VPN router and VPN identification method by using logical channel identifiers

Abstract

The present invention provides a VPN edge router with the ability of identifying VPNs by using the identifiers of logical channels multiplexed on a single input line.

1 . A router connected to a core network, a first local area network (LAN) belonging to a first virtual private network (VPN), a second Local Area Network (LAN) belonging to a second VPN, a third LAN belonging to a third VPN and a fourth LAN belonging to a fourth VPN, comprising: 
 a first interface for accommodating a first line connected to the first LAN and the second LAN, and for receiving Internet Protocol (IP) packets from the first and the second LANs via the first line, the IP packets from the first and the second LANs being encapsulated by a first protocol;    a second interface connected to the core network; and    means for identifying which of the first VPN and the second VPN to which an IP packet received at the first interface belongs based on correspondence information between header information of the first protocol and a VPN identifier,    wherein IP packets from the third and the fourth LANs being encapsulated by a second protocol different from the first protocol.    
   
   
       2 . The router according to  claim 1 , further comprising: 
 a first routing information of the first VPN for mapping each IP addresses used in the first VPN to each of capsule headers used in the core network;    a second routing information of the second VPN for mapping each IP addresses used in the second VPN to each of capsule headers used in the core network; and    a processing unit for adding an capsule header used in the core network to an IP packet belonging to the first VPN by referring to the first routing information, and adding a capsule header used in the core network to an IP packet belonging to the second VPN by referring to the second routing information.    
   
   
       3 . The router according to  claim 1 , wherein the first protocol is an asynchronous transfer mode protocol and the header information is expressed in combined VPI and VCI values, and 
 wherein the second protocol is a Point-to-point Protocol (PPP) over a Synchronous Optical Network (SONET).    
   
   
       4 . The router according to  claim 1 , wherein the first protocol is an Layer2 Tunneling Protocol (L2TP) and the header information is expressed in L2TP encapsulating header.  
   
   
       5 . The router according to  claim 1 , wherein the first protocol is Ethernet and the header information is expressed as VLAN Tag based on IEEE802.1Q.  
   
   
       6 . A router connected to a core network, a first local area network (LAN) belonging to a first virtual private network (VPN), a second LAN belonging to a second VPN, a third LAN belonging to a third VPN and a fourth LAN belonging to a fourth VPN, comprising: 
 means for receiving Internet Protocol (IP) packets from the first and the second LANs being encapsulated by a first protocol;    a first interface connected to the core network;    a second interface for accommodating a first line connected to the third LAN and a second line connected to the fourth LAN, and for receiving IP packets from the third LAN via the first line and the IP packets from the fourth LAN via the second line, the IP packets from the third and the fourth LANs being encapsulated by a second protocol different from the first protocol; and    means for identifying which of the third VPN and the fourth VPN to which an IP packet received at the second interface belongs based on correspondence information between the VPN identifier and physical interface numbers assigned to interface between the second interface and the first line and interface between the second interface and the second line.    
   
   
       7 . The router according to  claim 6 , further comprising: 
 a first routing information of the third VPN for mapping each IP addresses used in the third VPN to each of capsule headers used in the core network;    a second routing information of the fourth VPN for mapping each IP addresses used in the fourth VPN to each of capsule headers used in the core network; and    a processing unit for adding an capsule header used in the core network to an IP packet belonging to the third VPN by referring the first routing information, and adding an capsule header used in the core network to an IP packet belonging to the fourth VPN by referring the second routing information.    
   
   
       8 . The router according to  claim 6 , wherein the first protocol is an asynchronous transfer mode protocol and the header information is expressed in combined VPI and VCI values, and 
 wherein the second protocol is a Point-to-point Protocol (PPP) over a Synchronous Optical Network (SONET).    
   
   
       9 . The router according to  claim 6 , wherein the second protocol is an Layer2 Tunneling Protocol (L2TP).  
   
   
       10 . The router according to  claim 6 , wherein the first protocol is Ethernet VLAN Tag based on IEEE802.1 Q.  
   
   
       11 . A method of transferring a packet in a router connected to a core network, a first local area network (LAN) belonging to a first virtual private network (VPN), a second LAN belonging to a second VPN, a third LAN belonging to a third VPN and a fourth LAN belonging to a fourth VPN, wherein the router receives IP packets from the first and the second LANs via a first line, the IP packets from the first and second LANs being encapsulated by a first protocol, receives IP packets from the third LAN via a second line and IP packets from the fourth LAN via a third line, the Internet Protocol (IP) packets from the third and the fourth LANs being encapsulated by a second protocol different from the first protocol, the method comprising the steps of: 
 identifying which of the first VPN and the second VPN to which an IP a packet received from the first line belongs on the basis of the correspondence information between header information of the first protocol and a VPN identifier.    
   
   
       12 . The method of transferring a packet in a router according to  claim 11 , wherein the router comprising: 
 a first routing information of the first VPN for mapping each IP addresses used in the first VPN to each of capsule headers used in the core network;    a second routing information of the second VPN for mapping each IP addresses used in the second VPN to each of capsule headers used in the core network; and    a processing unit for adding an capsule header used in the core network to an IP packet belonging to the first VPN by referring the first routing information, and adding an capsule header used in the core network to an IP packet belonging to the second VPN by referring the second routing information.    
   
   
       13 . The method of transferring a packet in a router according to  claim 11 , wherein the first protocol is an asynchronous transfer mode protocol and the header information is expressed in combined VPI and VCI, and 
 wherein the second protocol is a Point-to-point Protocol (PPP) over a Synchronous Optical Network (SONET).    
   
   
       14 . The method of transferring a packet in a router according to  claim 11 , wherein the first protocol is an Layer2 Tunneling Protocol (L2TP) and the header information is expressed in L2TP encapsulating header.  
   
   
       15 . The method of transferring a packet in a router according to  claim 11 , wherein the first protocol is Ethernet and the header information is expressed as VLAN Tag based on IEEE802.1Q.  
   
   
       16 . A method of transferring a packet in a router connected to a core network, a first local area network (LAN) belonging to a first virtual private network (VPN), a second LAN belonging to a second VPN, a third LAN belonging to a third VPN and a fourth LAN belonging to a fourth VPN, wherein the router receives IP packets from the first and the second LANs via a first line, the IP packets from the first and second LANs being encapsulated by a first protocol, receives IP packets from the third LAN via a second line and IP packets from the fourth LAN via a third line, the Internet Protocol (IP) packets from the third and the fourth LANs being encapsulated by a second protocol different from the first protocol, the method comprising the steps of: 
 identifying which of the third VPN and the fourth VPN to which an IP a packet received from the second line belongs based on correspondence information between the VPN identifier and physical interface numbers assigned to interface between the router and the first line and interface between the router and the second line.    
   
   
       17 . The method of transferring a packet in a router according to  claim 16 , wherein the router comprising: 
 a first routing information of the third VPN for mapping each IP addresses used in the third VPN to each of capsule headers used in the core network;    a second routing information of the fourth VPN for mapping each IP addresses used in the fourth VPN to each of capsule headers used in the core network; and    a processing unit for adding an capsule header used in the core network to an IP packet belonging to the third VPN by referring the first routing information, and adding an capsule header used in the core network to an IP packet belonging to the fourth VPN by referring the second routing information.    
   
   
       18 . The method of transferring a packet in a router according to  claim 16 , wherein the first protocol is an asynchronous transfer mode protocol and the header information is expressed in combined VPI and VCI, and 
 wherein the second protocol is a Point-to-point Protocol (PPP) over a Synchronous Optical Network (SONET).    
   
   
       19 . The method of transferring a packet in a router according to  claim 16 , wherein the first protocol is an Layer2 Tunneling Protocol (L2TP) and the header information is expressed in L2TP encapsulating header.  
   
   
       20 . The method of transferring a packet in a router according to  claim 16 , wherein the first protocol is Ethernet and the header information is expressed as VLAN Tag based on IEEE802.1Q.