JP2007036455A - Network control method and information processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the drawbacks that superimposition of IP addresses occurs during resuming if a client shifts to a sleeping mode while maintaining an IP address, and that it takes a long time for resuming in a method in which the client shifts to a sleeping mode after releasing the IP address when shifted to the sleeping mode, in a resuming method of an information processing apparatus in a DHCP (dynamic host configuration protocol) environment. <P>SOLUTION: In acquiring an IP address, first, an IP address having an unlimited lease period is requested. If it is rejected, a time valid for power management (e.g. one day) is required. If it is rejected, a server is selected for supplying a time IP address having the longest lease period and after that, power management control is performed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control technology for an apparatus equipped with a resume function in various devices in a local area network (LAN) environment.

  The local area network (LAN) has a protocol called DHCP (Dynamic Host Configuration Protocol). DHCP is a method in which a DHCP server is installed on a network and an IP address is dynamically assigned to a client PC similarly connected to the network (see Non-Patent Document 1).

  When a fixed IP is used, a network administrator manages an IP address, assigns this IP to each client, and the client needs to set this IP address. In a network environment in which this fixed IP address is allocated, the administrator must always manage the network, which places a burden on the administrator, and a misconfiguration of the client's IP address can greatly affect the network. There is sex.

  However, in DHCP, it becomes possible for a DHCP server to automatically assign an IP address in response to a request from a client PC connected to the network. For this reason, by using DHCP, it has been possible to save the troublesome work of resetting the IP address every time the network configuration is changed.

  In DHCP, there are the following three methods for assigning IP addresses.

  In "automatic assignment", DHCP assigns an address that the client can use all the time. In “dynamic allocation”, the DHCP server leases an address to the client PC for a certain period of time. In “manual assignment”, the network administrator determines an IP address to be assigned, and the DHCP server is used only for distributing the IP address to the client PC.

  Among these methods, “dynamic allocation” is a method in which a DHCP server allocates an IP address to a client PC for a certain period. This “dynamic allocation” mechanism requests that a client wants to use an IP address, and when a DHCP server allocates an IP address, the IP address is not allocated to another client. If a client leaves the network, the DHCP server may assign the same IP address to other clients. This reuse operation prevents IP address exhaustion. Since such a limited IP address can be used efficiently, it is most often used.

  In this “dynamic allocation”, the IP address is leased by negotiating between the server and the client as follows.

  1) Broadcast a DHCPDISCOVER signal requesting an IP address.

  2) Receive a DHCPOFFER signal, which is a response from the DHCP server.

  3) Send DHCPREQUEST requesting DHCP server to assign IP address.

  4) Receive a DHCPACK telling that the DHCP server has assigned an IP address.

  On the other hand, in recent years, mobile devices such as notebook personal computers have become widespread, but such mobile devices are required to reduce power consumption and be able to be used for a longer time with a built-in battery.

  In recent years, there has been a worldwide movement to promote a reduction in power consumption. There are cases where restrictions are set, such as not permitting sales of electrical appliances that have regulations at the national level and that do not meet environmental regulations. In the future, regulations on power consumption will also become stricter.

  For this reason, it is considered that it is necessary to provide a resume function for the devices that will be put on the market in the future. The resume function is a function that stops part of the function while the user is not using it, reduces power consumption, and returns to the normal state when there is a user operation or access from another host used by the user. is there.

  However, there is a problem with using the resume function in the DHCP environment.

  As a resume method in the DHCP environment, when the client shifts to the sleep mode while holding the IP address, duplication of the IP address occurs during the resume. On the other hand, if the method of entering the sleep mode after releasing the IP address at the time of transition to the sleep mode is required, negotiation for the IP address lease as described above is necessary, and thus it takes a long time for resuming.

In order to avoid this problem, a conventional technique has been proposed in which when a certain network device enters a sleep mode, another network device performs packet processing on behalf of the other network device (see Patent Document 1).
RFC2131 (Network Working Group Request for Comments: 2131) Japanese Patent No. 3342507

  However, in the conventional technique, a device that performs packet processing on behalf of the proxy cannot enter the sleep mode.

  In addition, trouble occurs when the proxy network device is in the sleep mode or turned off, or when the network configuration is changed.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a network control method and an information processing apparatus that can save power by reducing the frequency of resume for IP acquisition. There is.

  According to the first aspect of the present invention, in the network control method of the information processing apparatus having the network communication control means and the power saving function, the lease expiration time is longer when performing control to acquire the IP address according to the DHCP protocol when connected to the network. A network control method characterized by performing control for acquiring an IP address.

  According to the second aspect of the present invention, in the network control method, when performing control to acquire an IP address according to a DHCP protocol when connected to a network, a packet requesting an IP address with an indefinite lease time limit is transmitted. The network control method according to claim 1, wherein

  According to a third aspect of the present invention, in the network control method, after transmitting a packet requesting an IP address whose lease term is indefinite, a packet permitting the use of one or more IP addresses is received. 3. The network control method according to claim 2, wherein when there is a server that provides an IP address that has an indefinite lease period, a server that provides an IP address that has an indefinite lease period is selected.

  According to a fourth aspect of the present invention, in the network control method, when a packet requesting an IP address with an indefinite lease period is transmitted and no packet permitting use of the IP address is received, the power management of the apparatus 3. The network control method according to claim 2, wherein a packet for requesting an IP address is transmitted by setting a valid lease term for the IP address.

  According to a fifth aspect of the present invention, in the network control method, if a packet requesting use of an IP address is not received after transmitting a packet requesting an IP address whose lease time is indefinite, the lease time is not expired. 3. The network control method according to claim 2, wherein a request for an expiration date is removed and a packet requesting an IP address is transmitted again.

  According to a sixth aspect of the present invention, in the network control method, after transmitting a packet requesting an IP address whose lease time is indefinite, a packet permitting use of one or more IP addresses is received, 3. The network according to claim 2, wherein when there is no server that provides an IP address whose lease term is indefinite, the request for the lease term is indefinite and the packet requesting the IP address is transmitted again. It is a control method.

  The invention according to claim 7 is the network control method, wherein a packet requesting use of one or more IP addresses is received after transmitting a packet requesting an IP address whose lease time is indefinite, 3. The network control method according to claim 2, wherein when there is no server that provides an IP address whose lease term is indefinite, a server that provides a lease term effective for power management of the apparatus is selected.

  According to an eighth aspect of the present invention, in the network control method, after transmitting a packet requesting an IP address whose lease time is indefinite, a packet permitting the use of one or more IP addresses is received. If there is no server that provides an IP address with an indefinite lease period, and there is no server that provides a lease period that is valid for power management of the device, the request with an indefinite lease period is removed, 8. The network control method according to claim 7, wherein a packet requesting an IP address is transmitted again.

  According to a ninth aspect of the present invention, in the network control method of the information processing apparatus having the network communication control means and the power saving function, when performing control for acquiring the IP address according to the DHCP protocol when connected to the network, the power management of the apparatus 2. The network control method according to claim 1, wherein a valid lease term is set and a packet requesting an IP address is transmitted.

  The tenth aspect of the present invention is the network control method, wherein a lease period is set, and after a packet requesting an IP address is transmitted and a packet permitting use of the IP address is not received, the lease period required The network control method according to claim 9, wherein a packet permitting use of the IP address is transmitted again without setting the IP address.

  According to the eleventh aspect of the present invention, in the network control method of the information processing apparatus having the network communication control means and the power saving function, the IP address is acquired when performing control to acquire the IP address according to the DHCP protocol when connected to the network 2. The network control method according to claim 1, further comprising: selecting a server that provides an IP address having a long lease period when receiving a packet permitting the use of one or more IP addresses after transmitting a packet for transmitting the packet. is there.

  In the network control method according to the twelfth aspect of the present invention, in the network control method, when a server that provides an IP address whose lease time is not indefinite is selected, the control is resumed for each lease period and re-acquisition of the IP address is requested. The network control method according to claim 1, wherein the network control method is performed.

  According to a thirteenth aspect of the present invention, in the network control method for an information processing apparatus having a network communication control means and a power saving function, the communication control means according to the first to twelfth aspects is provided.

  According to a fourteenth aspect of the present invention, in the network control method for an information processing apparatus having a network communication control means and a power saving function, the information processing apparatus includes the server selection means according to the third, seventh, and eleventh aspects. .

  According to the present invention, when acquiring an IP address, first, an IP address with an infinite lease period is requested. If it is rejected, it requests power management for a valid time (eg 1 day). If it is rejected, the server that supplies the IP address for the longest lease period is selected, and then power management control is performed.

  By performing this control, the frequency of resuming for IP acquisition can be reduced, so that power can be saved.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
FIG. 1 is a configuration diagram of an image forming apparatus that performs power management control in a network environment according to Embodiment 1 of the present invention.

  In the embodiment described below, an example using an image forming apparatus connected to a host is given. However, the present invention is not limited to the image forming apparatus, and other peripheral devices or a host PC may be connected to a network. The information processing apparatus is included in the subject of the present invention.

  In FIG. 1, reference numeral 100 denotes an overall configuration diagram of an image forming apparatus. A controller unit 110 processes data received from the host. An operation panel unit 119 includes keys for setting the state of the image forming apparatus, a liquid crystal panel for performing display, and LEDs.

  A controller CPU 111 controls a controller unit of the image forming apparatus. A ROM 112 stores a program for controlling the controller unit. Reference numeral 113 denotes a RAM, which is a readable / writable memory. An image forming unit 114 processes the received image and prints it. A network communication control unit 115 is connected to the network environment, and can receive image data from a host connected to the network environment and print it on the image forming apparatus. Reference numeral 116 denotes an RTC (Real Time Clock), which manages a return time for extending the lease of the IP address. An operation panel I / F unit 118 communicates with the operation panel.

  FIG. 2 is a flowchart for acquiring an IP address at the time of start-up by the client in this embodiment.

  In the following explanation, there is an optional part, but permission / non-permission and reply / ignore are determined by the policy of the server administrator, so the flow must be determined in consideration of all possibilities. Don't be.

  In S201, the lease indefinite IP address is set in the requested configuration, and DHCPDISCOVER is transmitted. Upon receiving DHCPDISCOVER, the server may send a DHCPOFFER only when it can respond to the request by looking at the configuration, or may ignore the configuration and send a DHCPOFFER. The client waits for an arbitrary time in S202. At this time, multiple DHCPOFFERs may be received. If DHCPOFFER is received as a result of waiting for an arbitrary time, the process proceeds to S203. If DHCPOFFER is not received from the server, the process proceeds to S211. In S203, the received configuration information is checked. If there is a server that supplies an IP address with an indefinite lease in S204, the process proceeds to S205. If there is no server that supplies an IP address for a lease indefinite period, the process proceeds to S225.

  In S205, a server that supplies an IP address with an indefinite lease is selected. In S206, DHCPREQUEST is transmitted to request an IP address.

  In S207, it is confirmed whether or not the server has received a DHCPACK that acknowledges the supply of the IP address. If DHCPNACK instead of DHCPACK is received or if there is no response, the IP address cannot be used, so the process returns to S201 and starts from transmitting the first DHCPDISCOVER. If DHCPACK is confirmed, the IP address is stored in S208. Thereafter, the process proceeds to S251.

  In S221, a DHCPDISCOVER requesting the DHCP IP address is transmitted. The server receives DHCPDISCOVER and sends DHCPOFFER if there is an IP address to be assigned. The client waits for an arbitrary time in S222. At this time, multiple DHCPOFFERs may be received. If DHCPO FFER is received as a result of waiting for an arbitrary time, the process proceeds to S223. If DHCPOFFER is not received from the server, the process returns to S221. If there is no DHCPOFFER even after repeated several times, a timeout error occurs, the IP address cannot be acquired, and the network cannot be connected. In S223, the received configuration information is checked.

  In S225, the server with the longest lease period is selected. In S216, DHCPREQUEST is transmitted to request an IP address.

  In step S227, it is confirmed whether or not the server has received a DHCPACK that acknowledges the supply of the IP address. If DHCPNACK is received or no reply is received, the IP address cannot be used, so the process returns to S221 and starts by sending DHCPDISCOVER. If DHCPACK is confirmed, the IP address is stored in S228. Thereafter, the process proceeds to S252.

  In S251, sleep mode 1 is set.

  In S252, the sleep mode 2 is set.

  The contents of the sleep modes 1 and 2 will be described later.

  After the above processing, it enters a standby state.

  FIG. 3 is a flowchart for explaining the operation of the server and the client in the sleep mode 1 in this embodiment.

  After a predetermined time in the standby state, in S311, the mode shifts to the sleep mode. A dotted line indicates an operation in the sleep mode. In S312, a Wake Up signal is awaited. If a signal is received, the standby state is restored in S313. In step S314, printing is executed. After the printing is completed, the printer waits for a predetermined time and shifts to the sleep mode in step S311. In this case, since the lease period of the IP address is set indefinitely, there is no need to resume for lease extension.

  FIG. 4 is a flowchart for explaining the operation of the server and the client in the sleep mode 2 in the present embodiment.

  After a certain time in the standby state, DHCPREQEST is transmitted in S411. If the server receives DHCPREQEST in S401 and the IP address can be re-released, the server transmits DHCPACK in S402. When the client receives DHCPACK in S412, the client shifts to the sleep mode in S413. A dotted line indicates an operation in the sleep mode. In S414, it waits for a Wake Up signal. If a signal is received, the standby state is restored in S417. In step S418, printing is performed. After the printing is finished, a predetermined time is waited. In steps S411 and S412, a DHCP lease extension operation is performed, and in step S413, the sleep mode is entered again.

  In S414, when T time set as the lease period has passed without receiving Wake Up, the lease state of the IP address is postponed, so that the standby state is restored in S416. Thereafter, the DHCP lease extension operation is performed in S411 and S412, and the sleep mode is again entered in S413.

  In sleep mode 2, the information processing apparatus resumes every time the lease period approaches, but depending on the nature of the apparatus, the information processing apparatus may consume more power than usual during warm-up. When this device is provided in an environment where the DHCP lease period is extremely short, the power consumption may increase due to the power management control. In this case, it is better not to enter sleep mode. Therefore, a minimum lease period for performing this control is determined depending on the nature of the apparatus, and control is performed so as not to enter the sleep mode when the lease period is not reached.

<Embodiment 2>
This embodiment is an example in consideration of a case where a request for extending the lease period is permitted after an IP address having an infinite lease period is requested.

  Although this control complicates the control, it can save more power than the first embodiment.

  FIG. 5 is a flowchart for acquiring an IP address when the client is started in the present embodiment.

  In the following explanation, there is an optional part, but permission / non-permission and reply / ignore are determined by the policy of the server administrator, so the flow must be determined in consideration of all possibilities. Don't be.

  In S201, an IP address with an indefinite lease is set in the requested configuration, and DHCPDISCOVER is transmitted. Upon receiving DHCPDISCOVER, the server may send a DHCPOFFER only when it can respond to the request by looking at the configuration, or may ignore the configuration and send a DHCPOFFER. The client waits for an arbitrary time in S202. At this time, multiple DHCPOFFERs may be received. If DHCPOFFER is received as a result of waiting for an arbitrary time, the process proceeds to S203. If DHCPOFFER is not received from the server, the process proceeds to S211. In S203, the received configuration information is checked. If there is a server that supplies an IP address with an indefinite lease in S204, the process proceeds to S205. If there is no server that supplies an IP address for a lease indefinite period, the process proceeds to S210.

  In S205, a server that supplies an IP address with an indefinite lease is selected. In S206, DHCPREQUEST is transmitted to request an IP address.

  In S207, it is confirmed whether or not the server has received a DHCPACK that acknowledges the supply of the IP address. If DHCPNACK instead of DHCPACK is received or if there is no response, the IP address cannot be used, so the process returns to S201 and starts from transmitting the first DHCPDISCOVER. If DHCPACK is confirmed, the IP address is stored in S208. Thereafter, the process proceeds to S251.

  If there is a server satisfying the requested IP lease period T1 in the received DHCPOFFER configuration in S210, the process proceeds to S215.

  In S211, the lease period T1 is set in the requested configuration, and DHCPDISCOVER is transmitted. Upon receiving DHCPDISCOVER, the server may send a DHCPOFFER only when it can respond to the request by looking at the configuration, or may ignore the configuration and send a DHCPOFFER. The client waits for an arbitrary time in S212. At this time, multiple DHCPOFFERs may be received. If DHCPOFFER is received as a result of waiting for an arbitrary time, the process proceeds to S213. If DHCPOFFER is not received from the server, the process proceeds to S221. In S213, the received configuration information is checked. If there is a server that supplies the IP address of the lease period T1 in S214, the process proceeds to S215. If there is no server that supplies the IP address of the lease period T1, the process proceeds to S221.

  In S215, the server that supplies the IP address of the lease period T1 is selected. In S216, DHCPREQUEST is transmitted to request an IP address.

  In S217, it is confirmed whether or not the server has received a DHCPACK that acknowledges the supply of the IP address. If DHCPNACK is received or no response is received, the IP address cannot be used, so the process returns to S211 and starts from transmitting DHCPDISCOVER. If DHCPACK is confirmed, the IP address is stored in S218. Thereafter, the process proceeds to S252.

S
In 221, a DHCPDISCOVER requesting the DHCP IP address is transmitted. The server receives DHCPDISCOVER and sends DHCPOFFER if there is an IP address to be assigned. The client waits for an arbitrary time in S222. At this time, multiple DHCPOFFERs may be received. If DHCPO FFER is received as a result of waiting for an arbitrary time, the process proceeds to S223. If DHCPOFFER is not received from the server, the process returns to S221. If there is no DHCPOFFER after repeated several times, a time-out error occurs, the IP address cannot be acquired, and the network is not connected. In S223, the received configuration information is checked.

  In S225, the server with the longest lease period is selected. In S216, DHCPREQUEST is transmitted to request an IP address.

  In step S227, it is confirmed whether or not the server has received a DHCPACK that acknowledges the supply of the IP address. If DHCPNACK is received or no reply is received, the IP address cannot be used, so the process returns to S221 and starts by sending DHCPDISCOVER. If DHCPACK is confirmed, the IP address is stored in S228. Thereafter, the process proceeds to S252.

  In S251, sleep mode 1 is set.

  In S252, the sleep mode 2 is set.

  The contents of the sleep modes 1 and 2 will be described later.

  After the above processing, it enters a standby state.

1 is a configuration diagram of an image forming apparatus that performs power management control in a network environment according to Embodiment 1 of the present invention. FIG. It is a flowchart for the client in Embodiment 1 of this invention to acquire an IP address at the time of starting. It is a flowchart explaining the operation | movement of the server and client in the sleep mode 1 in Embodiment 1 of this invention. It is a flowchart explaining the operation | movement of the server and client in the sleep mode 2 in Embodiment 1 of this invention. It is a flowchart for the client in 2 of embodiment of this invention to acquire an IP address at the time of starting.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 110 Controller part 111 CPU
112 ROM
113 RAM
114 Image forming unit 115 Network control unit 116 RTC
118 Operation panel I / F section 119 Operation panel section

Claims (14)

In a network control method for an information processing apparatus having a network communication control means and a power saving function,
A network control method characterized by performing control for acquiring an IP address having a longer lease term when performing control for acquiring an IP address according to a DHCP protocol at the time of network connection.   2. The network control method according to claim 1, wherein a packet requesting an IP address with an indefinite lease period is transmitted when performing control to acquire an IP address according to a DHCP protocol when connected to the network.   After transmitting a packet requesting an IP address with an indefinite lease period, a server that receives one or more IP address-permitted packets and provides an IP address with an indefinite lease period 3. The network control method according to claim 2, wherein if there is a server, a server that provides an IP address whose lease term is indefinite is selected.   After transmitting a packet requesting an IP address with an indefinite lease period, if a packet permitting use of the IP address is not received, a lease period that is valid for the power management of the device is set, and the IP address is 3. The network control method according to claim 2, wherein a request packet is transmitted.   After transmitting a packet requesting an IP address with an indefinite lease period, if a packet permitting use of the IP address is not received, the request with an indefinite lease period is removed and the IP address is requested again The network control method according to claim 2, wherein the packet is transmitted.   After transmitting a packet requesting an IP address with an indefinite lease period, a server that receives one or more IP address-permitted packets and provides an IP address with an indefinite lease period 3. The network control method according to claim 2, wherein if there is no request, the request with an indefinite lease period is removed, and a packet requesting an IP address is transmitted again.   After transmitting a packet requesting an IP address with an indefinite lease period, a server that receives one or more IP address-permitted packets and provides an IP address with an indefinite lease period 3. The network control method according to claim 2, wherein if there is no server, a server that provides a lease term effective for power management of the apparatus is selected.   After transmitting a packet requesting an IP address with an indefinite lease period, a server that receives one or more IP address-permitted packets and provides an IP address with an indefinite lease period In addition, when there is no server that provides a lease term effective for power management of the apparatus, the request for the lease term is indefinite and the packet requesting the IP address is transmitted again. The network control method according to claim 7. In a network control method for an information processing apparatus having a network communication control means and a power saving function,
2. A packet for requesting an IP address is set by setting a lease term effective for power management of a device when performing control for acquiring an IP address according to a DHCP protocol when connected to a network. The network control method described.   After transmitting a packet requesting an IP address after setting a lease period, if a packet permitting use of the IP address is not received, a packet permitting the use of the IP address again without setting the requested lease period The network control method according to claim 9, wherein: In a network control method for an information processing apparatus having a network communication control means and a power saving function,
When performing control to acquire an IP address according to the DHCP protocol when connected to the network, if a packet permitting use of one or more IP addresses is received after transmitting a packet for acquiring an IP address, the lease period is 2. The network control method according to claim 1, wherein a server that provides a long IP address is selected.   The control according to any one of claims 1 to 7, wherein when a server that provides an IP address whose lease term is not indefinite is selected, control is resumed for each lease period and re-acquisition of the IP address is requested. The network control method according to any one of the above. In a network control method for an information processing apparatus having a network communication control means and a power saving function,
An information processing apparatus comprising the communication control means according to claim 1. In a network control method for an information processing apparatus having a network communication control means and a power saving function,
An information processing apparatus comprising the server selection unit according to claim 3.

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