PCE Working Group Zafar Ali
Internet Draft Siva Sivabalan
Intended status: Standard Track Clarence Filsfils
Expires: July 31, 2013 Cisco Systems
Robert Varga
Pantheon Technologies
Victor Lopez
Oscar Gonzalez de Dios
Telefonica I+D
February 1, 2013
Path Computation Element Communication Protocol (PCEP)
Extensions for remote-initiated GMPLS LSP Setup
draft-ali-pce-remote-initiated-gmpls-lsp-00.txt
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Abstract
PCEP Extensions for PCE-initiated LSP Setup in a Stateful PCE Model
draft [I-D. draft-crabbe-pce-pce-initiated-lsp] specifies
procedures that can be used for creation and deletion of PCE-
initiated LSPs under the active stateful PCE model. However, this
specification is focused on MPLS networks, and does not cover
remote instantiation of GMPLS paths. This document complements
PCEP Extensions for PCE-initiated LSP Setup in a Stateful PCE Model
draft by addressing the extensions required for GMPLS applications,
for example for OTN and WSON networks.
When active stateful PCE is used for managing PCE-initiated LSP,
PCC may not be aware of the intended usage of the LSP (e.g., in a
multi-layer network). PCEP Extensions for PCE-initiated LSP Setup
in a Stateful PCE Model draft does not address this requirement.
This draft also addresses the requirement to specify on how PCC
should use the PCEP initiated LSPs.
Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in
this document are to be interpreted as described in RFC 2119
[RFC2119].
Table of Contents
1. Introduction...............................................3
2. Use Cases................................................. 4
2.1. Single-layer provisioning from Active stateful PCE.... 4
2.2. Bandwidth-on-demand for multi-layer networks.......... 5
2.3. Higher-layer signaling trigger........................ 6
2.4. NMS-VNTM cooperation model (separated flavor)......... 7
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3. GMPLS Requirements for Remote-Initiated LSPs.............. 9
4. Remote Initiated LSP Usage Requirement.................... 9
5. PCEP Extensions for Remote-Initiated GMPLS LSPs.......... 10
5.1. Generalized Endpoint in LSP Create Message........... 10
5.2. GENERALIZED-BANDWIDTH object in LSP Create Message... 11
5.3. Protection Attributes in LSP Create Message.......... 11
5.4. ERO in LSP Create Object............................. 12
5.4.1. ERO with explicit label control................ 12
5.4.2. ERO with Path Keys............................. 12
5.4.3. Switch Layer Object ............................13
6. PCEP extension for PCEP Initiated LSP Usage Specification.13
6.1. LSP_TUNNEL_INTERFACE_ID Object in LSP Create Message. 13
6.2. Communicating LSP usage to Egress node............... 15
6.3. LSP delegation and cleanup ...........................15
7. Security Considerations.................................. 15
8. IANA Considerations.......................................15
8.1. END-POINT Object......................................15
8.2. PCEP-Error Object.....................................16
9. Acknowledgments...........................................16
10. References...............................................16
10.1. Normative References.................................16
10.2. Informative References...............................16
1. Introduction
The Path Computation Element communication Protocol (PCEP)
provides mechanisms for Path Computation Elements (PCEs) to
perform route computations in response to Path Computation
Clients (PCCs) requests. PCEP Extensions for PCE-initiated LSP
Setup in a Stateful PCE Model draft [I-D. draft-ietf-pce-
stateful-pce] describes a set of extensions to PCEP to enable
active control of MPLS-TE and GMPLS tunnels.
[I-D. draft-crabbe-pce-pce-initiated-lsp] describes the setup
and teardown of PCE-initiated LSPs under the active stateful PCE
model, without the need for local configuration on the PCC, thus
allowing for a dynamic network that is centrally controlled and
deployed. However, this specification is focused on MPLS
networks, and does not cover the GMPLS networks (e.g., WSON,
OTN, SONET/ SDH, etc. technologies). GMPLS requirements for PCEP
initiated LSPs are outlined in Section 3. This document
complements [I-D. draft-crabbe-pce-pce-initiated-lsp] by
addressing the requirements for remote-initiated GMPLS LSPs. The
PCEP extensions for PCEP initiated GMPLS LSPs are specified in
Section 5. The mechanism described in this document is
applicable not only to active PCEs initiating LSPs, but to any
entity that initiates LSPs remotely.
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When an active stateful PCE is used for managing remote-
initiated LSP, the PCC may not be aware of the intended usage of
the remote-initiated LSP. For example, the PCC may not know the
target IGP instance in which the remote-initiated LSP is to be
used. These requirements are outlined in Section 4. [RFC6107]
defines LSP_TUNNEL_INTERFACE_ID Object for communicating target
IGP instance and usage of the forwarding and/ or routing
adjacency from the ingress node to the egress node. However,
current PCEP specifications do not include signaling of the
LSP_TUNNEL_INTERFACE_ID TLV in the PCEP message. Furthermore,
[I-D. draft-crabbe-pce-pce-initiated-lsp] does not address this
requirement. This draft also addresses the requirement to
specify on how PCC should use the PCEP initiated LSPs. This is
achieved by using LSP_TUNNEL_INTERFACE_ID Object defined in
[RFC6107] in PCEP, as detailed in Section 6.
2. Use Cases
2.1. Single-layer provisioning from active stateful PCE
Figure 1 shows a single-layer topology with optical nodes with a
GMPLS control plane. In this scenario, the active PCE can
dynamically create or delete L0 services between client
interfaces. This process can be triggered by the deployment of a
new network configuration or a re-optimization process. This
operation can be human-driven (e.g. through an NMS) or an
automatic process.
[Please refer to pdf version for the Figure]
Figure 1. Single-layer provisioning from active stateful PCE.
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L0 PCE obtains resources information via control plane
collecting LSAs messages. The request contains, at least, two
optical transport interfaces (OT i/f), so PCE computes the path
and sends a message to the optical equipment with ERO path
information.
2.2. Bandwidth-on-demand for multi-layer networks
This use case assumes there is a multi-layer network composed by
routers and optical equipment. In this scenario, there is an
entity, which decides it needs extra bandwidth between two
routers. This certain moment a GMPLS LSP connecting both routers
via the optical network can be established on-the-fly. This
entity can be a router, an active stateful PCE or even the NMS
(with or without human intervention).
It is important to note that the bandwidth-on-demand interfaces
and spare bandwidth in the optical network could be shared to
cover many under capacity scenarios in the L3 network. For
example, in this use-case, if we assume all interfaces are 10G
and there is 10G of spare bandwidth available in the optical
network, the spare bandwidth in the optical network can be used
to connect any router, depending on bandwidth demand of the
router network. For example, if there are three routers, it is
not known a priori if the demand will make bandwidth-on-demand
interface at R1 to be connected to bandwidth-on-demand interface
at R2 or R3. For this reason, bandwidth-on-demand interfaces
cannot be pre-provisioned with the IP services that are expected
to carry.
According to [RFC5623], there are four options of Inter-Layer
Path Computation and Inter-Layer Path Control Models: (1) PCE-
VNTM cooperation, (2) Higher-layer signaling trigger, (3) NMS-
VNTM cooperation model (integrated flavor) and (4) NMS-VNTM
cooperation model (separated flavor). In all scenarios there is
a certain moment when entities are using an interface to request
for a path provisioning. In this document we have selected two
use cases in a scenario with routers and optical equipment to
obtain the requirements for this draft, but it is applicable to
the four options.
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[Please refer to pdf version for the Figure]
Figure 2. Use case higher-layer signaling trigger
2.3. Higher-layer signaling trigger
Figure 2 depicts a multi-layer network scenario similar to the
presented in section 4.2.2. [RFC5623], with the difference that
PCE is an active stateful PCE [I-D. draft-ietf-pce-stateful-
pce].
In this example, O1, O2 and O3 are optical nodes that are
connected with router nodes R1, R2 and R3, respectively. The
network is designed such that the interface between R1-O1, R2-O2
and R3-O3 are setup to provide bandwidth-on-demand via the
optical network.
The example assumes that an active stateful PCE is used for
setting and tearing down bandwidth-on-demand connectivity.
Although the simple use-case assumes a single PCE server (PCE1),
the proposed technique is generalized to cover multiple co-
operating PCE case. Similarly, although the use case assumes
PCE1 only has knowledge of the L3 topology, the proposed
technique is generalized to cover multi-layer PCE case.
The PCE server (PCE1) is assumed to be receiving L3 topology
data. It is also assumed that PCE learns L0 (optical) addresses
associated with bandwidth-on-demand interfaces R1-O1, R2-O2 and
R3-O3. These addresses are referred by OTE-IP-R1 (optical TE
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link R1-O1 address at R1), OTE-IP-R2 (optical TE link R2-O2
address at R2) and OTE-IP-R3 (optical TE link R3-O3 address at
R3), respectively. How PCE learns the optical addresses
associated with the bandwidth-on-demand interfaces is beyond the
scope of this document.
How knowledge of the bandwidth-on-demand interfaces is utilized
by the PCE is exemplified in the following. Suppose an
application requests 8 Gbps from R1 to R2 (recall all interfaces
in Figure 1 are assumed to be 10G). PCE1 satisfies this by
establishing a tunnel using R1-R4-R2 path. PCEP initiated LSP
using techniques specified in [I-D. draft-crabbe-pce-pce-
initiated-lsp] can be used to establish a PSC tunnel using the
R1-R4-R2 path. Now assume another application requests 7 Gbps
service between R1 and R2. This request cannot be satisfied
without establishing a GMPLS tunnel via optical network using
bandwidth-on-demand interfaces. In this case, PCE1 initiates a
GMPLS tunnel using R1-O1-O2-R2 path (this is referred as GMPLS
tunnel1 in the following). The PCEP initiated LSP using
techniques specified in document are used for this purpose.
As mentioned earlier, the GMPLS tunnel created on-the-fly to
satisfy bandwidth demand of L3 applications cannot be pre-
provisioned in IP network, as bandwidth-on-demand interfaces and
spare bandwidth in the optical network are shared. Furthermore,
in this example, as active stateful PCE is used for managing
PCE-initiated LSP, PCC may not be aware of the intended usage of
the PCE-initiated LSP. Specifically, when the PCE1 initiated
GMPLS tunnel1, PCC does not know the IGP instance whose demand
leads to establishment of the GMPLS tunnel1 and hence does not
know the IGP instance in which the GMPLS tunnel1 needs to be
advertised. Similarly, the PCC does not know IP address that
should be assigned to the GMPLS tunnel1. In the above example,
this IP address is labeled as TUN-IP-R1 (tunnel IP address at
R1). The PCC also does not know if the tunnel needs to be
advertised as forwarding and/ or routing adjacency and/or to be
locally used by the target IGP instance. Similarly, egress node
for GMPLS signaling (R2 node in this example) may not know the
intended usage of the tunnel (tunnel1 in this example). For
example, the R2 node does not know IP address that should be
assigned to the GMPLS tunnel1. In the above example, this IP
address is labeled as TUN-IP-R2 (tunnel IP address at R2).
Section 6 of this draft addresses the requirement to specify on
how PCC and egress node for signaling should use the PCEP
initiated LSPs.
2.4. NMS-VNTM cooperation model (separated flavor)
Figure 3 depicts NMS-VNTM cooperation model. This is the
separated flavor, because NMS and VNTM are not in the same
location.
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A new L3 path is requested from NMS, because there is an
automated process in the NMS or after human intervention. NMS
does not have information about all network information, so it
consults L3 PCE. For shake of simplicity L3-PCE is used, but any
other multi-layer cooperating PCE model is applicable. In case
that there are enough resources in the L3 layer, L3-PCE returns
a L3 only path. On the other hand, if there is a lack of
resources at the L3 layer, the response does not have any path
or may contain a multilayer path with L3 and L0 (optical)
information in case of a ML-PCE. In case of there is not a path
in L3; NMS sends a message to the VNTM to create a GMPLS LSP in
the lower layer. When the VNTM receives this message, based on
the local policies, accepts the suggestion and sends a similar
message to the router, which can create the lower layer LSP via
UNI signaling in the routers, like in use case in section 2.3.1.
Similarly, VNTM may talk with L0-PCE to set-up the path in the
optical domain (section 2.2). This second option looks more
complex, because it requires VNTM configuring inter-layer TE-
links.
Requirements for the message from VNTM to the router are the
same than in the previous use case (section 2.3.1). Regarding
NMS to VNTM message, the requirements here depends on who has
all the information. Three different addresses are required in
this use case: (1) L3, (2) L0 and (3) inter-layer addressing. In
case there is a non-cooperating L3-PCE, information about inter-
layer connections have to be stored (or discovered) by VNTM. If
there is a ML-PCE and this information is obtained from the
network, the message would be the same than in section 2.3.1.
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[Please refer to pdf version for the Figure]
Figure 3. Use case NMS-VNTM cooperation model
3. GMPLS Requirements for Remote-Initiated LSPs
[I-D. draft-crabbe-pce-pce-initiated-lsp] specifies procedures
that can be used for creation and deletion of PCE-initiated LSPs
under the active stateful PCE model. However, this specification
does not address GMPLS requirements outlined in the following:
- GMPLS support multiple switching capabilities on per TE link
basis. GMPLS LSP creation requires knowledge of LSP switching
capability (e.g., TDM, L2SC, OTN-TDM, LSC, etc.) to be used
[RFC3471], [RFC3473].
- GMPLS LSP creation requires knowledge of the encoding type
(e.g., lambda photonic, Ethernet, SONET/ SDH, G709 OTN, etc.)
to be used by the LSP [RFC3471], [RFC3473].
- GMPLS LSP creation requires information of the generalized
payload (G-PID) to be carried by the LSP [RFC3471], [RFC3473].
- GMPLS LSP creation requires specification of data flow
specific traffic parameters (also known as Tspec), which are
technology specific.
- GMPLS also specifics support for asymmetric bandwidth
requests [RFC6387].
- GMPLS extends the addressing to include unnumbered interface
identifiers, as defined in [RFC3477].
- In some technologies path calculation is tightly coupled with
label selection along the route. For example, path calculation
in a WDM network may include lambda continuity and/ or lambda
feasibility constraints and hence a path computed by the PCE
is associated with a specific lambda (label). Hence, in such
networks, the label information needs to be provided to a PCC
in order for a PCE to initiate GMPLS LSPs under the active
stateful PCE model. I.e., explicit label control may be
required.
- GMPLS specifics protection context for the LSP, as defined in
[RFC4872] and [RFC4873].
4. Remote Initiated LSP Usage Requirement
The requirement to specify usage of the LSP to the PCC includes
but not limited to specification of the following information.
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- The target IGP instance for the Remote-initiated LSP needs to
be specified.
- In the target IGP instance, should the PCE-initiated LSP be
advertised as a forwarding adjacency and/ or routing adjacency
and/ or to be used locally by the PCC?
- Should the as Remote-initiated LSP be advertised an IPv4 FA/
RA, IPv6 FA/ RA or as unnumbered FA/ RA.
- If Remote-initiated LSP is to be advertised an IPv4 FA/ RA,
IPv6 FA/ RA, what is the local and remote IP address is to be
used for the advertisement.
5. PCEP Extensions for Remote-Initiated GMPLS LSPs
Section 3 outlines GMPLS and application requirements that need
to be satisfied in order for a PCE to initiate GMPLS LSPs under
the active stateful PCE model. The section provides PCEP
protocol extensions required to meet these requirements.
LSP create message defined in [I-D. draft-crabbe-pce-pce-
initiated-lsp] needs to be extended to include GMPLS specific
PCEP objects as follows:
5.1. Generalized Endpoint in LSP Create Message
This document does not modify the usage of END-POINTS object for
PCE initiated LSPs as specified in [I-D. draft-crabbe-pce-pce-
initiated-lsp]. It augments the usage as specified below.
END-POINTS object has been extended by [I-D. draft-ietf-pcep-
gmpls-ext] to include a new object type called ''Generalized
Endpoint''. PCCreate message sent by a PCE to a PCC to trigger a
GMPLS LSP instantiation SHOULD include the END-POINTS with
Generalized Endpoint object type. Furthermore, the END-POINTS
object MUST contain ''label request'' TLV. The label request TLV
is used to specify the switching type, encoding type and GPID of
the LSP being instantiated by the PCE.
As mentioned earlier, the PCE server is assumed to be receiving
topology data. In the use case of higher-layer signaling
trigger, the addresses associated with bandwidth-on-demand
interfaces are included, e.g., OTE-IP-R1, OTE-IP-R2 and OTE-IP-
R3, in the use case example. These addresses and R1, R2 and R3
router IDs are used to derive source and destination address of
the END-POINT object. As previously mentioned, in the case of
NMS-VNMT cooperation model with L3 PCE, VNTM must receive such
inter-layer interface association to configure the whole path.
The unnumbered endpoint TLV can be used to specify unnumbered
endpoint addresses for the LSP being instantiated by the PCE.
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The END-POINTS MAY contain other TLVs defined in [I-D. draft-
ietf-pcep-gmpls-ext].
If the END-POINTS Object of type Generalized Endpoint is missing
the label request TLV, the PCC MUST send a PCErr message with
Error-type=6 (Mandatory Object missing) and Error-value= TBA
(LSP request TLV missing).
If the PCC does not support the END-POINTS Object of type
Generalized Endpoint, the PCC MUST send a PCErr message with
Error-type= TBA and Error-value= TBA. [may be already defined].
5.2. GENERALIZED-BANDWIDTH object in LSP Create Message
LSP create message defined in [I-D. draft-crabbe-pce-pce-
initiated-lsp] can optionally include the BANDWIDTH object.
However, the following possibilities cannot be represented in
the BANDWIDTH object:
- Asymmetric bandwidth (different bandwidth in forward and
reverse direction), as described in [RFC6387].
- Technology specific GMPLS parameters (e.g., Tspec for
SDH/SONET, G.709, ATM, MEF, etc.) are not supported.
GENERALIZED-BANDWIDTH object has been defined in [I-D. draft-
ietf-pcep-gmpls-ext] to address the above-mentioned limitation
of the BANDWIDTH object.
This document specifies the use of GENERALIZED-BANDWIDTH object
in PCCreate message. Specifically, GENERALIZED-BANDWIDTH object
MAY be included in the PCCreate message. The GENERALIZED-
BANDWIDTH object in PCCreate message is used to specify
technology specific Tspec and asymmetrical bandwidth values for
the LSP being instantiated by the PCE.
5.3. Protection Attributes in LSP Create Message
This document does not modify the usage of LSPA object for PCE
initiated LSPs as specified in [I-D. draft-crabbe-pce-pce-
initiated-lsp]. It augments the usage of LSPA object in LSP
Create Message to carry the end-to-end protection context this
also includes the protection state information.
The LSP Protection Information TLV of LSPA in the PCCreate
message can be used to specify protection attributes of the LSP
being instantiated by the PCE.
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5.4. ERO in LSP Create Object
This document does not modify the usage of ERO object for PCE
initiated LSPs as specified in [I-D. draft-crabbe-pce-pce-
initiated-lsp]. It augments the usage as specified in the
following sections.
5.4.1. ERO with explicit label control
As mentioned earlier, there are technologies and scenarios where
active stateful PCE requires explicit label control in order to
instantiate an LSP.
Explicit label control (ELC) is a procedure supported by RSVP-
TE, where the outgoing label(s) is (are) encoded in the ERO. [I-
D. draft-ietf-pcep-gmpls-ext] extends the <ERO> object of PCEP
to include explicit label control. The ELC procedure enables the
PCE to provide such label(s) directly in the path ERO.
The extended ERO object in PCCreate message can be used to
specify label along with ERO to PCC for the LSP being
instantiated by the active stateful PCE.
5.4.2. ERO with Path Keys
There are many scenarios in packet and optical networks where
the route information of an LSP may not be provided to the PCC
for confidentiality reasons. A multi-domain or multi-layer
network is an example of such networks. Similarly, a GMPLS User-
Network Interface (UNI) [RFC4208] is also an example of such
networks.
In such scenarios, ERO containing the entire route cannot be
provided to PCC (by PCE). Instead, PCE provides an ERO with Path
Keys to the PCC. For example, in the case UNI interface between
the router and the optical nodes, the ERO in the LSP Create
Message may be constructed as follows:
- The first hop is a strict hop that provides the egress
interface information at PCC. This interface information is
used to get to a network node that can extend the rest of the
ERO. (Please note that in the cases where the network node is
not directly connected with the PCC, this part of ERO may
consist of multiple hops and may be loose).
- The following(s) hop in the ERO may provide the network node
with the path key [RFC5520] that can be resolved to get the
contents of the route towards the destination.
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- There may be further hops but these hops may also be encoded
with the path keys (if needed).
This document does not change encoding or processing roles for
the path keys, which are defined in [RFC5520].
5.4.3. Switch Layer Object
[draft-ietf-pce-inter-layer-ext-07] specifies the SWITCH-LAYER
object which defines and specifies the switching layer (or
layers) in which a path MUST or MUST NOT be established. A
switching layer is expressed as a switching type and encoding
type. [I-D. draft-ietf-pcep-gmpls-ext], which defines the GMPLS
extensions for PCEP, suggests using the SWITCH-LAYER object.
Thus, SWITCH-LAYER object can be used in the PCCreate message to
specify the switching layer (or layers) of the LSP being
remotely initiated.
6. PCEP extension for PCEP Initiated LSP Usage Specification
The requirement to specify on how PCC should use the PCEP
initiated LSPs in outlined in Section 4. This subsection
specifies PCEP extension used to satisfy this requirement.
PCEP extensions specified in this section are equally applicable
to PCEP initiated MPLS as well as GMPLS LSPs.
6.1. LSP_TUNNEL_INTERFACE_ID Object in LSP Create Message
[RFC6107] defines LSP_TUNNEL_INTERFACE_ID Object for
communicating usage of the forwarding or routing adjacency from
the ingress node to the egress node. This document extends the
LSP Create Message to include LSP_TUNNEL_INTERFACE_ID object
defined in [RFC6107]. Object class and type for the
LSP_TUNNEL_INTERFACE_ID object are as follows:
Object Name: LSP_TUNNEL_INTERFACE_ID
Object-Class Value: TBA by Iana (suggested value: 40)
Object-type: 1
The contents of this object are identical in encoding to the
contents of the RSVP-TE LSP_TUNNEL_INTERFACE_ID object defined
in [RFC6107] and [RFC3477]. The following TLVs of RSVP-TE
LSP_TUNNEL_INTERFACE_ID object are acceptable in this object.
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The PCEP LSP_TUNNEL_INTERFACE_ID object's TLV types correspond
to RSVP-TE LSP_TUNNEL_INTERFACE_ID object's TLV types. Please
note that use of TLV type 1 defined in [RFC3477] is not
specified by this document.
TLV TLV
Type Description Reference
-- ------------------------------------------------- ----------
2 IPv4 interface identifier with target IGP instance [RFC6107]
3 IPv6 interface identifier with target IGP instance [RFC6107]
4 Unnumbered interface with target IGP instance [RFC6107]
The meanings of the fields of PCEP LSP_TUNNEL_INTERFACE_ID
object are identical to those defined for the RSVP-TE
LSP_TUNNEL_INTERFACE_ID object. Similarly, meanings of the
fields of PCEP LSP_TUNNEL_INTERFACE_ID object's supported TLV
are identical to those defined for the corresponding RSVP-TE
LSP_TUNNEL_INTERFACE_ID object's TLVs. The following fields have
slightly different usage.
- IPv4 Interface Address field in IPv4 interface identifier
with target IGP instance TLV: This field indicates the local
IPv4 address to be assigned to the tunnel at the PCC (ingress
node for RSVP-TE signaling). In the example use case of
Section 2, IP address TUN-IP-R1 (tunnel IP address at R1) is
carried in this field (if TUN-IP-R1 is a v4 address).
- IPv6 Interface Address field in IPv4 interface identifier
with target IGP instance TLV: This field indicates the local
IPv6 address to be assigned to the tunnel at the PCC (ingress
node for RSVP-TE signaling). In the example use case of
Section 2, IP address TUN-IP-R1 (tunnel IP address at R1) is
carried in this field (if TUN-IP-R1 is a v6 address).
- LSR's Router ID field in Unnumbered interface with target IGP
instance: The PCC SHOULD use the LSR's Router ID in Unnumbered
interface with target IGP instance in advertising the LSP
being initiated by the PCE. In the example use case of Section
2, this field carries router-id of R1 in the target IGP
instance.
- Interface ID (32 bits) field in unnumbered interface with
target IGP instance: All bits of this field MUST be set to 0
by the PCE server and MUST be ignored by PCC. PCC SHOULD
allocate an Interface ID that fulfills Interface ID
requirements specified in [RFC3477].
When the Ingress PCC receives an LPS Request Message with
LSP_TUNNEL_INTERFACE_ID TLV, it uses the information contained
in the TLV to drive the IGP instance, treatment of the LSP being
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initiated in the target IGP instance (e.g., FA, RA or local
usage), the local IPv4 or IPv6 address or router-id for
unnumbered case to be used for advertisement of the LSP being
instantiated.
6.2. Communicating LSP usage to Egress node
PCE does not need to send LSP Create message to egress node
(node R2 in the example of section 2) to communicate LSP usage
information. Instead PCC (Ingres signaling node) uses RSVP-TE
signaling mechanism specified in [RFC6107] to send the LSP usage
to Egress node. Specifically, when the Ingress PCC receives an
LPS Request Message with LSP_TUNNEL_INTERFACE_ID TLV, it SHOULD
add LSP_TUNNEL_INTERFACE_ID object in RSVP TE Path message. For
this purpose, it is RECOMMENDED that the ingress PCC uses
content of the LSP_TUNNEL_INTERFACE_ID TLV in LSP Create Message
in PCEP to drive LSP_TUNNEL_INTERFACE_ID object in RSVP-TE. This
document does not modify usage of LSP_TUNNEL_INTERFACE_ID Object
in RSVP-TE signaling as specified in [RFC6107].
The egress node uses information contained in the
LSP_TUNNEL_INTERFACE_ID object in RSVP-TE Path message to drive
the IGP instance, treatment of the LSP being initiated in the
target IGP instance (e.g., FA, RA or local usage), the local
IPv4 or IPv6 address or router-id for unnumbered case to be used
for advertisement of the LSP being instantiated.
6.3. LSP delegation and cleanup
LSP delegation and cleanup procedure specified in [I-D. draft-
ietf-pcep-gmpls-ext] are equally applicable to GMPLS LSPs and
this document does not modify the associated usage.
7. Security Considerations
To be added in future revision of this document.
8. IANA Considerations
8.1. END-POINT Object
This document extends the LSP Create Message to include
LSP_TUNNEL_INTERFACE_ID object defined in [RFC6107]. Object
class and type for the LSP_TUNNEL_INTERFACE_ID object are as
follows:
Name Class value Type
---- ----------- ----
LSP_TUNNEL_INTERFACE_ID TBA by Iana (Suggested:40) 1
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8.2. PCEP-Error Object
This document defines the following new Error-Value:
Error-Type Error Value
6 Error-value=TBA: LSP Request TLV missing
9. Acknowledgments
The authors would like to thank George Swallow and Jan Medved
for their comments.
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[I-D. draft-crabbe-pce-pce-initiated-lsp] Crabbe, E., Minei,
I., Sivabalan, S., Varga, R., ''PCEP Extensions for
PCE-initiated LSP Setup in a Stateful PCE Model'',
draft-crabbe-pce-pce-initiated-lsp, work in progress.
[RFC5440] Vasseur, JP., Ed., and JL. Le Roux, Ed., "Path
Computation Element (PCE) Communication Protocol
(PCEP)", RFC 5440, March 2009.
[RFC5623] Oki, E., Takeda, T., Le Roux, JL., and A. Farrel,
"Framework for PCE-Based Inter-Layer MPLS and GMPLS
Traffic Engineering", RFC 5623, September 2009.
[RFC 6107] Shiomoto, K., Ed., and A. Farrel, Ed., "Procedures
for Dynamically Signaled Hierarchical Label Switched
Paths", RFC 6107, February 2011.
10.2. Informative References
[RFC3471] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Functional Description",
RFC 3471, January 2003.
[RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation
Protocol-Traffic Engineering (RSVP-TE) Extensions",
RFC 3473, January 2003.
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[RFC 5467] Berger, L., Takacs, A., Caviglia, D., Fedyk, D., and
J. Meuric, "GMPLS Asymmetric Bandwidth Bidirectional
Label Switched Paths (LSPs)", RFC 5467, March 2009.
[RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered
Links in Resource ReSerVation Protocol - Traffic
Engineering (RSVP-TE)", RFC 3477, January 2003.
[RFC4872] Lang, J., Ed., Rekhter, Y., Ed., and D. Papadimitriou,
Ed., "RSVP-TE Extensions in Support of End-to-End
Generalized Multi-Protocol Label Switching (GMPLS)
Recovery", RFC 4872, May 2007.
[RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A.
Farrel, "GMPLS Segment Recovery", RFC 4873, May 2007.
[RFC4208] Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter,
"Generalized Multiprotocol Label Switching (GMPLS)
User-Network Interface (UNI): Resource ReserVation
Protocol-Traffic Engineering (RSVP-TE) Support for the
Overlay Model", RFC 4208, October 2005.
[RFC5520] Bradford, R., Ed., Vasseur, JP., and A. Farrel,
"Preserving Topology Confidentiality in Inter-Domain
Path Computation Using a Path-Key-Based Mechanism",
RFC 5520, July 2009.
Authors' Addresses
Zafar Ali
Cisco Systems
Email: zali@cisco.com
Siva Sivabalan
Cisco Systems
Email: msiva@cisco.com
Clarence Filsfils
Cisco Systems
Email: cfilsfil@cisco.com
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Robert Varga
Pantheon Technologies
Victor Lopez
Telefonica I+D
Email: vlopez@tid.es
Oscar Gonzalez de Dios
Telefonica I+D
Email: ogondio@tid.es
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