| Network Working Group | C. Margaria, Ed. |
| Internet-Draft | Juniper |
| Intended status: Standards Track | O. Gonzalez de Dios, Ed. |
| Expires: April 17, 2020 | Telefonica Investigacion y Desarrollo |
| F. Zhang, Ed. | |
| Huawei Technologies | |
| October 15, 2019 |
PCEP extensions for GMPLS
draft-ietf-pce-gmpls-pcep-extensions-15
A Path Computation Element (PCE) provides path computation functions for Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks. Additional requirements for GMPLS are identified in RFC7025.
This memo provides extensions to the Path Computation Element communication Protocol (PCEP) for the support of the GMPLS control plane to address those requirements.
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 17, 2020.
Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
Although [RFC4655] defines the PCE architecture and framework for both MPLS and GMPLS networks, most preexisting PCEP RFCs [RFC5440], [RFC5521], [RFC5541], [RFC5520] are focused on MPLS networks, and do not cover the wide range of GMPLS networks. This document complements these RFCs by addressing the extensions required for GMPLS applications and routing requests, for example for Optical Transport Network (OTN) and Wavelength Switched Optical Network (WSON) networks.
The functional requirements to be addressed by the PCEP extensions to support these applications are fully described in [RFC7025] and [RFC7449].
This document uses terminologies from the PCE architecture document [RFC4655], the PCEP documents including [RFC5440], [RFC5521], [RFC5541], [RFC5520], [RFC7025] and [RFC7449], and the GMPLS documents such as [RFC3471], [RFC3473] and so on. Note that it is expected the reader is familiar with these documents. The following abbreviations are used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
The document [RFC7025] describes the set of PCEP requirements to support GMPLS TE-LSPs. This document assumes a significant familiarity with [RFC7025] and existing PCEP extensions. As a short overview, those requirements can be broken down into the following categories.
[RFC7025] apply to several objects conveyed by PCEP, this is described in Section 1.3. Some of the requirements of [RFC7025] are already supported in existing documents, as described in Section 1.4.
The requirements of
This document describes a set of PCEP extensions, including new object types, TLVs, encodings, error codes and procedures, in order to fulfill the aforementioned requirements not covered in existing RFCs.
This section follows the organization of [RFC7025] Section 3 and indicates, for each requirement, the affected piece of information carried by PCEP and its scope.
The support provided by specifications in [RFC8282] and [RFC5440] for the requirements listed in [RFC7025] is summarized in Table 1 and Table 2. In some cases the support may not be complete, as noted, and additional support need to be provided in this specification.
| Req. | Name | Support |
| 1 | Switching capability/type | SWITCH-LAYER (RFC8282) |
| 2 | Encoding type | SWITCH-LAYER (RFC8282) |
| 3 | Signal type | SWITCH-LAYER (RFC8282) |
| 4 | Concatenation type | No |
| 5 | Concatenation number | No |
| 6 | Technology-specific label | (Partial) ERO (RFC5440) |
| 7 | End-to-End (E2E) path protection type | No |
| 8 | Administrative group | LSPA (RFC5440) |
| 9 | Link protection type | No |
| 10 | Support for unnumbered interfaces | (Partial) ERO (RFC5440) |
| 11 | Support for asymmetric bandwidth requests | No |
| 12 | Support for explicit label control during the path computation | No |
| 13 | Support of label restrictions in the requests/responses | No |
| Req. | Name | Support |
| 1 | Path computation with concatenation | No |
| 2 | Label constraint | No |
| 3 | Roles of the routes | No |
As described in Section 1.3 PCEP as of [RFC5440], [RFC5521] and [RFC8282], supports the following objects, included in requests and responses, related to the described requirements.
From [RFC5440]:
From [RFC5521]:
From [RFC8282]:
The gaps in functional coverage of the base PCEP objects are:
The PCEP extensions defined later in this document to cover the gaps are:
This section describes the necessary PCEP objects and extensions. The PCReq and PCRep messages are defined in [RFC5440]. This document does not change the existing grammars.
IGP-based PCE Discovery (PCED) is defined in [RFC5088] and [RFC5089] for the OSPF and IS-IS protocols. Those documents have defined bit 0 in PCE-CAP-FLAGS Sub-TLV of the PCED TLV as "Path computation with GMPLS link constraints". This capability is optional and can be used to detect GMPLS-capable PCEs. PCEs that set the bit to indicate support of GMPLS path computation MUST follow the procedures in Section 2.1.2 to further qualify the level of support during PCEP session establishment.
In addition to the IGP advertisement, a PCEP speaker MUST be able to discover the other peer GMPLS capabilities during the Open message exchange. This capability is also useful to avoid misconfigurations. This document defines a GMPLS-CAPABILITY TLV for use in the OPEN object to negotiate the GMPLS capability. The inclusion of this TLV in the Open message indicates that the PCEP speaker support the PCEP extensions defined in the document. A PCEP speaker that is able to support the GMPLS extensions defined in this document MUST include the GMPLS-CAPABILITY TLV on the Open message. If one of the PCEP peers does not include the GMPLS-CAPABILITY TLV in the Open message, the peers MUST NOT make use of the objects and TLVs defined in this document.
If the PCEP speaker supports the extensions of this specification but did not advertise the GMPLS-CAPABILITY capability, upon receipt of a message from the PCE including an extension defined in this document, it MUST generate a PCEP Error (PCErr) with Error-Type=10 (Reception of an invalid object) and Error-value=TBA-42 (Missing GMPLS-CAPABILITY TLV), and it SHOULD terminate the PCEP session.
IANA has allocated value TBA-1 from the "PCEP TLV Type Indicators" sub-registry, as documented in Section 5.3 ("New PCEP TLVs"). The description is "GMPLS-CAPABILITY". Its format is shown in the following figure.
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=TBA-1 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
No Flags are defined in this document, they are reserved for future use.
Explicit label control (ELC) is a procedure supported by RSVP-TE, where the outgoing labels are encoded in the ERO. As a consequence, the PCE can provide such labels directly in the path ERO. Depending on policies or switching layer, it can be necessary for the PCC to use explicit label control or explicit link ids, thus it needs to indicate in the PCReq which granularity it is expecting in the ERO. This corresponds to requirement 12 of [RFC7025]. The possible granularities can be node, link or label. The granularities are inter-dependent, in the sense that link granularity implies the presence of node information in the ERO; similarly, a label granularity implies that the ERO contains node, link and label information.
A new 2-bit routing granularity (RG) flag (Bits TBA-13) is defined in the RP object. The values are defined as follows
| 0: | reserved |
| 1: | node |
| 2: | link |
| 3: | label |
The flag in the RP object indicates the requested route granularity. The PCE SHOULD follow this granularity and MAY return a NO-PATH if the requested granularity cannot be provided. The PCE MAY return any granularity on the route based on its policy. The PCC can decide if the ERO is acceptable based on its content.
If a PCE honored the requested routing granularity for a request, it MUST indicate the selected routing granularity in the RP object included in the response. Otherwise, the PCE MUST use the reserved RG to leave the check of the ERO to the PCC. The RG flag is backward-compatible with [RFC5440]: the value sent by an implementation (PCC or PCE) not supporting it will indicate a reserved value.
From [RFC5440] the object carrying the requested size for the TE-LSP is the BANDWIDTH object. The object types 1 and 2 defined in [RFC5440] do not describe enough information to describe the TE-LSP bandwidth in GMPLS networks. The BANDWIDTH object encoding has to be extended to allow the object to express the bandwidth as described in [RFC7025]. RSVP-TE extensions for GMPLS provide a set of encodings allowing such representation in an unambiguous way, this is encoded in the RSVP-TE TSpec and FlowSpec objects. This document extends the BANDWIDTH object with new object types reusing the RSVP-TE encoding.
The following possibilities are supported by the extended encoding: [RFC7025] Section 3.1.
This corresponds to requirements 3, 4, 5 and 11 of
This document defines two Object Types for the BANDWIDTH object:
The definitions below apply for Object Type TBA-2 and TBA-3. The body is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth Spec Length | Rev. Bandwidth Spec Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bw Spec Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Generalized Bandwidth ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Optional: Reverse Generalized Bandwidth ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Optional TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The BANDWIDTH object type TBA-2 and TBA-3 have a variable length. The 16-bit Bandwidth Spec Length field indicates the length of the Generalized Bandwidth field. The Bandwidth Spec Length MUST be strictly greater than 0. The 16-bit Reverse Bandwidth Spec Length field indicates the length of the Reverse Generalized Bandwidth field. The Reverse Bandwidth Spec Length MAY be equal to 0.
The Bw Spec Type field determines which type of bandwidth is represented by the object.
The Bw Spec Type corresponds to the RSVP-TE SENDER_TSPEC (Object Class 12) C-Types
The encoding of the fields Generalized Bandwidth and Reverse Generalized Bandwidth is the same as the Traffic Parameters carried in RSVP-TE, it can be found in the following references. It is to be noted that the RSVP-TE traffic specification MAY also include TLVs (e.g., [RFC6003] different from the PCEP TLVs).
| Bw Spec Type | Name | Reference |
|---|---|---|
| 2 | Intserv | [RFC2210] |
| 4 | SONET/SDH | [RFC4606] |
| 5 | G.709 | [RFC4328] |
| 6 | Ethernet | [RFC6003] |
| 7 | OTN-TDM | [RFC7139] |
| 8 | SSON | [RFC7792] |
When a PCC requests a bi-directional path with symmetric bandwidth, it SHOULD only specify the Generalized Bandwidth field, and set the Reverse Bandwidth Spec Length to 0. When a PCC needs to request a bi-directional path with asymmetric bandwidth, it SHOULD specify the different bandwidth in the forward and reverse directions with a Generalized Bandwidth and Reverse Generalized Bandwidth fields.
The procedure described in [RFC5440] for the PCRep is unchanged: a PCE MAY include the BANDWIDTH objects in the response to indicate the BANDWIDTH of the path.
As specified in [RFC5440] in the case of the reoptimization of a TE-LSP, the bandwidth of the existing TE-LSP MUST also be included in addition to the requested bandwidth if and only if the two values differ. The Object Type TBA-3 MAY be used instead of the previously specified object type 2 to indicate the existing TE-LSP bandwidth originally specified with object type TBA-2. A PCC that requested a path with a BANDWIDTH object of object type 1 MUST use object type 2 to represent the existing TE-LSP BANDWIDTH.
OPTIONAL TLVs MAY be included within the object body to specify more specific bandwidth requirements. No TLVs for the Object Type TBA-2 and TBA-3 are defined by this document.
The LOAD-BALANCING object [RFC5440] is used to request a set of at most Max-LSP TE-LSP having in total the bandwidth specified in BANDWIDTH, with each TE-LSP having at least a specified minimum bandwidth. The LOAD-BALANCING follows the bandwidth encoding of the BANDWIDTH object, and thus the existing definition from [RFC5440] does not describe enough details for the bandwidth specification expected by GMPLS.
Similarly to the BANDWIDTH object, a new object type is defined to allow a PCC to represent the bandwidth types supported by GMPLS networks.
This document defines the Generalized Load Balancing object type TBA-4 for the LOAD-BALANCING object. The Generalized Load Balancing object type has a variable length.
The format of the Generalized Load Balancing object type is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth Spec Length | Reverse Bandwidth Spec Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bw Spec Type | Max-LSP | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Min Bandwidth Spec |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Min Reverse Bandwidth Spec (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Optional TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Bandwidth Spec Length (16 bits): the total length of the Min Bandwidth Spec field. The length MUST be strictly greater than 0.
Reverse Bandwidth Spec Length (16 bits): the total length of the Min Reverse Bandwidth Spec field. It MAY be equal to 0.
Bw Spec Type (8 bits): the bandwidth specification type, it corresponds to the RSVP-TE SENDER_TSPEC (Object Class 12) C-Types.
Max-LSP (8 bits): maximum number of TE-LSPs in the set.
Min Bandwidth Spec (variable): specifies the minimum bandwidth specification of each element of the TE-LSP set.
Min Reverse Bandwidth Spec (variable): specifies the minimum reverse bandwidth specification of each element of the TE-LSP set.
The encoding of the fields Min Bandwidth Spec and Min Reverse Bandwidth Spec is the same as in RSVP-TE SENDER_TSPEC object, it can be found in Table 4 from Section 2.3 from this document.
When a PCC requests a bi-directional path with symmetric bandwidth while specifying load balancing constraints it SHOULD specify the Min Bandwidth Spec field, and set the Reverse Bandwidth Spec Length to 0. When a PCC needs to request a bi-directional path with asymmetric bandwidth while specifying load balancing constraints, it MUST specify the different bandwidth in forward and reverse directions through a Min Bandwidth Spec and Min Reverse Bandwidth Spec fields.
OPTIONAL TLVs MAY be included within the object body to specify more specific bandwidth requirements. No TLVs for the Generalized Load Balancing object type are defined by this document.
The semantic of the LOAD-BALANCING object is not changed. If a PCC requests the computation of a set of TE-LSPs with at most N TE-LSPs so that it can carry generalized bandwidth X , each TE-LSP must at least transport bandwidth B, it inserts a BANDWIDTH object specifying X as the required bandwidth and a LOAD-BALANCING object with the Max-LSP and Min Bandwidth Spec fields set to N and B, respectively. When the BANDWIDTH and Min Bandwidth Spec can be summarized as scalars, the sum of all TE-LSPs bandwith in the set is greater than X. The mapping of X over N path with (at least) bandwidth B is technology and possibly node specific. Each standard definition of the transport technology is defining those mappings and are not repeated in this document. A simplified example for SDH is described in Appendix A
In all other cases, including for technologies based on statistical multiplexing (e.g., InterServ, Ethernet), the exact bandwidth management (e.g., Ethernet's Excessive Rate) is left to the PCE's policies, according to the operator's configuration. If required, further documents may introduce a new mechanism to finely express complex load balancing policies within PCEP.
The BANDWITH and LOAD-BALANCING Bw Spec Type can be different depending on the endpoint nodes architecture. When the PCE is not able to handle those two Bw Spec Type, it MUST return a NO-PATH with the bit "LOAD-BALANCING could not be performed with the bandwidth constraits " set in the NO-PATH-VECTOR TLV.
The END-POINTS object is used in a PCEP request message to specify the source and the destination of the path for which a path computation is requested. From [RFC5440], the source IP address and the destination IP address are used to identify those. A new Object Type is defined to address the following possibilities:
The Object encoding is described in the following sections.
In path computation within a GMPLS context the endpoints can:
The IPv4 and IPv6 endpoints are used to represent the source and destination IP addresses. The scope of the IP address (Node or numbered Link) is not explicitly stated. It is also possible to request a Path between a numbered link and an unnumbered link, or a P2MP path between different type of endpoints.
This document defines the Generalized Endpoint object type TBA-5 for the END-POINTS object. This new type also supports the specification of constraints on the endpoint label to be used. The PCE might know the interface restrictions but this is not a requirement. This corresponds to requirements 6 and 10 of [RFC7025].
The Generalized Endpoint object type format consists of a body and a list of TLVs scoped to this object. The TLVs give the details of the endpoints and are described in Section 2.5.2. For each Endpoint Type, a different grammar is defined. The TLVs defined to describe an endpoint are: [RFC4003] in signaling for egress endpoint, but ingress endpoint properties can be local to the PCC and not signaled. To support this case the label set allows indication which label are used in case of reoptimization. The label range restrictions are valid in GMPLS-controlled networks, either by PCC policy or depending on the switching technology used, for instance on given Ethernet or ODU equipment having limited hardware capabilities restricting the label range. Label set restriction also applies to WSON networks where the optical senders and receivers are limited in their frequency tunability ranges, consequently restricting the possible label ranges on the interface in GMPLS. The END-POINTS Object with Generalized Endpoint object type is encoded as follow:
The Label set TLV is used to restrict or suggest the label allocation in the PCE. This TLV expresses the set of restrictions which may apply to signaling. Label restriction support can be an explicit or a suggested value (Label set describing one label, with the L bit respectively cleared or set), mandatory range restrictions (Label set with L bit cleared) and optional range restriction (Label set with L bit set). Endpoints label restriction may not be part of the RRO or IRO. They can be included when following
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Endpoint Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Reserved bits SHOULD be set to 0 when a message is sent and ignored when the message is received.
The Endpoint Type is defined as follow:
| Value | Type | Meaning |
|---|---|---|
| 0 | Point-to-Point | |
| 1 | Point-to-Multipoint | New leaves to add |
| 2 | Old leaves to remove | |
| 3 | Old leaves whose path can be modified/reoptimized | |
| 4 | Old leaves whose path has to be | |
| left unchanged | ||
| 5-244 | Reserved | |
| 245-255 | Experimental range |
The Endpoint Type is used to cover both point-to-point and different point-to-multipoint endpoints. A PCE may accept only Endpoint Type 0: Endpoint Types 1-4 apply if the PCE implementation supports P2MP path calculation. A PCE not supporting a given Endpoint Type SHOULD respond with a PCErr with Error-Type=4 (Not supported object), Error-value=TBA-15 (Unsupported endpoint type in END-POINTS Generalized Endpoint object type). As per [RFC5440], a PCE unable to process Generalized Endpoints may respond with Error-Type=3 (Unknown Object), Error-value=2 (Unrecognized object Type) or Error-Type=4 (Not supported object), Error-value=2 (Not supported object Type). The TLVs present in the request object body MUST follow the following [RFC5511] grammar:
<generalized-endpoint-tlvs>::=
<p2p-endpoints> | <p2mp-endpoints>
<p2p-endpoints> ::=
<endpoint> [<endpoint-restriction-list>]
<endpoint> [<endpoint-restriction-list>]
<p2mp-endpoints> ::=
<endpoint> [<endpoint-restriction-list>]
<endpoint> [<endpoint-restriction-list>]
[<endpoint> [<endpoint-restriction-list>]]...
For endpoint type Point-to-Point, 2 endpoint TLVs MUST be present in the message. The first endpoint is the source and the second is the destination.
For endpoint type Point-to-Multipoint, several END-POINT objects MAY be present in the message and the exact meaning depending on the endpoint type defined for the object. The first endpoint TLV is the root and other endpoints TLVs are the leaves. The root endpoint MUST be the same for all END-POINTS objects. If the root endpoint is not the same for all END-POINTS, a PCErr with Error-Type=17 (P2MP END-POINTS Error), Error-value=4 (The PCE cannot satisfy the request due to inconsistent END-POINTS) MUST be returned. The procedure defined in [RFC8306] Section 3.10 also apply to the Generalized Endpoint with Point-to-Multipoint endpoint types.
An endpoint is defined as follows:
<endpoint>::=<IPV4-ADDRESS>|<IPV6-ADDRESS>|<UNNUMBERED-ENDPOINT>
<endpoint-restriction-list> ::= <endpoint-restriction>
[<endpoint-restriction-list>]
<endpoint-restriction> ::=
[<LABEL-REQUEST>][<label-restriction-list>]
<label-restriction-list> ::= <label-restriction>
[<label-restriction-list>]
<label-restriction> ::= <LABEL-SET>
The different TLVs are described in the following sections. A PCE MAY support any or all of IPV4-ADDRESS, IPV6-ADDRESS, and UNNUMBERED-ENDPOINT TLVs. When receiving a PCReq, a PCE unable to resolve the identifier in one of those TLVs MUST respond using a PCRep with NO-PATH and set the bit "Unknown destination" or "Unknown source" in the NO-PATH-VECTOR TLV. The response SHOULD include the END-POINTS object with only the unsupported TLV(s).
A PCE MAY support either or both of the LABEL-REQUEST and LABEL-SET TLVs. If a PCE finds a non-supported TLV in the END-POINTS the PCE MUST respond with a PCErr message with Error-Type=4 (Not supported object) and Error-value=TBA-15 (Unsupported TLV present in END-POINTS Generalized Endpoint object type) and the message SHOULD include the END-POINTS object in the response with only the endpoint and endpoint restriction TLV it did not understand. A PCE supporting those TLVs but not being able to fulfil the label restriction MUST send a response with a NO-PATH object which has the bit "No endpoint label resource" or "No endpoint label resource in range" set in the NO-PATH-VECTOR TLV. The response SHOULD include an END-POINTS object containing only the TLV(s) related to the constraints the PCE could not meet.
All endpoint TLVs have the standard PCEP TLV header as defined in [RFC5440] Section 7.1. For the Generalized Endpoint Object Type the TLVs MUST follow the ordering defined in Section 2.5.1.
This TLV represents a numbered endpoint using IPv4 numbering, the format of the IPv4-ADDRESS TLV value (TLV-Type=TBA-6) is as follows:
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This TLV MAY be ignored, in which case a PCRep with NO-PATH SHOULD be returned, as described in Section 2.5.1.
This TLV represents a numbered endpoint using IPV6 numbering, the format of the IPv6-ADDRESS TLV value (TLV-Type=TBA-7) is as follows:
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 address (16 bytes) | | | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This TLV MAY be ignored, in which case a PCRep with NO-PATH SHOULD be returned, as described in Section 2.5.1.
This TLV represents an unnumbered interface. This TLV has the same semantic as in [RFC3477]. The TLV value is encoded as follows (TLV-Type=TBA-8)
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LSR's Router ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Interface ID (32 bits) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This TLV MAY be ignored, in which case a PCRep with NO-PATH SHOULD be returned, as described in Section 2.5.1.
The LABEL-REQUEST TLV indicates the switching capability and encoding type of the following label restriction list for the endpoint. The value format and encoding is the same as described in [RFC3471] Section 3.1 Generalized label request. The LABEL-REQUEST TLV uses TLV-Type=TBA-9. The Encoding Type indicates the encoding type, e.g., SONET/SDH/GigE etc., of the LSP with which the data is associated. The Switching type indicates the type of switching that is being requested on the endpoint. G-PID identifies the payload. This TLV and the following one are defined to satisfy requirement 13 of [RFC7025] for the endpoint. It is not directly related to the TE-LSP label request, which is expressed by the SWITCH-LAYER object.
On the path calculation request only the GENERALIZED-BANDWIDTH and SWITCH-LAYER need to be coherent, the endpoint labels could be different (supporting a different LABEL-REQUEST). Hence the label restrictions include a Generalized label request in order to interpret the labels. This TLV MAY be ignored, in which case a PCRep with NO-PATH SHOULD be returned, as described in Section 2.5.1.
Label or label range restrictions can be specified for the TE-LSP endpoints. Those are encoded using the LABEL-SET TLV. The label value need to be interpreted with a description on the Encoding and switching type. The REQ-ADAP-CAP object from [RFC8282] can be used in case of mono-layer request, however in case of multilayer it is possible to have more than one object, so it is better to have a dedicated TLV for the label and label request. These TLVs MAY be ignored, in which case a response with NO-PATH SHOULD be returned, as described in Section 2.5.1. TLVs are encoded as follows (following [RFC5440]):
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action | Reserved |L|O|U| Label Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Subchannel 1 | | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ : : : : : : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Subchannel N | | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
A LABEL-SET TLV represents a set of possible labels that can be used on an interface. If the L bit is cleared, the label allocated on the first endpoint MUST be within the label set range. The action parameter in the Label set indicates the type of list provided. These parameters are described by [RFC3471] Section 3.5.1.
The U, O and L bits have the following meaning:
| U: | Upstream direction: The U bit is set for upstream (revers) direction in case of bidirectional LSP. |
| O: | Old Label: set when the TLV represent the old (previously allocated) label in case of re-optimization. The R bit of the RP object MUST be set to 1. If the L bit is set, this bit SHOULD be set to 0 and ignored on receipt. When this bit is set, the Action field MUST be set to 0 (Inclusive List) and the Label Set MUST contain one subchannel. |
| L: | Loose Label: set when the TLV indicates to the PCE a set of preferred (ordered) labels to be used. The PCE MAY use those labels for label allocation. |
Several LABEL_SET TLVs MAY be present with the O bit cleared, LABEL_SET TLVs with L bit set can be combined with a LABEL_SET TLV with L bit cleared. At most 2 LABEL_SET TLVs MAY be present with the O bit set, with at most one of these having the U bit set and at most one of these having the U bit cleared. For a given U bit value, if more than one LABEL_SET TLV with the O bit set is present, the first TLV MUST be processed and the following TLVs with the same U and O bit MUST be ignored.
A LABEL-SET TLV with the O and L bit set MUST trigger a PCErr message with Error-Type=10 (Reception of an invalid object) Error-value=TBA-25 (Wrong LABEL-SET TLV present with O and L bit set).
A LABEL-SET TLV with the O bit set and an Action Field not set to 0 (Inclusive list) or containing more than one subchannel MUST trigger a PCErr message with Error-Type=10 (Reception of an invalid object) Error-value=TBA-26 (Wrong LABEL-SET TLV present with O bit and wrong format).
If a LABEL-SET TLV is present with O bit set, the R bit of the RP object MUST be set, otherwise a PCErr message MUST be sent with Error-Type=10 (Reception of an invalid object) Error-value=TBA-24 (LABEL-SET TLV present with O bit set but without R bit set in RP).
The IRO as defined in [RFC5440] is used to include specific objects in the path. RSVP-TE allows the inclusion of a label definition. In order to fulfill requirement 13 of [RFC7025] the IRO needs to support the new subobject type as defined in [RFC3473]:
| Type | Sub-object |
| TBA-38 | LABEL |
The Label subobject MUST follow a subobject identifying a link, currently an IP address subobject (Type 1 or 2) or an interface ID (type 4) subobject. If an IP address subobject is used, then the given IP address MUST be associated with a link. More than one label subobject MAY follow each link subobject. The procedure associated with this subobject is as follows.
If the PCE is able to allocate labels (e.g., via explicit label control) the PCE MUST allocate one label from within the set of label values for the given link. If the PCE does not assign labels, then it sends a response with a NO-PATH object, containing a NO-PATH-VECTOR TLV with the bit 'No label resource in range' set.
The XRO as defined in [RFC5521] is used to exclude specific objects in the path. RSVP-TE allows the exclusion of certain labels ([RFC6001]). In order to fulfill requirement 13 of [RFC7025] Section 3.1, the PCEP's XRO needs to support a new subobject to enable label exclusion.
The encoding of the XRO Label subobject follows the encoding of the Label ERO subobject defined in [RFC3473] and XRO subobject defined in [RFC5521]. The XRO Label subobject represent one Label and is defined as follows:
XRO Subobject Type TBA-39: Label Subobject.
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |X| Type=TBA-39 | Length |U| Reserved | C-Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Label | | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Label subobject MUST follow a subobject identifying a link, currently an IP address subobject (Type 1 or 2) or an interface ID (type 4) subobject. If an IP address subobject is used, then the given IP address MUST be associated with a link. More than one label subobject MAY follow each link subobject.
| Type | Sub-object |
| 3 | LABEL |
The LSPA carries the LSP attributes. In the end-to-end recovery context, this also includes the protection state information. A new TLV is defined to fulfil requirement 7 of [RFC7025] Section 3.1 and requirement 3 of [RFC7025] Section 3.2. This TLV contains the information of the PROTECTION object defined by [RFC4872] and can be used as a policy input. The LSPA object MAY carry a PROTECTION-ATTRIBUTE TLV defined as: Type TBA-12: PROTECTION-ATTRIBUTE
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |S|P|N|O| Reserved | LSP Flags | Reserved | Link Flags| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |I|R| Reserved | Seg.Flags | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The content is as defined in [RFC4872] Section 14, [RFC4873] Section 6.1.
LSP (protection) Flags or Link flags field can be used by a PCE implementation for routing policy input. The other attributes are only meaningful for a stateful PCE.
This TLV is OPTIONAL and MAY be ignored by the PCE. If ignored by the PCE, it MUST NOT include the TLV in the LSPA of the response. When the TLV is used by the PCE, a LSPA object and the PROTECTION-ATTRIBUTE TLV MUST be included in the response. Fields that were not considered MUST be set to 0.
The NO-PATH object is used in PCRep messages in response to an unsuccessful path computation request (the PCE could not find a path satisfying the set of constraints). In this scenario, PCE MUST include a NO-PATH object in the PCRep message. The NO-PATH object MAY carry the NO-PATH-VECTOR TLV that specifies more information on the reasons that led to a negative reply. In case of GMPLS networks there could be some additional constraints that led to the failure such as protection mismatch, lack of resources, and so on. Several new flags have been defined in the 32-bit flag field of the NO-PATH-VECTOR TLV but no modifications have been made in the NO-PATH object.
The modified NO-PATH-VECTOR TLV carrying the additional information is as follows:
A PCEP-ERROR object is used to report a PCEP error and is characterized by an Error-Type that specifies the type of error while Error-value that provides additional information about the error. An additional error type and several error values are defined to represent some of the errors related to the newly identified objects related to GMPLS networks. For each PCEP error, an Error-Type and an Error-value are defined. Error-Type 1 to 10 are already defined in [RFC5440]. Additional Error-values are defined for Error-Types 4 and 10. A new Error-Type is defined (value TBA-27).
The Error-Type TBA-27 (path computation failure) is used to reflect constraints not understood by the PCE, for instance when the PCE is not able to understand the generalized bandwidth. If the constraints are understood, but the PCE is unable to find with those constraints, the NO-PATH is to be used.
| Error-Type | Error-value | |
|---|---|---|
| 4 | Not supported object | |
| value=TBA-14: | Bandwidth Object type TBA-2 or TBA-3 not supported | |
| value=TBA-15: | Unsupported endpoint type in | |
| END-POINTS Generalized Endpoint | ||
| object type | ||
| value=TBA-16: | Unsupported TLV present in END-POINTS Generalized Endpoint object type | |
| value=TBA-17: | Unsupported granularity in the RP object flags | |
| 10 | Reception of an invalid object | |
| value=TBA-18: | Bad Bandwidth Object type TBA-2(Generalized bandwidth) or TBA-3( Generalized bandwidth of existing TE-LSP for which a reoptimization is requested) | |
| value=TBA-20: | Unsupported LSP Protection Flags in PROTECTION-ATTRIBUTE TLV | |
| value=TBA-21: | Unsupported Secondary LSP Protection Flags in PROTECTION-ATTRIBUTE TLV | |
| value=TBA-22: | Unsupported Link Protection Type in PROTECTION-ATTRIBUTE TLV | |
| value=TBA-24: | LABEL-SET TLV present with 0 bit set but without R bit set in RP | |
| value=TBA-25: | Wrong LABEL-SET | |
| TLV present with | ||
| 0 and L bit set | ||
| value=TBA-26: | Wrong LABEL-SET with O bit set and wrong format | |
| value=TBA-42: | Missing GMPLS-CAPABILITY TLV | |
| TBA-27 | Path computation failure | |
| value=0: | Unassigned | |
| value=TBA-28: | Unacceptable request message | |
| value=TBA-29: | Generalized bandwidth value not supported | |
| value=TBA-30: | Label Set constraint could not be | |
| met | ||
| value=TBA-31: | Label constraint could not be | |
| met |
This section follows the guidance of [RFC6123].
This document makes no change to the basic operation of PCEP and so the requirements described in [RFC5440] Section 8.1. also apply to this document. In addition to those requirements a PCEP implementation may allow the configuration of the following parameters: [RFC5440] Section 8.1 (by default, per PCEP peer, etc.).
The configuration of the above parameters is applicable to the different sessions as described in
This document makes no change to the basic operation of PCEP and so the requirements described in [RFC5440] Section 8.2. also apply to this document. This document does not introduce any new ERO sub objects, so that the, ERO information model is already covered in [RFC4802].
This document makes no change to the basic operation of PCEP and so there are no changes to the requirements for liveness detection and monitoring set out in [RFC4657] and [RFC5440] Section 8.3.
This document makes no change to the basic operations of PCEP and considerations described in [RFC5440] Section 8.4. New errors defined by this document should satisfy the requirement to log error events.
No new Requirements on Other Protocols and Functional Components are made by this document. This document does not require ERO object extensions. Any new ERO subobject defined in the TEAS or CCAMP working group can be adopted without modifying the operations defined in this document.
This document makes no change to the basic operations of PCEP and considerations described in [RFC5440] Section 8.6. In addition to the limit on the rate of messages sent by a PCEP speaker, a limit MAY be placed on the size of the PCEP messages.
IANA assigns values to the PCEP objects and TLVs. IANA is requested to make some allocations for the newly defined objects and TLVs defined in this document. Also, IANA is requested to manage the space of flags that are newly added in the TLVs.
As described in Section 2.3, Section 2.4 and Section 2.5.1 new Objects types are defined. IANA is requested to make the following Object-Type allocations from the "PCEP Objects" sub-registry.
| Object Class | 5 |
| Name | BANDWIDTH |
| Object-Type | TBA-2: Generalized bandwidth |
| TBA-3: Generalized bandwidth of an existing TE-LSP for which a reoptimization is requested | |
| Reference | This document (Section 2.3) |
| Object Class | 14 |
| Name | LOAD-BALANCING |
| Object-Type | TBA-4: Generalized Load Balancing |
| Reference | This document (Section 2.4) |
| Object Class | 4 |
| Name | END-POINTS |
| Object-Type | TBA-5: Generalized Endpoint |
| Reference | This document (Section 2.5) |
IANA is requested to create a registry to manage the Endpoint Type field of the END-POINTS object, Object Type Generalized Endpoint and manage the code space.
New endpoint type in the Reserved range are assigned by Standards Action [RFC8126]. Each endpoint type should be tracked with the following attributes:
New endpoint type in the Experimental range are for experimental use; these will not be registered with IANA and MUST NOT be mentioned by RFCs.
The following values have been defined by this document. (Section 2.5.1, Table 5):
| Value | Type | Meaning |
|---|---|---|
| 0 | Point-to-Point | |
| 1 | Point-to-Multipoint | New leaves to add |
| 2 | Old leaves to remove | |
| 3 | Old leaves whose path can be modified/reoptimized | |
| 4 | Old leaves whose path has to be | |
| left unchanged | ||
| 5-244 | Unassigned | |
| 245-255 | Experimental range |
IANA manages the PCEP TLV code point registry (see [RFC5440]). This is maintained as the "PCEP TLV Type Indicators" sub-registry of the "Path Computation Element Protocol (PCEP) Numbers" registry. IANA is requested to do the following allocation. Note: TBA-11 is not used
| Value | Meaning | Reference |
|---|---|---|
| TBA-6 | IPV4-ADDRESS | This document (Section 2.5.2.1) |
| TBA-7 | IPV6-ADDRESS | This document (Section 2.5.2.2) |
| TBA-8 | UNNUMBERED-ENDPOINT | This document (Section 2.5.2.3) |
| TBA-9 | LABEL-REQUEST | This document (Section 2.5.2.4) |
| TBA-10 | LABEL-SET | This document (Section 2.5.2.5) |
| TBA-12 | PROTECTION-ATTRIBUTE | This document (Section 2.8) |
| TBA-1 | GMPLS-CAPABILITY | This document (Section 2.1.2) |
As described in Section 2.2 new flag are defined in the RP Object Flag IANA is requested to make the following Object-Type allocations from the "RP Object Flag Field" sub-registry.
| Bit | Description | Reference |
|---|---|---|
| TBA-13 | routing granularity (2 bits) | This document, Section 2.2 |
| (RG) |
As described in Section 3, new PCEP Error-Types and Error-values are defined. IANA is requested to make the following allocation in the "PCEP-ERROR Object Error Types and Values" registry.
| Error | name | Reference |
|---|---|---|
| Type=4 | Not supported object | [RFC5440] |
| Value=TBA-14: | Bandwidth Object type TBA-2 or TBA-3 not supported | This Document |
| Value=TBA-15: | Unsupported endpoint type in END-POINTS Generalized Endpoint object type | This Document |
| Value=TBA-16: | Unsupported TLV present in END-POINTS Generalized Endpoint object type | This Document |
| Value=TBA-17: | Unsupported granularity in the RP object flags | This Document |
| Type=10 | Reception of an invalid object | [RFC5440] |
| Value=TBA-18: | Bad Bandwidth Object type TBA-2(Generalized bandwidth) or TBA-3(Generalized bandwidth of existing TE-LSP for which a reoptimization is requested) | This Document |
| Value=TBA-20: | Unsupported LSP Protection Flags in PROTECTION-ATTRIBUTE TLV | This Document |
| Value=TBA-21: | Unsupported Secondary LSP Protection Flags in PROTECTION-ATTRIBUTE TLV | This Document |
| Value=TBA-22: | Unsupported Link Protection Type in PROTECTION-ATTRIBUTE TLV | This Document |
| Value=TBA-24: | LABEL-SET TLV present with 0 bit set but without R bit set in RP | This Document |
| Value=TBA-25: | Wrong LABEL-SET TLV present with 0 and L bit set | This Document |
| Value=TBA-26: | Wrong LABEL-SET with O bit set and wrong format | This Document |
| Value=TBA-42: | Missing GMPLS-CAPABILITY TLV | This Document |
| Type=TBA-27 | Path computation failure | This Document |
| Value=0 | Unassigned | This Document |
| Value=TBA-28: | Unacceptable request message | This Document |
| Value=TBA-29: | Generalized bandwidth value not supported | This Document |
| Value=TBA-30: | Label Set constraint could not be met | This Document |
| Value=TBA-31: | Label constraint could not be met | This Document |
As described in Section 2.9.1, new NO-PATH-VECTOR TLV Flag Fields have been defined. IANA is requested to do the following allocations in the "NO-PATH-VECTOR TLV Flag Field" sub-registry.
The "PCEP Parameters" registry contains a subregistry "IRO Subobjects" with an entry for the Include Route Object (IRO).
IANA is requested to add a further subobject that can be carried in the IRO as follows:
| Subobject | type | Reference |
|---|---|---|
| TBA-38 | Label subobject | This Document |
The "PCEP Parameters" registry contains a subregistry "XRO Subobjects" with an entry for the XRO object (Exclude Route Object).
IANA is requested to add a further subobject that can be carried in the XRO as follows:
| Subobject | type | Reference |
|---|---|---|
| TBA-39 | Label subobject | This Document |
IANA is requested to create a sub-registry to manage the Flag field of the GMPLS-CAPABILITY TLV within the "Path Computation Element Protocol (PCEP) Numbers" registry.
New bit numbers are to be assigned by Standards Action [RFC8126]. Each bit should be tracked with the following qualities:
The initial contents of the sub-registry are empty, with all bits marked unassigned
GMPLS controls multiple technologies and types of network elements. The LSPs that are established using GMPLS, whose paths can be computed using the PCEP extensions to support GMPLS described in this document, can carry a high volume of traffic and can be a critical part of a network infrastructure. The PCE can then play a key role in the use of the resources and in determining the physical paths of the LSPs and thus it is important to ensure the identity of PCE and PCC, as well as the communication channel. In many deployments there will be a completely isolated network where an external attack is of very low probability. However, there are other deployment cases in which the PCC-PCE communication can be more exposed and there could be more security considerations. Three main situations in case of an attack in the GMPLS PCE context could happen: [RFC8253] provides origin verification, message integrity and replay protection, and ensures that a third party cannot decipher the contents of a message.
The security mechanisms can provide authentication and confidentiality for those scenarios where the PCC-PCE communication cannot be completely trusted.
In order to protect against the malicious PCE case the PCC SHOULD have policies in place to accept or not the path provided by the PCE. Those policies can verify if the path follows the provided constraints. In addition, technology specific data plane mechanism can be used (following [RFC5920] Section 5.8) to verify the data plane connectivity and deviation from constraints.
The document [RFC8253] describes the usage of Transport Layer Security (TLS) to enhance PCEP security. The document describes the initiation of the TLS procedures, the TLS handshake mechanisms, the TLS methods for peer authentication, the applicable TLS ciphersuites for data exchange, and the handling of errors in the security checks. PCE and PCC SHOULD use [RFC8253] mechanism to protect against malicious PCC and PCE.
Finally, as mentioned by [RFC7025] the PCEP extensions to support GMPLS should be considered under the same security as current PCE work and this extension will not change the underlying security issues. However, given the critical nature of the network infrastructures under control by GMPLS, the security issues described above should be seriously considered when deploying a GMPLS-PCE based control plane for such networks. For more information on the security considerations on a GMPLS control plane, not only related to PCE/PCEP, [RFC5920] provides an overview of security vulnerabilities of a GMPLS control plane.
Elie Sfeir
Coriant
St Martin Strasse 76
Munich, 81541
Germany
Email: elie.sfeir@coriant.com
Franz Rambach
Nockherstrasse 2-4,
Munich 81541
Germany
Phone: +49 178 8855738
Email: franz.rambach@cgi.com
Francisco Javier Jimenez Chico
Telefonica Investigacion y Desarrollo
C/ Emilio Vargas 6
Madrid, 28043
Spain
Phone: +34 91 3379037
Email: fjjc@tid.es
Huawei Technologies
CTTC - Centre Tecnologic de Telecomunicacions de Catalunya
The research of Ramon Casellas, Francisco Javier Jimenez Chico, Oscar Gonzalez de Dios, Cyril Margaria, and Franz Rambach leading to these results has received funding from the European Community's Seventh Framework Program FP7/2007-2013 under grant agreement no 247674 and no 317999.
The authors would like to thank Julien Meuric, Lyndon Ong, Giada Lander, Jonathan Hardwick, Diego Lopez, David Sinicrope, Vincent Roca and Tianran Zhou for their review and useful comments to the document.
For example a request for one co-signaled n x VC-4 TE-LSP will not use the LOAD-BALANCING. In case the VC-4 components can use different paths, the BANDWIDTH with object type TBA-2 will contain a traffic specification indicating the complete n x VC-4 traffic specification and the LOAD-BALANCING the minimum co-signaled VC-4. For an SDH network, a request to have a TE-LSP group with 10 VC-4 containers, each path using at minimum 2 x VC-4 containers, can be represented with a BANDWIDTH object with OT=TBA-2, Bw Spec Type set to 4, the content of the Generalized Bandwidth is ST=6, RCC=0, NCC=0, NVC=10, MT=1. The LOAD-BALANCING, OT=TBA-4 with Bw Spec Type set to 4, Max-LSP=5, Min Bandwidth Spec is (ST=6, RCC=0, NCC=0, NVC=2, MT=1). The PCE can respond with a response with maximum 5 paths, each of them having a BANDWIDTH OT=TBA-2 and Generalized Bandwidth matching the Min Bandwidth Spec from the LOAD-BALANCING object of the corresponding request.