U.S. patent application number 14/611530 was filed with the patent office on 2015-05-28 for apparatus and method for layer-2 and layer-3 vpn discovery.
The applicant listed for this patent is Rockstar Consortium US LP. Invention is credited to Hamid OULD-BRAHIM.
Application Number | 20150146573 14/611530 |
Document ID | / |
Family ID | 34739069 |
Filed Date | 2015-05-28 |
United States Patent
Application |
20150146573 |
Kind Code |
A1 |
OULD-BRAHIM; Hamid |
May 28, 2015 |
APPARATUS AND METHOD FOR LAYER-2 AND LAYER-3 VPN DISCOVERY
Abstract
An apparatus and a method for layer-2 and layer-3 VPN discovery
are disclosed. The apparatus is incorporated in a network, and the
network includes a first carrier network. The first carrier network
includes at least two layer-1 provider edge devices. Layer-1 VPN
information is created within the first carrier network. BGP next
hop information passes within the first carrier network. The BGP
next hop information is for a selected one of the following: a
layer-2 VPN-based provider edge device, a layer-3 VPN-based
provider edge device, and a layer-2 and layer-3 VPN-based provider
edge device. The network also includes a second carrier network
within which the BGP next hop information is used for VPN
discovery.
Inventors: |
OULD-BRAHIM; Hamid; (Kanata,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rockstar Consortium US LP |
Plano |
TX |
US |
|
|
Family ID: |
34739069 |
Appl. No.: |
14/611530 |
Filed: |
February 2, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13473181 |
May 16, 2012 |
8949460 |
|
|
14611530 |
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|
10747346 |
Dec 29, 2003 |
8190772 |
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13473181 |
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Current U.S.
Class: |
370/255 |
Current CPC
Class: |
H04L 69/323 20130101;
H04L 45/02 20130101; H04L 45/50 20130101; H04L 12/4641
20130101 |
Class at
Publication: |
370/255 |
International
Class: |
H04L 12/751 20060101
H04L012/751; H04L 29/08 20060101 H04L029/08; H04L 12/46 20060101
H04L012/46 |
Claims
1. A layer-1 Virtual Private Network (VPN) provider edge device for
a layer-1 VPN network, the layer-1 VPN provider edge device being
configured: to receive Border Gateway Protocol (BGP) next hop
information from a higher-layer customer network, the BGP next hop
information comprising BGP next hop information for at least one
of: a layer-2 VPN based provider edge device; a layer-3 VPN based
provider edge device; and a layer-2 and layer-3 VPN based provider
edge device; and to distribute the BGP next hop information to at
least one other layer-1 VPN provider edge devices over the layer-1
VPN provider network to enable the higher-layer customer network to
use the BGP next hop information for VPN discovery.
2. The layer-1 VPN provider edge device of claim 1, configured to
distribute the BGP next hop information with layer-1 VPN
information.
3. The layer-1 VPN provider edge device of claim 2, configured to
generate the layer-1 VPN information.
4. The layer-1 VPN provider edge device of claim 1, configured to
implement a VPN auto-discovery mechanism.
5. The layer-1 VPN provider edge device of claim 1, wherein the
layer-1 VPN provider edge device is Generalized VPN (GVPN)
based.
6. The layer-1 VPN provider edge device of claim 3, configured to
receive the BGP next hop information as normal GVPN port
information.
7. A higher-layer provider edge device for a higher layer carrier
network, the higher-layer provider edge device being one of: a
layer-2 Virtual Private Network (VPN) based provider edge device; a
layer-3 VPN based provider edge device; and a layer-2 and layer-3
based provider edge device; and being configured: to advertise a
(Border Gateway Protocol (BGP) next hop via a layer-1 VPN provider
network connected between the at least two higher-layer provider
edge devices; and to pass BGP next hop information to another of
the at least two higher-layer edge devices via the layer-1 VPN
provider network.
8. The higher-layer provider edge device of claim 7, configured to
pass the BGP next hop information via the layer-1 carrier network
as normal Generalized VPN (GVPN) port information.
9. The higher-layer carrier network of claim 8, wherein the
higher-layer carrier network is configured to couple at least one
customer VPN to the layer-1 carrier network.
10. A higher-layer provider edge device for a higher layer carrier
network, the higher-layer provider edge device being one of: a
layer-2 Virtual Private Network (VPN) based provider edge device; a
layer-3 VPN based provider edge device; and a layer-2 and layer-3
based provider edge device; and being configured to use Border
Gateway Protocol (BGP) next hop information for VPN discovery.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 13/473,181, filed May 16, 2012. U.S. patent
application Ser. No. 13/473,181 is a continuation of U.S. patent
application Ser. No. 10/747,346, filed Dec. 29, 2003. The contents
of both documents are hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to virtual private networks (VPNs)
and, in particular, a method for layer-2 and layer-3 VPN
auto-discovery using a generalized VPN auto-discovery
mechanism.
BACKGROUND OF THE INVENTION
[0003] Many definitions of VPNs can be considered:
[0004] Definition 1: A VPN is a set of users (devices attached to
the network) sharing common membership information and intended to
establish inter-site connectivity (within that group).A user can be
a member of multiple groups (VPNs).
[0005] Definition 2: A VPN is a client private network that
subscribes to restricted connectivity services.
[0006] Definition 3: A VPN is a service where a customer requests
multi-site connectivity services provided through a shared network
infrastructure.
[0007] Definition 4: A VPN is a service where a partition of
internal provider network resources is allocated to a customer.
[0008] Using specialized tunneling protocols and optionally secured
encryption techniques, data integrity and privacy may be maintained
in a VPN.
[0009] Categories of VPNs include layer-1, layer-2 and layer-3.
"Layer-n" is in reference to the network layer used to perform the
hand-off between the customer and provider network.
[0010] Layer-1 VPNs can be simple, point-to-point connections such
as leased lines, ISDN links, or dial-up connections. They are known
to be simple for the provider, as they place all responsibility for
operating the network over the connection on the customer. In other
words, the customer needs to provide and manage all the routing and
switching equipment that operates over the connection.
[0011] Layer-2 VPN is a VPN in which the service provider connects
customer sites using leased circuits connecting into a point of
presence (POP) or node on a shared core network. Layer-2 VPNs are
typically based on Frame Relay or ATM. Exemplary VPN mechanisms at
layer-2 include virtual private LAN service (VPLS) (see Waldemar
Augustyn et al., "Requirements for Virtual Private LAN Services
(VPLS)", October 2002) and virtual private wire (VPW) (see Eric
Rosen et al, "L-2 VPN Framework", February 2003).
[0012] Layer-3 VPN is a VPN in which the service provider supplies
a leased circuit connection between the customer site and the
nearest POP on the edge of the service provider network or manages
customer routing on behalf of the customer. The service provider
takes care of the routing and addressing of the customer traffic.
The service provider distributes the IP addressing information for
a company across all of its relevant sites. Exemplary VPN
mechanisms at layer-3 include virtual routing (VR)--base
mechanisms, such as VR using border gateway protocol (BGP) (see
Hamid Ould-Brahim et al "Network-based IPN VPN Architecture using
Virtual Routers", July 2002) or VPN-based RFC 2547 bis (see Eric
Rosen, et al, "BGP/MPLS VPNs", October 2002).
[0013] There are various possible arrangements for unifying
different types of VPNs. In one known network arrangement, two
carriers are provided. The first carrier is a provider providing
layer-2 or layer-3 VPN services. The second carrier is a
sub-provider providing layer-1 or generalized VPN (GVPN) services.
GVPN service (which in this case the first carrier subscribes to)
is a VPN service that uses BGP as a VPN auto-discovery (VPN
discovery is a process in which VPN routing information is
distributed) and generalized multi-protocol label switching (GMPLS)
(which will be discussed) as signaling and routing mechanisms.
[0014] The known methods for running this network arrangement have
problems. Manual configuration is required for all the BGP-TCP
sessions for the purpose of distributing layer-2/3 VPN information.
Scaling problems also exist. The known provisioning model is a
double-sided provisioning model.
SUMMARY OF THE INVENTION
[0015] The invention provides a network which allows scaling of the
operational aspects of layer-2 and/or layer-1 MPLS-based VPN by
scaling the operational aspects of the layer-2 and/or layer-3 VPN
provider edge-based devices. Further, provides a network which
simplifies the mode of operations on a layer-2/layer-3 VPN provider
edge router or switch by eliminating the need for configuring the
list of BGP next hops of the remote provider edge routers or
switches. As well, the invention takes advantage of layer-1 VPN
auto-discovery implemented on its carrier network by piggybacking
layer-2/layer-3 BGP next hop information on top of it.
Additionally, the network provides layer-1 VPN providers with the
ability to offer added-value services that extend to
layer-2/layer-3 VPN without requiring the layer-1 VPN provider to
support and offer a complete suite of layer-2/layer-3 VPN
services.
[0016] The present invention provides a network having the above
features and additional advantages which will be evident in the
reading of the description and drawings which follow.
[0017] According to a first aspect of the present invention, there
is disclosed a network that includes a first carrier network. The
first carrier network includes at least two layer-1 provider edge
devices. Layer-1 VPN information is created within the first
carrier network. BGP next hop information passes within the first
carrier network. The BGP next hop information is for a selected one
of the following: a layer-2 VPN-based provider edge device, a
layer-3 VPN-based provider edge device, and a layer-2 and layer-3
VPN-based provider edge device. The network also includes a second
carrier network within which the BGP next hop information is used
for VPN discovery.
[0018] In the preferred embodiment, the BGP next hop information
passes into the first carrier network as normal GVPN port
information via one or more of the at least two layer-1 provider
edge devices.
[0019] According to another aspect of the invention, there is
disclosed a method for layer-2 and layer-3 VPN auto-discovery
including the steps of:
[0020] (1) using BGP sessions and a discovery mechanism of a
GVPN-based provider edge device to distribute BGP next hop
information to a remote GVPN-based provider edge device;
[0021] (2) passing the BGP next hop information from the remote
GVPN-based provider edge device to an attached provider edge
device, the attached provider edge device being a selected one of
the following: a layer-2 VPN-based provider edge device, a layer-3
VPN-based provider edge device, and a layer-2 and layer-3 VPN-based
provider edge device; and
[0022] (3) using the attached provider edge device in combination
with the BGP next hop information to automatically create a set of
BGP sessions thereby permitting a selected one of the following:
layer-2 VPN discovery, layer-3 VPN discovery, and layer-2 and
layer-3 VPN discovery.
[0023] In the preferred embodiment, the BGP next hop information is
conveyed across a backbone during the step of using the BGP
sessions and the discovery mechanism.
[0024] According to yet another aspect of the invention, there is
disclosed a network including a backbone and at least two provider
edge devices. The at least two provider edge devices are connected
to and work with the backbone. Layer-1 VPN information is created
within the network. BGP next hop information is also created within
the network. The BGP next hop information is for a selected one of
the following: a layer-2 VPN-based provider edge device, a layer-3
VPN-based provider edge device, and a layer-2 and layer-3 VPN-based
provider edge device.
[0025] In the preferred embodiment, the network includes a layer-1
VPN service provider and a second VPN service provider. The second
VPN service provider is a customer of the layer-1 VPN service
provider. The second VPN service provider is a selected one of the
following: a layer-2 VPN service provider, a layer-3 VPN service
provider, and a layer-2 and layer-3 VPN service provider.
[0026] Further features and advantages will become apparent from
the following detailed description taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a schematic diagram illustrating a network
reference model within which the apparatus and method of the
invention can be utilized according to an embodiment of the
invention.
[0028] FIG. 2 is a flow diagram illustrating a method of operation
implementable in the model of FIG. 1 according to an embodiment of
the invention.
DETAILED DESCRIPTION
[0029] Referring to FIG. 1, there is illustrated a network 10
connecting together VPNs 14 with remote VPNs 18. The VPNs 14 are
customer networks which interface with a provider network via
customer edge routers 20. Provider edge routers or switches 24 are
associated with the provider network. The router 24 is a portion of
the provider's network that interfaces with a particular VPN 14.
This provider or first carrier provides layer-2 and/or layer-3
(L-2/3 or layer-2/3) VPN services to its customers.
[0030] The provider routers 24 also interface with a network 28 of
a sub-provider or second carrier. The sub-provider's network 28
connects to the provider's network via a provider edge device 30.
The device 30 is a portion of the network 28. Portions of the
network 28 may also interface with a backbone. An example of a
backbone would be an Internet backbone. Of course those skilled in
the art will appreciate that other types of backbones are
possible.
[0031] The second carrier provides GVPN services or layer-1
services to the first carrier. GVPN service is a
provider-provisioned VPN service that uses BGP as a VPN
auto-discovery mechanism. BGP is an important protocol for VPNs and
the Internet. BGP is also an Internet standard for inter-domain
autonomous system (AS) exterior routing. Furthermore, BGP is the
routing protocol employed on the Internet. All Internet Service
Providers must use BGP to establish routing between one
another.
[0032] GVPN service also uses GMPLS as a signaling and routing
mechanism. One way of defining GMPLS is as follows. In a
multi-protocol label switching (MPLS) network, incoming packets are
assigned a label by a label edge router. Packets are forwarded
along a label switch path where each label switch router makes
forwarding decisions based solely on the contents of the label. At
each hop, the label switch router strips off the existing label and
applies a new label which tells the next hop how to forward the
packet. GMPLS extends MPLS from supporting packet (PSC) interfaces
and switching to include support of the following three classes of
interfaces and switching: time-division multiplex (TDM), lambda
switch (LSC) and fiber-switch (FSC).
[0033] The remote side of the network 10 can have an arrangement
substantially mirroring the proximate side. A provider edge device
34 interfaces the network 28 with a remote network of a layer-2/3
VPN service provider. This remote service provider has a provider
edge router or switch 36. The router 36 interfaces the network of
the layer-2/3 VPN service provider with the network 28.
[0034] The router 36 also interfaces the remote network of the
layer-2/3 service provider with one or more of the remote VPNs 18.
The VPNs 18 interface with the remote network of the layer-2/3 VPN
service provider via customer edge routers 40.
[0035] With respect to the L-2/3 VPN provider edge routers used in
the network 10, previous implementations required manual
configuration of all BGP-TCP sessions for the purpose of
distributing layer-2/3 VPN information. Furthermore, the previous
implementations required each L-2/3 VPN provider edge router to be
configured with all possible addresses used to establish the set of
BGP sessions. This created a full mesh situation.
[0036] A full mesh is when every router in a group must be
configured as a peer of every other router. When a group of routers
(e.g. the L-2/3 VPN provider edge routers) need to be configured in
a full mesh, scaling problems occur. Configuring in a full mesh
causes scaling problems because the number of required connections
grows quadratically with the number of routers involved.
[0037] In the preferred embodiment of the apparatus and method for
layer-2 and layer-3 VPN discovery, BGP address information is
communicated between an L-2/3 VPN provider edge router or switch
and the sub-provider as normal GVPN port information. Furthermore,
layer-1 VPN port information is used to discover the BGP next hop
address information of the remote end router 40.
[0038] The concept of BGP next hop can be understood as follows. In
BGP, the type of message used to advertise a route is called an
update message. The update message contains an address prefix
called a BGP next hop. Also, an IP address that is used to reach an
advertising router is sometimes referred to as a BGP next hop
attribute. Discovery of the BGP next hop address information of a
remote end router using layer-1 VPN port information is absent from
known solutions.
[0039] The preferred apparatus and method also differ from the
previous implementations with respect to auto-discovery at the
layer-1/GVPN-based provider edge device. In the previous
implementations, BGP/TCP sessions were established for the purpose
of distributing layer-1 VPN information. For auto-discovery at the
layer-1/GVPN-based provider edge device in accordance with the
invention, BGP/TCP sessions are established for the purpose of
distributing both layer-1 VPN information and BGP next hop
information for layer-2 and layer-3 VPN-based provider edge routers
or switches.
[0040] FIG. 2 is a flow diagram illustrating the preferred method
of operation of layer-2/layer-3 VPN discovery. Starting at step 60,
the BGP next hop is configured. The BGP next hop is used for the
purpose of layer-2 and/or layer-3 VPN discovery at a
layer-2/layer-3 VPN provider edge router or switch.
[0041] At step 62, a router or switch (such as the router 24 of
FIG. 1) will pass the BGP next hop address information to a
provider edge device (such as the device 30). This step is
accomplished using normal GVPN customer edge-provider edge
mechanisms.
[0042] At step 64, a provider edge device of the sub-provider uses
its BGP sessions and discovery mechanisms to distribute the
layer-2/layer-3 BGP next hop information. This information is
distributed to all remote layer-1 provider edge devices.
[0043] At step 66, the remote layer-1 provider edge devices have
received the layer-2/layer-3 BGP next hop information. This
information is passed by the remote layer-1 provider edge devices
to one or more attached layer-2/layer-3 provider edge routers or
switches (such as the router 36 of FIG. 1).
[0044] At step 68, the router 36 automatically creates a set of BGP
sessions to be used for the purpose of layer-2 and/or layer-3 VPN
discovery.
[0045] Finally, at step 70, the created BGP sessions are used, and
VPN discovery occurs.
GLOSSARY OF ACRONYMS USED
[0046] BGP--Border Gateway Protocol [0047] GMPLS--generalized MPLS
[0048] GVPN--generalized VPN [0049] L-2/3--layer-2 and/or layer-3
[0050] MPLS--multi-protocol label switching [0051] VPLS--Virtual
Private LAN Service [0052] VPN--Virtual Private Network
[0053] While the invention has been described in conjunction with
specific embodiments thereof, it is evident that many alternatives,
modifications, and variations will be apparent to those skilled in
the art in light of the foregoing description. Accordingly, it is
intended to embrace all such alternatives, modifications, and
variations as fall within the spirit and broad scope of the
appended claims.
* * * * *