PCE Working Group A. Wang Internet-Draft China Telecom Intended status: Standards Track B. Khasanov Expires: March 18, 2021 S. Fang R. Tan Huawei Technologies,Co.,Ltd C. Zhu ZTE Corporation September 14, 2020 PCEP Extension for Native IP Network draft-ietf-pce-pcep-extension-native-ip-08 Abstract This document defines the Path Computation Element Communication Protocol (PCEP) extension for Central Control Dynamic Routing (CCDR) based application in Native IP network. The scenario and framework of CCDR in native IP is described in [RFC8735] and [I-D.ietf-teas-pce-native-ip]. This draft describes the key information that is transferred between Path Computation Element (PCE) and Path Computation Clients (PCC) to accomplish the End to End (E2E) traffic assurance in Native IP network under central control mode. Status of This Memo 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 March 18, 2021. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. Wang, et al. Expires March 18, 2021 [Page 1] Internet-Draft PCEP Extension for Native IP Network September 2020 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions used in this document . . . . . . . . . . . . . . 3 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. STATEFUL-PCE-CAPABILITY TLV . . . . . . . . . . . . . . . . . 3 5. PCE-Initiated Native IP TE Procedures . . . . . . . . . . . . 4 6. New Objects Extension . . . . . . . . . . . . . . . . . . . . 4 7. Objects Formats . . . . . . . . . . . . . . . . . . . . . . . 4 7.1. BGP Peer Info Object . . . . . . . . . . . . . . . . . . 5 7.2. Explicit Peer Route Object . . . . . . . . . . . . . . . 9 7.3. Peer Prefix Association Object . . . . . . . . . . . . . 13 8. New Error-Types and Error-Values Defined . . . . . . . . . . 16 9. Management Consideration . . . . . . . . . . . . . . . . . . 17 10. Security Considerations . . . . . . . . . . . . . . . . . . . 18 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 11.1. PCEP Object Types . . . . . . . . . . . . . . . . . . . 18 12. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 18 13. Normative References . . . . . . . . . . . . . . . . . . . . 18 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 1. Introduction Traditionally, Multiprotocol Label Switching Traffic Engineering (MPLS-TE) requires the corresponding network devices support Multiprotocol Label Switching (MPLS) or Resource ReSerVation Protocol (RSVP)/Label Distribution Protocol (LDP) technologies to assure the End-to-End (E2E) traffic performance. But in native IP network, there will be no such signaling protocol to synchronize the action among different network devices. It is necessary to use the central control mode that described in [RFC8283] to correlate the forwarding behavior among different network devices. Draft [I-D.ietf-teas-pce-native-ip] describes the architecture and solution philosophy for the E2E traffic assurance in Native IP network via Dual/Multi Border Gateway Protocol (BGP) solution. This draft describes the corresponding Path Computation Element Communication Protocol (PCEP) extensions to transfer the key information about peer Wang, et al. Expires March 18, 2021 [Page 2] Internet-Draft PCEP Extension for Native IP Network September 2020 address list, peer prefix association and the explicit peer route on on-path routers. 2. 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]. 3. Terminology This document uses the following terms defined in [RFC5440]: PCE, PCEP The following terms are defined in this document: o CCDR: Central Control Dynamic Routing o E2E: End to End o BPI: BGP Peer Info o EPR: Explicit Peer Route o PPA: Peer Prefix Association o QoS: Quality of Service 4. STATEFUL-PCE-CAPABILITY TLV The format of STATEFUL-PCE-CAPABILITY is defined in [RFC8231] and included here for easy reference with the addition of the new N flag. The right bits of N flag have been defined by other RFC documents. 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=4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags |N|*|*|*|*|*|*|I|S|U| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+ Figure 1: STATEFUL-PCE-CAPABILITY TLV Format A new flag is defined to indicate the sender's support for traffic engineering in Native IP network. The newly defined PCEP Objects and its proceeding procedures, as stated in Section 6 MUST be supported by PCC or PCE when this flag is set. Wang, et al. Expires March 18, 2021 [Page 3] Internet-Draft PCEP Extension for Native IP Network September 2020 N( NATIVE-IP-TE-CAPABILITY-----1 bit): If set to 1 by a PCC/PCE, the N flag indicate that the PCC/PCE can support the traffic engineering in Native IP network. The NATIVE-IP-TE-CAPABILITY flag MUST be set by both the PCC and PCE in order to enable PCE-initiated Native IP traffic engineering. 5. PCE-Initiated Native IP TE Procedures PCE-Initated Native IP TE solution utilizing the existing PCE LSP Initate Request message(PCInitiate)[RFC8281], PCE Report message(PCRpt) [RFC8281]and PCE Update message(PCUpd)[RFC8281] to accomplish the multi BGP sessions establishment, end to end TE path deployment, and route prefixes advertisement among different BGP sessions. There is no label switch path within the Native IP environment, but there exist end to end forwarding path that assigned to the priority traffic. Such path can be identified by the PLSP-ID that defined in Label Switched Path(LSP) object [RFC8231]_. _The PLSP-ID is assigned by each PCC, based on the Symbolic Path Name TLV in the LSP object that from PCInitiate message. The Symbolic Path Name TLV can be used to identify the end to end TE path in Native IP environment. The association of Symbolic Path Name and each PLSP-ID in every PCC assures the TE policies are assigned end to end in the network. 6. New Objects Extension Three new objects are defined in this draft: o BPI Object: BGP Peer Info Object, used to indicate the PCC which BGP peer it should be peered with dynamically. o EPR Object: Explicit Peer Route object, used to indicate the PCC which route should be taken into to arrive to the peer. o PPA Object: Peer Prefix Association Object, used to indicate the PCC which prefixes should be advertised via the corresponding BGP peer. 7. Objects Formats Each extension object takes the similar format, that is to say, it began with the common object header defined in [RFC5440] as the following: Wang, et al. Expires March 18, 2021 [Page 4] Internet-Draft PCEP Extension for Native IP Network September 2020 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Object-Class | OT |Res|P|I| Object Length(bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | (Object body) | // // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: PCEP Object Format Different object-class, object type and the corresponding object body is defined separately in the following sections. 7.1. BGP Peer Info Object The BGP Peer Info object is used to specify the information about the peer that the PCC should establish the BGP relationship with. This object should only be included and sent to the head and end router of the E2E path in case there is no Route Reflection (RR) involved. If the RR is used between the head and end routers, then such information should be sent to head router, RR and end router respectively. By default, there MUST be no prefix be distributed via such BGP session that established by this object. By default, the Local/Peer IP address SHOULD be dedicated to the usage of native IP TE solution, and SHOULD not be used by other BGP sessions that established by manual or non PCE initiated configuration. BGP Peer Info Object-Class is TBD BGP Peer Info Object-Type is 1 for IPv4 and 2 for IPv6 The format of the BGP Peer Info object body for IPv4(Object-Type=1) is as follows: Wang, et al. Expires March 18, 2021 [Page 5] Internet-Draft PCEP Extension for Native IP Network September 2020 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Peer AS Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ETTL | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Local IP Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Peer IP Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Additional TLVs | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: BGP Peer Info Object Body Format for IPv4 The format of the BGP Peer Info object body for IPv6(Object-Type=2) 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Peer AS Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ETTL | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | Local IP Address (16 bytes) | + + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | Peer IP Address (16 bytes) | + + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Additional TLVs | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: BGP Peer Info Object Body Format for IPv6 Peer AS Number: 4 Bytes, to indicate the AS number of Remote Peer. Wang, et al. Expires March 18, 2021 [Page 6] Internet-Draft PCEP Extension for Native IP Network September 2020 ETTL: 1 Bytes, to indicate the multi hop count for EBGP session. It should be 0 and ignored when Local AS and Peer AS is same. Reserved: Bits reserved for future use. Local IP Address(4/16 Bytes): IP address of the local router, used to peer with other end router. When Object-Type is 1, length is 4 bytes; when Object-Type is 2, length is 16 bytes. Peer IP Address(4/16 Bytes): IP address of the peer router, used to peer with the local router. When Object-Type is 1, length is 4 bytes; when Object-Type is 2, length is 16 bytes; Additional TLVs: TLVs that associated with this object, can be used to convey other necessary information for dynamic BGP session establishment. Its definition is out of the current document. The detail procedures for the usage of this object is shown below(PCInitiate and PCRpt message pair, other message pairs are similar) The PCInitiate message should be sent to R1(M1), R3(M2 & M3) and R7(M4) when R3 acts as RR. Wang, et al. Expires March 18, 2021 [Page 7] Internet-Draft PCEP Extension for Native IP Network September 2020 M2 PCInitiate Message: M3 PCInitiate Message: PLSP-ID=X3(Symbolic Path Name=Class A) PLSP-ID=X3(Symbolic Path Name=Class A) BPI Object(Local IP=R3_A, Peer IP=R1_A) BPI Object(Local IP=R3_A, Peer IP=R7_A) M2-R PCRpt Message: M3-R PCRpt Message: PLSP-ID=X3 PLSP-ID=X3 BPI Object(Local IP=R3_A, Peer IP=R1_A) BPI Object(Local IP=R3_A, Peer IP=R7_A) ^ ^ | | +------------------------------------^------------------+ | | | | +------------------+ M1 PCInitiate Message: +----------+ PCE +-----------+ PLSP-ID=X1(Symbolic Path Name=Class A) | | +--------^---------+ | BPI Object(Local IP=R1_A, Peer IP=R3_A) | | | | | | | | <------+ +-------------+ +---+ M1-R PCRpt Message: | | | | PLSP-ID=X1 | +v-+ | | BPI Object(Local IP=R1_A, Peer IP=R3_A +------------------+R3+-------------------+ | ) | +--+ | | | | | +v-+ +--+ +--+ +-v+ | |R1+----------+R5+----------+R6+---------+R7| | ++-+ +--+ +--+ +-++ | M4 PCInitiate Message: | | | PLSP-ID=X7(Symbolic Path Name=Class A) | | | BPI Object(Local IP=R7_A,Peer IP=R3_A) | +--+ +--+ | | +------------+R2+----------+R4+-----------+ | | M4-R PCRpt Message: | PLSP-ID=X7 <----------------------------------------------------+ BPI Object(Local IP=R3_A, Peer IP=R1_A) Figure 5: BGP Peer Establishment Procedures(R3 act as RR) When PCC receives this object with the R bit set to 0 in SRP object in PCInitiate message, the PCC should try to establish the BGP session with the indicated Peer AS and Local/Peer IP address. When PCC creates successfully the BGP session that is indicated by the associated information, it should report the result via the PCRpt messages, with this object included, and the corresponding SRP and LSP object. Wang, et al. Expires March 18, 2021 [Page 8] Internet-Draft PCEP Extension for Native IP Network September 2020 When PCC receives this object with the R bit set to 1 in SRP object in PCInitiate message, the PCC should clear the BGP session that indicated by Local/Peer IP address. When PCC clears successfully the specified BGP session, it should report the result via the PCRpt message, with this object included, and the corresponding SRP and LSP object. When PCC receives this object with the LSP object in PCE Update message, the PCC should update the BGP session that identified by the PLSP-ID with the updated information contained in this object. When PCC updates successfully the BGP session that is indicated by the PLSP-ID, it should report the result via the PCRpt message, with this object included, and the corresponding SRP and LSP object. Upon PCC can't build the BGP session that required by this object, it should report the error values with the newly defined error type and error value, which is indicated in Section 8 7.2. Explicit Peer Route Object The Explicit Peer Route object is defined to specify the explicit peer route to the corresponding peer address on each device that is on the E2E assurance path. This Object should be sent to all the devices that locates on the E2E assurance path that calculated by PCE. The path established by this object should have higher priority than other path calculated by dynamic IGP protocol, but should be lower priority that the static route configured by manual or NETCONF channel. Explicit Peer Route Object-Class is TBD. Explicit Peer Route Object-Type is 1 for IPv4 and 2 for IPv6 The format of Explicit Peer Route object body for IPv4(Object-Type=1) is as follows: Wang, et al. Expires March 18, 2021 [Page 9] Internet-Draft PCEP Extension for Native IP Network September 2020 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Route Priority | Resv. | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 Peer Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Next Hop Address to the IPv4 Peer Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6: Explicit Peer Route Object Body Format for IPv4 The format of Explicit Peer Route object body for IPv6(Object-Type=2) 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Route Priority | Resv. | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | IPv6 Peer Address | + + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | Next Hop Address to the IPv6 Peer Address | + + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7: Explicit Peer Route Object Body Format for IPv6 Route Priority: 2 Bytes, The priority of this explicit route. The higher priority should be preferred by the device. Resv.: Bit reserved for future use. Peer Address: To indicate the peer address. Next Hop Address to the Peer: To indicate the next hop address to the corresponding peer. Wang, et al. Expires March 18, 2021 [Page 10] Internet-Draft PCEP Extension for Native IP Network September 2020 The detail procedures for the usage of this object is shown below(PCInitiate and PCRpt message pair, other message pairs are similar) For explicit route from R1 to R7, the PCIniitate message should be sent to R1(M1), R2(M2) and R4(M3). +------------------+ M1 PCInitiate Message: +----------+ PCE +-----------+ PLSP-ID=X1(Symbolic Path Name=Class A) | +----^---^---^-----+ | EPR Object(Peer Address=R7_A | | | | | Next Hop=R2_A) | | | | | | | | | | M1-R PCRpt Message: <---------------+ | | | | PLSP-ID=X1 | | +v-+ | | EPR Object(Peer Address=R7_A +------------+ +---+R3+-------------------+ ) Next Hop=R2_A) | | +--+ | | | | | | +v-+ +--+ | | +--+ +-v+ |R1+------+R5++ +----------------+R6+----+R7| ++-+ +--+ | | +--+ +-++ | | | | M2 PCInitiate Message | +---+ +---+ | PLSP-ID=X2(Symbolic Path Name=Class A) | +v-+ | | +v-+ | EPR Object(Peer Address=R7_A +----------+R2+-+ +--------+R4+-----------+ Next Hop=R4_A) | | | | M2-R PCRpt Message | | PLSP-ID=X2(Symbolic Path Name=Class A) <----------------------+ | EPR Object(Peer Address=R7_A | Next Hop=R4_A) | v M3 PCInitiate Message PLSP-ID=X4(Symbolic Path Name=Class A) EPR Object(Peer Address=R7_A Next Hop=R7_A) M3-R PCRpt Message PLSP-ID=X4(Symbolic Path Name=Class A) EPR Object(Peer Address=R7_A Next Hop=R7_A) Figure 8: Explicit Route Establish Procedures(From R1 to R7) For explicit route from R7 to R1, the PCIniitate message should be sent to R7(M1), R4(M2) and R2(M3). Wang, et al. Expires March 18, 2021 [Page 11] Internet-Draft PCEP Extension for Native IP Network September 2020 -------------------------------------------------------------------------+ | | v +------------------+ | M1 PCInitiate Message: +----------+ PCE +-----+-----+ PLSP-ID=X7(Symbolic Path Name=Class A) | +----^---^---^-----+ | EPR Object(Peer Address=R1_A | | | | | Next Hop=R4_A) | | | | | | | | | | M1-R PCRpt Message: | | | | | PLSP-ID=X7 | | +v-+ | | EPR Object(Peer Address=R1_A +------------+ +---+R3+-------------------+ ) Next Hop=R4_A) | | +--+ | | | | | | +v-+ +--+ | | +--+ +-v+ |R1+------+R5++ +----------------+R6+----+R7| ++-+ +--+ | | +--+ +-++ | | | | M3 PCInitiate Message | +---+ +---+ | PLSP-ID=X2(Symbolic Path Name=Class A) | +v-+ | | +v-+ | EPR Object(Peer Address=R1_A +----------+R2+-+ +--------+R4+-----------+ Next Hop=R1_A) | | | | M3-R PCRpt Message | | PLSP-ID=X2(Symbolic Path Name=Class A) <----------------------+ | EPR Object(Peer Address=R1_A | Next Hop=R1_A) | v M2 PCInitiate Message PLSP-ID=X4(Symbolic Path Name=Class A) EPR Object(Peer Address=R1_A Next Hop=R2_A) M2-R PCRpt Message PLSP-ID=X4(Symbolic Path Name=Class A) EPR Object(Peer Address=R1_A Next Hop=R2_A) Figure 9: Explicit Route Establish Procedures(From R7 to R1) When PCC receives this object with the R bit set to 0 in SRP object in PCInitiate message, the PCC should install the explicit route to the the peer. When PCC install successfully the explicit route to the peer, it should report the result via the PCRpt messages, with this object included, and the corresponding SRP and LSP object. Wang, et al. Expires March 18, 2021 [Page 12] Internet-Draft PCEP Extension for Native IP Network September 2020 When PCC receives this object with the R bit set to 1 in SRP object in PCInitiate message, the PCC should clear the explicit route to the peer that indicated by this object. When PCC clear successfully the explicit route that indicated by this object, it should report the result via the PCRpt message, with this object included, and the corresponding SRP and LSP object. When PCC receives this object in PCUpd message, the PCC should update the explicit route according to info indicated in this object. When PCC updates the path successfully, it should report the result via the PCRpt message, with this object included, and the corresponding SRP and LSP object. Upon the error occurs, the PCC SHOULD send the corresponding error information that defined in Section 8 7.3. Peer Prefix Association Object The Peer Prefix Association object is defined to specify the IP prefixes that should be advertised to the corresponding peer. This object should only be included and sent to the head/end router of the end2end path. The prefixes information included in this object MUST only be advertised to the indicated peer, MUST not be advertised to other BGP peers. Peer Prefix Association Object-Class is TBD Peer Prefix Association Object-Type is 1 for IPv4 and 2 for IPv6 The format of the Peer Prefix Association object 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Peer IPv4 Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // IPv4 Prefix subobjects // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 10: Peer Prefix Association Object Body Format for IPv4 Wang, et al. Expires March 18, 2021 [Page 13] Internet-Draft PCEP Extension for Native IP Network September 2020 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Peer IPv6 Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // IPv6 Prefix subobjects // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 11: Peer Prefix Association Object Body Format for IPv6 Peer IPv4 Address: 4 Bytes. Identifies the peer IPv4 address that the associated prefixes will be sent to. IPv4 Prefix subojects: List of IPv4 Prefix subobjects that defined in [RFC3209], identify the prefixes that will be sent to the peer that identified by Peer IPv4 Address List. Peer IPv6 Address: 16 Bytes. Identifies the peer IPv6 address that the associated prefixes will be sent to. IPv6 Prefix subojects: List of IPv6 Prefix subobjects that defined in [RFC3209], identify the prefixes that will be sent to the peer that identified by Peer IPv6 Address List. The detail procedures for the usage of this object is shown below(PCInitiate and PCRpt message pair, other message pairs are similar) The PCInitiate message should be sent to R1(M1) and R7(M2) respectively. Wang, et al. Expires March 18, 2021 [Page 14] Internet-Draft PCEP Extension for Native IP Network September 2020 M2 PCInitiate Message: PLSP-ID=X7(Symbolic Path Name=Class A) PPA Object(Peer IP=R1_A, Prefix=7_A) <-----+ M2-R PCRpt Message: | PLSP-ID=X7 | PPA Object(Peer IP=R1_A, Prefix=7_A) | | | | +------------------+ | M1 PCInitiate Message: +----------+ PCE +-----------+ | PLSP-ID=X1(Symbolic Path Name=Class A) | +------------------+ | | PPA Object(Peer IP=R7_A, Prefix=1_A) | | | | | | <----------+ +---+ M1-R PCRpt Message: | | PLSP-ID=X1 | +--+ | PPA Object(Peer IP=R7_A,Prefix=1_A) +------------------+R3+-------------------+ ) | +--+ | | | +v-+ +--+ +--+ +-v+ |R1+----------+R5+----------+R6+---------+R7| ++-+ +--+ +--+ +-++ | | | | | +--+ +--+ | +------------+R2+----------+R4+-----------+ Figure 12: BGP Prefix Advertisement Procedures When PCC receives this object with the R bit set to 0 in SRP object in PCInitiate message, the PCC should send the prefixes indicated in this object to the appointed BGP peer. When PCC sends successfully the prefixes to the appointed BGP peer, it should report the result via the PCRpt messages, with this object included, and the corresponding SRP and LSP object. When PCC receives this object with the R bit set to 1 in SRP object in PCInitiate message, the PCC should withdraw the prefixes advertisement to the peer that indicated by this object. When PCC withdraws successfully the prefixes that indicated by this object, it should report the result via the PCRpt message, with this object included, and the corresponding SRP and LSP object. Wang, et al. Expires March 18, 2021 [Page 15] Internet-Draft PCEP Extension for Native IP Network September 2020 When PCC receives this object in PCUpd message, it should update the BGP routes advertised to the associated peer. When PCC updates the advertised BGP routes successfully, it should report the result via the PCRpt message, with this object included, and the corresponding SRP and LSP object. The IPv4 prefix MUST only be advertised via the IPv4 BGP session and the IPv6 prefix MUST only be advertised via the IPv6 BGP session. If mismatch occur, an error should be reported. When the peer info that associated with the PLSP-ID is not the same as the peer info that indicated in this object in PCC, a error should be reported via the PCRpt message. Upon the error occurs, the PCC SHOULD send the corresponding error information that defined in Section 8 The object type of the above three objects should be identical to assure the prefixes from one address family are advertised via the peer belong to same address family, and the traffic is forwarded to the next hop also belong to same address family. If the mismatch occur, the error should be reported to the PCE. For one PLSP-ID on the PCC, the object type of PAL object should be equal to object type of PPA object. If not, the mismatch occurs and the related error should be reported. 8. New Error-Types and Error-Values Defined A PCEP-ERROR object is used to report a PCEP error and is characterized by an Error-Type that specifies that type of error and an Error-value that provides additional information about the error. An additional Error-Type and several Error-values are defined to represent some the errors related to the newly defined objects, which are related to Native IP TE procedures. Wang, et al. Expires March 18, 2021 [Page 16] Internet-Draft PCEP Extension for Native IP Network September 2020 +============+===============+==============================+ | Error-Type | Meaning | Error-value | +============+===============+==============================+ | TBD | Native IP | | | | TE failure | | +------------+---------------+------------------------------+ | | | 0: Unassigned | +------------+---------------+------------------------------+ | | | 1: Peer AS not match | +------------+---------------+------------------------------+ | | | 2: Peer IP can't be reached | +------------+---------------+------------------------------+ | | | 3: Peer Address mismatch | +------------+---------------+------------------------------+ | | | 4: PAL/PPA Object AF mismatch| +------------+---------------+------------------------------+ | | | 5: PAL/EPR Object AF mismatch| +------------+---------------+------------------------------+ | | | 6: PPA/EPR object AF mismatch| +------------+---------------+------------------------------+ | | | 7: | +------------+---------------+------------------------------+ | | | 8: | +------------+---------------+------------------------------+ | | | 9: | +------------+---------------+------------------------------+ Figure 13: Newly defined Error-Type and Error-Value 9. Management Consideration The information transferred in this draft is mainly used for the light weight BGP session setup, explicit route deployment and the prefix distribution. The planning, allocation and distribution of the peer addresses within IGP should be accomplished in advanced and they are out of the scope of this draft. [RFC8232] describes the state synchronization procedure between stateful PCE and PCC. The communication of PCE and PCC described in this draft should also follow this procedures, treat the three newly defined objects that associated with the same symbolic path name as the attribute of the same path in the LSP-DB. When PCE detects one or some of the PCCs are out of control, it should recompute and redeploy the traffic engineering path for native IP on the active PCCs. When PCC detects that it is out of control of the PCE, it should clear the information that initiated by the PCE. The PCE should assures the avoidance of possible transient loop in such node failure when it deploy the explicit peer route on the PCCs. Wang, et al. Expires March 18, 2021 [Page 17] Internet-Draft PCEP Extension for Native IP Network September 2020 10. Security Considerations Service provider should consider the protection of PCE and their communication with the underlay devices, which is described in document [RFC5440] and [RFC8253] 11. IANA Considerations 11.1. PCEP Object Types IANA is requested to allocate new registry for the PCEP Object Type: Object-Type Value Name Reference TBD BGP Peer Info This document Object-Type 1: IPv4 address 2: IPv6 address TBD Explicit Peer Route This document Object-Type 1: IPv4 address 2: IPv6 address TBD Peer Prefix Association This document Object-Type 1: IPv4 address 2: IPv6 address 12. Acknowledgement Thanks Dhruv Dhody, Mike Koldychev, Siva Sivabalan, Adam Simpson for his valuable suggestions and comments. 13. Normative References [I-D.ietf-teas-pce-native-ip] Wang, A., Khasanov, B., Zhao, Q., and H. Chen, "PCE in Native IP Network", draft-ietf-teas-pce-native-ip-11 (work in progress), August 2020. [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, . Wang, et al. Expires March 18, 2021 [Page 18] Internet-Draft PCEP Extension for Native IP Network September 2020 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation Element (PCE) Communication Protocol (PCEP)", RFC 5440, DOI 10.17487/RFC5440, March 2009, . [RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path Computation Element Communication Protocol (PCEP) Extensions for Stateful PCE", RFC 8231, DOI 10.17487/RFC8231, September 2017, . [RFC8232] Crabbe, E., Minei, I., Medved, J., Varga, R., Zhang, X., and D. Dhody, "Optimizations of Label Switched Path State Synchronization Procedures for a Stateful PCE", RFC 8232, DOI 10.17487/RFC8232, September 2017, . [RFC8253] Lopez, D., Gonzalez de Dios, O., Wu, Q., and D. Dhody, "PCEPS: Usage of TLS to Provide a Secure Transport for the Path Computation Element Communication Protocol (PCEP)", RFC 8253, DOI 10.17487/RFC8253, October 2017, . [RFC8281] Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path Computation Element Communication Protocol (PCEP) Extensions for PCE-Initiated LSP Setup in a Stateful PCE Model", RFC 8281, DOI 10.17487/RFC8281, December 2017, . [RFC8283] Farrel, A., Ed., Zhao, Q., Ed., Li, Z., and C. Zhou, "An Architecture for Use of PCE and the PCE Communication Protocol (PCEP) in a Network with Central Control", RFC 8283, DOI 10.17487/RFC8283, December 2017, . [RFC8735] Wang, A., Huang, X., Kou, C., Li, Z., and P. Mi, "Scenarios and Simulation Results of PCE in a Native IP Network", RFC 8735, DOI 10.17487/RFC8735, February 2020, . Authors' Addresses Wang, et al. Expires March 18, 2021 [Page 19] Internet-Draft PCEP Extension for Native IP Network September 2020 Aijun Wang China Telecom Beiqijia Town, Changping District Beijing, Beijing 102209 China Email: wangaj3@chinatelecom.cn Boris Khasanov Huawei Technologies,Co.,Ltd Moskovskiy Prospekt 97A St.Petersburg 196084 Russia Email: khasanov.boris@huawei.com Sheng Fang Huawei Technologies,Co.,Ltd Huawei Bld., No.156 Beiqing Rd. Beijing China Email: fsheng@huawei.com Ren Tan Huawei Technologies,Co.,Ltd Huawei Bld., No.156 Beiqing Rd. Beijing China Email: tanren@huawei.com Chun Zhu ZTE Corporation 50 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: zhu.chun1@zte.com.cn Wang, et al. Expires March 18, 2021 [Page 20]