAPI CPE, the following traffic protection method is implemented: the CPE switches the uplink wireless flow to a first standby wireless connection; the CPE disconnects the first main wireless link, and then a second main wireless link is established with a second AP by using a radio frequency interface A; switching CPE uplink flow to a second main wireless link; disconnecting the first standby wireless link and establishing a second standby wireless link with a second AP by using the radio frequency interface B; the invention can effectively reduce the flow packet loss when the WAPI CPE equipment performs AP switching, and achieves the level that the time of the relevant flow packet loss is lower than 50 milliseconds.

Description

Method and equipment for reducing packet loss during switching of WAPI CPE (wireless local area network interface) equipment between APs (access points)

Technical Field

The invention relates to a WAPI wireless network technology, in particular to a method and equipment for reducing packet loss when WAPI CPE equipment is switched among APs.

Background

With the wide development of the application of the internet of things, the broadband internet of things based on the WLAN technology is also increasingly applied, and particularly, the WLAN network based on the WAPI technology is increasingly applied in some fields such as industrial fields, key infrastructures, and the like, because the identity of a Wireless Access Point (AP) and a Wireless terminal (STA) is identified by adopting a certificate, and the identity Authentication of the AP and the STA is performed based on a ternary Authentication system, so that the security of the Wireless access Authentication is ensured. Among these wireless networks, the application of a WAPI Customer Premise Equipment (WAPI CPE) device, which is a WAPI CPE device, as a terminal device of a wireless network in scenes such as industrial fields and key infrastructures is increasing, and especially in recent years, the application of robot inspection based on wireless networking is increasing;

the WAPI CPE can generate 700-3000 ms packet loss when switching among APs, which affects some key applications, for example, in the inspection application of an intelligent substation robot, video blocking is caused by overlong packet loss time to further affect video observation, and particularly affect services such as equipment state analysis based on video data analysis.

Disclosure of Invention

The reason why the packet loss time is too long when the WAPI wireless terminal equipment CPE is switched among the APs includes:

when the wireless terminal is switched between the APs, the currently connected AP is disconnected, then a new AP is associated, and the link layer authentication is carried out, wherein the link layer authentication is not carried out on the WAPI wireless network based on an OPEN authentication mode, but the link layer authentication between the wireless terminal and the AP is still not reduced. This process takes a certain amount of time.

The wireless terminal also needs to perform wireless access authentication when switching among the APs, and a certain time is consumed in the process of accessing the authentication based on the WAPI, which involves multiple interactions among the wireless terminal, the APs and the authentication server. This time cost can be saved by fast roaming if the AP and the WAPI CPE device support pre-authentication. However, in the WAPI certificate authentication method, even though the AP supports the WAPI pre-authentication and can perform fast roaming, if the CPE and the AP to be connected do not perform the first ternary authentication, there is no BKID, i.e., the base key ID, shared between the terminal and the AP to be connected, and thus the WAPI terminal cannot perform fast roaming with the AP.

It also takes a certain time to perform password negotiation between the wireless terminal and the AP.

There is currently no method or apparatus for reducing the packet loss time of a WAPI wireless terminal when it switches from a currently connected AP to another neighboring AP, or to reduce this packet loss time to less than 50 milliseconds.

The technical problem to be solved by the invention is to provide a method and equipment for reducing packet loss when WAPI CPE equipment is switched between APs; the WAPI CPE equipment is provided with two wireless radio frequency hardware, two wireless connections can be established with an AP of a wireless network at the same time, one of the wireless links is selected as a main wireless link, the other wireless link is selected as a standby wireless link, the traffic packet loss of the WAPI CPE equipment during AP switching in the WAPI wireless network can be effectively reduced, the level that the time of the relevant traffic packet loss is lower than 50 milliseconds is achieved, and the level can be reduced to 20-30 milliseconds from the practical test.

The invention reduces the equipment lost packet when the WAPI CPE equipment is switched among APs, and is realized by the following technical proposal: comprises a wireless network based WAPI CPE device; a first AP, a second AP, a first terminal and a second terminal are arranged in the wireless network; a wireless radio frequency interface A and a wireless radio frequency interface B are arranged in the WAPI CPE equipment; the wireless radio frequency interface A and the wireless radio frequency interface B are connected with a first AP to form a first main wireless link M and a first standby wireless link S; the wireless network transmits the flow through a first main wireless link M;

the first terminal and the second terminal are connected with WAPI CPE equipment; a GW gateway is connected between the first AP and the second AP.

The method for reducing the packet loss of the WAPI CPE equipment during the switching between the APs is realized by the following technical scheme: the first step is as follows: the WAPI CPE equipment switches the uplink flow to a first standby wireless link S, then reads a terminal IP-MAC table in the WAPI CPE equipment to obtain an IP address of a terminal connected with the WAPI CPE equipment, broadcasts a free ARP announcement through the first standby wireless link S aiming at each terminal IP address, and guides the downlink flow from a wireless network to the CPE to be quickly switched to the first standby wireless link S, wherein a sender MAC of the free ARP is the MAC address of a radio frequency B, and the sender IP address is the IP address of the terminal.

The second step is that: the WAPI CPE device disconnects a first main wireless link M connected with a first AP; a second active wireless link M is then established with the second AP.

The third step: the WAPI CPE switches the uplink flow to a second main wireless link M, then reads a terminal IP-MAC table in WAPI CPE equipment to obtain the IP address of a terminal connected with the CPE, broadcasts a free ARP announcement through the second main wireless link M aiming at each terminal IP address, and guides the downlink flow from the wireless network to the CPE to be quickly switched to the second wireless connection M, wherein the MAC of a sender of the free ARP is the MAC address of the radio frequency A, and the IP address of the sender is the IP address of the terminal.

The fourth step: the WAPI CPE device disconnects a first standby wireless link S connected with the first AP and establishes a second standby wireless link S with the second AP.

The invention has the beneficial effects that: the WAPI CPE equipment is designed to be provided with two wireless radio frequency hardware, namely a radio frequency interface A and a radio frequency interface B, and can establish two wireless connections with a first AP of a wireless network at the same time, one of the wireless radio frequency hardware is selected as a main wireless link, the other wireless radio frequency hardware is selected as a standby wireless link, namely the WAPI CPE equipment firstly switches uplink wireless flow to the first standby wireless link before switching the AP, and broadcasts free ARP aiming at all terminals connected with the WAPI CPE to the wireless network through the standby wireless link, wherein the MAC address of a sender of the free ARP is the MAC address of the radio frequency interface related to the standby wireless link of the WAPI CPE equipment, and the IP of the sender is the IP address of the terminal connected with the CPE, so that the downlink flow from the wireless network to the WAPI CPE equipment is guided to be quickly switched to the standby wireless link. After establishing a new wireless connection between the WAPI CPE equipment and the AP to be switched and accessed, switching the flow to the new wireless connection by adopting the same method, then establishing a backup wireless link between the WAPI CPE equipment and the newly accessed AP, and effectively reducing the flow packet loss of the WAPI CPE equipment when the AP is switched in the WAPI wireless network, wherein the time of the relevant flow packet loss is lower than the level of 50 milliseconds, and the level can be reduced to 20-30 milliseconds from the actual test.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic diagram illustrating the operation steps of a method for reducing packet loss in the handoff of the WAPI CPE device between APs according to the present invention;

fig. 2 is a schematic diagram of device connection for reducing packet loss when the WAPI CPE device switches between APs based on the WAPI wireless network.

Detailed Description

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.

Any feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

In the description of the present invention, it is to be understood that the terms "one end", "the other end", "outside", "upper", "inside", "horizontal", "coaxial", "central", "end", "length", "outer end", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the present invention.

Further, in the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

The use of terms such as "upper," "above," "lower," "below," and the like in describing relative spatial positions herein is for the purpose of facilitating description to describe one element or feature's relationship to another element or feature as illustrated in the figures. The spatially relative positional terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In the present invention, unless otherwise explicitly specified or limited, the terms "disposed," "sleeved," "connected," "penetrating," "plugged," and the like are to be construed broadly, e.g., as a fixed connection, a detachable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

As shown in fig. 2, an apparatus for reducing packet loss when a WAPI CPE device switches between APs according to the present invention includes a wireless network-based WAPI CPE device; a first AP221, a second AP222, a first terminal and a second terminal are arranged in a wireless network; a wireless radio frequency interface A211 and a wireless radio frequency interface B212 are arranged in the WAPI CPE equipment; the radio frequency interface a211 and the radio frequency interface B212 are connected to the first AP221 to form a first active radio link M241 and a first standby radio link S242; the wireless network transmits traffic through a first primary wireless link M241;

the first terminal and the second terminal are connected with WAPI CPE equipment; a GW gateway 260 is connected between the first AP221 and the second AP 222.

As shown in fig. 1, in an initial state 100, a first active wireless link M241 and a first standby wireless link S242 are established between the WAPI CPE and a first AP221, and the first active wireless link M241 is used as transmission wireless traffic. The operation steps when the WAPI CPE210 device needs to switch the wireless connection and wireless traffic to the second AP222 during mobility are as follows

The first step is as follows: the WAPI CPE210 switches the uplink flow to the first standby wireless link S242, then reads a terminal IP-MAC table in the CPE to obtain the IP address of a terminal connected with the CPE, broadcasts a gratuitous ARP announcement through the first standby wireless link S242 aiming at each terminal IP address, and guides the downlink flow from the wireless network to the WAPI CPE210 equipment to be quickly switched to the first standby wireless link S242, wherein the sender MAC of the ARP announcement is the MAC address MAC _ B of the radio frequency interface B212, and the sender IP address is the IP address of the terminal. Referring to fig. two, the WAPI CPE device will send two gratuitous ARP announcements, one of which is MAC _ b for sender, IP address of sender is IP1, and the other of which is MAC _ b for sender, IP address of sender is IP 2; the gateway GW260 of the wireless network will receive the two ARP advertisements, and the gateway GW260 will update the ARP table entries of the first terminal 231 and the second terminal 232 to IP1-MAC _ b and IP2-MAC _ b. As such, downstream traffic from the wireless network to the WAPI CPE device 210 is sent to the radio interface B212 of the WAPI CPE device.

The second step is that: the WAPI CPE device disconnects a first active wireless link M241 connected with the first AP 221; a second active wireless link M251 is then established with the second AP 222.

The third step: the WAPI CPE210 switches the uplink flow to the second main wireless link S251, then reads a terminal IP-MAC table in the CPE to obtain the IP address of a terminal connected with the CPE, broadcasts a free ARP announcement through the second main wireless link S251 aiming at each terminal IP address, and guides the downlink flow from the wireless network to the WAPI CPE210 equipment to be quickly switched to the second main wireless link S251, wherein the sender MAC of the ARP announcement is the MAC address MAC _ a of the radio frequency interface A211, and the sender IP address is the IP address of the terminal. Referring to fig. two, the WAPI CPE device will send two gratuitous ARP announcements, one of which is MAC _ a for sender, IP address of sender is IP1, and the other of which is MAC _ a for sender, IP address of sender is IP 2; the gateway GW260 of the wireless network will receive the two ARP advertisements, and the gateway GW260 will update the ARP table entries of the first terminal 231 and the second terminal 232 to IP1-MAC _ a and IP2-MAC _ a. As such, downstream traffic from the wireless network to the WAPI CPE device 210 is sent to the radio interface a211 of the WAPI CPE device. .

The fourth step: the WAPI CPE device disconnects the first standby wireless link S242 with the first AP221 and establishes a second standby wireless link S252 with the second AP 222.

In this embodiment, there are a first AP221 and a second AP222 in the wireless network to which the WAPI CPE device 210 is connected, and certainly there may be more AP devices; the first terminal 231 and the second terminal 232 are connected to the WAPI CPE device 210, although more terminal devices or only one terminal may be connected.

In this embodiment, the two radio frequency interfaces a211 and B212 on the CPE may be two radio frequencies of the same type or different types, such as two 2.4G radio frequencies, two 5.8G radio frequencies, or one 2.4G radio frequency and one 5.8G radio frequency, or other radio frequency types and combinations, but do not affect the method and the effect of the method and the device for reducing packet loss when the wap CPE device is switched between APs.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that are not thought of through the inventive work should be included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope defined by the claims.

Claims

1. An apparatus for reducing packet loss in a WAPI CPE device (210) during inter-AP handoff, comprising: comprises a wireless network based WAPI CPE device (210); the wireless network is provided with a first AP (221), a second AP (222), a first terminal and a second terminal; a wireless radio frequency interface A (211) and a wireless radio frequency interface B (212) are arranged in the WAPI CPE equipment (210); the radio frequency interface A (211) and the radio frequency interface B (212) are connected with a first AP (221) to form a first active radio link M (241) and a first standby radio link S (242); the wireless network transmitting traffic over a first primary wireless link M (241);

the first terminal and the second terminal are connected with WAPI CPE equipment (210); a GW gateway (260) is connected between the first AP (221) and the second AP (222);

a method for reducing packet loss in a handoff between APs in a WAPI CPE device (210), comprising the steps of:

the first step is as follows: the method comprises the steps that the WAPI CPE equipment (210) switches uplink flow to a first standby wireless link S (242), then a terminal IP-MAC table in the WAPI CPE equipment (210) is read to obtain an IP address of a terminal connected with the WAPI CPE equipment (210), a gratuitous ARP notification is broadcasted through the first standby wireless link S (242) aiming at each terminal IP address, the downlink flow from a wireless network to the CPE is guided to be quickly switched to the first standby wireless connection S, wherein a sender MAC of the gratuitous ARP is the MAC address of a radio frequency B, and the sender IP address is the IP address of the terminal;

the second step is that: the WAPI CPE equipment (210) disconnects a first active wireless link M (241) connected with a first AP (221); then a second active wireless link M (251) is established with a second AP (222);

the third step: the WAPI CPE switches the uplink flow to a second main wireless link M (251), then reads a terminal IP-MAC table in WAPI CPE equipment (210) to obtain the IP address of a terminal connected with the CPE, broadcasts a free ARP announcement through the second main wireless link M (251) aiming at each terminal IP address, and guides the downlink flow from the wireless network to the CPE to be quickly switched to the second main wireless link M (251), wherein the MAC of a sender of the free ARP is the MAC address of radio frequency A, and the IP address of the sender is the IP address of the terminal;

the fourth step: the WAPI CPE device (210) disconnects a first standby wireless link S (242) with a first AP (221) and establishes a second standby wireless link S (252) with a second AP (222).