WO2016004868A1

WO2016004868A1 - Packet processing

Info

Publication number: WO2016004868A1
Application number: PCT/CN2015/083538
Authority: WO
Inventors: Jiajia FU
Original assignee: Hangzhou H3C Technologies Co Ltd
Current assignee: Hangzhou H3C Technologies Co Ltd
Priority date: 2014-07-09
Filing date: 2015-07-08
Publication date: 2016-01-14
Anticipated expiration: 2017-01-09
Also published as: CN105338660B; CN105338660A

Abstract

An access controller (AC) allocates buffer queues for buffering downlink messages to access points (APs) in an AP group. Then the AC receives a query packet for querying the buffered downlink messages in the buffer queues corresponding to the APs in the AP group sent from an intermediate AP in the AP group. When the AC determines that a buffer queue corresponding to an AP has a buffered downlink message, the AC sends a prompt message to the intermediate AP to trigger the intermediate AP notifying the AP group. The AC receives a query packet for querying the buffered downlink message in the buffer queue sent from the AP corresponding to the buffer queue; and sends the buffered downlink message in the buffer queue to the AP.

Description

Packet Processing

Background

When an access controller (AC) communicates with access points (APs) over Internet, controlling and provisioning of wireless access point (CAPWAP) messages generated during the communications generally cannot pass through various kinds of firewalls on the Internet, while hypertext transfer protocol (HTTP) packets generally are not filtered out by firewalls. Therefore, CAPWAP over HTTP is a natural choice for communication between ACs and APs. Generally, an AC has a public network address, and therefore serves as a HTTP server； and APs are located in an intranet, and therefore act as HTTP clients.

Brief Description of Drawings

FIG. 1 is a schematic diagram of a packet processing method of an AC according to examples of the present disclosure；

FIG. 2A is a schematic diagram of a packet processing method of an AP according to examples of the present disclosure；

FIG. 2B is a schematic diagram of a packet processing method of an AP according to examples of the present disclosure；

FIG. 3 is a schematic diagram of CAPWAP over HTTP network networking according to examples of the present disclosure；

FIG. 4 is a schematic diagram of hardware structure of an AC including a packet processing apparatus according to examples of the present disclosure； and

FIG. 5 is a schematic diagram of hardware structure of an AP including a packet processing apparatus according to examples of the present disclosure.

Detailed Description

Generally, when CAPWAP Over HTTP is used for communications between an access controller (AC) which serves as a server and access points (APs) which serve as clients, a HTTP mechanism is that the server does not send packets to a client actively, but after the client launches a query to the server, the server sends a response to the client.

In traditional implementations, an AC establishes two HTTP connections, i.e., an uplink connection and a downlink connection, with each AP. The downlink connection adopts a long-poll mechanism, in which after the AC receives a HTTP query packet from an AP, the AC waits and does not send a HTTP response to the AP until there is a downlink message for the AP, and each time when an AP receives a response packet from the AC, the AP pushes an empty query packet to the AC so as to maintain a long-poll status； and the uplink connection receives and sends HTTP messages in a normal way.

A packet processing method is provided according to examples of the present disclosure, in which first an AC sends a prompt message to an intermediate AP in an AP group, and then the intermediate AP distributes the prompt message over the AP group. In this way, in a CAPWAP over HTTP network, the AC is able to push messages to APs actively, which reduces the number of HTTP connections and number of messages, and thus reduces occupancy of internet bandwidth.

The AC may configure the AP group locally and record information about each AP in the AP group, such as an identity (e.g., an ID or a name) , and/or an address (e.g., an IP address and/or a MAC address) of each AP. When the AC is to communicate with APs in multiple AP groups, the AC assigns a global unique identifier for each AP group to distinguish the AP groups. In specific implementations, which APs belong to a same AP group is determined according to actual needs. For example, APs in a same local area network are divided into an AP group.

The AC may allocate a buffer queue for each AP in the AP group to buffer downlink messages, i.e., APs and buffer queues being one-to-one correspondence. For example, an ID or a name of each AP maps to a buffer queue.

The AC may establish a long-connection-no-poll HTTP connection with each AP (including the intermediate AP) in the AP group for the AC to receive a query packet for querying a downlink message in a buffer queue corresponding to an AP from the AP and push a downlink message to the AP.

The AC may establish a long-connection-long-poll HTTP connection with the intermediate AP in the AP group to receive a query packet for querying all the buffer queues of the APs in the AP group from the intermediate AP and send a prompt message to the intermediate AP.

The long-connection refers that after a connection is established between the AC and an AP, the connection holds and does not exit or is re-established until a related server program on the AC or client program on the AP exits or breaks down.

The long-poll refers that the intermediate AP sends a query request for querying all the buffer queues of the APs in the AP group to the AC, and after the AC receives the query request, the AC holds a connection established with the intermediate AP (e.g., neither closes the session actively, nor ages the session) , and will not send a prompt message to the intermediate AP until there is a new downlink message in the buffer queues needs to be pushed. After the intermediate AP receives a prompt message sent from the AC, the intermediate AP sends a new query request to the AC. In this way, under the circumstance where there is no downlink message on the AC, the APs will not make requests to the AC frequently.

The intermediate AP in the AP group may be determined by the AC. For example, the AC determines a first online AP in the AP group as intermediate AP of the AP group； or the intermediate AP may be elected by the AP group.

Referring to Fig. 1, Fig. 1 is a schematic diagram of a packet processing method of an AC according to examples of the present disclosure. The method includes the following process.

Block 101, the AC allocates a buffer queue for each AP in an AP group for buffering downlink messages.

Block 102, the AC receives a query packet for querying downlink messages in buffer queues corresponding to APs in the AP group from an intermediate AP in the AP group.

Block 103, when the AC determines that not all the buffer queues of the APs in the AP group are empty, i.e., at least one buffer queue having a downlink message, the AC sends a prompt message to the intermediate AP to enable the intermediate AP to send the prompt message to other APs in the AP group. The intermediate AP may multicast the prompt message in the AP group, or may unicast the prompt message to APs whose buffer queues have downlink messages respectively.

After the AC receives the query packet from the intermediate AP, if the AC determines that the buffer queues corresponding to the respective APs in the AP group are all empty, then the AC will not send a prompt message to the intermediate AP. Until at least one buffer queue is not empty, the AC sends a prompt message to the intermediate AP through the long-connection-long-poll connection (e.g., HTTP connection) established between the AC and the intermediate AP. The prompt message is to notify whether the buffer queues corresponding to the respective APs in the AP group are empty or not.

After the intermediate AP receives the prompt message sent from the AC, the intermediate AP sends another query packet to the AC through the long-connection-long-poll-connection established between the AC and the intermediate AP.

In specific implementations, the prompt message may carry an identity of an AP whose buffer queue is not empty, or the prompt message may carry a status bitmap to notify the respective APs whose buffer queue has downlink messages and whose buffer queue is empty.

If the AC uses a status bitmap to notify the respective APs, then the AC first should notify the respective APs of buffer queue status positions of the respective APs in the status bitmap through the intermediate AP. The AC may negotiate with the respective APs about the buffer queue status positions of the APs in the status bitmap based on identities of the APs.

When the AC sends the prompt message to the intermediate AP of the AP group, the prompt message carries a status bitmap, the status bitmap indicates whether a buffer queue of an AP is empty or not on a buffer queue status position of the AP. For example, “1” indicates the buffer queue is not empty, and “0” identifies the buffer queue is empty. In this way, the APs may know whether their buffer queues are empty or not according to their buffer queue status positions in the status bitmap, and when a buffer queue of an AP is not empty, the AP sends a query packet for querying downlink messages in its buffer queue to the AC.

When the intermediate AP in the AP group receives the prompt message, if the respective APs in the AP group belong to a same local network, then the intermediate AP distributes the prompt message to the respective APs (i.e., other APs in the AP group) in the local network in a multicast way.

When all the APs in the AP group, including the intermediate AP, receive the prompt message, the APs determine whether their buffer queues have a downlink message or not according to content of the prompt message, and if an AP determines its buffer queue has a downlink message, then the AP sends a query packet for querying the downlink message in its buffer queue to the AC through a long-connection-no-poll connection (e.g., a HTTP connection) established with the AC； or otherwise, the AP discards the prompt message and does not process it any more.

When all the buffer queues of the respective APs in the AP group are empty, the AC will not send a prompt message to the intermediate AP.

Since when all the buffer queues of the respective APs in the AP group are empty, the AC will not send a prompt message to the intermediate AP, therefore, the intermediate AP may not receive a prompt message during a certain time. When a first preset time ends and the intermediate AP has not received a prompt message from the AC yet, the intermediate AP may send an empty prompt message to other APs in the AP group to protect the intermediate AP. For example, the first preset time is counted from a time when the intermediate AP sends the query packet for querying the downlink messages in all the buffer queues of the APs in the AP group to the AC.

When an AP which is not the intermediate AP in the AP group determines a second preset time ends, and it has not received a prompt message from the intermediate AP, then the AP will send a request packet to the AC to request for switching to be intermediate AP. The second preset time is larger than the first preset time, and may be a multiple of the first preset time. The second preset time for example may be counted from a time when the AP receives a prompt message from the intermediate AP last time. If the AP has not received a prompt message sent from the intermediate AP within the second preset time period, then the AP considers that the intermediate AP may break down.

When the AC receives a request packet requesting for switching to be intermediate AP from any AP which is not the intermediate AP, the AC determines whether the current intermediate AP in the AP group is online or not. If the AC determines that the current intermediate AP is online, then the AC notifies the AP not to switch to be intermediate AP； or otherwise, the AC notifies the AP to switch to be intermediate AP of the AP group.

When the AP which is not the intermediate AP receives a notification of switching to be intermediate AP from the AC, the AP switches to be intermediate AP. When the first preset time ends, if the AP has not received a prompt message from the AC, then the AP sends an empty prompt message to other APs in the AP group.

When the AP which is not the intermediate AP receives a notification of not switching to be intermediate AP from the AC, the AP continues to wait for receiving a prompt message from the intermediate AP. If the AP waits for a third preset time, but has not received a prompt message, the AP will send a request packet requesting for switching to be intermediate AP to the AC again.

Block 104, the AC receives a query packet for querying a downlink message in a buffer queue of an AP from the AP whose buffer queue has the downlink message, and sends the downlink message in the buffer queue of the AP to the AP.

During implementations, block 104 may be that when the AC receives the query packet sent from the AP whose buffer queue has more than one downlink message, then when the AC sends one downlink message to the AP, the downlink message carries an indication indicating there are still downlink messages in the buffer queue, so that the AP sends another query packet to the AC, until the AC sends a last downlink message in the buffer queue.

The packet processing method of AP will be described in the following in combination with drawings.

Refer to Figs. 2A and 2B. Fig. 2A is a schematic diagram of a packet processing method of an AP according to examples of the present disclosure. The detail process of the method includes the following blocks.

Block 201, An AP serving as intermediate AP in an AP group sends a query packet for querying downlink messages in buffer queues corresponding to all APs in the AP group. The buffer queues are allocated to the APs by the AC.

Block 202, the intermediate AP receives a prompt message sent from the AC. The prompt message is to notify the AP group to which the intermediate AP belongs that at least one buffer queue corresponding to the APs in the AP group has a buffered downlink message.

Block 203, the intermediate AP sends the prompt message to other APs in the AP group.

When the intermediate AP determines that a buffer queue corresponding to the intermediate AP is not empty according to the prompt message, the intermediate AP sends a query packet for querying buffered downlink messages in the buffer queue corresponding to the intermediate AP to the AC and receives a downlink message sent from the AC through a long-connection-no-poll HTTP connection established with the AC.

The AC allocates a buffer queue for each AP. Therefore, the APs determine whether buffer queues corresponding thereto are empty or not according to the notification message, i.e., determining whether there are downlink messages in the buffer queues allocated to the APs.

When the intermediate AP sends the prompt message to other APs in the AP group, the intermediate AP may send the prompt message to other APs in a same local area network in a multicast way, or may unicast the prompt message to APs whose buffer queues have downlink messages respectively.

When the first preset time ends, if the intermediate AP has not received a prompt message from the AC, then the intermediate AP sends an empty prompt message to other APs in the AP group. For example, the first preset time is counted from a time when the intermediate AP sends the query packet for querying the downlink messages in all the buffer queues of the APs in the AP group to the AC.

The intermediate AP receives the prompt message from the AC through a long-connection-long-poll HTTP connection established with the AC.

Fig. 2B is a schematic diagram of a packet processing method of an AP according to examples of the present disclosure. The process of the method is as follows.

Block 204, an AP except for the intermediate AP in the AP group receives a prompt message sent from the intermediate AP.

Block 205, when the AP determines that a buffer queue corresponding to it has a buffered downlink message based on the prompt message, the AP sends a query packet for querying the buffered downlink message in the buffer queue corresponding to the AP and receives the downlink message sent from the AC, in which the buffer queue is allocated to the AP by the AC.

There is not a specific order for execution of blocks 201-205. The blocks are processing flows of an AP in different roles.

Each AP in the AP group sends a query packet for querying downlink messages in a buffer queue corresponding to the AP and receives a downlink message through a long-connection-no-poll HTTP connection established with the AC.

When the downlink message received by the AP from the AC carries an indication indicating the buffer queue still has downlink messages, the AP sends another query packet to the AC, until a downlink message received by the AP does not carry an indication indicating the buffer queue has more downlink messages.

In specific implementations, the prompt message may carry an identity of an AP whose buffer queue is not empty, or the prompt message may carry a status bitmap to notify the respective APs whose buffer queue has a downlink message and whose buffer queue is empty.

When the AC sends the prompt message to the intermediate AP of the AP group, the prompt message carries a status bitmap, the status bitmap indicates whether a buffer queues of an AP is empty or not on a buffer queue status position of the AP. For example, “1” indicates the buffer queue is not empty, and “0” identifies the buffer queue is empty.

When the respective APs in the AP group, including the intermediate AP, receive the prompt message, the APs determine whether their buffer queues are empty or not according to their buffer queue status positions in the status bitmap. If an AP determines its buffer queue is not empty, the AP sends a query packet to the AC； and if the AP determines its buffer queue is empty, then the AP discards the prompt message and does not send a query packet to the AC.

Since when the AC determines that all the buffers of the APs in the AP group are empty, the AC will not send a prompt message to the intermediate AP, therefore, the intermediate AP may not receive a prompt message during a long time.

When a first preset time ends, and the intermediate AP has not received a prompt message from the AC, then the intermediate AP sends an empty prompt message to other APs in the AP group to protect its role as intermediate AP in the AP group. For example, the first preset time is counted from a time when the intermediate AP sends the query packet for querying the downlink messages in all the buffer queues of the APs in the AP group to the AC.

When the intermediate AP breaks down, or a link between the intermediate AP and another AP fails, the other AP which is not the intermediate AP will not receive the prompt message from the intermediate AP.

When an AP which is not the intermediate AP in the AP group determines a second preset time ends and it has not received a prompt message from the intermediate AP, the AP will send a request packet to the AC to request for switching to be intermediate AP. If the AP receives a notification of switching to be intermediate AP to receive and send a prompt message after the AC determines that the intermediate AP is not on line； or receives a notification of not switching to be intermediate AP after the AC determines that the intermediate AP is on line, and waits for receiving a prompt message. The second preset time for example may be counted from a time when the AP receives a prompt message from the intermediate AP last time.

With the technical solution of the present disclosure, the smallest number of internet messages between the AC and the APs is: the number of uplink messages*the number of APs+the number of downlink messages*the number of APs+the number of downlink messages*the number of AP groups, i.e., every prompt message being notified to all the APs in the AP groups. In this way, when there are N APs, where N is a positive integer, (N-1) query messages are reduced； the largest number of internet messages between the AC and the APs is: (the number of uplink messages +2*the number of downlink messages) *the number of APs, i.e., each prompt message only containing a prompt for an AP, which amounts to each AP sending a query message.

In traditional implementations, i.e., establishing two HTTP connections between an AC and each AP, the number of internet messages between the AC and the APs is: (the number of uplink messages+2*the number of downlink messages) *the number of APs.

Since there is little possibility that each time when the AC sends a prompt message, there is only one buffer queue is not empty, therefore, compared to the traditional implementations, the detailed implementation of the present disclosure largely reduces the number of internet messages between the AC and the APs.

Further, since the AC only establishes the long-connection-long-poll HTTP connection with the intermediate AP, therefore the number of HTTP connections that needs to be maintained by the AC is largely reduced.

An interaction process between an AC and APs will be elaborated hereafter in combination with the drawings. Referring to Fig. 3, Fig. 3 is a schematic diagram of a CAPWAP over HTTP network according to the present disclosure.

In Fig. 3, the AC configures two AP groups: AP group 1 and AP group 2 respectively, where the AP group 1 includes AP1, AP2, and AP3 which belong to a same local area network； and the AP group 2 includes AP 4 and AP5 which belong to a same local area network. The APs in the AP group 1 and AP group 2 do not belong to a same local area network.

In the following, as an example, the APs in the AP group 1 communicate with the AC. The AC establishes a long-connection-no-poll HTTP connection with the AP1, AP2, and AP3 respectively.

The AC allocates a buffer queue for each AP for buffering downlink messages. Buffer queues and APs are one-to-one correspondence. When the AC uses a bitmap to show buffer queue statuses corresponding to the APs, it determines a buffer queue status position for each AP in the bitmap. For example, the AC uses one bit to represent a buffer queue status position and a buffer queue status of each AP； and notifies the buffer queue status position of each AP to the AP. During notification, the AC may process as in the following. First, the AC sends the notification to the intermediate AP, and then the intermediate AP multicasts the notification to other APs, so that the respective APs may know their buffer queue status positions in the bitmap.

In specific implementations, the AC may arrange the buffer queue status positions of the APs in the bitmap according to identities of the APs, so that the respective APs automatically obtain their buffer queue status positions in the bitmap, i.e., the APs and the AC negotiating the buffer queue status positions of the APs in the bitmap.

There are three APs in the AP group 1, then 3 bits may be used, in which “1” indicates there is a downlink message in a buffer queue of an AP, and “0” indicates there is no downlink message in a buffer queue of an AP, i.e., empty.

When the first bit is used to identify the AP1, the second bit is used to identify the AP2, and the third bit is used to identify the AP3, e.g., “001” , then “001” indicates there is no downlink message in the buffer queues of the AP1 and AP2, i.e., empty； and there is a downlink message in the buffer queue of the AP3.

The AC establishes a long-connection-long-poll HTTP connection with an AP which is first online in the AP group 1. The first online AP serves as intermediate AP of the AP group 1, i.e., an AP used to transfer messages. For example, the intermediate AP in the AP group 1 is the AP1.

When there is an AP whose buffer queue is not empty in the AP group 1, the AC sends a prompt message to the AP1 through the long-connection-long-poll HTTP connection established between the AC and the AP1, and carries prompt statuses of the respective APs in the prompt message, i.e., carrying a bitmap indicating whether there is a downlink message in the buffer queues of the respective APs, e.g., the carried bitmap is “001” .

When the AP 1 receives the prompt message, the AP1 multicasts the prompt message in the AP group 1, i.e., multicasting the prompt message in the local area network.

The respective APs which receive the prompt message, including the AP1, AP2, and AP3, based on their buffer queue status positions in the bitmap stored locally and based on values of bits on the buffer queue status positions, determine whether there is a downlink message in the buffer queue corresponding to the APs. When a value of a bit on a buffer queue status position is “1” , an AP determines that there is a downlink message in its buffer queue； and when a value of a bit on a buffer queue status position is “0” , an AP determines that there is no downlink message in its buffer queue.

Since the bitmap is “001” , then only the buffer queue corresponding to the AP3 has a downlink message. The AP1 and AP2 do not process the prompt message； and the AP3 sends a query packet for requesting for the downlink message buffered in its buffer queue through a long-connection-no-poll HTTP connection established between the AP3 and the AC, and the AC uses the query packet to send the messages in the buffer queue to the AP3.

Each time the AC sends a downlink message to the AP3. If there are N downlink messages in the buffer queue corresponding to the AP3, when the AC sends the 1 to N-1 downlink messages, the downlink messages carry a “more” indication, indicating there are still downlink messages in the buffer queue.

When the AP3 receives the 1 to N-1 downlink messages and finds that the downlink messages carry the “more” indication, then the AP3 sends a query packet to the AC each time when the AP3 receives a downlink message, until there is no “more” indication in the received downlink message, and the communication of this time ends.

When the buffer queues of the AP1, AP2, and AP3 are all empty, then the AC does not send a prompt message to the AP1. In this way, when a first preset time ends, the AP1 may not receive a prompt message sent from the AC, then the AP1 may send a multicast empty prompt message to the AP2 and the AP3 to protect the AP1 serving as intermediate AP.

When a second preset time ends, but the AP2 or the AP3 has not received a prompt message from the AP1 yet, then the AP2 and the AP3 may send request packets requesting for switching to be intermediate AP, assuming that the AP2 sends the request packet first.

When the AC receives the request packet sent from AP2, the AC determines to or not to switch the AP2 to be intermediate AP according to the buffer queue status of the AP1. When the AP1 is on line, the AC notifies the AP2 not to switch to be intermediate AP； and when the AP1 is not on line, the AC notifies the APs to switch to be intermediate AP and establishes a long-connection-long-poll HTTP connection with the AP2 for the AP2 to send and receive prompt messages.

The AC in the examples of the present disclosure may be a programmable device which combines software and hardware. For detailed information on the hardware aspect, please refer to Fig. 4. Fig. 4 is a schematic diagram of a hardware structure of an AC including a packet processing apparatus. The AC includes: a non-transitory storage device 41, a processor such as a CPU 42, a forwarding chip 43, and a memory 44.

The non-transitory storage device 41 includes a non-transitory machine readable storage medium to store machine readable instructions that are executable by a processor such as the CPU 42. The operations carried out by the machine readable instructions when executed by the CPU 42 are the functions carried out by the packet processing apparatus 45 in the memory.

The CPU 42 is to communicate with the forwarding chip 43, to receive and send prompt messages, downlink messages, and query packets； communicate with the non-transitory storage device 41 to read and execute the instruction code stored on the non-transitory storage device 41 so as to carry out functions carried out by a buffering unit 401, a receiving unit 402, and a sending unit 403 in the packet processing apparatus 45； and process query packets sent from the forwarding chip 43.

The forwarding chip 43 is to be connected to the AP through a port on it, responsible for receiving and sending messages and packets, sending downlink messages and prompt messages sent from the CPU to the AP, and sending the query packet sent from the AP to the CPU.

The memory 44 is to cooperate with the CPU 42 to instantiate the instruction code to form the buffering unit 401, the sending unit 402, and the receiving unit 403 to carry out the packet processing method.

The buffering unit 401 is to allocate a buffer queue for each AP in the AP group； and buffer downlink messages in the buffer queue corresponding to the AP.

The sending unit 402 is to, when not all the buffer queues configured for the respective APs in the AP group are empty, send a prompt message to the intermediate AP in the AP group to enable the intermediate AP to send the prompt message to other APs in the AP group. The prompt message is to notify whether the buffer queues corresponding to the APs in the AP group are empty. The intermediate AP is the first online AP in the AP group. When the receiving unit 403 receives a query packet sent from any AP, the sending unit 402 is further to send a buffered downlink message in the buffer queue of the AP to the AP.

The receiving unit 403 is to receive the query packet from the AP.

In addition, the sending unit 402 is to, when sending the prompt message to the intermediate AP, enable the intermediate AP to multicast the prompt message to other APs in the AP group, in which the respective APs in the AP group are APs within a same local area network； and send the prompt message to the intermediate AP through the long-connection-long-query HTTP connection established between the AP and the AC.

The receiving unit 403 is to receive the query packet sent from an AP through a long-connection-no-poll HTTP connection established with the AP, and sends a downlink message buffered in the buffer queue of the AP to the AP.

Further, the sending unit 402 is to notify buffer queue status positions of the respective APs in a status bitmap to the respective APs； when sending a prompt message to the intermediate AP of the AP group to notifies APs whose buffer queues are not empty, carry a status bitmap in the prompt message, and indicate whether a buffer queue of an AP is empty or not on a buffer queue status position of the AP in the status bitmap； enable the respective APs to know whether their buffer queues are empty or not according to their buffer queue status positions in the status bitmap, and when a buffer queue of an AP is not empty, send a query packet to the AC.

In addition, the sending unit 402 is to, when it is determined that the buffer queue corresponding to the AP has more than one downlink message, when send one downlink message to the AP, the downlink message carries an indication indicating there are still downlink messages in the buffer queue so that the AP sends another query packet to the AC until the AP sends a last downlink message in the buffer queue.

The packet processing apparatus is a logic apparatus, which may be implemented by the CPU reading machine readable instructions in the non-transitory storage device into a memory and executing the computer program instructions. When the corresponding machine readable instructions are executed, the packet processing apparatus executes the corresponding operations according to the foregoing method.

In the example of Fig. 4, the packet processing apparatus 45 is described separately from the non-transitory storage device 41 and the CPU 42. During implementations, the packet processing apparatus 45 on the AC may at least include the non-transitory storage device 41 and the CPU 42 which communicates with the non-transitory storage device 41. Computer program instructions are stored on the non-transitory storage device 41. When the computer program instructions are executed, the following operations are executed:

allocating buffer queues for buffering downlink messages to access points (APs) in an AP group；

receiving a query packet for querying the buffered downlink messages in the buffer queues corresponding to the APs in the AP group sent from an intermediate AP in the AP group；

sending a prompt message to the intermediate AP to trigger the intermediate AP notifying the AP group, when it is determined that a buffer queue corresponding to an AP has a buffered downlink message；

receiving a query packet for querying the buffered downlink message in the buffer queue sent from the AP corresponding to the buffer queue； and

sending the buffered downlink message in the buffer queue to the AP.

Sending the prompt message to the intermediate AP includes:

sending the prompt message to the intermediate AP through a connection for maintaining a query status established with the intermediate AP.

Receiving the query packet for querying the buffered downlink message in the buffer queue sent from the AP corresponding to the buffer queue, and sending the buffered downlink message in the buffer queue to the AP includes:

receiving the query packet for querying the buffered downlink message in the buffer queue sent from the AP corresponding to the buffer queue, and sending the buffered downlink message in the buffer queue to the AP through a long-connection-no-poll session connection established between the AC and the AP.

The intermediate AP may be determined by the AC or elected by the AP group； and

the APs in the AP group are APs in a same local area network.

The operations further include:

notifying the AP of a buffer queue status position of the AP in a status bitmap through the intermediate AP.

When the AC sends the prompt message to the intermediate AP, the prompt message carries the status bitmap to indicate whether there is a downlink message in the buffer queue corresponding to the AP on the buffer queue status position of the AP in the status bitmap； the status bitmap enables the AP to know whether there is a downlink message in the buffer queue corresponding to the AP, and send the query packet when there is a downlink message in the buffer queue corresponding to the AP.

Sending the buffered downlink message in the buffer queue to the AP includes:

after receiving the query packet sent from the AP, when it is determined that there is more than one downlink message in the buffer queue corresponding to the AP, carrying an indication indicating there is still a downlink message in the buffer queue corresponding to the AP when sending one downlink message to the AP to enable the AP sends another query packet, until sending a last downlink message in the buffer queue corresponding to the AP.

The operations further include:

receiving a request packet requesting for switching to be intermediate AP from an AP which is not the intermediate AP in the AP group；

determining whether the intermediate AP is online or not；

notifying the AP which is not the intermediate AP to switch to be intermediate AP for receiving and sending prompt messages when it is determined that the intermediate AP is not online； and

notifying the AP which is not the intermediate AP not to switch to be intermediate AP when it is determined that the intermediate AP is online, .

The APs in the examples of the present disclosure are programmable devices which combine hardware and software. For detailed information on the hardware aspect, please refer to Fig. 5. Fig. 5 is a schematic diagram of a hardware structure of an AP including a packet processing apparatus. The AP includes: a non-transitory storage device 51, a processor such as a CPU 52, a forwarding chip 53, and a memory 54.

The non-transitory storage device 51 includes a non-transitory machine readable storage medium to store machine readable instructions that are executable by a processor such as the CPU 52. The operations carried out by the machine readable instructions when executed by the CPU 52 are the functions carried out by the packet processing apparatus 55 in the memory.

The CPU 52 is to communicate with the forwarding chip 53, to receive and send prompt messages, downlink messages, and query packets； communicate with the non-transitory storage device 51 to read and execute the instruction code stored on the non-transitory storage device 51 so as to carry out functions carried out by a receiving unit 501, a sending unit 502, a determination unit 503, and a processing unit 504, and process prompt messages and downlink messages sent from the forwarding chip 53.

The forwarding chip 53 is to be connected to the AC through a port on the chip, responsible for receiving and sending messages and packets, sending query packets sent from the CPU to the AC, and sending downlink messages and prompt messages sent from the AC to the CPU.

The memory 54 is to cooperate with the CPU 52 to instantiate the instruction code to form the receiving unit 501, the sending unit 502, the determination unit 503, and the processing unit 504 to carry out the packet processing method.

From the software aspect, the packet processing apparatus 55 implemented on the AP includes: a receiving unit 501, a sending unit 502, and a determination unit 503.

The receiving unit 501 is to receive downlink messages； and when the AP serving as intermediate AP of the AP group, receive a prompt message sent from the AC；when the AP does not serve as intermediate AP, receive a prompt message sent from an intermediate AP； in which the intermediate AP is the first online AP in the AP group； and the prompt message is to notify whether the buffer queues corresponding to the APs in the APs are empty or not.

The sending unit 502 is to, send the prompt message to other APs in the AP group when the prompt message sent from the AC is received； and send a query packet to the AC when the determination unit 503 determines that a buffer queue corresponding to the AP is not empty.

The determination unit 503 is to determine whether a buffer queue corresponding thereto is empty according to the received prompt message； the buffer queue is allocated by the AC for the AP.

The sending unit 502 is to, when the AP is intermediate AP of the AP group and sends a prompt message to other APs in the AP group, multicast the prompt message to other APs in the AP group, and send a query packet to the AC through a long-connection-no-poll HTTP connection established with the AC； and when the AP serves as intermediate AP, send a query packet to the AC through the long-connection-no-poll HTTP connection.

The receiving unit 501 is to receive the downlink message through the long-connection-no-poll HTTP connection established with the AC.

Further, the sending unit 502 is further to, when the prompt message received by the AP sent from the AC carries an indication indicating there are still downlink messages in the buffer queue, send a query packet to the AC again.

Further, the apparatus includes: a processing unit 504.

The sending unit 502 is further to, when the AP serves as intermediate AP of the AP group, when a first preset time ends and the receiving unit 501 has not received a prompt message from the AC, send an empty prompt message to other APs in the AP group； when the AP does not serve as intermediate AP of the AP group, when a second preset time ends and the receiving unit 501 has not received a prompt message from the intermediate AP, send a request packet requesting for switching to be intermediate AP to the AC.

The processing unit 504 is to, when the receiving unit 501 receives a notification from the AC after the AC determines that the intermediate AP is not on line and notifies the AP to switch to be intermediate AP, switch to be intermediate AP to receive and send prompt messages； and when the receiving unit 501 receives a notification from the AC after the AC determines that the intermediate AP is on line and notifies the AP not to switch to be intermediate AP, trigger the receiving unit 501 continuing to wait for receiving a prompt message for a third preset time.

The packet processing apparatus as a logic apparatus, which may be implemented by the CPU reading machine readable instructions in the non-transitory storage device into a memory and executing the computer program instructions. When the corresponding machine readable instructions are executed, the packet processing apparatus executes the corresponding operations according to the foregoing method.

In the example of Fig. 5, the packet processing apparatus 55 is described separately from the non-transitory storage device 51 and the CPU 52. During implementations, the packet processing apparatus 55 on the AC may at least include the non-transitory storage device 51 and the processor 52 which communicates with the non-transitory storage device 51. Computer program instructions are stored on the non-transitory storage device 51. When the computer program instructions are executed, the following operations are executed:

when the AP serves as intermediate AP,

sending a query packet for querying downlink messages in buffer queues corresponding to APs in an AP group to which the intermediate AP belongs to an access controller (AC) , wherein the buffer queues are allocated to the APs by the AC；

receiving a prompt message sent from the AC, the prompt message being to notify the AP group that there is a buffered downlink message in a buffer queue corresponding to an AP in the AP group； and

sending the prompt message to other APs in the AP group.

The operations further include:

determining whether there is a buffered downlink message in a buffer queue corresponding to the intermediate AP ； and

when it is determined that there is a buffered downlink message in a buffer queue corresponding to the intermediate AP, sending a query packet for querying the buffered downlink message in the buffer queue corresponding to the intermediate AP and receiving the downlink message sent from the AC.

The intermediate AP sends the query packet for querying the downlink messages in the buffer queues corresponding to the APs in the AP group to the AC and receives the prompt message sent from the AC through a connection for maintaining a query status established between the intermediate AP and the AC； and sends the query packet for querying the buffered downlink message in the buffer queue corresponding to the intermediate AP and receives the downlink message through a long-connection-no-poll connection established between the intermediate AP and the AC.

The operations further include:

when a first preset time ends and the intermediate AP has not received the prompt message from the AC, sending an empty prompt message to other APs in the AP group, wherein the first preset time is counted from a time when the intermediate AP sends the query packet for querying the downlink messages in the buffer queues corresponding to the APs in the AP group to the AC.

When the AP is not intermediate AP, the operations executed by the packet processing apparatus may include:

receiving a prompt message forwarded from an intermediate AP in an AP group to which the AP belongs, in which the prompt message is received from an access controller (AC) ； and

when it is determined that there is a buffered downlink message in a buffer queue corresponding to the AP, sending a query packet for querying the buffered downlink message in the buffer queue corresponding to the AP to the AC and receiving the downlink message sent from the AC, in which the buffer queue is allocated to the AP by the AC.

The AP sends the query packet for querying the buffered downlink message in the buffer queue corresponding to the AP to the AC and receives the downlink message from the AC through a long-connection-no-poll session connection.

The operations further include:

when a second preset time ends, determining whether the AP receives a prompt message from the intermediate AP, in which the second preset time is counted from a time when the AP receives a prompt message from the intermediate AP last time；

when it is determined that the AP has not received a prompt message from the intermediate AP, sending a request packet requesting for switching to be intermediate AP to the AC；

switching to be intermediate AP to receive and send a prompt message when receiving a notification of switching to be intermediate AP after the AC determines that the intermediate AP is not online and notifies the AP to switch to be intermediate AP； or

continuing to wait for receiving a prompt message for a third preset time when receiving a notification of not switching to be intermediate AP after the AC determines that the intermediate AP is on line, and notifies the AP not to switch to be intermediate AP.

After the AP switches to be intermediate AP, the AP sends a query packet for querying downlink messages in all the buffer queues corresponding to the APs in the AP group to the AC and receives a prompt message sent from the AC through a connection for maintaining a query status established between the AP and AC.

The exemplary units may be integrated together or deployed separately； and may be integrated into a unit or be separated into multiple sub-units.

The non-transitory storage device may be a magnetic disk, an optical disk, a read-only memory (ROM) , a random access memory (RAM) , etc.

In the present disclosure, an AC distributes a prompt message through an intermediate AP in an AP group. In this way, in a CAPWAP over HTTP network, the AC is able to push messages to APs actively, which reduces the number of HTTP connections and number of messages, and thus reduces occupancy of internet bandwidth.

What is described in the foregoing are only examples of the present disclosure, and should not be construed as limitations to the present disclosure. Any changes, equivalent replacements, modifications made without departing from the scope and spirit of the present disclosure are intended to be included within the protecting scope of the present disclosure.

Claims

A packet processing method, implemented on an access controller (AC) , comprising:

allocating buffer queues for buffering downlink messages to access points (APs) in an AP group；

receiving a query packet for querying the buffered downlink messages in the buffer queues corresponding to the APs in the AP group sent from an intermediate AP in the AP group；

sending a prompt message to the intermediate AP to trigger the intermediate AP notifying the AP group, in response to determining that a buffer queue corresponding to an AP in the AP group has a buffered downlink message；

receiving, from the AP corresponding to the buffer queue, a query packet for querying the buffered downlink message in the buffer queue ； and

sending the buffered downlink message in the buffer queue to the AP.
The method of claim 1, wherein sending the prompt message to the intermediate AP comprises:

sending the prompt message to the intermediate AP through a connection for maintaining a query status established between the AC and the intermediate AP.
The method of claim 1, wherein receiving the query packet for querying the buffered downlink message in the buffer queue sent from the AP corresponding to the buffer queue, and sending the buffered downlink message in the buffer queue to the AP comprises:

receiving the query packet for querying the buffered downlink message in the buffer queue sent from the AP corresponding to the buffer queue, and sending the buffered downlink message in the buffer queue to the AP through a long-connection-no-poll session connection established between the AC and the AP.
The method of claim 1, wherein

the intermediate AP is determined by the AC or elected by the AP group； and

the APs in the AP group are APs in a same local area network.
The method of claim 1, wherein the method further comprises:

notifying the AP of a buffer queue status position of the AP in a status bitmap through the intermediate AP,

wherein when the AC sends the prompt message to the intermediate AP, the prompt message carries the status bitmap to indicate whether there is a downlink message in the buffer queue corresponding to the AP on the buffer queue status position of the AP in the status bitmap； the status bitmap enables the AP to know whether there is a downlink message in the buffer queue corresponding to the AP, and send the query packet when there is a downlink message in the buffer queue corresponding to the AP.
The method of claim 1, wherein receiving the query packet for querying the buffered downlink message in the buffer queue sent from the AP corresponding to the buffer queue and sending the buffered downlink message in the buffer queue to the AP comprises:

after receiving the query packet sent from the AP, in response to determining that there is more than one downlink message in the buffer queue corresponding to the AP, carrying an indication indicating there is still a downlink message in the buffer queue corresponding to the AP when sending one downlink message to the AP to enable the AP to send another query packet, until sending a last downlink message in the buffer queue corresponding to the AP.
The method of claim 1, wherein the method further comprises:

receiving a request packet requesting for switching to be intermediate AP from an AP which is not the intermediate AP in the AP group；

determining whether the intermediate AP is online or not；

notifying the AP which is not the intermediate AP to switch to be intermediate AP for receiving and sending prompt messages in response to determining that the intermediate AP is not online； and

notifying the AP which is not the intermediate AP not to switch to be intermediate AP in response to determining that the intermediate AP is online.
A non-transitory machine readable storage medium storing machine readable instructions for implementing a packet processing method by an intermediate access point (AP) , the machine readable instructions including instructions that are executable by a processor to::

send a query packet for querying downlink messages in buffer queues corresponding to APs in an AP group to which the intermediate AP belongs to an access controller (AC) , wherein the buffer queues are allocated to the APs by the AC；

receive a prompt message sent from the AC, the prompt message being to notify the AP group that there is a buffered downlink message in a buffer queue corresponding to an AP in the AP group； and

send the prompt message to other APs in the AP group.
The non-transitory machine readable storage medium of claim 8, wherein the machine readable instructions include instructions to:

determine whether there is a buffered downlink message in a buffer queue corresponding to the intermediate AP； and

in response to determining that there is a buffered downlink message in a buffer queue corresponding to the intermediate AP, send a query packet for querying the buffered downlink message in the buffer queue corresponding to the intermediate AP and receiving the downlink message sent from the AC.
The non-transitory machine readable storage medium of claim 8, wherein the machine readable instructions include instructions to:

send the query packet for querying the downlink messages in the buffer queues corresponding to the APs in the AP group to the AC, and receive the prompt message sent from the AC is through a connection for maintaining a query status established between the intermediate AP and the AC； and

send the query packet for querying the buffered downlink message in the buffer queue corresponding to the intermediate AP and receive the downlink message is through a long-connection-no-poll connection established between the intermediate AP and the AC.
The non-transitory storage medium of claim 8, wherein the machine readable instructions include instructions to:

in response to determining that a first preset time ends and the intermediate AP has not received the prompt message from the AC, send an empty prompt message to other APs in the AP group, wherein the first preset time is counted from a time when the intermediate AP sends the query packet for querying the downlink messages in the buffer queues corresponding to the APs in the AP group to the AC.
A packet processing method, implemented on an access point (AP) , the method comprising:

receiving a prompt message forwarded from an intermediate AP in an AP group to which the AP belongs, in which the prompt message is received from an access controller (AC) ； and

in response to determining that there is a buffered downlink message in a buffer queue corresponding to the AP, sending a query packet for querying the buffered downlink message in the buffer queue corresponding to the AP to the AC and receiving the downlink message sent from the AC, wherein the buffer queue is allocated to the AP by the AC.
The method of claim 12, wherein

sending the query packet for querying the buffered downlink message in the buffer queue corresponding to the AP to the AC and receiving the downlink message from the AC is through a long-connection-no-poll session connection.
The method of claim 12, wherein the method further comprises:

in response to determining that a second preset time ends, determining whether the AP receives a prompt message from the intermediate AP, wherein the second preset time is counted from a time when the AP receives a prompt message from the intermediate AP last time；

in response to determining that the AP has not received a prompt message from the intermediate AP, sending a request packet requesting for switching to be intermediate AP to the AC；

switching to be intermediate AP to receive and send a prompt message in response to receiving a notification of switching to be intermediate AP after the AC determines that the intermediate AP is not online and notifies the AP to switch to be intermediate AP； or

continuing to wait for receiving a prompt message for a third preset time in response to receiving a notification of not switching to be intermediate AP after the AC determines that the intermediate AP is on line, and notifies the AP not to switch to be intermediate AP.
A packet processing apparatus, comprising:

a processor, and

a non-transitory storage medium on which is to store machine readable instructions that when executed by the processor cause the processor to:

allocate buffer queues for buffering downlink messages to access points (APs) in an AP group；

receive a query packet for querying the buffered downlink messages in the buffer queues corresponding to the APs in the AP group sent from an intermediate AP in the AP group；

send a prompt message to the intermediate AP to trigger the intermediate AP notifying the AP group, in response to determining that a buffer queue corresponding to an AP in the AP group has a buffered downlink message；

receive, from the AP corresponding to the buffer queue, a query packet for querying the buffered downlink message in the buffer queue ； and

send the buffered downlink message in the buffer queue to the AP.