JP4900492B2 - Packet transfer device - Google Patents

Description

  The present invention relates to an access node corresponding to a plurality of access methods.

  On an IP network typified by the Internet, data is transferred according to the IP protocol. As a service for accommodating users in such an IP network, there is an Internet service. Carriers that provide Internet services are also called Internet Service Providers (ISPs). As a means for accessing ISPs from users, Point to Point Protocol (PPP), which has been standardized as Request for Comments (RFC) 1661 in the Internet Engineering Task Force (IETF), is often used. In addition, there is an IP connection service as a service for relaying access from a user to a plurality of ISPs. Carriers providing IP connection services are also called carriers and access providers, and sometimes connect and distribute PPP access from users to ISPs using tunnels. A typical example of such a tunnel is L2TP (Layer 2 Tunneling Protocol) shown in RFC2661.

  FIG. 20 is an example of a network that realizes a conventional high-speed IP connection service and a high-speed IP connection service when a DSL represented by an Asymmetric Digital Subscriber Line (ADSL) is used as an access method. The high-speed IP connection network is composed of a high-speed access server BS that accepts access from users and distributes it to the ISP network, and a core network CN1 that configures between the access control servers AC12 and BS that perform access control. A host such as a terminal or server is connected to The core network consists of transmission lines and IP routers. When the high-speed access server BS11 receives a PPP connection request from the user's IP terminal IT20 via the DSL network MN11 and the DSL Access Multiplexer (DSLAM) DL11 that are access media networks, the high-speed access server BS11 inquires the access control server AC12 to query the ISP network. Determine PN11. If there is no L2TP tunnel TL22 relayed to the high speed access server BS13 connected to the PN11, the high speed access server BS11 issues a request to set it. BS13 inquires of access control server AC13 possessed by PN11 whether it is a correct user who has contracted, and if it is authenticated as correct, TL22 and an L2TP session are set between BS11 and BS13. In this way, when a PPP session PS10 as shown by a thick broken line is established from IT20 to BS13, IT20 is connected to the Internet via PN11 at high speed IP. In FIG. 20, since the IP transfer from the BS 13 to the Internet is no longer used by PPP, it is distinguished by a thin broken line. In FIG. 20, the access control servers AC12 and AC13 are also called Radius servers. In the case of L2TP, the control at AC12 is sometimes called primary authentication, and the control at AC13 is sometimes called secondary authentication. The high-speed access servers BS11 and BS13 are also called broadband access servers (BAS). In the case of L2TP, BS11 is functionally called L2TP Access Concentrator (LAC) and BS13 is called L2TP Network Server (LNS).

  Next, FIG. 21 shows an example of a network that realizes a conventional low-speed IP connection service and a low-speed IP connection service when a telephone is used as an access method. In the low-speed IP connection service, unlike the high-speed IP connection service, first, a dial-up telephone connection is made from the terminal IT22. The exchange SW11 that has received the telephone connection via the switching network MN11 that is an access media network passes the connection to the access control server AC11 via the telephone control network MN10, and the AC11 activates the access server AS11. Thereafter, the AS 11 receives the PPP connection request from the IT 22, and thereafter, through the same procedure as in FIG. 20, the L2TP tunnel TL 26 and the PPP session PS11 are established. As a result, the IT 22 is connected to the Internet via the PN11 at a low speed IP. In FIG. 21, a common line signal network such as SS7 is often used as the telephone control network MN10. The access control server AC11 is also called a signaling gateway. The access servers AS11 and AS13 are also called Remote Access Servers (RAS), and AS11 is functionally called LAC and AS13 is LNS.

  Next, FIG. 22 shows an example of a network that realizes a conventional mobile network IP connection service and a mobile network IP connection service when a mobile network such as a radio is used as an access method. In the mobile IP connection service, unlike the high-speed or low-speed IP connection service, the connection request from the terminal IT24 is first received by the mobile node MoN11 via the mobile network MN13 which is the access media network, and the mobile access node MA11 receives the connection from the MoN11. Tunnel TL34 is set using Generic Routing Encapsulation (GRE). After that, through the same procedure as in FIG. 20, the L2TP tunnel or Mobile IP tunnel TL31 and the PPP session PS12 are established, so that the IT 24 is IP-connected to the Internet via the PN11. Also, if the IT24 moves from place to place, the MA11, MA13, etc. will change the tunnel along with the move and will continue to provide the IP connection service even if the user moves. In FIG. 22, examples of the mobile network MN13 include a General Packet Radio Service (GPRS) network, an IMT2000 network, and a High Data Rate (HDR) network. The mobile node MoN11 includes a packet control function (PCF) and an access point (AP). The mobile access node MA11 includes a Serving GPRS Support Node (SGSN) and a Packet Data Serving Node (PDSN), and the mobile access node MA13 includes a Home Agent (HA) and a Gateway GPRS Support Node (GGSN).

  FIG. 23 shows a device configuration example of a conventional high-speed IP router. Here, the high-speed IP router has a line interface unit, an IP processing unit, and the like on the input side and the output side, and connects between them by a switch unit. The control unit controls each unit and the entire apparatus. Since the IP processing unit performs high-speed processing by specializing in transfer according to the IP protocol using an ASIC, etc., session and tunnel processing such as PPP and L2TP required for IP connection services as described above Generally do not.

  FIG. 24 shows an example of a conventional RAS apparatus configuration. Here, RAS has a line interface unit, a modem, an HDLC processing unit, etc. on the input side and the output side, and connects between them by a bus or a switch unit. The control unit realizes the function as RAS by performing control of each unit and control of the entire apparatus, as well as session processing such as IP processing, PPP, and L2TP.

  As described above, depending on the access method, a high-speed access server implements a mobile network IP connection service for a network that implements a high-speed IP connection service, and an access server implements a network that implements a low-speed IP connection service. The network required a separate mobile access node. For this reason, for example, when a communication provider providing a low-speed IP connection service attempts to provide a high-speed IP connection service, it is necessary to purchase another device, which increases costs. In addition, management becomes complicated as the number of types of devices increases. There is also a problem that capital investment is wasted when a user shifts from a low-speed IP connection service to a high-speed IP connection service. The same applies to the case of providing a mobile network IP connection service, and it was one of the reasons that a fixed network carrier and a mobile network carrier had to be provided separately.

  In order to make the access device compatible with these multiple access methods, a method of changing the software of the IP router that performs software transfer processing is conceivable. However, in recent years, routers that perform IP transfer are also configured with hardware to realize high-speed transfer of data packets. If it is supported by software processing, the performance is significantly inferior to that of a high-speed router configured by hardware, so it cannot be put into practical use when high-speed processing is required, regardless of RAS that only requires low-speed IP connection. In addition, RAS generally has an STM line interface specialized for telephone access and a connection to an access control server, and there is a problem that the structure is different from other devices.

  In order to solve this problem, output information is searched by a set of an input port, an input tunnel identifier, an input session identifier, and the like as input information of a search table in the access device. Depending on the access method, all of these input information may be used, or only a part may be used. In addition, an output port, an output tunnel identifier, an output session identifier, and the like are set as output information of the search table. Depending on the transfer method, all of the output information may be used or only a part may be used. Thus, by sharing the input / output setting information of the table according to a plurality of access methods, it becomes possible to uniformly cope with a plurality of access methods and a plurality of IP connection services. In addition, as for the device configuration, it is possible to freely replace multiple types of line interfaces, and at the same time, a connection from the control unit to the access control server is also prepared, so that the same device can handle access methods with different call control etc. And

  According to the present invention, an access node corresponding to a plurality of access methods can be provided.

1 is a diagram illustrating an example of a network and an access node that perform a low-speed IP connection service, a high-speed IP connection service, and a mobile network IP connection service according to the present invention, and particularly shows a session and a tunnel of a high-speed IP connection service. It is also a figure. It is a figure explaining the structural example of the access node which implement | achieves 1st Example by this invention. It is a figure explaining the example of the input / output information corresponding table used in the access node near the user terminal in the first embodiment according to the present invention. It is a figure explaining the example of the input-output information corresponding table used in the access node near the internet in the 1st Example by this invention. It is a sequence diagram explaining the example of a session and tunnel setting in the case of performing a high-speed IP connection service in 1st Example by this invention. It is a figure which shows the session and tunnel of a low-speed IP connection service in 1st Example by this invention. It is a sequence diagram explaining the example of a session and a tunnel setting in the case of performing a low-speed IP connection service in 1st Example by this invention. It is a figure which shows the session and tunnel of a mobile network IP connection service in 1st Example by this invention. FIG. 6 is a sequence diagram illustrating an example of session and tunnel setting when performing a mobile network IP connection service in the first embodiment of the present invention. FIG. 5 is a diagram illustrating a session and a tunnel when a terminal moves beyond a mobile node in a mobile network IP connection service according to the first embodiment of the present invention. FIG. 7 is a sequence diagram illustrating an example of session and tunnel setting when a terminal moves beyond a mobile node in a mobile network IP connection service according to the first embodiment of the present invention. FIG. 6 is a diagram illustrating a session and a tunnel when a terminal moves beyond an access node in a mobile network IP connection service according to the first embodiment of the present invention. In the first embodiment of the present invention, an example of an input / output information correspondence table used in an access node closer to the user terminal when the terminal moves beyond the access node at the time of mobile network IP connection service will be described. FIG. The figure explaining the example of the input / output information corresponding table used in the access node near the Internet when the terminal moves beyond the access node in the mobile network IP connection service in the first embodiment of the present invention. It is. FIG. 8 is a diagram for explaining an example of a network and an access node that perform a low-speed IP connection service, a high-speed IP connection service, and a mobile network IP connection service with the same device for a plurality of ISP networks according to the second embodiment of the present invention. . In the 2nd Example by this invention, it is a figure explaining the example of the input / output information corresponding table used in the access node near the user terminal. In the 2nd Example by this invention, it is a figure explaining the example of the input / output information corresponding table used in the access node near the internet. FIG. 10 is a diagram for explaining an example of a network and an access node that perform a low-speed IP connection service, a high-speed IP connection service, and a mobile network IP connection service without performing tunnel setting between access nodes. It is a figure explaining the example of the input / output information corresponding table used in an access node in 3rd Example by this invention. It is a figure explaining the example of the network which performs a high-speed IP connection service by the conventional high-speed access server. It is a figure explaining the example of the network which performs a low-speed IP connection service by the conventional access server. It is a figure explaining the example of the network which performs a mobile network IP connection service by the conventional mobile access node. It is a figure explaining the structural example of the conventional high-speed IP router. It is a figure explaining the structural example of the conventional RAS.

  The first embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is an example of a network and an access node that perform a low-speed IP connection service, a high-speed IP connection service, and a mobile network IP connection service. Here, the area indicated by the ellipse in the center is the IP core network CN1 through which data packets are transferred by IP, and access nodes AN11, AN12, AN13, and AN14 are provided at the entrance and exit of the core network. Between access nodes across the core network, tunnels TL11 to TL14 such as L2TP are set up. Although not shown in the figure, there is an IP router in the core network, and the IP router transfers the tunneled packets. You only need to be aware of the IP level for forwarding. When the tunnel is L2TP, the access nodes AN11 and AN12 correspond to LAC, and the access nodes AN13 and AN14 correspond to LNS. Outside the core network CN1, access media networks MN11 to MN13, which are different depending on the access method, and node equipment connected to the access node AN11, such as the switch SW11, DSLAM DL11, mobile nodes MoN11, and MoN12, are connected to the user side Has been. On the other hand, a plurality of ISP networks PN11 and PN12 are connected to the Internet side. The same applies when a corporate network is connected instead of the ISP network.

  FIG. 2 shows a device configuration example of the access nodes AN11 (LAC) and AN13 (LNS) corresponding to a plurality of access methods as described above. The access node device 10 in FIG. 2 includes a control unit 11, a switch unit 12, a plurality of input processing units 13, and a plurality of output processing units 14. The input processing unit 13 and the output processing unit 14 may be separated in hardware or the same. Here, the ingress processing unit 13 includes an ingress session processing unit 20 and a plurality of various ingress line interface units 30, and the egress processing unit 14 includes an egress session processing unit 40 and a plurality of various egress sides. It consists of a line interface unit 50. Here, the session processing unit and the line interface unit may be the same in hardware, but may be separated. The difference between the two is a unit in which the line type can be freely exchanged. These line interface units have a plurality of line ports and are connected to other network devices via an external transmission line. The data packet is input from the input line interface unit 30, and after the session processing unit 20 such as PPP performs session processing such as PPP, IP processing, tunnel processing such as L2TP, etc., it is internally exchanged through the switch unit 12. Thereafter, session processing such as PPP, IP processing, tunnel processing such as L2TP, and the like are performed by the egress session processing unit 40 and output from the egress line interface unit 50. When the ingress processing unit 13 and the egress processing unit 14 are the same in terms of hardware, the switch unit 12 may not be passed when exiting to another line interface port connected to the same session processing unit. The control unit 11 is connected to the input side processing unit 13, the output side processing unit 14, and the switch unit 13 to control and manage these, and when used as protocol signal processing such as PPP and L2TP, or as LAC Call control related processing is also performed via the control line 15.

  The access node AN11 (LAC) has a table 110 corresponding to the transfer of a session such as a plurality of PPPs as shown in FIG. In FIG. 3, a table used when data is connected by low speed IP, a table used when data is connected by high speed IP, and a table used when data is connected by mobile network IP are shared. Yes. 3 include input port IN11 that is input information IN1, input tunnel identifier IN12, input session identifier IN13, output port OUT11 that is output information OUT1, output tunnel identifier OUT12, output session identifier OUT13, and the like. included. The table shown in FIG. 3 collectively shows the input / output relationship of the entire AN11 apparatus, and actually, the table may be divided into the incoming session processing unit 20 and the outgoing session processing unit 40 of FIG.

  Further, the access node AN13 (LNS) has a table 120 corresponding to the transfer of a session such as a plurality of PPPs as shown in FIG. Also in FIG. 4, a table used when data is connected by low speed IP, a table used when data is connected by high speed IP, and a table used when data is connected by mobile network IP are shared. Yes. 4 are the input port IN21 that is the input information IN2, the input tunnel identifier IN22, the input session identifier IN23, the output port OUT21 that is the output information OUT2, the output tunnel identifier OUT22, and the output session. The identifier OUT23 and the like are included.

  In the network of FIG. 1, first, a PPP session that is connected to the ISP network PN11 via the DSL network MN12 from the IP terminal IT12 by high-speed IP is PS1, and a PPP session, an L2TP tunnel, and a session are set using the sequence diagram of FIG. How to do will be described. However, in the following, in order to simplify the description, not all protocol messages including the names are accurately shown in the sequence diagrams, and processing such as accounting is omitted. The IP terminal IT21 first initializes PPP over Ethernet (PPPoE) indicated in RFC2516 for the access node AN11. This process is necessary when a PPP session is established and multiple PPP frames are identified on the Ethernet. In the case of ADSL, this PPPoE frame may be further carried on the ATM transmission path, and in such a case, it may be referred to as PPPoE on ATM (PPPoEoA). The PPPoE initialization process corresponds to, for example, the incoming session processing unit 20 in AN11. This PPPoE initialization process is an unnecessary process in the case of PPP over ATM (PPPoA) shown in RFC2364. Next, PPP protocol signal processing starts. First, Link Control Protocol (LCP) processing is performed to set a link layer. Next, processing based on the Challenge Handshake Authentication Protocol (CHAP) shown in RFC1994 is performed. Here, the control unit 11 acquires LNS information, L2TP tunnel tunnel information, and the like from the access control server AC12 using the Radius protocol indicated in RFC2865 and the like. Since it is now desired to make an IP connection to the ISP network PN11, the LNS is the access node AN13. If the L2TP tunnel is not set, the AN11 issues an L2TP tunnel setting request to the AN13. Based on this information, the AN 13 inquires of the access control server AC13 of the ISP network PN11 about the L2TP tunnel and returns to the AN 11 to set the L2TP tunnel TL11 between the AN 11 and AN 13. Next, a session corresponding to the PPP session is set in the same procedure in the L2TP tunnel. At this time, the user ID and password are passed from AN13 to AC13, and user authentication is performed. When the setting of the L2TP session is finished as described above, the CHAP processing is finished, and then the IP layer is set by the IP Control Protocol (IPCP) shown in RFC1332. As a result, the session setting by the protocol signal processing is completed, and the PPP session PS1 from IT12 to AN13 is set through the tunnel TL11 between AN11 and AN13 as shown in FIG. It is transferred according to the session. Ethernet is a registered trademark.

  By setting the PPP session PS1, the input / output relationship shown in the entry 111 of FIG. 3 is set in the access node AN11. Here, there is no input tunnel identifier, and input information is identified by the input port and the input session identifier. As output information, an output port, an output tunnel identifier, and an output session identifier are all set. Further, the input / output relationship shown in the entry 121 of FIG. 4 is set in the access node AN13. Here, as input information, an input port, an input tunnel identifier, and an input session identifier are all set, but as output information, an output tunnel identifier and an output session identifier are not set, and only an output port is set. As described above, thereafter, the data packet is searched from the set of input information to obtain output information and transferred. The above is an example of DSL access using PPPoEoA, but the same applies to access using PPPoE over Ethernet instead of ATM lines, such as Fiber To The Home (FTTH).

  Next, as shown in FIG. 6, the PPP session connected to the ISP network PN11 from the IP terminal IT11 through the telephone network MN11 is set to PS2, and the PPP session, the L2TP tunnel and the session are used by using the sequence diagram of FIG. A method of setting is described. First, a dial-up telephone connection is made from the IP terminal IT11. The exchange SW11 that has received the telephone connection request message via the switching network MN11 passes the connection to the access control server AC11 via the telephone control network MN10, and the AC11 uses the protocol such as Megaco shown in RFC2885 to access node AN11. The controller 11 is activated. The access node AN11 authenticates the incoming / outgoing telephone number using Radius and responds to Megaco. As a result, the telephone connection response message returns to the terminal IT11 via the exchange SW11, and telephone connection is performed. Next, PPP protocol signal processing starts, but since it is the same as the high-speed IP connection, the description thereof is omitted. As shown in Fig.1 and Fig.6, as the L2TP tunnel between AN11 and AN13, the same tunnel as the session of the high-speed IP connection service may be shared using the already established TL11, or the high-speed IP connection service There may be a case where an L2TP tunnel is set separately. By setting the PPP session PS2, the input / output relationship indicated by the entry 112 in FIG. 3 is set in the access node AN11, and the input / output relationship indicated by the entry 122 in FIG. 4 is set in the access node AN13. .

  Next, as shown in FIG. 8, the PPP session connected to the ISP network PN11 from the IP terminal IT13 through the mobile network MN13 to the mobile network IP is PS3, and using the sequence diagram of FIG. A method for setting a session will be described. From the IP terminal IT13, first, processing such as location registration is performed on the mobile node MoN11, and a connection setting request is made. Next, based on this, a tunnel such as GRE is set between the mobile node MoN11 and the access node AN11. After that, PPP protocol signal processing starts, but since it is the same as the high-speed IP connection, description thereof will be omitted. As shown in FIGS. 1 and 10, there is a case where the same tunnel as the session of the high-speed IP connection service is shared as the L2TP tunnel between AN11 and AN13 using the already established TL11, or the high-speed IP connection service There may be a case where an L2TP tunnel is set separately. By setting the PPP session PS3, the input / output relationship indicated by the entry 113 in FIG. 3 is set in the access node AN11, and the input / output relationship indicated by the entry 123 in FIG. 4 is set in the access node AN13. .

  Next, as shown in FIG. 10, when the IP terminal IT13 moves from the area connected to the mobile node MoN11 to the area connected to MoN12 in the mobile network MN13, the PPP session is PS4, and the sequence diagram of FIG. 11 is used. explain. The IP terminal IT13 first performs a process such as location registration again on the mobile node MoN12, and based on this, a tunnel such as GRE is set again between the mobile node MoN12 and the access node AN11. In the access node AN11, the input / output relationship shown in the entry 114 of FIG. 3 is set again, so that the PPP session PS3 is taken over by PS4. At this time, the access node AN13 is not particularly changed while the input / output relationship shown in the entry 123 of FIG. 4 is set. Further, since the GRE tunnel set between the mobile node MoN11 and the access node AN11 is no longer necessary, it is released and the entry 113 in FIG. 3 may be deleted.

  As shown above, the PPP session PS3 of FIG. 8 is transferred to the PPP session PS4 of FIG. 10, for example, so that the PPP session PS1 of FIG. 1 is transferred to the PPP session PS4 of FIG. Service is also conceivable. For example, when the terminal IT12 connected to the DSL network is IP-connected to the ISP network PN11, as described above, the access node AN11 has the input / output relationship shown in the entry 111 of FIG. Data transfer as shown at the bottom is performed. Considering the case where this terminal IT12 moves to the mobile network MN13 and comes to the position of the terminal IT13 shown in FIG. 10, the sequence of FIG. Through the same procedure, the session is taken over via the GRE tunnel corresponding to the tunnel TL16. At this time, in the table of FIG. 3, the entry 111 is inherited and set by the entry 114 (however, the output identifier of the entry 114 remains 1 as in the entry 111). In this way, in addition to movement within the mobile network, a service in which a session is taken over from a fixed network such as a DSL network to the mobile network can be realized.

  Next, as shown in FIG. 12, the PPP session when the IP terminal IT13 moves from the area connected to the mobile node MoN11 to the area connected to MoN13 in the mobile network MN13 is assumed to be PS5. Since the mobile node MoN11 is connected to the access node AN11 and the MoN13 is connected to the access node AN12, in the case of L2TP, when changing from the tunnel TL11 to TL13, the PPP session PS3 is once disconnected and a PPP session PS5 is set up again. There is a way. In addition, when using the Mobille IP shown in RFC2002 or the like instead of L2TP as the tunnel, it is possible to move from the tunnel TL11 to the tunnel TL13 around the access node AN13 without disconnecting the PPP session. In any case, for the PPP session PS5, the input / output relationship shown in the entry 131 in FIG. 13 is set in the access node AN12, and the input / output shown in the entry 143 in FIG. 14 is set in the access node AN13. A relationship is set.

  By sharing tables and devices in this way and changing the setting information according to the access method and network service, device costs can be reduced by integrating devices, management costs can be reduced, management can be centralized, etc. Is possible. This facilitates the transition and coexistence of different network services, such as the transition from low-speed IP connection service to high-speed IP connection service, service coexistence with phased transition, and addition of mobile network IP connection service.

  The second embodiment of the present invention will be described below with reference to the drawings.

  FIG. 15 is an example of a network and an access node that perform a low-speed IP connection service, a high-speed IP connection service, and a mobile network IP connection service, as in FIG. However, although the access nodes AN11 and AN12 having the LAC function are placed at the same positions as in FIG. 1, the access node AN15 having the LNS function is placed in common for the plurality of ISP networks PN15 and PN16. In the network of FIG. 15, the PPP session connected to the ISP network PN15 from the IP terminal IT15 via the DSL network MN12 is PS6, and the low speed IP connection is established from the IP terminal IT14 to the ISP network PN16 via the telephone network MN11. Let the PPP session be PS7. In the case of a network configuration in which access nodes are divided for each ISP network as shown in FIG. 1, a session corresponding to PS6 is set to pass through tunnel TL11, and a session corresponding to PS7 is set to pass through tunnel TL12. In the 15 network configuration, the PPP session PS6 is set to pass through the tunnel TL18, and the PS7 is set to pass through the tunnel TL19.

  As table setting information for the PPP sessions PS6 and PS7, the input / output relationship shown in the entry 151 and the entry 152 in FIG. 16 is set in the access node AN11, respectively, and the entry 161 and the entry in FIG. The input / output relationships shown at 162 are set respectively. Here, when the PPP sessions PS1 and PS2 from the terminals IT12 and IT11 to the ISP network PN11 as shown in FIG. 1 and FIG. 6 have already been set, the input ports 32 and 31 of the access node AN11 already have FIG. As shown in entry 111 and entry 12 of FIG. 16, 1 is used as the input session identifier. Therefore, in distinction from this, entry 151 and entry 152 in FIG. 16 use 2 as the input session identifier. The same output port 51 is used for the PPP sessions PS6 and PS7, but TL18 and TL19 are set separately as output tunnel identifiers. Further, in FIG. 17, data traffic directed to the ISP networks PN15 and PN16 is shown separately depending on the output port. In this way, by applying the present invention to a plurality of ISP networks and enterprise networks such as ISP networks PN15 and PN16, the access node AN15 can virtually function as a plurality of devices with a single device as a virtual router. In addition, network services corresponding to a plurality of access methods can be realized. The same applies to the case of mobile network IP connection.

  The third embodiment of the present invention will be described below with reference to the drawings.

  FIG. 18 is an example of a network and an access node that perform a low-speed IP connection service, a high-speed IP connection service, and a mobile network IP connection service, as in FIG. However, tunnels such as L2TP are not used here. If it is considered that the access node AN16 has both the LAC function and the LNS function, it can be considered that the network configuration in FIG. 15 is degenerated. In the network of FIG. 18, a PPP session connected to the ISP network PN17 via the DSL network MN12 from the IP terminal IT18 is designated as PS8, and a low-speed IP connection is established from the IP terminal IT17 to the ISP network PN18 via the telephone network MN11. Set the PPP session to PS9.

  As table setting information for the PPP sessions PS8 and PS9, the input / output relationship shown in the entry 171 and the entry 172 in FIG. 19 is set in the access node AN16, respectively. In this case, since no tunnel is set on the right side of the figure from AN16, nothing is always set in the output tunnel identifier OUT72. The input tunnel identifier IN72 may be set in the case of a mobile network IP connection service. In FIG. 18, since a tunnel such as L2TP is not used between access nodes, setting time is shortened at the protocol signal processing stage, and even a network with improved data transfer efficiency without tunnel overhead supports multiple access methods. Network services can be realized.

  As described above, according to this embodiment, the low-speed IP connection service corresponding to the access method from the telephone network, the high-speed IP connection service corresponding to the access method from the DSL network or the FTTH network, and the access from the mobile network. It is possible to provide a plurality of access methods and network services such as a mobile network IP connection service corresponding to the method. In addition, by sharing tables and devices and changing the setting information according to the access method and network service, it is possible to reduce device costs by integrating devices, reduce management costs, and centralize management. It becomes. This facilitates the transition and coexistence of different network services, such as the transition from low-speed IP connection service to high-speed IP connection service, service coexistence with phased transition, and addition of mobile network IP connection service. For example, in addition to movement within a mobile network, a service in which a session is taken over from a fixed network such as a DSL network to the mobile network can be realized. In addition, when the present invention is applied to a plurality of ISP networks or corporate networks, a network corresponding to a plurality of access methods can be used as a virtual router even when a single device virtually functions as a plurality of devices. Service can be realized. In addition, by applying the present invention to a network configuration that does not use a tunnel between access nodes, it is possible to shorten the setting time at the protocol signal processing stage, and even in a network that improves data transfer efficiency without tunnel overhead, a plurality of access methods A network service compatible with

  DESCRIPTION OF SYMBOLS 10 ... Access node apparatus, 11 ... Control part, 12 ... Switch part, 13 ... Incoming side processing part, 14 ... Outgoing side processing part, 20 ... Incoming side session processing part, 30-x ... Input line interface part, 40 ... Outgoing -Side session processing unit, 50-x ... output line interface unit, 1x0 ... access node input / output information correspondence table, 1xy ... table entry, 210 ... router, 2xy ... router component, 310 ... RAS, 3xy ... RAS component, ACx ... access control server, ANx ... access node, CNx ... IP core network, DLx ... DSLAM, INx ... table input information, ITx ... IP terminal, MNx ... access media network, MoNx ... mobile node, OUTx ... table output information, PNx ... ISP network, PSx ... PPP session, SWx ... exchange, TLx ... tunnel (x and y represent numbers).

Claims (6)

Packets transmitted from terminals connected to the first network according to the first communication protocol and the second network according to the second communication protocol and accommodated in the first network or the second network are sent to the terminal and the destination. In a packet transfer device that transmits and receives packets to and from a network based on a session,
A first input interface for receiving packets from the first communication protocol;
A second input interface for receiving packets from the second communication protocol;
An input session processing unit for processing a packet received by the first input interface and the second input interface;
The input session processing unit
Corresponding to each input port on the first interface and the second interface, the output port identification information of the received packet and one or more sessions are bundled to logically pass the packet to a certain point in the network. Holds a route information table that defines output tunnel identification information and output session identification information.
The input session processing unit
Receiving a packet from the first network or the second network;
With reference to the path information table, search for output port identification information corresponding to the input port of the received packet, output tunnel identification information , and output session identification information,
Further, the packet transfer device includes:
Process the received packet according to the retrieved output port, output tunnel identification information, and output session identification information,
A reception packet processing unit that outputs a reception packet to an output port indicated by the output port identification information ;
When the output tunnel identification information corresponding to the input port of the packet received from the first interface and the second interface is the same based on the path information table, the first interface and the second interface A packet transfer apparatus for outputting a received packet to a tunnel identified by the output tunnel identification information.   2. The packet transfer apparatus according to claim 1, wherein Point to Point Protocol (PPP) is used as the session.   2. The packet transfer apparatus according to claim 1, wherein a Layer 2 Tunneling Protocol (L2TP) system is used as the output tunnel system.   2. The packet transfer apparatus according to claim 1, wherein a Mobile IP system is used as the output tunnel system.   2. The packet transfer apparatus according to claim 1, wherein a generic routing encapsulation (GRE) system is used as the input tunnel system. Connected to the first network according to the first communication protocol and the second network according to the second communication protocol, and forwards the packet transmitted from the terminal accommodated in the first network or the second network to the destination network In the packet transfer device
A first input interface for receiving packets from the first communication protocol;
A second input interface for receiving packets from the second communication protocol;
An input packet processing unit that processes packets received by the first input interface and the second input interface;
The input packet processing unit
Corresponding to each input port on the first interface and the second interface, output port identification information of a received packet, first identification information for identifying communication between a specific transmission source and destination network Holding a route information table defining second identification information for logically passing packets from a specific source to a certain point in the network;
The input packet processing unit
Receiving a packet from the first network or the second network;
With reference to the path information table, search for output port identification information corresponding to the input port of the received packet, first identification information, and second identification information;
Processing the received packet according to the retrieved output port, the first identification information, and the second identification information;
Further, the packet transfer device includes:
A reception packet processing unit that outputs a reception packet to an output port indicated by the output port identification information ;
If the second identification information corresponding to the input ports of the packets received from the first interface and the second interface is the same based on the path information table, the first interface and the second interface A packet transfer apparatus that outputs a packet received from the second path to a path identified by the second identification information.

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