US20030088699A1 - System, device, and method for supporting virtual private networks in a label switched communication network - Google Patents

System, device, and method for supporting virtual private networks in a label switched communication network Download PDF

Info

Publication number
US20030088699A1
US20030088699A1 US09/434,338 US43433899A US2003088699A1 US 20030088699 A1 US20030088699 A1 US 20030088699A1 US 43433899 A US43433899 A US 43433899A US 2003088699 A1 US2003088699 A1 US 2003088699A1
Authority
US
United States
Prior art keywords
label
next hop
resolution protocol
forward path
path
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US09/434,338
Other languages
English (en)
Inventor
James V. Luciani
Andre N. Fredette
Bill Hawe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nortel Networks Ltd
Original Assignee
Nortel Networks Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nortel Networks Ltd filed Critical Nortel Networks Ltd
Priority to US09/434,338 priority Critical patent/US20030088699A1/en
Assigned to NORTEL NETWORKS CORPORATION reassignment NORTEL NETWORKS CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: FREDETTE, ANDRE N., HAWE, BILL, LUCIANI, JAMES V.
Assigned to NORTEL NETWORKS LIMITED reassignment NORTEL NETWORKS LIMITED CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: NORTEL NETWORKS CORPORATION
Priority to CA002324805A priority patent/CA2324805A1/fr
Priority to EP00309779A priority patent/EP1122914A3/fr
Priority to KR1020000065359A priority patent/KR20010070190A/ko
Priority to JP2000338050A priority patent/JP2001189751A/ja
Assigned to NORTEL NETWORKS LIMITED reassignment NORTEL NETWORKS LIMITED CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: NORTEL NETWORKS CORPORATION
Publication of US20030088699A1 publication Critical patent/US20030088699A1/en
Priority to US11/301,162 priority patent/US7174388B2/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/46—Interconnection of networks
    • H04L12/4641—Virtual LANs, VLANs, e.g. virtual private networks [VPN]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/17—Shortcut routing, e.g. using next hop resolution protocol [NHRP]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/50—Routing or path finding of packets in data switching networks using label swapping, e.g. multi-protocol label switch [MPLS]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/50—Routing or path finding of packets in data switching networks using label swapping, e.g. multi-protocol label switch [MPLS]
    • H04L45/502—Frame based
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L63/00—Network architectures or network communication protocols for network security
    • H04L63/02—Network architectures or network communication protocols for network security for separating internal from external traffic, e.g. firewalls
    • H04L63/0272—Virtual private networks

Definitions

  • the present invention relates generally to communication systems, and more particularly to supporting virtual private networks in a multi-protocol label switching (MPLS) environment.
  • MPLS multi-protocol label switching
  • VPNs Virtual Private Networks
  • a LSP is established for a VPN by including label information and a VPN identifier in NHRP messages and using the NHRP messages to establish the LSP for the VPN.
  • the ingress device In order to establish a LSP for a forward path from an ingress device to an egress device, the ingress device sends a NHRP request message including a label request and the VPN identifier.
  • the NHRP request message is forwarded hop-by-hop from the ingress device to the egress device by each intermediate device on the forward path.
  • the egress device allocates a forward path label for a LSP segment from a previous hop device to the egress device, and sends a NHRP reply message including the forward path label and the VPN identifier.
  • Each intermediate device on the forward path receives from the next hop device on the forward path a NHRP reply message including a forward path label for a LSP segment to the next hop device and the VPN identifier.
  • Each intermediate device establishes a LSP to the next hop device using the forward path label from the NHRP reply message, allocates a forward path label for a LSP segment from the previous hop device on the forward path to the intermediate device, and sends a NHRP reply message including the forward path label and the VPN identifier.
  • the ingress device Upon receiving a NHRP reply message including a forward path label and the VPN identifier, the ingress device establishes a LSP to the next hop device on the forward path using the forward path label from the NHRP reply message.
  • the ingress device sends a NHRP request message including a return path label for a LSP segment from a next hop device to the ingress device and the VPN identifier.
  • Each intermediate device on the forward path receives from the previous hop device on the forward path a NHRP request message including a return path label and the VPN identifier.
  • Each intermediate device establishes a LSP to the previous hop device using the return path label from the NHRP request message, allocates a return path label for a LSP segment from a next hop device to the intermediate device, and sends to the next hop device a NHRP request message including the return path label and the VPN identifier.
  • the egress device Upon receiving a NHRP request message including a return path label and the VPN identifier, the egress device establishes a LSP to the previous hop device using the return path label from the NHRP request message.
  • each intermediate device that forwards the NHRP request message may maintain previous hop state information for the previous hop device, in which case the intermediate device forwards the NHRP reply message to the previous hop device based upon the previous hop state information.
  • each intermediate device that forwards the NHRP request message may insert a device address into a forward path address list, in which case the intermediate device forwards the NHRP reply message to the previous hop device based upon a previous hop device address in a return path address list included in the NHRP reply message.
  • FIG. 1 is a block diagram showing an exemplary MPLS communication system including an Ingress Station in communication with an Egress Station via an MPLS Network;
  • FIG. 2 is a block diagram showing an exemplary MPLS communication system in which the MPLS Network includes four (4) intermediate devices;
  • FIG. 3A is a block diagram showing an exemplary communication system where the forward path and the return path traverse the same intermediate devices;
  • FIG. 3B is a block diagram showing an exemplary communication system where the forward path and the return path traverse different intermediate devices;
  • FIG. 4 is a block diagram showing the format of an exemplary VPN-ID TLV field in accordance with an embodiment of the present invention
  • FIG. 5 is a block diagram showing an exemplary communication system in which a label request is included along with a VPN identifier in the NHRP Resolution Request message in accordance with an embodiment of the present invention
  • FIG. 6 is a block diagram showing an exemplary communication system in which the label mappings and VPN identifier are conveyed in NHRP Resolution Reply messages that are forwarded hop-by-hop along the return path in accordance with an embodiment of the present invention
  • FIG. 7 is a block diagram showing an exemplary communication system in which NHRP Label Mapping messages are used to convey label mapping information and the VPN identifier to the devices along the forward path in accordance with an embodiment of the present invention
  • FIG. 8 is a block diagram showing an exemplary communication system in which NHRP Resolution Reply messages are used to convey label mapping information and the VPN identifier to the devices along the forward path in accordance with an embodiment of the present invention
  • FIG. 9A is a logic flow diagram showing exemplary intermediate device logic for forcing the NHRP Resolution Reply messages to follow the forward path rather than the return path by maintaining previous hop information in accordance with an embodiment of the present invention
  • FIG. 9B is a logic flow diagram showing exemplary egress device logic for forcing the NHRP Resolution Reply messages to follow the forward path rather than the return path by maintaining previous hop information in accordance with an embodiment of the present invention
  • FIG. 9C is a logic flow diagram showing exemplary intermediate device logic for forcing the NHRP Resolution Reply messages to follow the forward path rather than the return path by maintaining previous hop information in accordance with an embodiment of the present invention
  • FIG. 10A is a logic flow diagram showing exemplary intermediate device logic for forcing the NHRP Resolution Reply messages to follow the forward path rather than the return path using a list of addresses in accordance with an embodiment of the present invention
  • FIG. 10B is a logic flow diagram showing exemplary egress device logic for forcing the NHRP Resolution Reply messages to follow the forward path rather than the return path using a list of addresses in accordance with an embodiment of the present invention
  • FIG. 10C is a logic flow diagram showing exemplary intermediate device logic for forcing the NHRP Resolution Reply messages to follow the forward path rather than the return path using a list of addresses in accordance with an embodiment of the present invention.
  • FIG. 11 is a block diagram showing an exemplary communication system for creating bi-directional paths in accordance with an embodiment of the present invention.
  • a common networking model routes packets of information within the communication network using a networking protocol such as the Internet Protocol (IP) or other network layer protocol.
  • IP Internet Protocol
  • IP Internet Protocol
  • each packet of information includes a network layer address, and each router forwards the packet of information based upon the network layer address according to a predetermined routing protocol such as the Open Shortest Path First (OSPF) protocol, the Routing Information Protocol (RIP), Hello, or other routing protocol.
  • OSPF Open Shortest Path First
  • RIP Routing Information Protocol
  • Hello or other routing protocol.
  • each router makes an independent forwarding decision for the packet based upon the network layer address.
  • each router partitions the entire set of network layer addresses into a number of Forwarding Equivalence Classes (FECs), and each FEC is mapped to a particular outgoing path (or set of paths, in the case of multi-path routing) based upon the routing protocol.
  • the router determines an FEC for each packet of information based upon the network layer address of the packet, and forwards the packet of information to the corresponding outgoing path (or set of paths).
  • FECs Forwarding Equivalence Classes
  • Network layer routing requires each router to process each packet of information at the network layer. This is an expensive and time-consuming operation that limits the performance of some routers and even prevents certain devices that do not support the networking protocol from performing routing and other functions on the packets.
  • Label switching can be used to eliminate the network layer processing by certain devices in the communication network. Label switching enables a packet to be transported across a network domain (referred to hereinafter as an “autonomous system” or “AS”) using labels rather than the network layer address. Specifically, a Label Switched Path (LSP) is established from an ingress point border device to an egress point border device in the AS. The LSP traverses a number of label switching devices. Each label switching device assigns a short, fixed-length value (i.e., a “label”) to each FEC that it supports.
  • LSP Label Switched Path
  • the ingress point border device uses the network address to assign the packet to a particular FEC, and inserts the corresponding label into the packet, specifically within a packet header.
  • Each subsequent label switching device along the LSP uses the label in the packet to determine the next hop FEC for the packet, and replaces the label in the packet with a new label corresponding to the next hop FEC for the packet.
  • the egress point border device removes the label from the packet. Thus, only the ingress point border device processes the packet at the network layer, and subsequent devices process the packet based upon the label only.
  • MPLS Multi-Protocol Label Switching
  • IETF Internet Engineering Task Force
  • MPLS Multi-Protocol Label Switching
  • An MPLS framework is described in an IETF Internet Draft document entitled A FRAMEWORK FOR MULTIPROTOCOL LABEL SWITCHING [draft-ietf-mpls-framework-02.txt (November 1997)], and is hereby incorporated by reference in its entirety.
  • the MPLS architecture is described in an IETF Internet Draft document entitled MULTIPROTOCOL LABEL SWITCHING ARCHITECTURE [draft-ietf-mpls-arch-05.txt (April 1999)], and is hereby incorporated by reference in its entirety.
  • LDP Label Distribution Protocol
  • LDP label switching in an Asynchronous Transfer Mode (ATM) network
  • ATM Asynchronous Transfer Mode
  • Each label switching device maintains a label information base (LIB) for mapping each FEC to a corresponding label.
  • LIB label information base
  • the label switching device utilizes the LIB to map the received label to a next hop FEC and to retrieve a label for the next hop FEC.
  • the label switching device then replaces the label in the packet with the label for the next hop FEC, and forwards the resulting packet to the corresponding outgoing path (or set of paths).
  • the communication network is divided into a number of Virtual Private Networks (VPNs), where each VPN emulates a single, private network.
  • VPNs Virtual Private Networks
  • label switching is used to support VPNs in an MPLS environment by establishing a LSP for each VPN.
  • Each station hosts or router
  • Each station maps each LSP to its respective VPN.
  • Protocol messages that are associated with a particular VPN are carried over the corresponding LSP, specifically by inserting the appropriate label into the protocol messages and forwarding the protocol messages over the LSP.
  • NHRP Next Hop Resolution Protocol
  • RRC Request For Comments
  • NHRP NBMA NEXT HOP RESOLUTION PROTOCOL
  • NHRP can be used to support VPNs, for example, as described in the IETF Internet Draft entitled NHRP SUPPORT FOR VIRTUAL PRIVATE NETWORKS [draft-ietf-ion-nhrp-vpn-00.txt], which is hereby incorporated by reference in its entirety, and in the related application entitled SYSTEM, DEVICE, AND METHOD FOR SUPPORTING VIRTUAL PRIVATE NETWORKS, which was incorporated by reference above.
  • FIG. 1 shows an exemplary MPLS communication system 100 including an Ingress Station 102 in communication with an Egress Station 106 via an MPLS Network 104 .
  • the MPLS Network 104 includes a number of intermediate devices, such as switches and routers, that physically and logically interconnect the Ingress Station 102 and the Egress Station 106 .
  • a LSP is established for a particular VPN from the Ingress Station 102 to the Egress Station 106 across the MPLS Network 104 , and particularly across a number of intermediate devices.
  • NHRP is used to convey label information and a VPN identifier hop-by-hop between the Ingress Station 102 and the Egress Station 106 , allowing the Ingress Station 102 , the Egress Station 106 , and the number of intermediate devices through which the Ingress Station 102 and the Egress Station 106 are interconnected to correlate the LSP with the particular VPN.
  • FIG. 2 shows an exemplary communication system 200 in which the MPLS Network 104 includes four (4) intermediate devices, namely the intermediate device I 1 ( 202 ), the intermediate device I 2 ( 204 ), the intermediate device I 3 ( 206 ), and the intermediate device I 4 ( 208 ).
  • the intermediate device I 1 ( 202 ) the intermediate device I 2 ( 204 )
  • the intermediate device I 3 ( 206 ) the intermediate device I 4 ( 208 ).
  • a NHRP Resolution Request message is forwarded hop-by-hop across a forward path from an ingress device to an egress device, and a NHRP Resolution Reply message including the addressing information is forwarded hop-by-hop across a return path from the egress device to the ingress device.
  • the forward path and the return path may traverse the same or different intermediate devices.
  • FIG. 3A shows an exemplary communication system where the forward path and the return path traverse the same intermediate devices.
  • the forward path and the return path traverse the intermediate devices I 1 ( 202 ) and I 2 ( 204 ).
  • the Ingress Station 102 sends a NHRP Resolution Request message 302 to the intermediate device I 1 ( 202 ), which in turn sends a NHRP Resolution Request message 304 to the intermediate device I 2 ( 204 ), which in turn sends a NHRP Resolution Request message 306 to the Egress Station 106 .
  • the Egress Station 106 sends a NHRP Resolution Reply message 308 to the intermediate device I 2 ( 204 ), which in turn sends a NHRP Resolution Reply message 310 to the intermediate device I 1 ( 202 ), which in turn sends a NHRP Resolution Reply message 312 to the Ingress Station 102 .
  • FIG. 3B shows an exemplary communication system where the forward path and the return path traverse different intermediate devices.
  • the forward path traverses the intermediate devices I 1 ( 202 ) and I 2 ( 204 ), while the return path traverses the intermediate devices I 4 ( 208 ) and I 3 ( 206 ).
  • the Ingress Station 102 sends a NHRP Resolution Request message 302 to the intermediate device I 1 ( 202 ), which in turn sends a NHRP Resolution Request message 304 to the intermediate device I 2 ( 204 ), which in turn sends a NHRP Resolution Request message 306 to the Egress Station 106 .
  • the Egress Station 106 sends a NHRP Resolution Reply message 314 to the intermediate device I 4 ( 208 ), which in turn sends a NHRP Resolution Reply message 316 to the intermediate deivce I 3 ( 206 ), which in turn sends a NHRP Resolution Reply message 318 to the Ingress Station 102 .
  • each device along the forward path from the ingress device to the egress device must “learn” a label for its next hop neighboring device and associate the label with the particular VPN. For example, with reference to FIG.
  • label information is conveyed in NHRP messages (often referred to as “piggybacking”) along with a VPN identifier so that each device along the forward path can correlate the LSP with the particular VPN.
  • a label request is conveyed along with a VPN identifier in a NHRP Resolution Request message that is forwarded hop-by-hop along the forward path from the ingress device to the egress device.
  • Label mapping information is conveyed along with a VPN identifier in NHRP reply messages that are forwarded hop-by-hop from the egress device to each device in the forward path and ultimately to the ingress device.
  • VPN-ID VPN Identifier
  • TLV Type-Length-Value
  • the VPN-ID TLV field includes, among other things, a VPN identifier identifying the VPN.
  • the VPN-ID TLV field is extended to include label information in addition to the VPN identifier.
  • FIG. 4 shows the format of an exemplary VPN-ID TLV field 400 including both a VPN identifier and label information.
  • the preferred VPN-ID TLV field 400 includes a header field 410 , a VPN-ID field 420 , and a Label Information field 430 .
  • the header field 410 includes a Compulsory field 411 , an unused field 412 , a Type field 413 , and Length field 414 .
  • the VPN-ID TLV field 400 is considered be “compulsory” as that term is used with reference to TLV extensions in the IETF RFC document entitled NBMA NEXT HOP RESOLUTION PROTOCOL (NHRP), which was incorporated by reference above, and therefore the Compulsory field 411 is always set to the value one (1).
  • the Length field 414 indicates the length of the VPN-ID TLV field 400 , which is preferably equal to twelve (12) bytes (0 ⁇ 0C in hexadecimal).
  • the Type field 413 for the VPN-ID TLV field 400 is not yet assigned.
  • the Label Information 430 field may contain label request information (in the case of a NHRP Resolution Request or other request message) or label mapping information (in the case of a NHRP reply message), as described in detail below.
  • label request information in the case of a NHRP Resolution Request or other request message
  • label mapping information in the case of a NHRP reply message
  • the ingress device sends a label request along with a VPN identifier to the egress device by including the label request and VPN identifier in a NHRP Resolution Request message.
  • the ingress device sends a NHRP Resolution Request message with a VPN-ID TLV field 400 including the label request and VPN identifier in the Label Information field 430 and VPN-ID field 420 , respectively.
  • Each device along the forward path transfers the VPN-ID TLV field 400 in a NHRP Resolution Request message that is forwarded to the next hop device.
  • FIG. 5 shows an exemplary communication system in which the label request is included along with a VPN identifier in the NHRP Resolution Request message.
  • the Ingress Station 102 sends to the intermediate device I 1 ( 202 ) a NHRP Resolution Request message 502 with a VPN-ID TLV field 400 including the label request in the Label Information field 430 .
  • the intermediate device It ( 202 ) in turn sends to the intermediate device I 2 ( 204 ) a NHRP Resolution Request message 504 with the VPN-ID TLV field 400 from the NHRP Resolution Request message 502 .
  • the intermediate device I 2 ( 204 ) in turn sends to the Egress Station 106 a NHRP Resolution Request message 506 with the VPN-ID TLV field 400 from the NHRP Resolution Request message 504 .
  • each device along the forward path from the ingress device to the egress device “learns” a label for its next hop neighboring device from label mapping information that is conveyed along with a VPN identifier in NHRP reply messages that are forwarded hop-by-hop from the egress device to each device in the forward path and ultimately to the ingress device.
  • a first exemplary embodiment of the present invention enables each device along the forward path to “learn” a label for its next hop neighboring device when the forward path and the return path traverse the same intermediate devices. Because the forward path and the return path traverse the same intermediate devices, message flows are described relative to the forward path for the sake of clarity. Thus, when sending a message to a neighboring device on the return path, a particular device is said to send a message to the previous hop device on the forward path rather than to the next hop device on the return path.
  • the label mapping information may be included along with a VPN identifier in NHRP Resolution Reply messages that are forwarded hop-by-hop across the return path.
  • the egress device upon receiving the NHRP Resolution Request message including the label request and the VPN identifier, allocates a label for the previous hop on the forward path and sends to the previous hop device on the forward path a NHRP Resolution Reply message with a VPN-ID TLV field 400 including the label for the previous hop on the forward path and the VPN identifier, specifically within the Label Information field 430 and VPN-ID field 420 of the VPN-ID TLV field 400 , respectively.
  • each device along the return path Upon receiving the NHRP Resolution Reply message from its next hop device on the forward path, each device along the return path extracts from the NHRP Resolution Reply message the label associated with the the next hop on the forward path and the VPN identifier, specifically from the Label Information field 430 and VPN-ID field 420 of the VPN-ID TLV field 400 , respectively.
  • Each device along the return path allocates a label for the previous hop on the forward path, and sends to the previous hop device on the forward path a NHRP Resolution Reply message with a VPN-ID TLV field 400 including the label for the previous hop on the forward path and the VPN identifier, specifically in the Label Information field 430 and VPN-ID field 420 of the VPN-ID TLV field 400 , respectively.
  • Each device along the return path creates the appropriate LIB entries in order to map the labels associated with the LSP to the particular VPN indicated by the VPN identifier.
  • FIG. 6 shows an exemplary communication system in which the label mappings and VPN identifier are conveyed in NHRP Resolution Reply messages that are forwarded hop-by-hop along the return path.
  • the Egress Station 106 Upon receiving the NHRP Resolution Request message 506 including the VPN-ID TLV field 400 including the label request and the VPN identifier, the Egress Station 106 allocates a label for the LSP segment from the intermediate device I 2 ( 204 ), and sends to the intermediate device I 2 ( 204 ) over the return path a NHRP Resolution Reply message 602 with a VPN-ID TLV field 400 including the label and the VPN identifier, specifically in the Label Information field 430 and the VPN-ID field 420 of the VPN-ID TLV field 400 , respectively.
  • the intermediate device I 2 ( 204 ) Upon receiving the NHRP Resolution Reply message 602 , the intermediate device I 2 ( 204 ) allocates a label for the LSP segment from the intermediate device I 1 ( 202 ), and sends to the intermediate device I 1 ( 202 ) over the return path a NHRP Resolution Reply message 604 with a VPN-ID TLV field 400 including the label and the VPN identifier, specifically in the Label Information field 430 and the VPN-ID field 420 of the VPN-ID TLV field 400 , respectively.
  • the intermediate device I 1 Upon receiving the NHRP Resolution Reply message 604 , the intermediate device I 1 ( 202 ) allocates a label for the LSP segment from the Ingress Station 102 , and sends to the Ingress Station 102 over the return path a NHRP Resolution Reply message 606 with a VPN-ID TLV field 400 including the label and the VPN identifier, specifically in the Label Information field 430 and the VPN-ID field 420 of the VPN-ID TLV field 400 , respectively.
  • the forward path and the return path may traverse different intermediate devices.
  • the label mapping information cannot simply be included along with a VPN identifier in NHRP Resolution Reply messages that are forwarded hop-by-hop across the return path, since such label mapping information will not be received by the devices along the forward path as required to establish the LSP for the VPN.
  • a new NHRP Label Mapping message is used to convey label mapping information to the devices along the forward path, while NHRP Resolution Reply messages are forwarded hop-by-hop across the return path as usual.
  • a device along the forward path receives a NHRP Resolution Request message with a VPN-ID TLV field 400 including a label request and a VPN identifier
  • the device forwards the NHRP Resolution Request message (in the case of an intermediate device) or sends a NHRP Resolution Reply message (in the case of the egress device).
  • the device also allocates a label for the previous hop of the forward path, and sends to the previous hop device on the forward path a NHRP Label Mapping message including the label and the VPN identifier.
  • Each device along the forward path creates the appropriate LIB entries in order to map the labels associated with the LSP to the particular VPN indicated by the VPN identifier.
  • FIG. 7 shows an exemplary communication system in which a NHRP Label Mapping message is used to convey label mapping information to the devices along the forward path from the ingress device and the egress device.
  • the Ingress Station 102 sends to the intermediate device I 1 ( 202 ) a NHRP Resolution Request message 502 with a VPN-ID TLV field 400 including the label request in the Label Information field 430 .
  • the intermediate device I 1 ( 202 ) Upon receiving the NHRP Resolution Request message 502 , the intermediate device I 1 ( 202 ) sends to the intermediate device I 2 ( 204 ) a NHRP Resolution Request message 504 with the VPN-ID TLV field 400 from the NHRP Resolution Request message 502 .
  • the intermediate device I 1 ( 202 ) also allocates a label for the LSP segment from the Ingress Station 102 , and sends to the Ingress Station 102 a NHRP Label Mapping message 706 including the label and the VPN identifier.
  • the intermediate device I 2 ( 204 ) Upon receiving the NHRP Resolution Request message 504 , the intermediate device I 2 ( 204 ) sends to the Egress Station 106 a NHRP Resolution Request message 506 with the VPN-ID TLV field 400 from the NHRP Resolution Request message 504 .
  • the intermediate device I 2 ( 204 ) also allocates a label for the LSP segment from the intermediate device I 1 ( 202 ), and sends to the intermediate device I 1 ( 202 ) a NHRP Label Mapping message 704 including the label and the VPN identifier.
  • the Egress Station 106 Upon receiving the NHRP Resolution Request message 506 , the Egress Station 106 sends to the intermediate device I 4 ( 208 ) a NHRP Resolution Reply message 314 .
  • the Egress Station 106 also allocates a label for the LSP segment from the intermediate device I 2 ( 204 ), and sends to the intermediate device I 2 ( 204 ) a NHRP Label Mapping message 702 including the label and the VPN identifier.
  • the intermediate device I 4 ( 208 ) Upon receiving the NHRP Resolution Reply message 314 , the intermediate device I 4 ( 208 ) sends a NHRP Resolution Reply message 316 to the intermediate device I 3 ( 206 ), which in turn sends a NHRP Resolution Reply message 318 to the Ingress Station 102 .
  • the Ingress Station 102 Based upon the label mapping information included in the NHRP Label Mapping messages 702 , 704 , and 706 , the Ingress Station 102 , the intermediate devices I 1 ( 202 ) and I 2 ( 204 ), and the Egress Station 106 create the appropriate LIB entries to map the LSP to the VPN.
  • the devices along the forward path may create the LSP for the VPN before the NHRP resolution procedure is complete.
  • the LSP may be created even if the NHRP resolution procedure ultimately fails.
  • the ingress device preferably includes “clean-up” logic that deletes the LSP if the NHRP resolution procedure does not successfully complete within a predetermined period of time.
  • the label mapping information is included along with a VPN identifier in NHRP Resolution Reply messages, as in the first exemplary embodiment described above with reference to FIG. 6, but the NHRP Resolution Reply messages are forced to follow the forward path rather than the return path.
  • FIG. 8 shows an exemplary communication system in which the NHRP Resolution Reply messages are forced to follow the forward path rather than the return path. As shown in FIG. 8, the return path from the Egress Station 106 to the Ingress Station 102 traverses hops 808 , 810 , and 812 . However, the NHRP Resolution Reply messages traverse hops 802 , 804 , and 806 .
  • One way to force the NHRP Resolution Reply messages to follow the forward path rather than the return path is for each device along the forward path to maintain state information relating to the previous hop device on the forward path and route the NHRP Resolution Reply messages according to the previous hop state information.
  • the intermediate device maintains the previous hop state information including, among other things, a route to the previous hop device on the forward path and the VPN identifier.
  • the egress device When the egress device receives a NHRP Resolution Request message including the label request and the VPN identifier, the egress device allocates a label for the previous hop LSP segment on the forward path, and sends to the previous hop device on the forward path a NHRP Resolution Reply message including the label and the VPN identifier.
  • the intermediate device receives a NHRP Resolution Reply message including label mapping information and the VPN identifier, the intermediate device allocates a label for the previous hop LSP segment on the forward path, and, using the previous hop state information, sends to the previous hop device on the forward path a NHRP Resolution Reply message including the label and the VPN identifier.
  • the VPN identifier in the NHRP Resolution Reply message allows each device along the forward path to match the NHRP Resolution Reply message to the correct previous hop state information for the VPN.
  • FIGS. 9A, 9B, and 9 C are logic flow diagrams showing exemplary intermediate device logic and egress device logic for forcing the NHRP Resolution Reply messages to follow the forward path rather than the return path by maintaining previous hop state information.
  • FIG. 9A beginning at step 902 , upon receiving a NHRP Resolution Request message including a label request and a VPN identifier from a previous hop device on the forward path, in step 904 , an intermediate device maintains previous hop state information including a route to the previous hop device on the forward path and the VPN identifier, in step 906 , forwards the NHRP Resolution Request message to the next hop device on the forward path, in step 907 , and terminates in step 908 . As shown in FIG.
  • step 9B beginning at step 910 , upon receiving a NHRP Resolution Request message including a label request and a VPN identifier from a previous hop device on the forwarding path, in step 912 , the egress device allocates a label for the previous hop LSP segment on the forward path, in step 914 , sends to the previous hop device on the forward path a NHRP Resolution Reply message including the label and the VPN identifier, in step 916 , and terminates in step 918 .
  • a NHRP Resolution Reply message including the label and the VPN identifier
  • step 9C beginning at step 920 , upon receiving a NHRP Resolution Reply message including label mapping information and the VPN identifier, in step 922 , an intermediate device allocates a label for the previous hop LSP segment on the forward path, in step 924 , sends to the previous hop device on the forward path a NHRP Resolution Reply message including the label and the VPN identifier, in step 926 , and terminates in step 928 .
  • Another way to force the NHRP Resolution Reply messages to follow the forward path rather than the return path is for each device along the forward path to add its address to a list of addresses in the NHRP Resolution Request messages forwarded along the forward path, preferably by adding a NHRP Forward Transit NHS Record Extension field to the NHRP Resolution Request message, and route the NHRP Resolution Reply messages back across the forward path by routing the NHRP Resolution Reply messages to the addresses in the list of addresses in reverse order.
  • the NHRP Forward Transit NHS Record Extension field and its uses are described in the ETF RFC document entitled NBMA NEXT HOP RESOLUTION PROTOCOL (NHRP), which was incorporated by reference above.
  • Each device along the forward path adds a NHRP Forward Transit NHS Record Extension field to the NHRP Resolution Request message such that, when the NHRP Resolution Request message reaches the egress device, the NHRP Resolution Request message includes the routing address of each device along the forward path.
  • the egress device Upon receiving the NHRP Resolution Request message including the list of addresses, the egress device allocates a label for the previous hop LSP segment on the forward path, and forwards to the previous hop device on the forward path a NHRP Resolution Reply message including at least the label, the VPN identifier, and the list of addresses for at least those devices to which the NHRP Resolution Reply message must be forwarded, specifically by routing the NHRP Resolution Reply message to the last address in the list of addresses.
  • an intermediate device Upon receiving a NHRP Resolution Reply message including label mapping information, the VPN identifier, and a list of remaining addresses, an intermediate device allocates a label for the previous hop LSP segment on the forward path, and sends to the previous hop device on the forward path a NHRP Resolution Reply message including at least the label, the VPN identifier, and the list of addresses for at least those devices to which the NHRP Resolution Reply message must be forwarded, specifically by routing the NHRP Resolution Reply message to the last address in the list of remaining addresses.
  • FIGS. 10A, 10B, and 10 C are logic flow diagrams showing exemplary intermediate device logic and egress device logic for forcing the NHRP Resolution Reply messages to follow the forward path rather than the return path using a list of addresses.
  • an intermediate device upon receiving a NHRP Resolution Request message including a label request, a VPN identifier, and a list of addresses, in step 1004 , an intermediate device adds its address to the list of addresses, in step 1006 , forwards the NHRP Resolution Request message to the next hop device on the forward path, in step 1008 , and terminates in step 1010 .
  • FIG. 10A begins at step 1002 , upon receiving a NHRP Resolution Request message including a label request, a VPN identifier, and a list of addresses, in step 1004 , an intermediate device adds its address to the list of addresses, in step 1006 , forwards the NHRP Resolution Request message to the next hop device on the forward path, in step 1008 , and terminates in step 1010 .
  • step 10B upon receiving a NHRP Resolution Request message including a label request, a VPN identifier, and a list of addresses, in step 1014 , the egress device allocates a label for the previous hop LSP segment on the forward path, in step 1016 , removes the last address from the list of addresses to form a list of remaining addresses, in step 1018 , sends to the last address from the list of addresses a NHRP Resolution Reply message including the label, the VPN identifier, and the list of remaining addresses, in step 1020 , and terminates in step 1022 .
  • NHRP Resolution Reply message including the label, the VPN identifier, and the list of remaining addresses
  • step 10C beginning at step 1024 , upon receiving a NHRP Resolution Reply message including a label, a VPN identifier, and a list of addresses, in step 1026 , an intermediate device allocates a label for the previous hop LSP segment on the forward path, in step 1028 , removes the last address from the list of addresses to form a list of remaining addresses, in step 1030 , sends to the last address from the list of addresses a NHRP Resolution Reply message including the label, the VPN identifier, and the list of remaining addresses, in step 1032 , and terminates in step 1034 .
  • NHRP is used to create a unidirectional path (i.e., the forward path) from the ingress device to the egress device.
  • NHRP can also be used to create bi-directional paths (i.e., a forward path and a return path) between the ingress device and the egress device.
  • the various mechanisms described above allow label mapping information to be distributed to all devices along the forward path.
  • an exemplary embodiment of the present invention includes label mapping information in the NHRP Resolution Request messages that are forwarded along the forward path, for example, in the VPN-ID TLV field 400 .
  • the ingress device allocates a label for next hop LSP segment on the return path, and sends to the next hop device on the forward path a NHRP Resolution Request message including the label for the next hop LSP segment on the return path and a VPN identifier, and also indicating that bi-directional paths should be created.
  • Each intermediate device along the forward path extracts the return path label from the NHRP Resolution Request message, allocates a label for the next hop LSP segment on the return path, and sends to the next hop device a NHRP Resolution Request message including the label for the next hop LSP segment on the return path and a VPN identifier.
  • the egress device extracts the return path label from the NHRP Resolution Request message, allocates a label for the previous hop LSP segment on the forward path, and sends the label along with the VPN identifier to the previous hop device on the forward path in a NHRP reply message (i.e., either a NHRP Resolution Reply message or a NHRP Label Mapping message, as described above).
  • a NHRP reply message i.e., either a NHRP Resolution Reply message or a NHRP Label Mapping message, as described above.
  • FIG. 11 shows an exemplary communication system for creating bi-directional paths.
  • the Ingress Station 102 allocates a label for the return path from the intermediate device I 1 ( 202 ), and sends to the intermediate device I 1 ( 202 ) a NHRP Resolution Request message 1102 including the return path label and the VPN identifier.
  • the intermediate device I 1 ( 202 ) extracts the return path label from the NHRP Resolution Request message, allocates a label for the return path from the intermediate device I 2 ( 204 ), and sends to the intermediate device I 2 ( 204 ) a NHRP Resolution Request message 1104 including the return path label and the VPN identifier.
  • the intermediate device I 2 Upon receiving the NHRP Resolution Request message 1104 , the intermediate device I 2 ( 204 ) extracts the return path label from the NHRP Resolution Request message, allocates a label for the return path from the Egress Station 106 , and sends to the Egress Station 106 a NHRP Resolution Request message 1106 including the return path label and the VPN identifier.
  • a preferred embodiment of the present invention predominantly all of the logic for supporting VPNs in a label switched communication system is implemented as a set of computer program instructions that are stored in a computer readable medium and executed by an embedded microprocessor system within the various MPLS devices, including the ingress device, the intermediate devices, and the egress device.
  • Preferred embodiments of the invention may be implemented in any conventional computer programming language. For example, preferred embodiments may be implemented in a procedural programming language (e.g., “C”) or an object oriented programming language (e.g., “C++”). Alternative embodiments of the invention may be implemented using discrete components, integrated circuitry, programmable logic used in conjunction with a programmable logic device such as a Field Programmable Gate Array (FPGA) or microprocessor, or any other means including any combination thereof.
  • FPGA Field Programmable Gate Array
  • Alternative embodiments of the invention may be implemented as a computer program product for use with a computer system.
  • Such implementation may include a series of computer instructions fixed either on a tangible medium, such as a computer readable media (e.g., a diskette, CD-ROM, ROM, or fixed disk), or fixed in a computer data signal embodied in a carrier wave that is transmittable to a computer system via a modem or other interface device, such as a communications adapter connected to a network over a medium.
  • the medium may be either a tangible medium (e.g., optical or analog communications lines) or a medium implemented with wireless techniques (e.g., microwave, infrared or other transmission techniques).
  • the series of computer instructions embodies all or part of the functionality previously described herein with respect to the system.
  • Those skilled in the art should appreciate that such computer instructions can be written in a number of programming languages for use with many computer architectures or operating systems.
  • such instructions may be stored in any memory device, such as semiconductor, magnetic, optical or other memory devices, and may be transmitted using any communications technology, such as optical, infrared, microwave, or other transmission technologies.
  • It is expected that such a computer program product may be distributed as a removable medium with accompanying printed or electronic documentation (e.g., shrink wrapped software), preloaded with a computer system (e.g., on system ROM or fixed disk), or distributed from a server or electronic bulletin board over the network (e.g., the Internet or World Wide Web).
  • the present invention may be embodied as a method for supporting virtual private networks in a label switched communication system having an ingress device in communication with an egress device via a number of intermediate devices by including label information and a virtual private network identifier in Next Hop Resolution Protocol messages, the virtual private network identifier identifying a virtual private network, and using said Next Hop Resolution Protocol messages to dynamically establish a label switched path for the virtual private network.
  • the label information and the virtual private network identifier may be included within a Next Hop Resolution Protocol message in a type-length-value field having at least a virtual private network identifier field for carrying the virtual private network identifier and a label information field for carrying the label information.
  • the method may be used to dynamically establish a label switched path for a forward path from the ingress device to the egress device for the virtual private network, specifically by sending a Next Hop Resolution Protocol request message by the ingress device, forwarding the Next Hop Resolution Protocol request message hop-by-hop from the ingress device to the egress device by each intermediate device that is on the forward path, sending a Next Hop Resolution Protocol reply message by the egress device, and forwarding the Next Hop Resolution Protocol reply message hop-by-hop from the egress device to the ingress device by each intermediate device that is on the forward path.
  • each intermediate device may maintain previous hop state information, in which case each intermediate device forwards the NHRP reply message based upon the previous hop state information, or else each intermediate device may insert its address into a forward path address list in the NHRP request message, in which case each intermediate device forwards the NHRP reply message based upon a return path address list in the NHRP reply message.
  • the egress device allocates a forward path label for a label switched path segment from the previous hop device on the forward path to the egress device, and includes the forward path label in the NHRP reply message.
  • Each intermediate device allocates a forward path label for a label switched path segment from the previous hop device on the forward path to the intermediate device, and includes the forward path label in the NHRP reply message.
  • the method may also be used to dynamically establish a label switched path for a return path from the egress device to the ingress device, specifically by sending a NHRP request message by the ingress device and forwarding the NHRP request message hop-by-hop from the egress device to the ingress device by each intermediate device that is on the forward path.
  • the ingress device allocates a return path label for a label switched path segment from a next hop device on the forward path to the ingress device, and includes the return path label in the NHRP request message.
  • Each intermediate device on the forward path allocates a return path label for a label switched path segment from a next hop device on the forward path to the intermediate device, and includes the return path label in the NHRP request message.
  • the present invention may also be embodied as a device for supporting virtual private networks in a label switched communication system.
  • the device includes label switching logic for establishing a label switched path for the virtual private network using Next Hop Resolution Protocol messages, wherein the label switching logic includes a label request and a virtual private network identifier in Next Hop Resolution Protocol request messages, and wherein the label switching logic includes label mapping information and the virtual private network identifier in Next Hop Resolution Protocol reply messages.
  • An ingress device includes transmitting logic for transmitting to a next hop device in the communication network a Next Hop Resolution Protocol request message including a label request and the virtual private network identifier and receiving logic for receiving from said next hop device in the communication network a Next Hop Resolution Protocol reply message including a forward path label for a label switched path segment to said next hop device in the communication network and the virtual private network identifier.
  • the label switching logic establishes a label switched path to said next hop device in the communication network using said forward path label.
  • the ingress device may also include return path label allocation logic for allocating a return path label for a label switched path segment from the next hop device in the communication network to the ingress device.
  • the ingress device includes the return path label in addition to the label request and the virtual private network identifier in the NHRP request message.
  • An intermediate device includes request message receiving logic for receiving from a previous hop device in the communication network a first Next Hop Resolution Protocol request message including a label request and the virtual private network identifier, request message transmitting logic for transmitting to a next hop device in the communication network a second Next Hop Resolution Protocol request message including the label request and the virtual private network identifier, reply message receiving logic for receiving from said next hop device in the communication network a first Next Hop Resolution Protocol reply message including label mapping information and the virtual private network identifier, forward path label allocation logic for allocating a forward path label for a label switched path segment from the previous hop device in the communication network, and reply message transmitting logic for transmitting to said previous hop device in the communication network a second Next Hop Resolution Protocol reply message including said forward path label and the virtual private network identifier.
  • the request message receiving logic may maintain previous hop state information for said previous hop device in the communication network upon receiving the first NHRP request message, in which case the reply message transmitting logic transmits the second NHRP reply message to said previous hop device in the communication network based upon the previous hop state information.
  • the request message transmitting logic may insert a device address into a forward path address list and include the forward path address list in the second NHRP request message, in which case the reply message transmitting logic transmits the second NHRP reply message to said previous hop device in the communication network based upon a previous hop device address in a return path address list in the NHRP reply message.
  • the intermediate device may receive a forward path label in the first NHRP reply message for a label switched path segment from the intermediate device to said next hop device in the communication network, in which case the label switching logic establishes a label switched path to said next hop device in the communication network using said forward path label.
  • the intermediate device may receive a return path label in the first NHRP request message for a label switched path segment from the intermediate device to said previous hop device in the communication network, in which case the label switching logic establishes a label switched path to said previous hop device in the communication network using said return path label.
  • the intermediate device may also include return path label allocation logic for allocating a return path label for a label switched path segment from said next hop device in the communication network to the intermediate device.
  • the intermediate device includes the return path label in addition to the label request and the virtual private network indicator in the second NHRP request message.
  • An egress device includes receiving logic for receiving from a previous hop device in the communication network a Next Hop Resolution Protocol request message including a label request and the virtual private network identifier, forward path label allocation logic for allocating a forward path label for a label switched path segment from said previous hop device in the communication network, and transmitting logic for transmitting to said previous hop device in the communication network a Next Hop Resolution Protocol reply message including said forward path label and the virtual private network identifier.
  • the egress device may receive a forward path address list in the NHRP request message, in which case the egress device includes a return path address list in the NHRP reply message.
  • the egress device may receive a return path label in the NHRP request message for a label switched path segment from the egress device to said previous hop device in the communication network, in which case the label switching logic establishes a label switched path to said previous hop device in the communication network using said return path label.
  • the present invention may also be embodied as a program product comprising a computer readable medium having embodied therein a computer program for supporting virtual private networks in a label switched communication system, the computer program comprising label switching logic programmed to establish a label switched path for the virtual private network using Next Hop Resolution Protocol messages, wherein the label switching logic is programmed to include a label request and a virtual private network identifier in Next Hop Resolution Protocol request messages, and wherein the label switching logic is programmed to include label mapping information and the virtual private network identifier in Next Hop Resolution Protocol reply messages.
  • the present invention may also be embodied as a communication system comprising an ingress device in communication with an egress device via a number of intermediate devices, wherein a label switched path is established for a virtual private network by including label information and a virtual private network identifier in Next Hop Resolution Protocol messages and using said Next Hop Resolution Protocol messages to dynamically establish the label switched path for the virtual private network.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Computer Security & Cryptography (AREA)
  • Computer Hardware Design (AREA)
  • Computing Systems (AREA)
  • General Engineering & Computer Science (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)
US09/434,338 1999-05-11 1999-11-04 System, device, and method for supporting virtual private networks in a label switched communication network Abandoned US20030088699A1 (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US09/434,338 US20030088699A1 (en) 1999-11-04 1999-11-04 System, device, and method for supporting virtual private networks in a label switched communication network
CA002324805A CA2324805A1 (fr) 1999-11-04 2000-10-31 Systeme, dispositif et methode de soutien de reseaux prives virtuels dans un reseau de communication a commutation d'etiquettes
EP00309779A EP1122914A3 (fr) 1999-11-04 2000-11-03 Système, appareil et méthode pour supporter des réseaux virtuels privés dans un réseau de communication à commutation avec étiquette
KR1020000065359A KR20010070190A (ko) 1999-11-04 2000-11-04 레이블 전환 통신 네트워크에서 가상 구내망을 지원하기위한 시스템, 장치 및 방법
JP2000338050A JP2001189751A (ja) 1999-11-04 2000-11-06 ラベル交換通信ネットワークの仮想専用ネットワークを支援するシステム、素子及び方法
US11/301,162 US7174388B2 (en) 1999-05-11 2005-12-12 System, device, and method for supporting virtual private networks in a label switched communication network

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US09/434,338 US20030088699A1 (en) 1999-11-04 1999-11-04 System, device, and method for supporting virtual private networks in a label switched communication network

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US09/309,530 Continuation US6614791B1 (en) 1999-05-11 1999-05-11 System, device, and method for supporting virtual private networks

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US11/301,162 Continuation US7174388B2 (en) 1999-05-11 2005-12-12 System, device, and method for supporting virtual private networks in a label switched communication network

Publications (1)

Publication Number Publication Date
US20030088699A1 true US20030088699A1 (en) 2003-05-08

Family

ID=23723820

Family Applications (2)

Application Number Title Priority Date Filing Date
US09/434,338 Abandoned US20030088699A1 (en) 1999-05-11 1999-11-04 System, device, and method for supporting virtual private networks in a label switched communication network
US11/301,162 Expired - Fee Related US7174388B2 (en) 1999-05-11 2005-12-12 System, device, and method for supporting virtual private networks in a label switched communication network

Family Applications After (1)

Application Number Title Priority Date Filing Date
US11/301,162 Expired - Fee Related US7174388B2 (en) 1999-05-11 2005-12-12 System, device, and method for supporting virtual private networks in a label switched communication network

Country Status (5)

Country Link
US (2) US20030088699A1 (fr)
EP (1) EP1122914A3 (fr)
JP (1) JP2001189751A (fr)
KR (1) KR20010070190A (fr)
CA (1) CA2324805A1 (fr)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020126681A1 (en) * 2001-03-08 2002-09-12 Michael Kazban Apparatus and methods for establishing virtual private networks in a broadband network
US20030002468A1 (en) * 2001-06-28 2003-01-02 Mohamed Khalil Virtual private network identification extension
US20040174882A1 (en) * 2001-07-26 2004-09-09 Willis Peter J Method and system for sending return messages in mpls networks
US20040202171A1 (en) * 2000-11-27 2004-10-14 Daisuke Hama Network and edge router
US20060095499A1 (en) * 1999-05-11 2006-05-04 Luciani James V System, device, and method for supporting virtual private networks in a label switched communication network
US7046669B1 (en) * 2000-06-28 2006-05-16 Nortel Networks Limited Communications network
US20060215661A1 (en) * 2001-03-29 2006-09-28 Newell Darren L Atm over mpls connection establishment mechanism
US7136374B1 (en) * 2001-03-19 2006-11-14 Juniper Networks, Inc. Transport networks supporting virtual private networks, and configuring such networks
US7151773B1 (en) * 2000-05-05 2006-12-19 Fujitsu Limited System and method for connectionless/connection oriented signal transport
US20070076725A1 (en) * 2005-10-05 2007-04-05 Alcatel Unified inverse address resolution
CN100373826C (zh) * 2003-09-28 2008-03-05 中兴通讯股份有限公司 一种自动交换光网络的隧道建立方法
US7373401B1 (en) * 2001-12-31 2008-05-13 Nortel Networks Limited Label switched path OAM wrapper
US7386631B1 (en) * 1999-11-19 2008-06-10 At&T Corp. Apparatus and methods for providing translucent proxies in a communications network
US7577143B1 (en) * 2001-09-25 2009-08-18 Juniper Networks, Inc. Decoupling functionality related to providing a transparent local area network segment service
US20090316713A1 (en) * 2008-06-20 2009-12-24 Fujitsu Limited Communication apparatus in label switching network
US7779461B1 (en) * 2004-11-16 2010-08-17 Juniper Networks, Inc. Point-to-multi-point/non-broadcasting multi-access VPN tunnels
US20110007743A1 (en) * 2001-11-21 2011-01-13 Juniper Networks, Inc. Filter-based forwarding in a network
US20120173694A1 (en) * 2009-09-18 2012-07-05 Zte Corporation Virtual private network implementation method and system
US20130018937A1 (en) * 2011-07-12 2013-01-17 Samsung Electronics Co., Ltd. Communication method of content requester, intermediate node, and content owner in content centric network
US20160028640A1 (en) * 2014-07-22 2016-01-28 Futurewei Technologies, Inc. Service Chain Header and Metadata Transport
US20160308758A1 (en) * 2015-04-17 2016-10-20 Huawei Technologies Co., Ltd Software Defined Network (SDN) Control Signaling for Traffic Engineering to Enable Multi-type Transport in a Data Plane
US20170012895A1 (en) * 2015-07-06 2017-01-12 Futurewei Technologies, Inc. Path Computation Element Central Controllers (PCECCs) for Network Services
US20210105210A1 (en) * 2012-12-27 2021-04-08 Sitting Man, Llc Methods, systems, and computer program products for associating a name with a network path

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1180582C (zh) * 2001-06-21 2004-12-15 华为技术有限公司 多标签协议交换虚拟私有网配置管理系统及其划分方法
US7463591B1 (en) * 2001-06-25 2008-12-09 Juniper Networks, Inc. Detecting data plane liveliness of a label-switched path
US7376828B1 (en) * 2002-07-01 2008-05-20 Cisco Technology, Inc. Method and apparatus for using incompletely trusted service provider point-to-point networks
US7283529B2 (en) 2003-03-07 2007-10-16 International Business Machines Corporation Method and system for supporting a dedicated label switched path for a virtual private network over a label switched communication network
US7631100B2 (en) * 2003-10-07 2009-12-08 Microsoft Corporation Supporting point-to-point intracluster communications between replicated cluster nodes
US8176201B1 (en) * 2003-11-05 2012-05-08 Juniper Networks, Inc. Controlling the signaling of label-switched paths using a label distribution protocol employing messages which facilitate the use of external prefixes
US20060133265A1 (en) * 2004-12-22 2006-06-22 Alcatel Virtual private networking methods and systems
US7499445B2 (en) * 2005-03-18 2009-03-03 Cisco Technology, Inc. System and method for routing ISIS traffic through unidirectional links of a computer network
GB2439572B (en) * 2006-06-29 2011-03-09 Hewlett Packard Development Co Remote connection between intermediary device and computing device via central authority software
US7940695B1 (en) 2007-06-08 2011-05-10 Juniper Networks, Inc. Failure detection for tunneled label-switched paths
CN101453399B (zh) 2007-11-30 2012-07-04 华为技术有限公司 虚拟网络配置方法及系统
US20090168779A1 (en) * 2007-12-31 2009-07-02 Nguyen Loc Q Integration of multi-protocol label switching (MPLS)
US8339973B1 (en) 2010-09-07 2012-12-25 Juniper Networks, Inc. Multicast traceroute over MPLS/BGP IP multicast VPN

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6079020A (en) * 1998-01-27 2000-06-20 Vpnet Technologies, Inc. Method and apparatus for managing a virtual private network
US6205488B1 (en) * 1998-11-13 2001-03-20 Nortel Networks Limited Internet protocol virtual private network realization using multi-protocol label switching tunnels
US6374303B1 (en) * 1997-11-17 2002-04-16 Lucent Technologies, Inc. Explicit route and multicast tree setup using label distribution
US6438100B1 (en) * 1998-08-07 2002-08-20 Alcatel Canada Inc. Method and apparatus for routing server redundancy in a network having carrier scale internetworking
US6493349B1 (en) * 1998-11-13 2002-12-10 Nortel Networks Limited Extended internet protocol virtual private network architectures
US6529958B1 (en) * 1998-07-17 2003-03-04 Kabushiki Kaisha Toshiba Label switched path set up scheme with reduced need for label set up retry operation
US6538991B1 (en) * 1999-08-03 2003-03-25 Lucent Technologies Inc. Constraint-based routing between ingress-egress points in a packet network
US6614791B1 (en) * 1999-05-11 2003-09-02 Nortel Networks Limited System, device, and method for supporting virtual private networks
US6693878B1 (en) * 1999-10-15 2004-02-17 Cisco Technology, Inc. Technique and apparatus for using node ID as virtual private network (VPN) identifiers

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6226751B1 (en) * 1998-04-17 2001-05-01 Vpnet Technologies, Inc. Method and apparatus for configuring a virtual private network
US7095740B1 (en) * 1998-06-30 2006-08-22 Nortel Networks Limited Method and apparatus for virtual overlay networks
US20030088699A1 (en) * 1999-11-04 2003-05-08 James V. Luciani System, device, and method for supporting virtual private networks in a label switched communication network

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6374303B1 (en) * 1997-11-17 2002-04-16 Lucent Technologies, Inc. Explicit route and multicast tree setup using label distribution
US6079020A (en) * 1998-01-27 2000-06-20 Vpnet Technologies, Inc. Method and apparatus for managing a virtual private network
US6529958B1 (en) * 1998-07-17 2003-03-04 Kabushiki Kaisha Toshiba Label switched path set up scheme with reduced need for label set up retry operation
US6438100B1 (en) * 1998-08-07 2002-08-20 Alcatel Canada Inc. Method and apparatus for routing server redundancy in a network having carrier scale internetworking
US6205488B1 (en) * 1998-11-13 2001-03-20 Nortel Networks Limited Internet protocol virtual private network realization using multi-protocol label switching tunnels
US6493349B1 (en) * 1998-11-13 2002-12-10 Nortel Networks Limited Extended internet protocol virtual private network architectures
US6614791B1 (en) * 1999-05-11 2003-09-02 Nortel Networks Limited System, device, and method for supporting virtual private networks
US20040095947A1 (en) * 1999-05-11 2004-05-20 Luciani James V. System, device, and method for supporting virtual private networks
US6538991B1 (en) * 1999-08-03 2003-03-25 Lucent Technologies Inc. Constraint-based routing between ingress-egress points in a packet network
US6693878B1 (en) * 1999-10-15 2004-02-17 Cisco Technology, Inc. Technique and apparatus for using node ID as virtual private network (VPN) identifiers

Cited By (59)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060095499A1 (en) * 1999-05-11 2006-05-04 Luciani James V System, device, and method for supporting virtual private networks in a label switched communication network
US7174388B2 (en) * 1999-05-11 2007-02-06 Nortel Networks Limited System, device, and method for supporting virtual private networks in a label switched communication network
US20080222304A1 (en) * 1999-11-19 2008-09-11 Sandeep Sibal Apparatus and methods for providing translucent proxies in a communications network
US7386631B1 (en) * 1999-11-19 2008-06-10 At&T Corp. Apparatus and methods for providing translucent proxies in a communications network
US7151773B1 (en) * 2000-05-05 2006-12-19 Fujitsu Limited System and method for connectionless/connection oriented signal transport
US7046669B1 (en) * 2000-06-28 2006-05-16 Nortel Networks Limited Communications network
US7072346B2 (en) * 2000-11-27 2006-07-04 Fujitsu Limited Network and edge router
US20040202171A1 (en) * 2000-11-27 2004-10-14 Daisuke Hama Network and edge router
US8014411B2 (en) 2001-03-08 2011-09-06 Tellabs San Jose, Inc. Apparatus and methods for establishing virtual private networks in a broadband network
US20070081542A1 (en) * 2001-03-08 2007-04-12 Tellabs San Jose, Inc. Apparatus and Methods for Establishing Virtual Private Networks in a Broadband Network
US7835353B2 (en) 2001-03-08 2010-11-16 Tellabs San Jose, Inc. Apparatus and methods for establishing virtual private networks in a broadband network
US20050099947A1 (en) * 2001-03-08 2005-05-12 Michael Kazban Apparatus and methods for establishing virtual private networks in a broadband network
US8553705B2 (en) 2001-03-08 2013-10-08 Tellabs San Jose, Inc. Apparatus and methods for establishing virtual private networks in a broadband network
US20020126681A1 (en) * 2001-03-08 2002-09-12 Michael Kazban Apparatus and methods for establishing virtual private networks in a broadband network
US6847641B2 (en) * 2001-03-08 2005-01-25 Tellabs San Jose, Inc. Apparatus and methods for establishing virtual private networks in a broadband network
US9025615B2 (en) 2001-03-08 2015-05-05 Tellabs Operations, Inc. Apparatus and methods for establishing virtual private networks in a broadband network
US20070019676A1 (en) * 2001-03-19 2007-01-25 Kireeti Kompella Transport networks supporting virtual private networks, and configuring such networks
US20100046526A1 (en) * 2001-03-19 2010-02-25 Kireeti Kompella Transport networks supporting virtual private networks, and configuring such networks
US7136374B1 (en) * 2001-03-19 2006-11-14 Juniper Networks, Inc. Transport networks supporting virtual private networks, and configuring such networks
US8009674B2 (en) * 2001-03-19 2011-08-30 Juniper Networks, Inc. Transport networks supporting virtual private networks, and configuring such networks
US7620069B2 (en) * 2001-03-19 2009-11-17 Juniper Networks, Inc. Transport networks supporting virtual private networks, and configuring such networks
USRE40826E1 (en) 2001-03-29 2009-07-07 Nortel Networks Limited ATM over MPLS connection establishment mechanism
US20060215661A1 (en) * 2001-03-29 2006-09-28 Newell Darren L Atm over mpls connection establishment mechanism
US7110375B2 (en) * 2001-06-28 2006-09-19 Nortel Networks Limited Virtual private network identification extension
US20030002468A1 (en) * 2001-06-28 2003-01-02 Mohamed Khalil Virtual private network identification extension
US20040174882A1 (en) * 2001-07-26 2004-09-09 Willis Peter J Method and system for sending return messages in mpls networks
US7843924B2 (en) * 2001-07-26 2010-11-30 British Telecommunications Public Limited Company Method and system for sending return messages in MPLS networks
US8693475B2 (en) * 2001-09-25 2014-04-08 Juniper Networks, Inc. Decoupling functionality related to providing a transparent local area network segment service
US20090296713A1 (en) * 2001-09-25 2009-12-03 Kireeti Kompella Decoupling functionality related to providing a transparent local area network segment service
US7577143B1 (en) * 2001-09-25 2009-08-18 Juniper Networks, Inc. Decoupling functionality related to providing a transparent local area network segment service
US9106506B2 (en) * 2001-11-21 2015-08-11 Juniper Networks, Inc. Filter-based forwarding in a network
US20110007743A1 (en) * 2001-11-21 2011-01-13 Juniper Networks, Inc. Filter-based forwarding in a network
US7373401B1 (en) * 2001-12-31 2008-05-13 Nortel Networks Limited Label switched path OAM wrapper
US20080205284A1 (en) * 2001-12-31 2008-08-28 Nortel Networks Limited Label switched path oam wrapper
US8024457B2 (en) 2001-12-31 2011-09-20 Nortel Networks Limited Label switched path OAM wrapper
US8971189B2 (en) 2001-12-31 2015-03-03 Rockstar Consortium Us Lp Label switched path OAM wrapper
CN100373826C (zh) * 2003-09-28 2008-03-05 中兴通讯股份有限公司 一种自动交换光网络的隧道建立方法
US20100278181A1 (en) * 2004-11-16 2010-11-04 Juniper Networks, Inc. Point-to-multi-point/non-broadcasting mutli-access vpn tunnels
US7779461B1 (en) * 2004-11-16 2010-08-17 Juniper Networks, Inc. Point-to-multi-point/non-broadcasting multi-access VPN tunnels
US8127349B2 (en) * 2004-11-16 2012-02-28 Juniper Networks, Inc. Point-to-multi-point/non-broadcasting multi-access VPN tunnels
US20120137358A1 (en) * 2004-11-16 2012-05-31 Juniper Networks, Inc. Point-to-multi-point/non-broadcasting multi-access vpn tunnels
US20070076725A1 (en) * 2005-10-05 2007-04-05 Alcatel Unified inverse address resolution
US7639692B2 (en) * 2005-10-05 2009-12-29 Alcatel Unified inverse address resolution
US8121138B2 (en) * 2008-06-20 2012-02-21 Fujitsu Limited Communication apparatus in label switching network
US20090316713A1 (en) * 2008-06-20 2009-12-24 Fujitsu Limited Communication apparatus in label switching network
US20120173694A1 (en) * 2009-09-18 2012-07-05 Zte Corporation Virtual private network implementation method and system
US9400852B2 (en) * 2011-07-12 2016-07-26 Samsung Electronics Co., Ltd. Communication method of content requester, intermediate node, and content owner in content centric network
US20130018937A1 (en) * 2011-07-12 2013-01-17 Samsung Electronics Co., Ltd. Communication method of content requester, intermediate node, and content owner in content centric network
US20210105210A1 (en) * 2012-12-27 2021-04-08 Sitting Man, Llc Methods, systems, and computer program products for associating a name with a network path
US20160028640A1 (en) * 2014-07-22 2016-01-28 Futurewei Technologies, Inc. Service Chain Header and Metadata Transport
US10637773B2 (en) 2014-07-22 2020-04-28 Futurewei Technologies, Inc. Service chain header and metadata transport
US10003530B2 (en) * 2014-07-22 2018-06-19 Futurewei Technologies, Inc. Service chain header and metadata transport
US11411863B2 (en) 2014-07-22 2022-08-09 Futurewei Technologies, Inc. Service chain header and metadata transport
US20160308758A1 (en) * 2015-04-17 2016-10-20 Huawei Technologies Co., Ltd Software Defined Network (SDN) Control Signaling for Traffic Engineering to Enable Multi-type Transport in a Data Plane
US9749225B2 (en) * 2015-04-17 2017-08-29 Huawei Technologies Co., Ltd. Software defined network (SDN) control signaling for traffic engineering to enable multi-type transport in a data plane
US10291514B2 (en) 2015-04-17 2019-05-14 Huawei Technologies Co., Ltd. Software defined network (SDN) control signaling for traffic engineering to enable multi-type transport in a data plane
US20170012895A1 (en) * 2015-07-06 2017-01-12 Futurewei Technologies, Inc. Path Computation Element Central Controllers (PCECCs) for Network Services
KR102057980B1 (ko) * 2015-07-06 2019-12-20 후아웨이 테크놀러지 컴퍼니 리미티드 네트워크 서비스를 위한 경로 계산 요소 중앙 제어기(PCECCs)
US10412019B2 (en) * 2015-07-06 2019-09-10 Futurewei Technologies, Inc. Path computation element central controllers (PCECCs) for network services

Also Published As

Publication number Publication date
EP1122914A3 (fr) 2004-04-28
JP2001189751A (ja) 2001-07-10
EP1122914A2 (fr) 2001-08-08
US7174388B2 (en) 2007-02-06
US20060095499A1 (en) 2006-05-04
KR20010070190A (ko) 2001-07-25
CA2324805A1 (fr) 2001-05-04

Similar Documents

Publication Publication Date Title
US7174388B2 (en) System, device, and method for supporting virtual private networks in a label switched communication network
WO2021063232A1 (fr) Procédé, appareil et système d'établissement d'élément de table d'acheminement bier
US7061921B1 (en) Methods and apparatus for implementing bi-directional signal interfaces using label switch paths
US10164838B2 (en) Seamless segment routing
US7082140B1 (en) System, device and method for supporting a label switched path across a non-MPLS compliant segment
US7023846B1 (en) System, device, and method for establishing and removing a label switched path in a communication network
CA2287721C (fr) Routeur et methode de commande de voie par commutation d'etiquette utilisant un regroupement amorce en amont
US6501756B1 (en) Method of managing hop-count in label switching network and node apparatus
US8363667B2 (en) Summarization and longest-prefix match within MPLS networks
US7075932B2 (en) Communication device for selecting route of packet
US6603769B1 (en) Method and system for improving traffic operation in an internet environment
US6751190B1 (en) Multihop nested tunnel restoration
US7076559B1 (en) System, device, and method for establishing label switched paths across multiple autonomous systems
US6389023B1 (en) Router device and frame transfer method using datalink layer frame switching
EP2005650B1 (fr) Connexion de réseaux maillés multisauts utilisant un pont de commande d'accès au support
US7613188B1 (en) Ethernet VLL spoke termination at an IP interface
US7277386B1 (en) Distribution of label switched packets
WO2008110751A1 (fr) Schéma de réseau de transport mpls
US7031312B1 (en) Method and system for assigning multiprotocol label switching (MPLS) VC (VC) labels when transporting asynchronous transfer mode (ATM) data over MPLS network
US20030012189A1 (en) Link identifier assignment system in connection-oriented communication network
US7450578B2 (en) Method of addressing and routing data
JPH1065735A (ja) アドレス解決装置
JP3991964B2 (ja) マルチキャスト転送経路設定方法

Legal Events

Date Code Title Description
AS Assignment

Owner name: NORTEL NETWORKS CORPORATION, CANADA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LUCIANI, JAMES V.;FREDETTE, ANDRE N.;HAWE, BILL;REEL/FRAME:010535/0044;SIGNING DATES FROM 19991208 TO 19991212

AS Assignment

Owner name: NORTEL NETWORKS LIMITED, CANADA

Free format text: CHANGE OF NAME;ASSIGNOR:NORTEL NETWORKS CORPORATION;REEL/FRAME:011195/0706

Effective date: 20000830

Owner name: NORTEL NETWORKS LIMITED,CANADA

Free format text: CHANGE OF NAME;ASSIGNOR:NORTEL NETWORKS CORPORATION;REEL/FRAME:011195/0706

Effective date: 20000830

AS Assignment

Owner name: NORTEL NETWORKS LIMITED, CANADA

Free format text: CHANGE OF NAME;ASSIGNOR:NORTEL NETWORKS CORPORATION;REEL/FRAME:012211/0581

Effective date: 20000501

Owner name: NORTEL NETWORKS LIMITED,CANADA

Free format text: CHANGE OF NAME;ASSIGNOR:NORTEL NETWORKS CORPORATION;REEL/FRAME:012211/0581

Effective date: 20000501

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION