JP2001136194A - Remote access server - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remote access server that can complete IP address assignment negotiation processing in a shorter time in the case of connecting a user terminal to a network. SOLUTION: The remote access server 110 is provided with a dialup server section 111 that conducts line connection to a user terminal 140 and IP address assignment negotiation, a communication processing section 112 that conducts major communication protocol processing, a DHCP message processing section 113 that makes communication and IP address assignment negotiation with DHCP servers 120, 130, and a network interface section 114. The DHCP message processing section 113 makes IP address assignment negotiation with the DHCP server in place of the user terminal 140 in the case of network connection to the user terminal 140 and adopts a reply received first unconditionally during waiting of a reply after broadcasting an assignment request to a network 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote access server device for connecting a user terminal device outside a network to a network.

[0002]

2. Description of the Related Art In recent years, users of information communication networks such as the Internet have been increasing. In order to connect a terminal device to the Internet, which is a network of the IP protocol, it is necessary to assign an IP address to each terminal device, but since the IP addresses are limited,
DHCP (Dynamic) for sharing a limited IP address when a plurality of terminal devices are required
Host Confi-guration Proto
col) protocol was developed. Below, the conventional DH
4 shows an example of IP address assignment negotiation according to the CP protocol.

FIG. 4 shows a terminal A (DHC) on a network.
FIG. 9 is an operation sequence diagram showing an operation flow of IP address assignment negotiation between a P client), a DHCP server A, and a DHCP server 130.

[0004] In FIG. 4, first, a terminal A receives an assignment request (D
An ISCOVER message) is broadcasted to broadcast on the network that an IP address is requested (S21). Each DHCP server A, 130 that has received the DISCOVER message responds (OF
FER message), and notifies terminal A that the IP address can be provided (S22). The terminal A collects the OFFER messages while waiting for a certain period, and selects an optimum one from the received OFFER messages. The terminal A broadcasts a request message (REQUEST message) including the selected server device information, and broadcasts which DHCP server has been selected (S23). Each DHCP server A 130 receiving the request message determines whether or not it has been selected from the server device information included in the request message. The selected DHCP server A checks the parameters and returns an ACK message to terminal A (S24). DHCP server 1 not selected
30 ends the negotiation process. In this way, the IP address is leased from the DHCP server A to the terminal A for a certain period.

[0005] In the above example, DHCP is used on the network.
There is a client (terminal A), but the subject of the lease of the IP address is not a terminal device on the network, but a remote user terminal device connected to the network through a remote access server device on the network.
(Hereinafter simply referred to as “user terminal device”), it is possible to negotiate an IP address by the DHCP protocol. In this case, the remote access server device communicates with the DHCP server device on behalf of the DHCP client. After negotiation, the assigned IP address is further assigned to the user terminal device.

[0006]

As described above, even if the subject of the lease of the IP address is not the terminal device on the network but the user terminal device connected to the network through the remote access server device on the network, the DHCP protocol is used. In such a case, during the connection process between the user terminal device and the remote access server device, IP address allocation negotiation between the remote access server device and the DHCP server device is performed. The process is entered, and a request is generated that the negotiation process must be completed in as short a time as possible. Therefore, in such a case, OFFER is required during negotiation as in the conventional IP address negotiation procedure.
There is a problem that the whole connection processing time becomes longer if the procedure including the waiting time for message collection is left as it is.

[0007] In this remote access server device, D is transmitted to the user terminal device through the remote access server device.
When assigning an IP address from the HCP server device, it is required that the IP address assignment negotiation process be completed in a shorter time.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a remote access server device capable of terminating an IP address assignment negotiation process in a shorter time when a user terminal device connects to a network.

[0009]

A remote access server device according to the present invention for solving this problem performs a main communication protocol process with a dial-up server unit which performs from a line connection with a user terminal device to negotiation of an IP address assignment. Communication processing unit, communication with DHCP server device, IP
A DHCP message processing unit for negotiating an address assignment;
A remote access server device having a network interface unit, wherein the DHCP message processing unit negotiates an IP address with the DHCP server device on behalf of the user terminal device when the user terminal device is connected to the network, and issues an allocation request. A configuration is provided in which a response first received during a response wait after being broadcast on the network is unconditionally adopted.

Thus, a remote access server device capable of completing the IP address assignment negotiation process by the DHCP protocol in a shorter time when connecting the user terminal device to the network is obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A remote access server according to a first aspect of the present invention includes a dial-up server for performing a process from line connection to a user terminal to negotiation of an IP address assignment, and a communication processing unit for performing a main communication protocol process. , A DHCP message processing unit for communicating with a DHCP server device and negotiating an IP address assignment, and a network interface unit, wherein the DHCP message processing unit is connected to the user terminal device when the user terminal device is connected to the network. DH on behalf of
Negotiate IP address assignment with the CP server device,
The response received first during the response waiting after the broadcast of the assignment request on the network is unconditionally adopted.

According to this configuration, there is no waiting time for collecting the OFFER message (response) during the negotiation of the IP address assignment, and the IP address assignment negotiation process by the DHCP protocol is completed immediately.

A remote access server according to a second aspect of the present invention communicates with a dial-up server which performs from a line connection with a user terminal to an IP address assignment negotiation, a communication processing which performs a main communication protocol process, and a DHCP server. , A remote access server device having a DHCP message processing unit for negotiating an IP address assignment and a network interface unit, comprising:
The message processing unit negotiates an IP address with the DHCP server device on behalf of the user terminal device when the user terminal device is connected to the network, and receives the first while waiting for a response after broadcasting the allocation request on the network. The response is adopted unconditionally, and when a response is received from another DHCP server device, a dummy request message is transmitted to another DHCP server device.

[0014] This configuration has the effect of preventing unnecessary consumption of IP address resources in another DHCP server device that has received the dummy request message.

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1 is a block diagram showing a network system having a remote access server device according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 100 denotes a LAN (local area network); 110, a remote access server connected to the LAN 100;
DHCP server connected to 00, 130 is also LA
A DHCP server 140 connected to the N100 is connected to the network (LA) through the remote access server 110.
N) A user terminal that accesses 100. The remote access server 110 communicates with the dial-up server unit 111 that performs from the line connection with the user terminal 140 to the negotiation of the IP address assignment, the communication processing unit 112 that performs the main communication protocol processing, and the DHCP servers 120 and 130, and performs the IP address assignment negotiation. Message processing unit 113 for performing
And

The operation of the remote access server 110 thus configured will be described with reference to FIG. FIG. 2 mainly illustrates the operation between the respective devices when the user terminal 140 connects to the LAN 100 through the remote access server 110 in the network system of FIG.
FIG. 4 is an operation sequence diagram focusing on the HCP protocol.

In FIG. 2, a user terminal 140 to be connected to the LAN 100 first requests the remote access server 110 to connect a data link (S0).
1). The processing in step S01 includes the user terminal 1
40, connection of telephone calls and wireless calls, which are physical line connections between the remote access servers 110, and setting processing of an IP lower layer protocol (often a PPP protocol). The dial-up server unit 111 of the remote access server 110, which has received the connection request from the user terminal 140, uses an internal message to start a negotiation process to receive an address lease from the DHCP server device after the end of processing such as user authentication. Request to the message processing unit 113. As a result, the remote access server 110 starts negotiation of IP address assignment with the DHCP server device. After that, D on LAN100
The exchange of messages with the HCP servers 120 and 130 is performed by the communication processing unit 112 and the network interface unit 1
14. The communication processing unit 112 includes the DHCP servers 120 and 13 in the layers below the DHCP protocol.
Responsible for communication processing with 0.

First, the remote access server 110
A DISCOVER message (assignment request) for searching for a DHCP server device that performs P address lease is broadcast to the LAN 100 (S02). DISC
Each DHCP server 12 that has received the OVER message
0 and 130 are OF if an IP address can be assigned
It returns an FER message (response) and notifies the remote access server 110 by broadcast transmission that the IP address can be provided (S03). The remote access server 110 waits for the OFFER message after transmitting the DISCOVER message, and
When a positive OFFER message is received from the server device, the OFFER message is immediately adopted without waiting for an OFFER message from another server device, and the process proceeds to the next process. In FIG. 2, the return of the OFFER message from the DHCP server 120 is earlier than the return of the DHCP server 130. The remote access server 110 again broadcasts a request message (REQUEST message) including the selected server device information, and broadcasts the selection of the DHCP server 120 to the LAN 100 (S04).

Each DHC that has received a request message
The P servers 120 and 130 determine whether or not they have been selected from the server device information included in the request message. The selected DHCP server 120 checks the parameters and returns an ACK message to the remote access server 110 (S05). The DHCP server 130 not selected ends the negotiation process. In this way, the IP address is lent to the remote access server 110 from the DHCP server 120 for a certain period. I
Remote access server 1 with leased P address
10 notifies the address to the user terminal 140 (S
06) Then, the user terminal 140 can use the IP address. Also, the remote access server 110
A data link setting confirmation message including confirmation of setting items other than the IP address is transmitted to the user terminal 140 (S07), and the connection between the user terminal 140 and the remote access server 110 is determined. In this way, the processing time of steps S01 to S07 is shortened as much as possible.
Address negotiation processing can be performed.

As described above, in the present embodiment, the DHCP message processing unit 113 of the remote access server 110
First OFFE after sending DISCOVER message to
By providing the function of unconditionally adopting R, the connection processing between the remote access server 110 and the user terminal 140 including the DHCP processing can be performed in a shorter time than before.

(Embodiment 2) The configuration of a network system having a remote access server device according to Embodiment 2 of the present invention is the same as that of FIG. 1, and a description thereof will be omitted.

The operation of the thus configured remote access server device will be described with reference to FIG.
FIG. 3 shows that the user terminal 140 is the remote access server 1
FIG. 3 is an operation sequence diagram showing an operation between devices when connecting to the LAN 100 through the LAN 10;

Steps S11 to S14 in FIG. 3 are the same as steps S01 to S04 in FIG. 2, and a description thereof will be omitted. When the remote access server 110 receives an OFFER message from another DHCP server 130 after transmitting the request message in step S14, it is discarded without performing any particular processing in the first embodiment. IP address to remote access server 110 to server 130
In order to make sure that the address assignment is not required, a dummy request message (DUMMY-REQUEST message) having the same format as the request message is unicast-transmitted to the DHCP server 130 (S15). This dummy request message includes information that the remote access server 110 has selected the DHCP server 120 as the DHCP server device. If the DHCP server 130 does not receive the dummy request message, the DHCP server 130 may be in a state of standing by while allocating the IP address resource uselessly for the remote access server 110. By receiving the request message, it is possible to release the IP address resource that has been prepared for allocation and to reliably prepare for the next allocation request from the DHCP client. Steps S16 to S18 indicating subsequent operations of the remote access server 110 and the DHCP server 120 are steps S05 to S18 in FIG.
Since it is the same as 07, its description is omitted.

As described above, in the present embodiment, the DHCP message processing unit 113 negotiates IP address allocation with the DHCP servers 120 and 130 on behalf of the user terminal 140 when the user terminal 140 is connected to the network, and A response first received while waiting for a response after broadcasting the request on the network is unconditionally adopted, and a DH different from the DHCP server 120 that responded first is used.
If a response is received from the CP server 130, another DH
Since the dummy request message is transmitted to the CP server 130, the DHCP server which is not selected
It is possible to reliably notify the server 130 that the other DHCP server 120 has been selected, and it is possible to prevent the unselected DHCP server 130 from allocating useless IP address resources.

[0027]

As described above, according to the remote access server device according to the first aspect of the present invention, the dial-up server unit that performs from the line connection with the user terminal device to the negotiation of the IP address assignment, and the main communication protocol processing A remote access server device having a communication processing unit for performing communication with a DHCP server device, negotiating an IP address assignment, and a network interface unit, wherein the DHCP message processing unit is connected to a network of a user terminal device. By negotiating an IP address assignment with a DHCP server device on behalf of the user terminal device at times and unconditionally adopting the first response received while waiting for a response after broadcasting the assignment request on the network, OF during address negotiation
Since the waiting time for collecting the FER message (response) can be eliminated, the IP address assignment negotiation process according to the DHCP protocol can be immediately completed, and the connection time between the user terminal device and the remote access server device can be reduced. The advantageous effect that it can be obtained is obtained.

According to the remote access server device of the second aspect, a dial-up server unit that performs from a line connection with the user terminal device to an IP address assignment negotiation,
A communication processing unit for performing main communication protocol processing, and a DHC
DH that communicates with P server device and negotiates IP address assignment
A remote access server device having a CP message processing unit and a network interface unit, wherein D
The HCP message processing unit negotiates an IP address assignment with the DHCP server device on behalf of the user terminal device when the user terminal device is connected to the network, and first receives the assignment request while waiting for a response after broadcasting the assignment request on the network. Unconditionally adopts the response and sends it to another DHCP
By transmitting a dummy request message to another DHCP server device when a response is received from the server device, in addition to the effect of claim 1, an IP address resource is transmitted to another DHCP server device that has received the dummy request message. An advantageous effect is obtained that wasteful consumption can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a network system having a remote access server device according to Embodiments 1 and 2 of the present invention.

FIG. 2 is an operation sequence diagram showing an operation between respective devices when a user terminal device connects to a network through a remote access server device in the network system of FIG. 1, mainly focusing on a DHCP protocol.

FIG. 3 is an operation sequence diagram showing operations between devices when a user terminal device connects to a network through a remote access server device.

FIG. 4 is an operation sequence diagram showing an operation flow of IP address assignment negotiation between a terminal device (DHCP client) and a DHCP server device on a network.

[Explanation of symbols]

 Reference Signs List 100 LAN 110 Remote access server 111 Dial-up server unit 112 Communication processing unit 113 DHCP message processing unit 114 Network interface unit 120, 130 DHCP server 140 User terminal

Claims (2)

[Claims] A dial-up server unit for performing a process from line connection with a user terminal device to negotiation of an IP address assignment; a communication processing unit for performing a main communication protocol process;
DHC that communicates with server device and negotiates IP address assignment
A remote access server device having a P message processing unit and a network interface unit, wherein the DHCP message processing unit communicates with the DHCP server device in place of the user terminal device when the user terminal device is connected to a network. A remote access server device which negotiates an IP address assignment and unconditionally employs a response first received while waiting for a response after broadcasting an assignment request on a network. 2. A dial-up server unit for performing from a line connection with a user terminal device to negotiating an IP address assignment, a communication processing unit for performing a main communication protocol process, and a DHCP server.
DHC that communicates with server device and negotiates IP address assignment
A remote access server device having a P message processing unit and a network interface unit, wherein the DHCP message processing unit communicates with the DHCP server device in place of the user terminal device when the user terminal device is connected to a network. Negotiate IP address assignment, unconditionally adopt the first response received while waiting for a response after broadcasting the allocation request on the network, and, if a response is received from another DHCP server device, A remote access server device for transmitting a dummy request message to a server device.