Domain Subobjects for Path Computation Element (PCE) Communication Protocol (PCEP). Huawei TechnologiesDivyashree Techno Park, WhitefieldBangaloreKarnataka560037Indiadhruv.ietf@gmail.comHuawei TechnologiesDivyashree Techno Park, WhitefieldBangaloreKarnataka560037Indiaudayasree.palle@huawei.comCTTCAv. Carl Friedrich Gauss n7CastelldefelsBarcelona 08860Spainramon.casellas@cttc.es
Routing
PCE Working GroupThe ability to compute shortest constrained Traffic Engineering Label Switched
Paths (TE LSPs) in Multiprotocol Label Switching (MPLS) and Generalized MPLS
(GMPLS) networks across multiple domains has been identified as a key requirement.
In this context, a domain is a collection of network elements within a common
sphere of address management or path computational responsibility such as an
Interior Gateway Protocol (IGP) area or an Autonomous System (AS). This document
specifies a representation and encoding of a Domain-Sequence, which is
defined as an ordered sequence of domains traversed to reach the destination domain
to be used by Path Computation Elements (PCEs) to compute inter-domain constrained shortest
paths across a predetermined sequence of domains . This document also
defines new subobjects to be used to encode domain identifiers. A Path Computation Element (PCE) may be used to compute end-to-end paths across multi-domain environments
using a per-domain path computation technique . The backward
recursive path computation (BRPC) mechanism
also defines a PCE-based path computation procedure to compute inter-domain constrained
path for (G)MPLS TE LSPs. However, both per-domain and BRPC techniques assume that the sequence
of domains to be crossed from source to destination is known, either fixed by the network
operator or obtained by other means. Also for inter-domain point-to-multi-point (P2MP)
tree computation, assumes the domain-tree is known
in priori.The list of domains (Domain-Sequence) in point-to-point (P2P) or a domain tree in
point-to-multipoint (P2MP) is usually a constraint in inter-domain path computation procedure.
The Domain-Sequence (the set of domains traversed to reach the destination domain)
is either administratively predetermined or discovered by some means like H-PCE. defines the Include Route Object (IRO) and the Explicit
Route Object (ERO). defines the Exclude Route Object (XRO)
and the Explicit Exclusion Route Subobject (EXRS).
The use of Autonomous System (AS)
(albeit with a 2-Byte AS number) as an abstract node representing a domain is defined
in . In the current document, we specify new subobjects to include or
exclude domains including IGP area or an Autonomous Systems (4-Byte as per
).Further, the domain
identifier may simply act as delimiter to specify where the domain boundary
starts and ends in some cases.This is a companion document to Resource ReserVation Protocol -
Traffic Engineering (RSVP-TE)
extensions for the domain identifiers .
The procedures described in this document are experimental. The experiment
is intended to enable research for the usage of Domain-Sequence at the PCEs
for inter-domain paths. For this purpose this document specifies new domain
subobjects as well as how they incorporate with existing subobjects to
represent a Domain-Sequence.The experiment will end two years after the RFC is published.
At that point, the RFC authors will attempt to determine how
widely this has been implemented and deployed.This document does not change the procedures for handling existing
subobjects in PCEP.The new subobjects introduced by this document will not be understood
by legacy implementations. If a legacy implementation receives one
of the subobjects that it does not understand in a PCEP object, the
legacy implementation will behave as described in .
Therefore,
it is assumed that this experiment will be conducted only when
both the PCE and the PCC form part of the experiment. It is
possible that a PCC or PCE can operate with peers some of which
form part of the experiment and some that do not. In this case,
since no capabilities exchange is used to identify which nodes
can use these extensions, manual configuration should be used to
determine which peerings form part of the experiment.When the result of implementation and deployment are available, this
document will be updated and refined, and then be moved from Experimental
to Standard Track.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 .The following terminology is used in this document.OSPF Area Border Router. Routers used to connect two IGP
areas.Autonomous System.Autonomous System Boundary Router.Boundary Node, Can be an ABR or ASBR.Backward Recursive Path ComputationAs per , any collection of
network elements within a common sphere of address management or path
computational responsibility. Examples of domains include Interior
Gateway Protocol (IGP) area and Autonomous System (AS).An ordered sequence of domains traversed
to reach the destination domain.Explicit Route ObjectHierarchical PCEInterior Gateway Protocol. Either of the two routing
protocols, Open Shortest Path First (OSPF) or Intermediate System to
Intermediate System (IS-IS).Include Route ObjectIntermediate System to Intermediate System.Open Shortest Path First.Path Computation Client: any client application
requesting a path computation to be performed by a Path Computation
Element.Path Computation Element. An entity (component,
application, or network node) that is capable of computing a network
path or route based on a network graph and applying computational
constraints.Point-to-MultipointPoint-to-PointResource Reservation ProtocolTraffic Engineering Label Switched Path.Exclude Route Object and define domain as a
separate administrative or geographic environment within the network. A
domain could be further defined as a zone of routing or computational ability.
Under these definitions a domain might be categorized as an AS or an IGP area.
Each AS can be made of several IGP areas. In order to encode a Domain-Sequence,
it is required to uniquely identify a domain in the Domain-Sequence. A domain can
be uniquely identified by area-id or AS number or both.A Domain-Sequence is an ordered sequence of domains traversed to reach
the destination domain. A Domain-Sequence can be applied as a constraint and carried in a path
computation request to PCE(s). A Domain-Sequence can also be the result
of a path computation. For example, in the case of Hierarchical PCE (H-PCE)
, Parent PCE could send the Domain-Sequence
as a result in a path computation reply. In a P2P path, the domains listed appear in the order that they are crossed.
In a P2MP path, the domain tree is represented as a list of Domain-Sequences. A Domain-Sequence enables a PCE to select the next domain and the PCE serving that domain to forward the path
computation request based on the domain information.Domain-Sequence can include Boundary Nodes
(ABR or ASBR) or Border links (Inter-AS-links) to be traversed
as an additional constraint. Thus a Domain-Sequence can be made up of one or more of -AS NumberArea IDBoundary Node IDInter-AS-Link AddressThese are encoded in the new subobjects defined in
this document as well as the existing subobjects to represent a Domain-Sequence.Consequently, a Domain-Sequence can be used: by a PCE in order to discover or select the next PCE in a collaborative
path computation, such as in BRPC ; by the Parent PCE to return the Domain-Sequence when unknown; this can
then be an input to the BRPC procedure ;by a Path Computation Client (PCC) or a PCE, to constrain the domains used in inter-domain path
computation, explicitly specifying which domains to be expanded or excluded;by a PCE in the per-domain path computation model
to identify the next domain.Domain-Sequence appears in PCEP messages, notably in - Include Route Object (IRO): As per ,
IRO can be used to specify a set of network elements to be traversed
to reach the destination, which includes subobjects used to
specify the Domain-Sequence.
Exclude Route Object (XRO): As per ,
XRO can be used to specify certain abstract nodes, to be excluded
from whole path, which includes subobjects used to
specify the Domain-Sequence.Explicit Exclusion Route Subobject (EXRS): As per
, EXRS can be used to specify exclusion of
certain abstract nodes (including domains) between a specific pair of nodes.
EXRS are a subobject inside the IRO. Explicit Route Object (ERO): As per ,
ERO can be used to specify a computed path in the network. For example,
in the case of H-PCE
, a Parent PCE can send the Domain-Sequence
as a result, in a path computation reply using ERO.As per , IRO (Include Route Object)
can be used to specify that the computed path needs to traverse a
set of specified network elements or abstract nodes.Some subobjects are defined in ,
, and
, but new subobjects related to
Domain-Sequence are needed.This document extends the support for
4-Byte AS numbers and IGP Areas.Note: The twins of these subobjects are carried in RSVP-TE messages as
defined in . already defines 2 byte AS number.To support 4 byte AS number as per
following subobject is defined: The L bit is an attribute of the subobject
as defined in and usage in IRO subobject
updated in .(TBD1 by IANA) indicating a 4-Byte AS Number.8 (Total length of the subobject in bytes).Zero at transmission, ignored at receipt.The 4-Byte AS Number. Note that if 2-Byte AS
numbers are in use, the low order bits (16 through 31) MUST be
used and the high order bits (0 through 15) MUST be set to zero. Since the length and format of Area-id is different for OSPF
and ISIS, following two subobjects are defined: For OSPF, the area-id is a 32 bit number. The subobject is encoded
as follows:The L bit is an attribute of the subobject as
defined in and usage in IRO subobject
updated in .(TBD2 by IANA) indicating a 4-Byte OSPF Area ID.8 (Total length of the subobject in bytes).Zero at transmission, ignored at receipt.The 4-Byte OSPF Area ID.For IS-IS, the area-id is of variable length and thus the length of
the Subobject is variable. The Area-id is as described in IS-IS by ISO
standard . The subobject is encoded as follows:The L bit is an attribute of the subobject as defined
in and usage in IRO subobject
updated in .(TBD3 by IANA) indicating IS-IS Area ID.Variable. The Length MUST be at least 8,
and MUST be a multiple of 4.Variable (Length of the actual (non-padded)
IS-IS Area Identifier in octets; Valid values are from 1 to 13 inclusive). Zero at transmission, ignored at receipt.The variable-length IS-IS area identifier.
Padded with trailing zeroes to a four-byte boundary. describes IRO as an optional object used to specify
network elements to be traversed by the computed path. It further
state that the L bit of such subobject has
no meaning within an IRO. It also did not mention if IRO is an ordered or
un-ordered list of subobjects. An update to IRO specification makes IRO as
an ordered list, as well as support for loose bit (L-bit) is added.The use of IRO for Domain-Sequence, assumes the updated specification for
IRO, as per .
The subobject type for IPv4, IPv6, and unnumbered
Interface ID can be used to specify
Boundary Nodes (ABR/ASBR) and Inter-AS-Links. The subobject type for the AS Number
(2 or 4 Byte) and the IGP Area are used to specify the domain identifiers in
the Domain-Sequence.The IRO can incorporate the new domain subobjects with the existing
subobjects in a sequence of traversal.Thus an IRO, comprising subobjects, that represents a Domain-Sequence,
define the domains involved in an inter-domain path computation, typically involving
two or more collaborative PCEs.A Domain-Sequence can have varying degrees of granularity. It is possible
to have a Domain-Sequence composed of, uniquely, AS identifiers. It is also
possible to list the involved IGP areas for a given AS.In any case, the mapping between domains and responsible PCEs is not
defined in this document. It is assumed that a PCE that needs to obtain a
"next PCE" from a Domain-Sequence is able to do so (e.g. via administrative
configuration, or discovery).A PCC builds an IRO to encode the Domain-Sequence, so that the
cooperating PCEs could compute an inter-domain shortest constrained path across the
specified sequence of domains. A PCC may intersperse Area and AS subobjects with other subobjects
without change to the previously specified processing of those
subobjects in the IRO.If a PCE receives an IRO in a
Path Computation request (PCReq) message that contains the subobjects
defined in this document, that it does not recognize,
it will respond according to the
rules for a malformed object as per . The PCE MAY
also include the IRO in the PCErr message as per .
The interpretation of Loose
bit (L bit) is as per section 4.3.3.1 of (as per ). In a Path Computation reply (PCRep), PCE MAY also supply IRO (with Domain-Sequence information)
with the NO-PATH object indicating
that the set of
elements (domains) of the request's IRO prevented the PCEs
from finding a path.The following processing rules apply for Domain-Sequence in IRO -
When a PCE parses an IRO, it interprets each subobject according
to the AS number associated with the preceding subobject. We call
this the "current AS". Certain subobjects modify the current AS,
as follows.
The current AS is initialized to the AS number of the PCC.If the PCE encounters an AS subobject, then it updates the current AS to this new AS number.If the PCE encounters an Area subobject, then it assumes that the area belongs to the current AS.If the PCE encounters an IP address that is globally routable, then it updates the current AS to the AS that owns this IP address. This document does not define how the PCE learns which AS owns the IP address.If the PCE encounters an IP address that is not globally routable, then it assumes that it belongs to the current AS.If the PCE encounters an unnumbered link, then it assumes that it belongs to the current AS.When a PCE parses an IRO, it interprets each subobject according
to the Area ID associated with the preceding subobject. We call
this the "current Area". Certain subobjects modify the current Area,
as follows.
The current Area is initialized to the Area ID of the PCC.If the current AS is changed, the current Area is reset and need to be determined again by current or subsequent subobject.If the PCE encounters an Area subobject, then it updates the current Area to this new Area ID.If the PCE encounters an IP address that belongs to a different area, then it updates the current Area to the Area that has this IP address. This document does not define how the PCE learns which Area has the IP address.If the PCE encounters an unnumbered link that belongs to a different area, then it updates the current Area to the Area that has this link.Otherwise, it assumes that the subobject belongs to the current Area.In case the current PCE is not responsible for the path computation in the current AS or Area, then the PCE selects the "next PCE" in the domain-sequence based on the current AS and Area.Note that it is advised that, PCC should use AS and Area subobject while building the domain-sequence in IRO and avoid using other mechanism to change the "current AS" and "current Area" as described above. The Exclude Route Object (XRO) is an optional
object used to specify exclusion of certain abstract nodes or resources
from the whole path.Some subobjects to be used in XRO as defined
in , , ,
and , but new subobjects related to Domain-Sequence
are needed.This document extends the support for 4-Byte
AS numbers and IGP Areas.
Note: The twins of these subobjects are carried in RSVP-TE messages as
defined in .
The new subobjects to support 4 byte AS and IGP (OSPF / ISIS) Area
MAY also be used in the XRO to specify exclusion of certain domains in
the path computation procedure.The X-bit indicates whether the exclusion is mandatory or desired. indicates that the AS specified MUST be excluded from the
path computed by the PCE(s).indicates that the AS specified SHOULD be avoided from the
inter-domain path computed by the PCE(s), but MAY be included subject to PCE
policy and the absence of a viable path that meets the other constraints.All other fields are consistent with the definition in .Since the length and format of Area-id is different for OSPF and ISIS,
following two subobjects are defined: For OSPF, the area-id is a 32 bit number. The subobject is encoded as
follows: The X-bit indicates whether the exclusion is mandatory or desired. indicates that the OSFF Area specified MUST be excluded
from the path computed by the PCE(s).indicates that the OSFF Area specified SHOULD be avoided
from the inter-domain path computed by the PCE(s), but MAY be included
subject to PCE policy and the absence of a viable path that meets the
other constraints.All other fields are consistent with the definition in .For IS-IS, the area-id is of variable length and thus the length of the
subobject is variable. The Area-id is as described in IS-IS by ISO standard
. The subobject is encoded as follows:The X-bit indicates whether the exclusion is mandatory or desired. indicates that the ISIS Area specified MUST be excluded
from the path computed by the PCE(s).indicates that the ISIS Area specified SHOULD be avoided
from the inter-domain path computed by the PCE(s), but MAY be included
subject to PCE policy and the absence of a viable path that meets the
other constraints.All other fields are consistent with the definition in .All the processing rules are as per .Note that, if a PCE receives an XRO in a
PCReq message that contains subobjects defined in this document, that it does not recognize,
it will respond according to the
rules for a malformed object as per .IGP Area subobjects in the XRO are local to the current AS. In case of multi-AS path computation to exclude an IGP area in a different AS,
IGP Area subobject should be part of Explicit Exclusion Route Subobject (EXRS) in the IRO to specify the AS in which the IGP area is to be excluded.
Further policy may be applied to prune/ignore Area subobjects in XRO after "current AS" change during path computation.EXRS is used to
specify exclusion of certain abstract nodes between a specific pair of nodes. The EXRS subobject can carry any of the subobjects defined for inclusion in
the XRO, thus the new subobjects to support 4 byte AS and IGP (OSPF / ISIS) Area
can also be used in the EXRS. The meanings of the fields of the new XRO subobjects
are unchanged when the subobjects are included in an EXRS, except that scope of
the exclusion is limited to the single hop between the previous and subsequent
elements in the IRO.The EXRS subobject should be interpreted in the context of the
current AS and current Area of the preceding subobject in the IRO.
The EXRS subobject does not change the current AS or current Area.
All other processing rules are as per .Note that, if a PCE that supports the EXRS in an IRO, parses an IRO, and
encounters an EXRS that contains subobjects defined in this document,
that it does not recognize, it will act according to the setting of
the X-bit in
the subobject as per .The Explicit Route Object (ERO) is used to specify
a computed path in the network. PCEP ERO subobject types correspond to RSVP-TE
ERO subobject types as defined in ,
, , ,
, and .
The subobjects related to Domain-Sequence are further defined in .The new subobjects to support 4 byte AS and IGP (OSPF / ISIS) Area
can also be used in the ERO to specify an abstract node (a group of
nodes whose internal topology is opaque to the ingress node of the LSP).
Using this concept of abstraction, an explicitly routed LSP can be
specified as a sequence of domains. In case of Hierarchical PCE , a Parent
PCE can be requested to find the Domain-Sequence. Refer example in
. The ERO in reply from parent PCE can then be
used in Per-Domain path computation or BRPC.If a PCC receives an ERO in a
PCRep message that contains subobject
defined in this document, that it does not recognize,
it will respond according to the
rules for a malformed object as per .The examples in this section are for illustration purposes only; to highlight
how the new subobjects could be encoded. They are not meant to be an
exhaustive list of all possible usecases and combinations.In an inter-area path computation where the ingress and the egress
nodes belong to different IGP areas within the same AS, the
Domain-Sequence could be represented using a ordered list of
Area subobjects. AS Number is 100.If the ingress is in Area 2, egress in Area 4 and transit through Area 0. Some possible way a PCC can encode the IRO: The Domain-Sequence can further include
encompassing AS information in the AS subobject.In inter-AS path computation, where ingress and egress belong to
different AS, the Domain-Sequence could be represented using an ordered
list of AS subobjects. The Domain-Sequence can further include
decomposed area information in the Area subobject.As shown in , where AS has a
single area,
AS subobject in the domain-sequence can uniquely identify the next domain and PCE.If the ingress is in AS A, egress in AS C and transit through AS B. Some possible way a PCC can encode the IRO: Note that to get a domain disjoint path, the ingress could also
request the backup path with -As described in , domain
subobject in IRO changes the domain information
associated with the next set of subobjects; till you encounter
a subobject that changes the domain too. Consider the following
IRO:On processing subobject "AS B", it changes the AS of the subsequent
subobjects till we encounter another subobject "AS C" which changes
the AS for its subsequent subobjects.Consider another IRO: Here as well, on processing "AS D", it changes the AS of the
subsequent subobjects till you encounter another subobject "C3"
which belong in another AS and
changes the AS for its subsequent subobjects.Further description for the Boundary Node and Inter-AS-Link can be found in .In , AS 200 is made up of
multiple areas.For LSP (A-B), where ingress A is in (AS 100, Area 0), egress B in (AS 200, Area 4) and transit through (AS 200, Area 0). Some possible way a PCC can encode the IRO: For LSP (A-C), where ingress A is in (AS 100, Area 0), egress C in (AS 200, Area 5) and transit through (AS 200, Area 0). Some possible way a PCC can encode the IRO: A PCC or PCE can include additional constraints covering which Boundary
Nodes (ABR or ASBR) or Border links (Inter-AS-link) to be traversed
while defining a Domain-Sequence. In which case the Boundary Node or
Link can be encoded as a part of the Domain-Sequence. Boundary Nodes (ABR / ASBR) can be encoded using the IPv4 or
IPv6 prefix subobjects usually the loopback address of 32 and
128 prefix length respectively. An Inter-AS link can be encoded
using the IPv4 or IPv6 prefix subobjects or unnumbered interface
subobjects. For , an ABR (say 203.0.113.1) to be traversed can be specified in IRO as:For , an inter-AS-link (say 198.51.100.1 - 198.51.100.2) to be traversed can be specified as:A single PCE can be responsible for multiple domains; for example
PCE function deployed on an ABR could be responsible for multiple areas.
A PCE which can support adjacent
domains can internally handle those domains in the Domain-Sequence without any impact on
the other domains in the Domain-Sequence. describes an experimental inter-domain P2MP
path computation mechanism where the path domain tree is described as
a series of Domain-Sequences, an example is shown in the below
figure:The domain tree can be represented as a series of domain-sequence - Domian D1, Domian D3, Domian D6Domian D1, Domian D3, Domian D5Domian D1, Domian D2, Domian D4The domain sequence handling described in this document could be applied to P2MP path domain tree. In case of H-PCE , the
parent PCE can be requested to
determine the Domain-Sequence and return it in the path computation reply,
using the ERO. .
For the example in section 4.6 of ,
the Domain-Sequence can possibly appear as:Instead of a Domain-Sequence, a sequence of PCEs MAY be enforced
by policy on the PCC, and this constraint can be carried in the
PCReq message (as defined in ).Note that PCE-Sequence can be used along with Domain-Sequence
in which case PCE-Sequence MUST have higher precedence in selecting
the next PCE in the inter-domain path computation procedures. already describes the notion of abstract
nodes, where an abstract node is a group of nodes whose internal
topology is opaque to the ingress node of the LSP. It further
defines a subobject for AS but with a 2-Byte AS Number. extends the notion of abstract
nodes by adding new subobjects for IGP Areas and 4-byte AS numbers.
These subobjects can be included in Explicit Route Object (ERO),
Exclude Route object (XRO) or Explicit Exclusion Route Subobject
(EXRS) in RSVP-TE.In any case subobject type defined in RSVP-TE are identical
to the subobject type defined in the related documents in PCEP.IANA maintains the "Path Computation Element Protocol (PCEP) Numbers"
at <http://www.iana.org/assignments/pcep>. Within this
registry IANA maintains two sub-registries:
IRO Subobjects (see IRO Subobjects at
http://www.iana.org/assignments/pcep)XRO Subobjects (see XRO Subobjects at
http://www.iana.org/assignments/pcep)Upon approval of this document, IANA is requested to make identical additions to these registries as
follows:Further upon approval of this document, IANA is requested to add a
reference to this document to the new RSVP numbers that are registered by
.The protocol extensions defined in this document do not substantially
change the nature of PCEP. Therefore, the security considerations
set out in apply unchanged. Note that further security
considerations for the use of PCEP over TCP are presented in
. This document specifies a representation of Domain-Sequence
and new subobjects, which could be used in inter-domain PCE scenarios as
explained in , ,
, etc. The
security considerations set out in each of these mechanisms remain unchanged
by the new subobjects and Domain-Sequence representation in this document. But the new subobjects do allow finer and more specific control
of the path computed by a cooperating PCE(s). Such control increases the
risk if a PCEP message is intercepted, modified, or spoofed because it
allows the attacker to exert control over the path that the PCE will
compute or to make the path computation impossible. Consequently, it is important that implementations
conform to the relevant security requirements of .
These mechanisms include:
Securing the PCEP session messages using TCP
security techniques (Section 10.2 of ).
PCEP implementations SHOULD also consider the additional security
provided by the TCP Authentication Option (TCP-AO)
or .Authenticating the PCEP messages to ensure the
message is intact and sent from an authorized node (Section 10.3
of ).PCEP operates over TCP, so it is also important to secure the PCE and
PCC against TCP denial-of-service attacks. Section 10.7.1 of
outlines a number of mechanisms for minimizing the risk of
TCP-based denial-of-service attacks against PCEs and PCCs.In inter-AS scenarios,
attacks may be particularly significant with commercial as well as
service-level implications.Note, however, that the Domain-Sequence mechanisms also provide
the operator with the ability to route around vulnerable parts of
the network and may be used to increase overall network security.The exact behaviour with regards to desired inclusion and exclusion of
domains MUST be available for examination by an operator and MAY be
configurable. Manual configurations
is needed to identify which PCEP peers understand the new domain
subobjects defined in this document.A MIB module for management of the PCEP is being specified in a
separate document . This document does not
imply any new extension to the current MIB module. Mechanisms defined in this document do not imply any new liveness
detection and monitoring requirements in addition to those already
listed in .Mechanisms defined in this document do not imply any new operation
verification requirements in addition to those already listed in
.In case of per-domain path computation ,
where the full path of an inter-domain TE LSP cannot be, or is not
determined at the ingress node, a signaling message can use
the domain identifiers. The Subobjects defined in this document
SHOULD be supported by RSVP-TE.
extends the notion of abstract nodes by adding new subobjects
for IGP Areas and 4-byte AS numbers.Apart from this, mechanisms defined in this document do not
imply any requirements on other protocols in addition to those
already listed in .The mechanisms described in this document can provide
the operator with the ability to exert finer and more specific control
of the path computation by inclusion or exclusion of
domain subobjects. There may be some scaling benefit when a single
domain subobject may substitute for many subobjects and can reduce the
overall message size and processing.Backward compatibility issues associated with the new subobjects arise
when a PCE does not recognize them, in which case PCE responds
according to the rules for a malformed object as per .
For successful operations
the PCEs in the network would need to be upgraded.Authors would like to especially thank Adrian Farrel for his detailed
reviews as well as providing text to be included in the document. Further, we would like to thank Pradeep Shastry,
Suresh Babu, Quintin Zhao, Fatai Zhang, Daniel King, Oscar Gonzalez,
Chen Huaimo, Venugopal Reddy, Reeja Paul, Sandeep Boina, Avantika
Sergio Belotti and Jonathan Hardwick for their useful comments and suggestions.Thanks to Jonathan Hardwick for shepherding this document.Thanks to Deborah Brungard for being the Responsible AD.Thanks to Amanda Baber for IANA Review.Thanks to Joel Halpern for Gen-ART Review.Thanks to Klaas Wierenga for SecDir Review.Thanks to Spencer Dawkins and Barry Leiba for comments during the IESG Review.
Intermediate system to Intermediate system routing information
exchange protocol for use in conjunction with the Protocol for
providing the Connectionless-mode Network Service (ISO
8473)
ISOUpdate to Include Route Object
(IRO) specification in Path Computation Element communication
Protocol (PCEP. (draft-ietf-pce-iro-update-02)Domain Subobjects for Resource ReserVation Protocol - Traffic Engineering (RSVP-TE). (draft-ietf-teas-rsvp-te-domain-subobjects-04)Secure Transport for PCEP
The Path Computation Element Communication Protocol (PCEP) defines the mechanisms for the communication between a Path Computation Client (PCC) and a Path Computation Element (PCE), or among PCEs. This document describe the usage of Transport Layer Security (TLS) to enhance PCEP security, hence the PCEPS acronym proposed for it. The additional security mechanisms are provided by the transport protocol supporting PCEP, and therefore they do not affect the flexibility and extensibility of PCEP.