WO2013170619A1

WO2013170619A1 - Configuring state of an s channel

Info

Publication number: WO2013170619A1
Application number: PCT/CN2013/000104
Authority: WO
Inventors: Qiang Wu
Original assignee: Hangzhou H3C Technologies Co., Ltd.
Priority date: 2012-05-17
Filing date: 2013-01-31
Publication date: 2013-11-21
Also published as: CN102710486A; CN102710486B

Abstract

A method for configuring a state of an S channel is provided. The method comprises sending, by one of a first device and a second device which communicates with said first device via an S channel, a request for said S channel to the other of said first device and said second device, wherein said request is an S channel suspension request or an S channel initiation request.

Description

CONFIGURING STATE OF AN S CHANNEL

Background

With increase of business in a data center, virtualizing resources in the data center has now become an important trend in integration of the data center. Among the virtualization techniques in a data center, server virtualization is the most important one. With management by a dedicated virtualization software (such as VMware), multiple virtual machines (VM) cam be virtualized onto a physical server. Each VM independently operates without affecting each other.

Brief Description of the Drawings

Fig. 1 is a flow chart of a method for configuring a state of an S channel according to an example;

Fig. 2 is a flow chart of another method for configuring a state of an S channel according to another example;

Fig. 3 is a flow chart of yet another method for configuring a state of an S channel according to yet another example;

Fig. 4 is a schematic diagram of the structure of SCID/SVID in a TLV of CDCP protocol according to an example;

Fig. 5 is a schematic diagram of a device for configuring a state of an S channel according to an example;

Fig. 6 is a schematic diagram of another device for configuring a state of an S channel according to another example; and

Fig. 7 is a schematic diagram of hardware architecture of a device for configuring a state of an S channel according to an example.

Detailed Description

A virtual switch for a VM (also referred to as a virtual Ethernet switch) is mainly used to enable traffic exchange between VM and an external network and between VMs. However, due to limitations such as cost and resource consumption, implementation of a virtual Ethernet switch has restrictions in regard to the ability for traffic monitoring, the network control strategy and management. For these reasons, the IEEE802.1 working group formulates a new standard 802.1Qbg (i.e. EVB), wherein traffic exchange and processing between virtual machines are handled by an edge switch directly connected to the server.

EVB functions are performed by a server in cooperation with an edge switch directly connected thereto, with their cooperation realized mainly through three protocols, i.e. the S-Channel Discovery and Configuration Protocol (CDCP protocol), the Edge Control Protocol (ECP protocol) and the VSI Discovery and Configuration Protocol (VDP protocol). The CDCP protocol is mainly used by the server and the edge switch to negotiate a virtual S channel on directly connected physical interfaces, including creation and removal of an S channel.

The virtual S channel may for example allow a physical server to distinguish between uplink ports of a plurality of internal virtual switches. In one example, the S-channel is a logical channel established between an EVB Bridge and an EVB station, which is used to separate uplink traffic between different internal virtual switches in the EVB station. In one example, the S-Channel may be in accordance with the IEEE 802.1Qbg standard. . A physical server may have multiple VMs and virtual switches configured thereon. A plurality of VMs inside a physical server might need to connect to an external network through the same or different virtual switches and the uplink ports of these virtual switches are multiplexed on a physical interface of the physical server, which directly connects to a physical interface of an edge switch. In order to separate the uplink channels of various virtual switches on the same physical interface, the physical server generates virtual S channels, i.e. inserts different S-VLAN tags into traffic for uplink ports of different virtual switches, to distinguish between the forwarded traffic. For example, in order to separate the uplink channels, the server sends a request to the edge switch for creating an S channel according to configurations of its own virtual switches and the edge switch assigns an SVID to the S channel according to the server's S channel creation request and replies with a response message. When the server needs to remove an S channel, it will send an S channel removal request to the edge switch, which will remove the SVID assigned to the S channel according to the server's S channel removal request.

The S channel creation request and S channel removal request are both implemented by carrying a TLV of CDCP protocol in an LLDP message. A TLV of CDCP protocol includes the following fields: a field of device Role, indicating that the device is a server when set to 1 , and indicating that the device is a bridge when set to 0; a field of ChnCap, indicating the number of S channels supported by the device, i.e. the maximum number of S channels that the device supports to be created; a field of SCID/SVID pair, indicating the S channel index and its corresponding SVID; and two reserved fields. The SCID/SVID pair occupies a total of N*3 octets, wherein SCID and SVID each occupy 12 bits. In a TLV for an S channel creation request, the value of SCID is the index of the S channel to be created and the value of SVID is 0; and in a TLV for a reply message returned after the edge switch successfully creates an S channel, the value of SCID is the index of the S channel and the value of SVID is the VLAN ID that has been successfully assigned.

In addition, the server may regularly send an LLDP message to the edge switch which carries information about all the created S channels (corresponding SCID/SVID pairs) to maintain the state of each S channel. When the server needs to remove an S channel, it can remove information about this S channel from the regularly sent LLDP message, indicating a request for removing this S channel and the edge switch can remove this S channel accordingly.

Because negotiation of an S channel only relates to creation and removal of an S channel, the state of an S channel (including the normal communication state and the removal state) is rather simple so that in some applications or under some faulty circumstances, the state of an S channel cannot be detected in time by the server or the edge switch. For example, when the edge bridge needs to interrupt traffic forwarding on an S channel temporarily or an uplink port of some virtual switch on the server needs to be temporarily interrupted according to some application, then if solely relying on regular transmission of LLDP messages, the server or the edge switch cannot detect in time the state of the S channel, because the transmission interval for the LLDP messages is relatively long in time. On the other hand, if a way of notifying to remove an S channel is adopted, then it can only be initiated by the server and an S channel cannot be quickly created if it is needed again and creation and removal of an S channel also need to consume resources of the device.

In the following, certain examples according to the present disclosure are described in detail with reference to the drawings.

With reference to Fig. 1 , Fig. 1 is a flow chart of a method for configuring a state of an S channel according to an example of the present disclosure. The method is generally referred to by the reference number 100. The method 100 can be used in a network comprising a virtual Ethernet switch, wherein a plurality of virtual machines (VMs) are provided on the virtual Ethernet switch and the plurality of VMs exchange data therebetween through an S channel. At block 101 , one of a first device and a second device which communicates with the first device via an S channel sends a request for said S channel to the other of the first device and the second device. According to an example, the first device can be a server and the second device can be an edge switch. According to another example, the first device can be an edge switch and the second device can be a server.

In this example, the request sent by one of the first device and the second device can be an S channel suspension request or an S channel initiation request, wherein the S channel suspension request is used to enable a device that has received the S channel suspension request to pause receiving and sending a message from and to a device where this request originate through said S channel. If one of the first device and the second device needs to disable any S channel that is in normal communication therebetween, it sends an S channel suspension request to the other device to enable the other device to pause receiving and sending a message through said S channel.

For example, if an edge switch needs to interrupt traffic forwarding on an S channel temporarily, it can send an S channel suspension request to the opposite end device (e.g. a server), so that the server can detect in time that this S channel needs to be suspended and then suspend this S channel and stop sending and receiving messages over this S channel. Or, if an uplink port of a virtual switch at the side of the server needs to interrupt traffic forwarding on an S channel temporarily according to an application, it can send an S channel suspension request to the opposite end device (i.e. the edge switch), so that the edge switch can detect in time that this S channel needs to be suspended and then suspend this S channel and stop sending and receiving messages over this S channel.

According to an example of the present disclosure, the S channel initiation request is used, after any S channel between the first device and the second device is suspended, to reinitiate the suspended S channel so that this channel can be used again to send and receive messages between the first and second devices. For example, after the first device sends to the second device an S channel suspension request to suspend an S channel, the second device can send an S channel initiation request for this S channel to the first device if the second device wants to reinitiate this suspended S channel. Please be noted that a device at either end of a suspended S channel can send an S channel initiation request to reinitiate this S channel. For instance, in the above example, the first device itself can send an S channel initiation request to the second device after the first device suspends the S channel through an S channel suspension request.

With reference to Fig. 2, Fig. 2 is a flow chart of another method for configuring a state of an S channel according to another example of the present disclosure. The method is generally referred to by the reference number 200. The method 200 can be used in a network comprising a virtual Ethernet switch, wherein a plurality of virtual machines (VMs) are provided on the virtual Ethernet switch and the plurality of VMs exchange data therebetween through an S channel. Block 201 is the same as block 101 described above, wherein one of a first device and a second device which communicates with said first device via an S channel sends a request for said S channel to the other of the first device and the second device. At block 202, if the request is an S channel suspension request, at least one of the first device and the second device sets the state of said S channel to be a suspended state; and if the request is an S channel initiation request, at least one of the first device and the second device sets the state of said S channel to be a normal communication state.

In this example, in order to meet the needs of the first device or the second device temporarily suspending an S channel, besides the state of normal communication and the state of removal as described above, a new S channel state is added, i.e. a suspended state. An S channel in the suspended state no longer carries any data traffic but it can be reinitiated by way of an S channel initiation request. After being reinitiated, the S channel will change to the normal communication state. An S channel in the suspended state can be directly removed.

For example, when a device (the first device or the second device) sends to the opposite end device (i.e. the second device or the first device) an S channel suspension request for suspending any S channel that is in normal communication, it can further set the state of said S channel to be a suspended state and until said S channel is reinitiated, the device no longer sends and receives message over said S channel. After a device receives from the opposite end device an S channel suspension request for any S channel, it can further set the state of said S channel to be a suspended state and until said S channel is reinitiated, the device no longer sends and receives message over said S channel.

In addition, when a device sends to the opposite end device an S channel initiation request for any suspended S channel, it can further set the state of said S channel to be a normal communication state. After a device receives from the opposite end device an S channel initiation request for any suspended S channel, it can further set the state of said S channel to be a normal communication state.

With reference to Fig. 3, Fig. 3 is a flow chart of yet another method for configuring a state of an S channel according to yet another example. The method is generally referred to by the reference number 300. The method 300 can be used in a network comprising a virtual Ethernet switch, wherein a plurality of virtual machines (VMs) are provided on the virtual Ethernet switch and the plurality of VMs exchange data therebetween through an S channel. Block 301 and block 302 are the same as block 201 and block 202 respectively, wherein at block 301 one of a first device and a second device which communicates with said first device via an S channel sends a request for said S channel to the other of the first device and the second device and at block 302, if the request is an S channel suspension request, at least one of the first device and the second device sets the state of said S channel to be a suspended state; and if the request is an S channel initiation request, at least one of the first device and the second device sets the state of said S channel to be a normal communication state. The method 300 then proceeds to block 303, where upon receiving an S channel suspension request, the other of the first device and the second device pauses receiving and sending a message through said S channel and upon receiving an S channel initiation request, the other of the first device and the second device restarts receiving and sending a message through said S channel.

In the above examples, the S channel suspension request can be a newly defined message or it can use an LLDP message to carry TLV information of CDCP protocol, wherein said TLV information carries a suspension flag to indicate that this LLDP message is an S channel suspension request. Likewise, the S channel initiation request can be a newly defined message or it can use an LLDP message to carry TLV information of CDCP protocol, wherein said TLV information carries an initiation flag to indicate that this LLDP message is an S channel initiation request.

In the following, examples are described in which an LLDP message is used to carry TLV information of CDCP protocol, with a flag carried in said TLV information indicating an S channel suspension request or an S channel initiation request.

In an example, a field can be added in the TLV structure to store a suspension flag and/or an initiation flag. In another example, as described above, the TLV of CDCP protocol has two reserved fields Resvl and Resv2, and thus either of these fields can be used to store a suspension flag and/or an initiation flag. For example, the Resvl field can be used, wherein the value of this field is set to 1 to indicate that a corresponding LLDP message is an S channel suspension request and the value is set to 2 to indicate that a corresponding LLDP message is an S channel initiation request. It can be understood that only some bits in the Resvl field can be used to store a suspension flag and/or an initiation flag.

Moreover, it is clearly specified in IEEE802.1Qbg that, the data length of S channels that can be supported at maximum on each Ethernet interface is 167 bits. Thus, the SCID field only needs to occupy 8 bits. However, the SCID field currently occupies 12 bits, and there can be 4 bits used for storing a suspension flag and/or an initiation flag. In order to take into account the extension of the value of SCID, only one, two or three bits in these four bits can be used to store a suspension flag and/or an initiation flag. As shown by Fig. 4, which illustrates a schematic diagram of the structure of SCID/SVID in a TLV of CDCP protocol according to an example of the present disclosure, the twelve bits occupied by SCID are divided into 3 bits and 9 bits, wherein the first 3 bits are used to store the suspension flag and/or the initiation flag and are called the status field, and the last 9 bits are used to store the value of SCID, with the twelve bits occupied by SCID remaining unchanged. In this way, the value of the status field can be defined to distinguish between LLDP messages. For example, when the value of the status field is 0, it indicates that this LLDP message is an S channel creation request; when the value of the status field is 1 , it indicates that this LLDP message is an S channel suspension request; and when the value of the status field is 2, it indicates that this LLDP message is an S channel initiation request. Other possible values of the status field can be used for further extension.

With reference to Fig. 5, Fig. 5 is a schematic diagram of a device for configuring a state of an S channel according to an example. The device

500 can be used in a network comprising a virtual Ethernet switch, wherein a plurality of virtual machines (VM) are provided on the virtual Ethernet switch and the plurality of VMs exchange data therebetween through an S channel.

As shown, the device 500 comprises a sending unit 501 and a receiving unit 502. The sending

unit 501 is used to send a request for an S channel, through which the device 500 communicates

with a peer device (not shown), to the peer device; and the receiving unit 502 is used to receive a request for said S channel sent by the peer device, wherein the request is an S channel suspension request or an S channel initiation request. In an example, the request is an LLDP message carrying TLV information of CDCP protocol, wherein said TLV information carries a flag indicating suspension or initiation of an S channel. The device 500 can be one of a server and an edge switch and the peer device can be the other of the server and the edge switch.

According to an example, the sending unit 501 sends an S channel suspension request to a peer device if the device 500 needs to disable any S channel that is in normal communication and sends an S channel initiation request to the peer device if the device 500 needs to reinitiate any suspended S channel.

The sending unit 501 is further used to, upon sending a request, set an S channel to a corresponding state according to the sent request, and the receiving unit 502 is further used to, upon receiving a request, set an S channel to a corresponding state according to the received request. In an example, if the request is an S channel suspension request, the sending unit

501 or the receiving unit 502 can set the state of said S channel to be a suspended state; and if the request is an S channel initiation request, the sending unit 501 or the receiving unit 502 can further set the state of said S channel to be a normal communication state.

According to an example, upon receiving an S channel suspension request by the receiving unit 501 , the device 500 pauses receiving and sending a message through said S channel; and upon receiving an S channel initiation request by the receiving unit 501 , the device 500 restarts receiving and sending a message through said S channel.

With reference to Fig. 6, Fig. 6 is a schematic diagram of another device for configuring a state of an S channel according to another example. Fig. 6 is identical with Fig. 5, except that the device 600 further comprises a storage unit 603, which is used to store the state of an S channel.

In the following the hardware structure of a device according to an example of the present disclosure is presented. The device can be a programmable device implemented by combination of hardware and software. With reference to Fig. 7, Fig. 7 is a schematic diagram of hardware architecture of a device for configuring a state of an S channel according to an example. As shown, the device 700 includes a memory 710, a processor 720, a communication interface 730 and an interconnect mechanism 740 that couples the memory 710, the processor 720, and the communication interface 730.

Wherein the memory 710 is used to store state information of an S channel and can be a processor readable and writable medium, including but not limited to a non-permanent storage card, a floppy disk, a magnetic disk, a hard drive, an optical disk (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, or DVD+RW), a flash memory, a magnetic tape, a ROM and etc.

The processor 720 includes a sending module 721 and a receiving module 722, wherein the sending module 721 is used to send to the opposite end device an S channel suspension request or an S channel initiation request through a communication interface 730 and perform a corresponding S channel state setting; and the receiving module 722 is used to receive from the opposite end device an S channel suspension request or an S channel initiation request through the communication interface 730 and perform a corresponding S channel state setting.

Please be noted that the device shown in Fig. 7 is just a specific example and it can also be implemented in a device with a different structure from the present example. The present invention is not limited in this regard.

According to another example of the present disclosure, there is provided a method for notifying a state of an S channel for use in a network comprising a virtual Ethernet switch, wherein a plurality of virtual machines (VM) are provided on said virtual Ethernet switch and said plurality of VMs exchange data therebetween through an S channel. The method comprises: if a present device needs to disable any S channel that is in normal communication, sending to an opposite end device an S channel suspension request for suspending said S channel, to enable the opposite end device to pause receiving and sending a message through said S channel; and if the present device receives from the opposite end device an S channel suspension request for any S channel, pausing receiving and sending a message through said S channel.

In an example, when the present device sends to an opposite end device an S channel suspension request for suspending said S channel, it further sets the state of said S channel to be a suspended state; and after the present device receives from the opposite end device an S channel suspension request for any S channel, said method further comprises setting the state of said S channel to be a suspended state. According to this example, the method further comprises: when the present device needs to reinitiate any suspended S channel, sending to the opposite end device an S channel initiation request for this S channel, to enable the opposite end device to restart receiving and sending a message through said S channel; and when the present device receives from the opposite end device an S channel initiation request for any suspended S channel, restarting to receive and send a message through said S channel. In an example, when the present device sends to the opposite end device an S channel initiation request for this S channel, it further sets the state of said S channel to be a normal communication state; and after the present device receives from the opposite end device an S channel initiation request for any suspended S channel, the method further comprises setting the state of said S channel to be a normal communication state.

In an example, the S channel suspension request is an LLDP message carrying TLV information of CDCP protocol, wherein said TLV information carries a suspension flag; and the S channel initiation request is an LLDP message carrying TLV information of CDCP protocol, wherein said TLV information carries an initiation flag. Wherein, the present device is a server and the opposite end device is an edge switch; or the present device is an edge switch and the opposite end device is a server.

According to yet another example of the present disclosure, there is provided a device for notifying a state of an S channel for use in a network comprising a virtual Ethernet switch, wherein a plurality of virtual machines (VM) are provided on said virtual Ethernet switch and said plurality of VMs exchange data therebetween through an S channel, wherein said device comprises a sending unit and a receiving unit. The sending unit is used to, if a present device needs to disable any S channel that is in normal communication, send to an opposite end device an S channel suspension request for suspending said S channel to enable the opposite end device to pause receiving and sending a message through said S channel; and the receiving unit is used to receive from the opposite end device an S channel suspension request for any S channel so as to pause receiving and sending a message through said S channel. Wherein, the present device is a server and the opposite end device is an edge switch; or the present device is an edge switch and the opposite end device is a server.

According to an example, said device further comprises a storage unit. When said sending unit sends to an opposite end device an S channel suspension request for suspending said S channel, it further sets the state of said S channel to be a suspended state and stores the state in said storage unit; and after said receiving unit receives from the opposite end device an S channel suspension request for any S channel, it is further used to set the state of said S channel to be a suspended state and store the state in said storage unit.

The sending unit is further used to, when the present device needs to reinitiate any suspended S channel, send to the opposite end device an S channel initiation request for this S channel, to enable the opposite end device to restart receiving and sending a message through said S channel; and the receiving unit is further used to receive from the opposite end device an S channel initiation request for any suspended S channel so as to restart receiving and sending a message through said S channel.

When sending to the opposite end device an S channel initiation request for this S channel, the sending unit is further used to set the state of said S channel to be a normal communication state and store the state in said storage unit; and after receiving from the opposite end device an S channel initiation request for any suspended S channel, the receiving unit is further used to set the state of said S channel to be a normal communication state and store the state in said storage unit.

By transmitting an S channel suspension request message and an S channel initiation request message between the server and the edge switch, an example of the present disclosure can enable the server and the edge switch to detect the state of an S channel in time so as to decrease traffic loss due to temporary interrupt of an S channel. In addition, according to an example of the present disclosure, both the edge switch and the server can initiate an S channel suspension request, which can satisfy the need of pausing traffic on an S channel at the side of the edge switch. Further, when there is need to temporarily disable an S channel, a way of suspending the S channel may be adopted which can avoid removal and recreation of the S channel, thereby reducing time and resource consumption at both sides.

The above examples can be implemented by hardware, software or firmware or a combination thereof. For example the various methods, processes and functional modules described herein may be implemented by a processor (the term processor is to be interpreted broadly to include a CPU, processing unit, ASIC, logic unit, or programmable gate array etc.). The processes, methods and functional modules may all be performed by a single processor or split between several processers; reference in this disclosure or the claims to a 'processor' should thus be interpreted to mean One or more processors' . The processes, methods and functional modules may be implemented as machine readable instructions executable by one or more processors, hardware logic circuitry of the one or more processors or a combination thereof. Further the teachings herein may be implemented in the form of a software product. The computer software product is stored in a storage medium and comprises a plurality of instructions for making a computer device (which can be a personal computer, a server or a network device such as a router, switch, access point etc.) implement the method recited in the examples of the present disclosure.

The figures described herein are only illustrations of an example, wherein the modules or procedure shown in the figures are not necessarily essential for implementing the present disclosure. Moreover, the sequence numbers of the above examples are only for description, and do not indicate an example is more superior to another.

The modules in the device in the example can be arranged in the device in the example as described in the example, or can be alternatively located in one or more devices different from that in the example. The modules in the aforesaid example can be combined into one module or further divided into a plurality of sub-modules.

Although the flow diagrams described above show a specific order of execution, the order of execution may differ from that which is depicted. For example, the order of execution of two or more blocks may be scrambled relative to the order shown. Also, two or more blocks shown in succession may be executed concurrently or with partial concurrence. All such variations are within the scope of the present invention.

Claims

1. A method for configuring a state of an S channel comprising:

sending, by one of a first device and a second device which is to communicate with said first device via an S channel, a request for said S channel to the other of said first device and said second device, wherein said request is an S channel suspension request or an S channel initiation request.

2. The method according to claim 1 , wherein said one of said first device and said second device sends an S channel suspension request if it needs to disable any S channel that is in normal communication and sends an S channel initiation request if it needs to reinitiate any suspended S channel.

3. The method according to claim 1 , further comprising: if said request is an S channel suspension request, at least one of said first device and said second device sets the state of said S channel to be a suspended state; and if said request is an S channel initiation request, at least one of said first device and said second device sets the state of said S channel to be a normal communication state.

4. The method according to claim 1 , further comprising: upon receiving said S channel suspension request, the other of said first device and said second device pauses receiving and sending a message through said S channel.

5. The method according to claim 1 , further comprising: upon receiving said S channel initiation request, the other of said first device and said second device restarts receiving and sending a message through said S channel.

6. The method according to claim 1 , wherein said first device is a server and said second device is an edge switch.

7. The method according to claim 1 , wherein said request is an LLDP message carrying TLV information of CDCP protocol, wherein said TLV information carries a flag indicating suspension or initiation of an S channel.

8. A device for configuring a state of an S channel, wherein said device comprises:

a sending unit, to send a request for an S channel through which said device is to communicate with a peer device, to said peer device; and

a receiving unit, to receive a request for said S channel sent by said peer device, wherein said request is an S channel suspension request or an S channel initiation request.

9. The device according to claim 8, wherein said sending unit sends an S channel suspension request to said peer device if said device is to disable any S channel that is in normal communication and sends an S channel initiation request to said peer device if said device is to reinitiate any suspended S channel.

10. The device according to claim 8, wherein said sending unit is further to, upon sending a request, set said S channel to a corresponding state according to said sent request, and wherein said receiving unit is further to, upon receiving a request, set said S channel to a corresponding state according to said received request.

11. The device according to claim 10, wherein said device further comprises a storage unit to store the state of an S channel.

12. The device according to claim 10, wherein if said request is an S channel suspension request, said sending unit or said receiving unit is further to set the state of said S channel to be a suspended state; and

if said request is an S channel initiation request, said sending unit or said receiving unit is further to set the state of said S channel to be a normal communication state.

13. The device according to claim 8, wherein upon receiving said S channel suspension request by said receiving unit, said device pauses receiving and sending a message through said S channel; and wherein upon receiving said S channel initiation request by said receiving unit, said device restarts receiving and sending a message through said S channel.

14. The device according to claim 8, wherein said device is one of a server and an edge switch and said peer device is the other of said server and said edge switch.

15. The device according to claim 8, wherein said request is an LLDP message carrying TLV information of CDCP protocol, wherein said TLV information carries a flag indicating suspension or initiation of an S channel.