JP3793393B2 - Communication device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a communication apparatus that reduces control packets on a communication line.
[0002]
[Prior art]
PPP (Point-to-Point Protocol) is frequently used as a DTE data link layer protocol used for connection to the Internet / intranet via a public communication network or a private communication network.
[0003]
PPP enables transfer of various network protocols such as IP (Internet Protocol) and Appletak. This PPP specification is defined as an RFC (Request For Comment) of IETF (Internet Engineering Task Force).
[0004]
FIG. 1 is a diagram illustrating an example of communication. In the example of FIG. 1, a DTE (Data Terminal Equipment) 2 and a DTE 10 perform communication via a DCE (Data Circuit-Terminating Equipment) 4, a network 6, and a DCE 8 based on PPP. Here, DCE4 and DCE8 can be mobile stations (cell phones), for example.
[0005]
FIG. 2 shows the PPP frame format. The flag represents the start or end of a PPP frame and is used to identify a frame break. The address field is information indicating the destination of the PPP frame, and a fixed value is generally used. The control field is information used to identify the frame type, and a fixed value is generally used. The protocol field is used to identify the protocol of the packet included in the information field, and the information field includes a packet of the protocol indicated by this protocol field. FCS (Frame Check Sequence) is used for error detection from the address field to the information field.
[0006]
FIG. 3 shows an outline of the PPP procedure. PPP moves to the link establishment phase when the physical layer is activated in the link stop phase. In the link establishment phase, an LCP (Link Control Protocol) link setting procedure is performed. After the LCP link is established, the process proceeds to an authentication phase, and an authentication procedure is performed as necessary. If the authentication is successful, PPP moves to the network layer protocol phase, and the NCP link setting procedure corresponding to each network protocol is performed. When each NCP link is established, a packet of a network protocol corresponding to each NCP can be transferred. Moreover, PPP shifts to a link end phase due to a communication end request or the like. The LCP transmits a termination request packet. When the confirmation packet is received, the PPP link is closed and an instruction is given to disconnect the physical layer. Further, the network layer is notified that the PPP link is closed. When the physical layer is disconnected, PPP returns to the link stop phase.
[0007]
FIG. 4 shows an example of a link establishment sequence of LCP or NCP. Here, the condition for establishing the link is that the node A and the node B each transmit / receive a setting confirmation packet. In each packet, the ID is used for associating a setting request packet with a response packet (setting confirmation packet, setting negative packet, or setting rejection packet), and the ID value of the response packet is the ID value received in the request packet. Is included. When transmitting a setting request packet, options (Opt_A to G in FIG. 4) can be specified.
[0008]
If the receiver of the setting request packet can recognize all the options included in the setting request packet and can accept all of the values, it responds with all the options included in the setting request packet in the setting confirmation packet. To do.
[0009]
If there is an option that cannot be recognized among the options included in the setting request packet, the receiving side of the setting request packet responds by including the option that cannot be recognized in the setting rejection packet.
[0010]
The receiver of the setting request packet can recognize all the options included in the setting request packet, but if there is an unacceptable option value, it includes only those options that are not allowed in the setting denial packet. Change to an acceptable value and respond. Further, when it is desired to request an option other than the options included in the setting request packet from the transmission side of the setting request packet, the option can be added to the packet.
[0011]
When receiving the setting rejection packet, the transmission side of the setting request packet removes the rejected option and transmits the setting request packet again.
[0012]
When receiving the setting denial packet, the transmission side of the setting request packet transmits the setting request packet changed to the option value included in the setting denial packet. However, when there are a plurality of values in the option of the setting negative packet, one of them is selected.
[0013]
With reference to FIG. 4, an example of a negotiation procedure until LCP or NCP link establishment will be described.
[0014]
(A) A setting request packet is transmitted from node A to node B, but is lost during transmission.
[0015]
(B) Since the response packet for the setting request packet in (a) is not received for a predetermined time, the node A transmits the setting request packet again. At this time, only the ID value was set to a value different from the setting request packet of (a).
[0016]
(C) A setting request packet is transmitted from the node B to the node A, but is lost during transmission.
[0017]
(D) Since the node B cannot recognize the options Opt_C, Opt_D, and Opt_E in the setting request packet of (b), the node B responded by including these options in the setting rejection packet.
[0018]
(E) The node A removes the options Opt_C, Opt_D, and Opt_E in the received setting reject packet of (d), changes the ID value, and transmits a setting request packet.
[0019]
(F) Since the node B can recognize all the options in the received setting request packet of (e) and can accept all the values, the node B responded by including all the options in the setting request packet in the setting confirmation packet. .
[0020]
(G) Since the response packet to the setting request packet in (c) is not received within a predetermined time, the node B transmits the setting request packet in the same format as the setting request packet in (c) again.
[0021]
(H) Since the node A cannot recognize the option Opt_G in the setting request packet of (g), the node A responded by including this option in the setting rejection packet.
[0022]
(I) The node B removes the option Opt_G in the received setting rejection packet of (h), changes the ID value, and transmits a setting request packet.
[0023]
(J) The node A can accept the value 02 of the option 0pt_A in the received setting request packet of (i), but cannot accept the value z1 of the option Opt_F, and can accept the value z2, so it is acceptable in the setting negative packet. The value of Opt_F was transmitted as z2.
[0024]
(K) The node B changes the option Opt_F in the received setting negative packet of (j) to z2 and transmits a setting request packet.
[0025]
(L) Since the node A can recognize all the options in the received setting request packet of (k) and can accept all the values, the node A responded by including all the options in the setting request packet in the setting confirmation packet. .
[0026]
FIG. 5 shows an example of an LCP link disconnection sequence.
[0027]
(A) The node A transmits an end request packet to request link release.
[0028]
(B) The Node B that has received the termination request packet transmits a termination confirmation packet. The node A that has received the end confirmation packet is in the link closed state.
[0029]
(C) The node B waits for a certain time from the transmission of the end confirmation packet, and then transmits the end request packet.
[0030]
(D) The node A that has received the termination request packet transmits a termination confirmation packet, disconnects the physical layer, and shifts to the link stop phase. The Node B that has received the end confirmation packet enters the link closed state, disconnects the physical layer, and moves to the link stop phase.
[0031]
FIG. 6 shows an example of a keep alive sequence using an LCP echo request / response packet. The LCP echo request / response packet is used during LCP link establishment and can be used to check whether the link is maintained.
[0032]
(A) Node A transmits an LCP echo request packet to confirm whether the LCP link is maintained.
[0033]
(B) The Node B that has received the LCP echo request packet transmits an LCP echo response packet in order to respond that the link is maintained.
[0034]
(C) Node B sent an LCP echo request packet to check if the LCP link is maintained.
[0035]
(D) The node A that has received the LCP echo request packet transmits an LCP echo response packet in order to respond that the link is maintained.
[0036]
[Problems to be solved by the invention]
As one of the features of packet communication, there is a communication node that can adopt a communication fee system based on the amount of data because a communication line is used only when data is generated. As a request condition in such a communication node, it is desirable that no communication fee is charged when there is no user data to be transmitted / received, that is, the communication line is not actually used.
[0037]
Conventionally, when PPP is used as a DTE data link layer protocol in a communication node adopting a communication fee system based on a data amount, PPP control packets at the start and end of communication, and connectivity of PPP links periodically Due to the transfer of the LCP echo request / response packet to be confirmed, there is a disadvantage that an extra communication fee is incurred from the user's point of view and communication cost and communication traffic volume are increased from the point of view of the communication carrier. there were.
[0038]
Accordingly, an object of the present invention is to reduce control packets on a communication line. As a result, it is possible to reduce the communication charge / communication cost and increase the subscriber capacity associated with the reduction of communication traffic.
[0039]
[Means for Solving the Problems]
In order to achieve the above object, the first aspect of the present invention provides the first node located between the first communication device of the first node and the second communication device of the second node. A communication method in the third communication device, the step of mediating a setting request packet from the second communication device to the first communication device, and a setting rejection packet or setting denial from the first communication device. Receiving a packet, generating a setting request packet in response to the setting rejection packet or setting negative packet, and transmitting the generated setting request packet to the first communication device, When a setting rejection packet or a setting denial packet is received from the first communication device after mediating a setting request packet from the second communication device to the first communication device , Only the information included in the Configure-Reject packet or setting negation packet, by transmitting to the second communication device, and notifies the set reject or setting negation to the second communication device.
[0040]
The invention according to claim 2 is communication in the third communication device of the first node located between the first communication device of the first node and the second communication device of the second node. A method of mediating a setting request packet from the second communication device to the first communication device; receiving a setting rejection packet or a setting negative packet from the first communication device; Generating a setting request packet corresponding to a setting rejection packet or a setting denial packet; and transmitting the generated setting request packet to the first communication device, from the second communication device to the first When a setting confirmation packet is received after receiving a setting rejection packet or a setting negative packet from the first communication device after mediating a setting request packet to one communication device The configuration confirmation packet is terminated, and when the configuration confirmation packet is received without receiving the configuration rejection packet or the configuration rejection packet from the first communication device, the configuration confirmation packet is not terminated. And
[0041]
The invention according to claim 3 is communication in the third communication device of the first node located between the first communication device of the first node and the second communication device of the second node. A method of mediating a setting request packet from the first communication device to the second communication device; and a setting rejection or setting denial from the second communication device to the first communication device. It comprises a step of mediating notification, a step of receiving a setting request packet from the first communication device, and a step of terminating the received setting request packet.
[0042]
A fourth aspect of the present invention is the communication method according to the third aspect, wherein the second communication apparatus is configured to mediate a setting request packet from the first communication apparatus to the second communication apparatus. When a setting rejection or setting denial notification is received from, a setting rejection packet or a setting denial packet is generated and transmitted to the first communication device.
[0043]
The invention according to claim 5 is the communication method according to claim 3 or 4, wherein the second communication is performed by mediating a setting request packet from the first communication device to the second communication device. After receiving a setting rejection or setting denial notification from the device to the first communication device, if all setting request packets corresponding to the notification are received from the first communication device, a setting confirmation packet is generated. And transmitting to the first communication device.
[0044]
The invention according to claim 6 is communication in the third communication device of the first node located between the first communication device of the first node and the second communication device of the second node. A method comprising: mediating notification of an end request from the first communication device to the second communication device; generating an end confirmation packet; and generating the end confirmation packet as the first And a step of transmitting to the second communication device, and after receiving an end request notification from the first communication device to the second communication device, a notification of end confirmation is received from the second communication device. Is characterized in that an end request packet is generated and transmitted to the first communication device.
[0045]
A seventh aspect of the present invention is the communication method according to the sixth aspect, wherein when a termination request packet is received from the first communication device, a termination request signal is generated and the second communication is performed. It transmits to an apparatus, It is characterized by the above-mentioned.
[0046]
The invention according to claim 8 is the communication method according to claim 6 or 7, wherein when the end confirmation packet is received from the first communication device after transmitting the generated end request packet. The termination confirmation packet is terminated.
[0047]
The invention according to claim 9 is a communication in the third communication device of the first node located between the first communication device of the first node and the second communication device of the second node. A method comprising: mediating notification of an end request from the second communication device to the first communication device; receiving an end confirmation packet from the first communication device; and the end confirmation packet And terminating when a termination request packet is received from the first communication device after mediating notification of a termination request from the second communication device to the first communication device. A confirmation signal is generated and transmitted to the second communication device.
[0048]
A tenth aspect of the present invention is the communication method according to the ninth aspect, wherein when a notification of an end request is received from the second communication device, an end request packet is generated, and the first It transmits to a communication apparatus, It is characterized by the above-mentioned.
[0049]
The invention according to claim 11 is the communication method according to claim 9 or 10, wherein after generating the generated end confirmation signal, an end confirmation packet is generated and transmitted to the first communication device. It is characterized by that.
[0050]
A twelfth aspect of the present invention is the communication method according to any one of the first to eleventh aspects, wherein the third communication device is a mobile station.
[0055]
According to the above configuration, control packets on the communication line can be reduced.
[0056]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 7 shows a sequence diagram when the present invention is applied to the LCP or NCP link establishment sequence example of FIG. The (communication) device 1 and the (communication) device 2 belong to the node A, and the (communication) device 3 and the (communication) device 4 belong to the node B, and may be physically different devices or the same device. . It is assumed that the apparatus 2 and the apparatus 3 are connected by a communication line. For example, DTE2 in FIG. 1 can be associated with apparatus 1, DCE4 with apparatus 2, DCE8 with apparatus 3, DTE10 with apparatus 4, and redundant packets between DCE4 and DCE8 can be deleted.
[0057]
The procedure will be described below.
[0058]
(A) A setting request packet is transmitted from the device 1 and disappears before reaching the node B via the device 2.
[0059]
(B) Since the response packet to the setting request packet in (a) is not received for a certain time, the apparatus 1 transmits the setting request packet again. At this time, only the ID value was set to a value different from the setting request packet of (a).
[0060]
(C) A setting request packet is transmitted from the device 4 and is lost before reaching the node A via the device 3.
[0061]
(D) Since the device 4 cannot recognize Opt_C, Opt_D, and Opt_E with respect to the setting request packet of (b) received via the device 3, the device 4 responded by including these options in the setting rejection packet. .
[0062]
(E) The device 3 does not transfer the setting reject packet of (d) to the device 2, removes Opt_C, Opt_D, and Opt_E, and transmits (generates) a setting request packet with the changed ID value to the device 4. .
[0063]
(F) Since the device 4 can recognize all the options in the received setting request packet of (e) and can accept all of the values, it responds with a setting confirmation packet. When receiving the setting confirmation packet from the device 4, the device 3 transmits only the information included in the packet (d) to the device 2. As in this example, when the device 3 receives the setting confirmation packet after receiving the setting rejection packet or the setting negative packet from the device 4, the device 3 terminates the setting confirmation packet. However, when the setting confirmation packet is received without receiving the setting rejection packet or the setting denial packet from the device 4, the setting confirmation packet is not terminated. In this case, the apparatus 2 is notified that the setting confirmation packet has been simply received (for example, by transmitting the setting confirmation packet).
[0064]
(G) The apparatus 2 transmits a setting rejection packet generated from information included in the packet of (d) to the apparatus 1. When the device 1 receives the setting rejection packet from the device 2, the device 1 removes Opt_C, Opt_D, and Opt_E, and transmits a setting request packet in which the ID value is changed. The packets (e) and (g) are setting request packets having the same option although the ID values may be different.
[0065]
(H) The device 2 did not transfer the setting request packet of (g) to the device 3, but responded with a setting confirmation packet. The packets (f) and (h) are setting confirmation packets having the same option although the ID values may be different.
[0066]
(I) Since the response packet to the setting request packet in (c) has not been received for a predetermined time, the device 4 transmits again the setting request packet having the same format as the setting request packet in (c).
[0067]
(J) Since the device 1 cannot recognize the option Opt_G of the received setting request packet in (i), the device 1 responds with the setting rejection packet including the option.
[0068]
(K) The device 2 did not transfer the setting rejection packet of (j) to the device 3, removed the option Opt_G, and transmitted a setting request packet with the changed ID value to the device 1.
[0069]
(L) The device 1 can accept the value w2 of the option Opt_A in the received setting request packet of (k), but can accept z2 instead of the value Opt_F of the option Opt_F. Was transmitted as z2.
[0070]
(M) The device 2 does not transfer the setting negative packet of (l) to the device 3, but changes the value of the option Opt_F to z2 and transmits a setting request packet to the device 1.
[0071]
(N) Since the apparatus 1 can recognize all the options in the received setting request packet of (m) and can accept all the values, it responds with a setting confirmation packet. Upon receiving the setting confirmation packet, the device 2 transmits only the information included in the packets (j) and (l) to the device 3.
[0072]
(O) Upon receiving information included in the packets (j) and (l) from the device 2, the device 3 first transmits a setting rejection packet generated from the information (j) to the device 4. The packets (j) and (o) are setting rejection packets having the same options.
[0073]
(P) The device 4 removes the option Opt_G in the received setting rejection packet of (o), changes the ID value, and transmits a setting request packet. The packets (k) and (p) are setting request packets having the same option although the ID values may be different.
[0074]
(Q) The device 3 does not transfer the setting request packet of (p) to the device 2, and from the information included in the packet of (l), the value w2 of the option Opt_A is acceptable, but the value Opt_F is not z1 but z2 Since it is understood that it is acceptable, the value of the option Opt_F is transmitted to the apparatus 4 as z2 in a setting negative packet. Although the packets of (l) and (q) may have different ID values, they are setting negative packets having the same options.
[0075]
(R) The device 4 changes the value of the option Opt_F in the received setting negative packet of (q) to z2 and transmits a setting request packet. The packets (m) and (r) are setting request packets having the same option although the ID values may be different.
[0076]
(S) The device 3 does not transmit the setting request packet of (r) to the device 2, and can recognize all the options in the setting request packet and can accept all of the values. Responded to. The packets (n) and (s) are setting confirmation packets having the same option although the ID values may be different.
[0077]
FIG. 8 shows a sequence diagram when the present invention is applied to the LCP link disconnection sequence example of FIG. The procedure will be described below.
[0078]
(A) The device 1 transmits an end request packet to request link release. The device 2 that has received the end request packet transmits a communication end request signal to the device 3. The device 3 that has received the communication end request signal generates an end request packet and transmits it to the device 4.
[0079]
(B) The device 2 that has received the end request packet from the device 1 transmits an end confirmation packet to the device 1. The device 1 that has received the completion confirmation packet is in a link closed state. On the other hand, the device 4 that has received the end request packet from the device 3 transmits an end confirmation packet. The device 3 does not transfer the end confirmation packet to the device 2.
[0080]
(C) The apparatus 4 transmits an end request packet after a certain time has elapsed since the end confirmation packet was transmitted. The device 3 that has received the end request packet transmits a communication end confirmation signal to the device 2. The device 2 that has received the communication end confirmation signal generates an end request packet and transmits it to the device 1.
[0081]
(D) The device 3 that has received the end request packet transmits an end confirmation packet to the device 4. The device 4 that has received the completion confirmation packet enters the link closed state, and after disconnecting the physical link, enters the link stop phase state. On the other hand, the device 1 that has received the termination request packet from the device 2 transmits a termination confirmation packet, disconnects the physical link, and enters the link stop phase state. The device 2 does not transfer the end confirmation packet to the device 3.
[0082]
FIG. 9 shows a sequence diagram when the present invention is applied to the LCP keep-alive sequence example of FIG. The procedure will be described below.
[0083]
(A) The device 1 transmits an LCP echo request packet to confirm whether the LCP link is maintained.
[0084]
(B) The device 2 did not transfer the received LCP echo request packet of (a) to the device 3, but transmitted an LCP echo response packet to the device 1.
[0085]
(C) The device 4 transmits an LCP echo request packet to confirm whether the LCP link is maintained.
[0086]
(D) The device 3 does not transfer the received LCP echo request packet of (c) to the device 2 but transmits an LCP echo response packet to the device 4.
[0087]
As described above, no signal is transferred between the device 2 and the device 3.
[0088]
In the present embodiment, an example in which the present invention is applied to communication based on the PPP protocol has been described. However, the present invention can also be applied to communication based on a similar protocol.
[0089]
【The invention's effect】
As described above, according to the present invention, control packets on the communication line can be reduced.
[0090]
As a result, for example, redundant packets in the end-to-end PPP link establishment procedure, disconnection procedure, and PPP link connectivity confirmation procedure are terminated in the same node, and the amount of control packets transferred on the communication line is reduced. It is possible to reduce the communication charge / communication cost and increase the subscriber capacity associated with the reduction of the communication traffic volume.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of communication.
FIG. 2 is an explanatory diagram showing a field configuration of a PPP frame.
FIG. 3 is an explanatory diagram showing an outline of a PPP procedure.
FIG. 4 is a sequence diagram showing an example of a PPP link establishment sequence.
FIG. 5 is a sequence diagram showing an example of a PPP link disconnection sequence.
FIG. 6 is a sequence diagram showing a PPP keep alive operation.
7 is a sequence diagram when the present invention is applied to the link establishment sequence example of FIG. 4;
8 is a sequence diagram when the present invention is applied to the link disconnection sequence example of FIG. 5;
FIG. 9 is a sequence diagram when the present invention is applied to the keep-alive sequence example of FIG. 6;
[Explanation of symbols]
2, 10 DTE
4, 8 DCE
6 network

Claims (12)

A communication method in a third communication device of the first node located between a first communication device of a first node and a second communication device of a second node,
Mediating a setting request packet from the second communication device to the first communication device;
Receiving a setting rejection packet or a setting denial packet from the first communication device;
Generating a setting request packet in response to the setting rejection packet or the setting rejection packet;
Transmitting the generated setting request packet to the first communication device,
If a setting rejection packet or a setting denial packet is received from the first communication device after mediating a setting request packet from the second communication device to the first communication device, the setting rejection packet or setting A communication method characterized by notifying the second communication device of setting refusal or setting denial by transmitting only information included in the negative packet to the second communication device. A communication method in a third communication device of the first node located between a first communication device of a first node and a second communication device of a second node,
Mediating a setting request packet from the second communication device to the first communication device;
Receiving a setting rejection packet or a setting denial packet from the first communication device;
Generating a setting request packet in response to the setting rejection packet or the setting rejection packet;
Transmitting the generated setting request packet to the first communication device,
When a setting confirmation packet is received after receiving a setting rejection packet or a setting rejection packet from the first communication device after mediating a setting request packet from the second communication device to the first communication device The setting confirmation packet is terminated, and when the setting confirmation packet is received without receiving the setting rejection packet or the setting denial packet from the first communication device, the setting confirmation packet is not terminated. Communication method. A communication method in a third communication device of the first node located between a first communication device of a first node and a second communication device of a second node,
Mediating a setting request packet from the first communication device to the second communication device;
Mediating notification of setting refusal or setting denial from the second communication device to the first communication device;
Receiving a setting request packet from the first communication device;
And a step of terminating the received setting request packet. The communication method according to claim 3, wherein
After receiving a setting rejection or setting denial notification from the second communication device after mediating a setting request packet from the first communication device to the second communication device, a setting rejection packet or a setting denial A communication method, comprising generating a packet and transmitting the packet to the first communication device. The communication method according to claim 3 or 4,
After mediating a setting request packet from the first communication device to the second communication device, and mediating a setting rejection or setting denial notification from the second communication device to the first communication device, A communication method characterized by generating a setting confirmation packet and transmitting it to the first communication device when all the setting request packets corresponding to the notification are received from the first communication device. A communication method in a third communication device of the first node located between a first communication device of a first node and a second communication device of a second node,
Mediating notification of an end request from the first communication device to the second communication device;
Generating an end confirmation packet;
Transmitting the generated completion confirmation packet to the first communication device,
After receiving an end confirmation notification from the second communication device after mediating the end request notification from the first communication device to the second communication device, generate an end request packet, A communication method comprising: transmitting to a first communication device. The communication method according to claim 6, comprising:
When a termination request packet is received from the first communication device, a termination request signal is generated and transmitted to the second communication device. The communication method according to claim 6 or 7, wherein
A communication method, comprising: terminating an end confirmation packet when an end confirmation packet is received from the first communication apparatus after transmitting the generated end request packet. A communication method in a third communication device of the first node located between a first communication device of a first node and a second communication device of a second node,
Mediating notification of an end request from the second communication device to the first communication device;
Receiving an end confirmation packet from the first communication device;
Terminating the termination confirmation packet,
When an end request packet is received from the first communication device after mediating notification of an end request from the second communication device to the first communication device, an end confirmation signal is generated, and the first A communication method comprising: transmitting to a second communication device. The communication method according to claim 9, comprising:
A communication method, comprising: generating a termination request packet and transmitting the termination request packet to the first communication device when a termination request notification is received from the second communication device. The communication method according to claim 9 or 10, comprising:
After transmitting the generated completion confirmation signal, a completion confirmation packet is generated and transmitted to the first communication device.   12. The communication method according to claim 1, wherein the third communication device is a mobile station.

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