SPRING Working Group Madhukar Anand Internet-Draft Sanjoy Bardhan Intended Status: Informational Ramesh Subrahmaniam Infinera Corporation Jeff Tantsura Individual Expires: June 25, 2017 December 22, 2016 Packet-Optical Integration in Segment Routing draft-anand-spring-poi-sr-02 Abstract This document illustrates a way to integrate a new class of nodes and links in segment routing to represent transport networks in an opaque way into the segment routing domain. An instance of this class would be optical networks that are typically transport centric. In the IP centric network, this will help in defining a common control protocol for packet optical integration that will include optical paths as 'transport segments' or sub-paths as an augmentation to the defined extensions of segment routing. The transport segment option also defines a general mechanism to allow for future extensibility of segment routing into non-packet domains. Requirements Language 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]. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." Anand et al., Expires June 25, 2017 [Page 1] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Copyright and License Notice Copyright (c) 2016 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 (http://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 . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Reference Taxonomy . . . . . . . . . . . . . . . . . . . . . . 3 3. Use case - Packet Optical Integration . . . . . . . . . . . . . 3 4. Mechanism overview . . . . . . . . . . . . . . . . . . . . . . 6 5. PCEP-LS extensions for supporting the transport segment . . . 6 6. OSPF extensions for supporting the transport segment . . . . . 8 7. OSPFv3 extensions for supporting the transport segment . . . . 9 8. IS-IS extensions for supporting the transport segment . . . . 10 9. BGP-LS extensions for supporting the transport segment . . . . 12 10. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 11. Security Considerations . . . . . . . . . . . . . . . . . . . 15 12 IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 12.1 PCEP . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 12.2 OSPF . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 12.3 OSPFv3 . . . . . . . . . . . . . . . . . . . . . . . . . . 16 12.4 IS-IS . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 12.5 BGP-LS . . . . . . . . . . . . . . . . . . . . . . . . . . 16 13 References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 13.1 Normative References . . . . . . . . . . . . . . . . . . . 16 13.2 Informative References . . . . . . . . . . . . . . . . . . 18 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18 Anand et al., Expires June 25, 2017 [Page 2] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 1 Introduction Packet and optical transport networks have evolved independently with different control plane mechanisms that have to be provisioned and maintained separately. Consequently, coordinating packet and optical networks for delivering services such as end-to-end traffic engineering or failure response has proved challenging. To address this challenge, a unified control and management paradigm that provides an incremental path to complete packet-optical integration while leveraging existing signaling and routing protocols in either domains is needed. This document introduces such a paradigm based on Segment Routing (SR) [I-D.ietf-spring-segment-routing]. This document introduces a new type of segment, Transport segment. Transport segment can be used to model abstracted paths through the optical transport domain and integrate it with the packet network for delivering end-to-end services. In addition, this also introduces a notion of a Packet optical gateway (POG). These are nodes in the network that map packet services to the optical domain that originate and terminate these transport segments. Given a transport segment, a POG will expand it to a path in the optical transport network. 2. Reference Taxonomy POG - Packet optical gateway Device SR Edge Router - The Edge Router which is the ingress device CE - Customer Edge Device that is outside of the SR domain PCE - Path Computation Engine Controller - A network controller 3. Use case - Packet Optical Integration Many operators build and operate their networks that are both multi- layer and multi-domain. Services are built around these layers and domains to provide end-to-end services. Due to the nature of the different domains, such as packet and optical, the management and service creation has always been problematic and time consuming. With segment routing, enabling a head-end node to select a path and embed the information in the packet is a powerful construct that would be used in the Packet Optical Gateways (POG). The path is usually Anand et al., Expires June 25, 2017 [Page 3] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 constructed for each domain that may be manually derived or through a stateful PCE which is run specifically in that domain. P5 P1 _ .-'-._ ,'P4 `._ .-' `-. ,' `. _.-' `-._ ,' `-. .-' `-. ,' P2`.-'--------------------------`-.- P3 |\ /| | \ / | Packet ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, | \ / | | \ / | Transport | \ / | | ................../ | | ,'O2 O3`. | | ,' `. | |,' `. | O1\ | O4 \ ,' \ ,' .......................- O6 O5 Figure 1: Representation of a packet-optical path In Figure 1 above, the nodes represent a packet optical network. P1,...,P5 are packet devices. Nodes P2 and P3 are connected via optical network comprising of nodes O1,...,O6. Nodes P2 and P3 are POGs that communicate with other packet devices and also with the devices in the optical transport domain. In defining a link in the packet domain between P2 and P3, we will need to specify both the nodes and the links in the optical transport domain that establish this link. To leverage segment routing to define a service between P1 and P4, the ingress node P1 would append all outgoing packets in a SR header consisting of the SIDs that constitute the path. In the packet domain this would mean P1 would send its packets towards P4 using a segment list {P2, P3, P4}. The operator would need to use a different mechanism in the optical domain to set up the optical paths comprising the nodes O1, O2 and O3. Each POG would announce the active optical path as a transport segment - for example, in the case of P1, the optical path Anand et al., Expires June 25, 2017 [Page 4] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 {O1, O2, O3} would be represented as a label Om. This path is not known to the packet SR domain and is only relevant to the optical domain D between P2 and P3. A PCE that is run in Domain D would be responsible for calculating path corresponding to label Om. The expanded segment list would read as {P2, Om, P3, P4}. +------------------------+ | | +--------------+----' PCE or Controller |----+---------------+ | | | | | | | | +------------------------+ | | | | | | | | .-----. | | | | ( ) | | +-------+ +-------+ .--( )--. +-------+ +-------+ | SR | |Packet | ( ) |Packet | | SR | | Edge | |Optical|-( Optical Transport )_ |Optical| | Edge | |Router | ... |Gateway| ( Domain ) |Gateway| ... |Router | +---+.--+ +-------+ ( ) +-------+ +---+.--+ | '--( )--' | ,--+. ( ) ,-+-. ( CE ) '-----' ( CE ) `---' `---' Figure 3. Reference Topology for Transport Segment Anand et al., Expires June 25, 2017 [Page 5] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 4. Mechanism overview The current proposal assumes that the SR domains run standard IGP protocols to discover the topology and distribute labels without any modification. There are also no modifications to the control plane mechanisms in the Optical transport domains. The mechanism for supporting the transport segment is as follows. 1. Firstly, the Packet Optical Gateway (POG) devices announce themselves in the SR domain. This is indicated by advertising a new SR node capability flag. The exact extensions to support this capability are described in the subsequent sections of this document. 2. Then, the POG devices announce paths to other POGs through the optical transport domain as a transport segment (transport segment binding SID) in the SR domain. The paths are announced with an appropriate optical transport domain ID, and a label (Packet-Optical Label) to be used to bind to the transport segment. The appropriate IGP segment routing extensions to carry this information is described in the subsequent sections of this document. 3. The transport segment can also optionally be announced with a set of attributes that characterizes the path in the optical transport domain between the two POG devices. For instance, those attributes could define the OTN mapping used (e.g., ODU4, ODU3,ODU3e1....ODU1), timeslots (1-8 or 4,6,7 or 1-2,5), or optical path protection schemes. 4. The POG device is also responsible for programming its forwarding table to map every transport segment label entry into an appropriate forwarding action relevant in the optical domain, such as mapping it to a label-switched path. 5. The transport segment is communicated to the PCE or Controller using extensions to BGP-LS or PCEP-LS as described in subsequent sections of this document. 6. Finally, the PCE or Controller then uses the transport segment label to influence the path leaving the SR domain into the optical domain, thereby defining the end-to-end path for a given service. 5. PCEP-LS extensions for supporting the transport segment To communicate the Packet-Optical Gateway capability of the device, we introduce a new PCEP capabilities TLV is defined as Anand et al., Expires June 25, 2017 [Page 6] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 follows(extensions to [I-D.draft-sivabalan-pce-segment-routing]): Value Meaning Reference -------- ------------------------------------ ----------------- 27 TRANSPORT-SR-PCE-CAPABILITY This document A new type of TLV to accommodate a transport segment is defined by extending Binding SIDs [I-D.draft-sivabalan-pce-binding-label-sid-01] 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Binding Type (BT) | Domain ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Binding Value | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Transport Segment Sub TLVs (variable length) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ where: Type: TBD, suggested value 32 Length: variable. Binding Type: 0 or 1 as defined in [I-D.draft-sivabalan-pce-binding-label-sid-01] Domain ID: An identifier for the transport domain Binding Value: is the transport segment label Transport Segment Sub TLVs: TBD IANA will be requested to allocate a new TLV type (recommended value Anand et al., Expires June 25, 2017 [Page 7] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 is 32) for TRANSPORT-SEGMENT-BINDING-TLV as specified in this document: 1 Transport Segment Label (This document) 6. OSPF extensions for supporting the transport segment To communicate the Packet-Optical Gateway capability of the device, we introduce an new optical informational capability bit in the Router Information capabilities TLV (as defined in [RFC4970]). Bit-24 - Optical - If set, then the router is capable of performing Packet Optical Gateway function. Further, a new OSPF sub-TLV (similar to the ERO SubTLV) of SID/Label Binding Sub-TLV (TRANSPORT-SEGMENT-BINDING-SUBTLV) to carry the transport segment label is defined 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Domain ID | Flags | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Packet-Optical Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Transport Segment Sub TLVs (variable length) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ where: Type : TBD, Suggested Value 9 Length: variable. Domain ID: An identifier for the transport domain Flags: 1 octet field of following flags: V - Value flag. If set, then the optical label carries a value. By default the flag is SET. L - Local. Local Flag. If set, then the value/index carried by the Adj-SID has local significance. By default the flag is SET. 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ Anand et al., Expires June 25, 2017 [Page 8] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 |V|L| +-+-+-+-+-+-+-+-+ Packet-Optical Label : according to the V and L flags, it contains either: * A 3 octet local label where the 20 rightmost bits are used for encoding the label value. In this case the V and L flags MUST be set. * A 4 octet index defining the offset in the label space advertised by this router. In this case V and L flags MUST be unset. Transport Segment Sub TLVs: TBD Multiple TRANSPORT-SEGMENT-BINDING-SUBTLV MAY be associated with a pair of POG devices to represent multiple paths within the optical domain 7. OSPFv3 extensions for supporting the transport segment To communicate the Packet-Optical Gateway capability of the device, we introduce an new optical informational capability bit in the Router Information capabilities TLV (as defined in [RFC4970]). Bit-24 - Optical - If set, then the router is capable of performing Packet Optical Gateway function. Further, a new OSPFv3 sub-TLV similar to the ERO SubTLV) of SID/Label Binding Sub-TLV (TRANSPORT-SEGMENT-BINDING-SUBTLV) to carry the transport segment label is defined 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Domain ID | Flags | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Packet-Optical Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Transport Segment Sub TLVs (variable length) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Anand et al., Expires June 25, 2017 [Page 9] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 where: Type : TBD,Suggested Value 12 Length: variable. Domain ID: An identifier for the transport domain Flags: 1 octet field of following flags: V - Value flag. If set, then the optical label carries a value. By default the flag is SET. L - Local. Local Flag. If set, then the value/index carried by the Adj-SID has local significance. By default the flag is SET. 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ |V|L| +-+-+-+-+-+-+-+-+ Packet-Optical Label : according to the V and L flags, it contains either: * A 3 octet local label where the 20 rightmost bits are used for encoding the label value. In this case the V and L flags MUST be set. * A 4 octet index defining the offset in the label space advertised by this router. In this case V and L flags MUST be unset. Transport Segment Sub TLVs: TBD Multiple TRANSPORT-SEGMENT-BINDING-SUBTLV MAY be associated with a pair of POG devices to represent multiple paths within the optical domain 8. IS-IS extensions for supporting the transport segment To communicate the Packet-Optical Gateway capability of the device, we introduce a new flag O in the SR Node Capabilities sub-TLV: 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ |I|V|H|O| | +-+-+-+-+-+-+-+-+ Anand et al., Expires June 25, 2017 [Page 10] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 I, V, H flags are defined in [I-D.ietf-isis-segment-routing-extensions] O-Flag: If set, then the router is capable of performing Packet Optical Gateway function. Further, a new IS-IS sub-TLV (similar to the ERO SubTLV) of SID/Label Binding Sub-TLV (TRANSPORT-SEGMENT-BINDING-SUBTLV) to carry the transport segment label is defined as follows. First, we define the O flag in the SID/Label Binding TLV 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ |F|M|S|D|A|O| | +-+-+-+-+-+-+-+-+ F, M, S, D, and A flags: are defined in [I-D.ietf-isis-segment-routing -extensions] O-Flag: If set, then the F flag, Range, Prefix Length FEC Prefix, must be ignored in the SID/Label Binding TLV Secondly, we define the SubTLV of the SID/Label Binding Sub-TLV: 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Domain ID | Flags | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Packet-Optical Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Transport Segment Sub TLVs (variable length) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ where: Type : TBD, Suggested Value 151 Length: variable. Domain ID: An identifier for the transport domain Flags: 1 octet field of following flags: V - Value flag. If set, then the optical label carries a value. By default the flag is SET. Anand et al., Expires June 25, 2017 [Page 11] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 L - Local. Local Flag. If set, then the value/index carried by the Adj-SID has local significance. By default the flag is SET. 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ |V|L| +-+-+-+-+-+-+-+-+ Packet-Optical Label : according to the V and L flags, it contains either: * A 3 octet local label where the 20 rightmost bits are used for encoding the label value. In this case the V and L flags MUST be set. * A 4 octet index defining the offset in the label space advertised by this router. In this case V and L flags MUST be unset. Transport Segment Sub TLVs: TBD Multiple TRANSPORT-SEGMENT-BINDING-SUBTLV MAY be associated with a pair of POG devices to represent multiple paths within the optical domain with perhaps different characteristics. 9. BGP-LS extensions for supporting the transport segment 9.1 Node Attribuites TLV To communicate the Packet-Optical Gateway capability of the device, we introduce an new optical informational capability the following new Node Attribute TLV is defined: +-----------+----------------------------+----------+---------------+ | TLV Code | Description | Length | Section | | Point | | | | +-----------+----------------------------+----------+---------------+ | 1172 | SR-Optical-Node-Capability | variable | | | | TLV | | | +-----------+----------------------------+----------+---------------+ Table 1: Node Attribute TLVs These TLVs can ONLY be added to the Node Attribute associated with the node NLRI that originates the corresponding SR TLV. Anand et al., Expires June 25, 2017 [Page 12] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 9.2 SR-Optical-Node-Capability TLV The SR Capabilities sub-TLV has following format: 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | RESERVED | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ where: Type : TBD, Suggested Value 1157 Length: variable. Flags: The Flags field currently has only one bit defined. If the bit is set it has the capability of an Packet Optical Gateway. 9.3 Prefix Attribute TLVs The following Prefix Attribute Binding SID Sub-TLVs have been added: +------------+-------------------------+----------+-----------------+ | TLV Code | Description | Length | Section | | Point | | | | +------------+-------------------------+----------+-----------------+ | 1173 | TRANSPORT-SEGMENT-SID | 12 | | | | | | | +------------+-------------------------+----------+-----------------+ Table 4: Prefix Attribute - Binding SID Sub-TLVs The Transport segment TLV allows a node to advertise an transport segment within a single IGP domain. The transport segment SID TLV TRANSPORT-SEGMENT-TLV has the following format: 9.3.1 Transport Segment SID Sub-TLV Further, a new sub-TLV (similar to the IPV4 ERO SubTLV) of Binding SID Sub-TLV (TRANSPORT-SEGMENT-BINDING-SUBTLV) to carry the transport segment label is defined as follows. 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 Anand et al., Expires June 25, 2017 [Page 13] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Domain ID | Flags | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Packet-Optical Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Transport Segment Sub TLVs (variable length) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ where: Type : TBD Length: variable. Domain ID: An identifier for the transport domain Flags: 1 octet field of following flags: V - Value flag. If set, then the optical label carries a value. By default the flag is SET. L - Local. Local Flag. If set, then the value/index carried by the Adj-SID has local significance. By default the flag is SET. 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ |V|L| +-+-+-+-+-+-+-+-+ Packet-Optical Label : according to the V and L flags, it contains either: * A 3 octet local label where the 20 rightmost bits are used for encoding the label value. In this case the V and L flags MUST be set. * A 4 octet index defining the offset in the label space advertised by this router. In this case V and L flags MUST be unset. Transport Segment Sub TLVs: TBD Multiple TRANSPORT-SEGMENT-TLV MAY be associated with a pair of POG devices to represent multiple paths within the optical domain Anand et al., Expires June 25, 2017 [Page 14] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 10. Summary The motivation for introducing a new type of segment - transport segment - is to integrate transport networks with the segment routing domain and expose characteristics of the transport domain into the packet domain. An end-to-end path across packet and transport domains can then be specified by attaching appropriate SIDs to the packet. An instance of transport segments has been defined here for optical networks, where paths between packet-optical gateway devices has been abstracted using binding SIDs. Extensions to various protocols to announce the transport segment have been proposed in this document. 11. Security Considerations This document does not introduce any new security considerations. 12 IANA Considerations This documents request allocation for the following TLVs and subTLVs. 12.1 PCEP Packet-Optical Gateway capability of the device Value Meaning Reference -------- ------------------------------------ ----------------- 27 TRANSPORT-SR-PCE-CAPABILITY This document A new type of TLV to accommodate a transport segment is defined by extending Binding SIDs [I-D.draft-sivabalan-pce-binding-label-sid-01] Value Description Reference 32 TRANSPORT-SR-PCEP-TLV This document This document requests that a registry is created to manage the value of the Binding Type field in the TRANSPORT-SR-PCEP TLV. Value Description Reference 1 Transport Segment Label This document 12.2 OSPF Transport-Segment SubTLV of OSPF Extended Prefix LSA Anand et al., Expires June 25, 2017 [Page 15] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 Value Description Reference 9 TRANSPORT-SR-OSPF-SUBTLV This document 12.3 OSPFv3 Transport-Segment SubTLV of OSPFv3 Extend-LSA Sub-TLV registry Value Description Reference 12 TRANSPORT-SR-OSPFv3-SUBTLV This document 12.4 IS-IS Transport-Segment SubTLV of Segment Identifier / Label Binding TLV Value Description Reference 151 TRANSPORT-SR-ISIS-SUBTLV This document 12.5 BGP-LS Node Attributes TLV: Value Description Reference 1172 TRANSPORT-SR-BGPLS-CAPABILITY This document Prefix Attribute Binding SID SubTLV: Value Description Reference 1173 TRANSPORT-SR-BGPLS-TLV This document 13 References 13.1 Normative References [I-D.ietf-spring-segment-routing] Filsfils, C., Previdi, S., Decraene, B., Litkowski, S., and r. rjs@rob.sh, "Segment Routing Architecture", draft- ietf-spring-segment-routing-04 (work in progress), July 2015. [I-D.ietf-isis-segment-routing-extensions] Anand et al., Expires June 25, 2017 [Page 16] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 Previdi, S., Filsfils, C., Bashandy, A., Gredler, H., Litkowski, S., Decraene, B., and J. Tantsura, "IS-IS Extensions for Segment Routing", draft-ietf-isis-segment- routing-extensions-05 (work in progress), June 2015. [I-D.ietf-ospf-segment-routing-extensions] Psenak, P., Previdi, S., Filsfils, C., Gredler, H., Shakir, R., Henderickx, W., and J. Tantsura, "OSPF Extensions for Segment Routing", draft-ietf-ospf-segment- routing-extensions-05 (work in progress), June 2015. [RFC4915] L. Nguyen, P. Psenak, S. Mirtorabi, P. Pillay-Esnault, and A. Roy, "Multi-Topology (MT) Routing in OSPF.", RFC4915, . [I-D.ietf-ospf-ospfv3-segment-routing-extensions] Psenak, P., Previdi, S., Filsfils, C., Gredler, H., Shakir, R., Henderickx, W., and J. Tantsura, "OSPFv3 Extensions for Segment Routing", draft-ietf-ospf-ospfv3- segment-routing-extensions-03 (work in progress), June 2015. [I-D.ietf-idr-ls-distribution] Gredler, H., Medved, J., Previdi, S., Farrel, A., and S. Ray, "North-Bound Distribution of Link-State and TE Information using BGP", draft-ietf-idr-ls-distribution-13 (work in progress), October 2015. [RFC4970] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and S. Shaffer, "Extensions to OSPF for Advertising Optional Router Capabilities", RFC 4970, DOI 10.17487/RFC4970, July 2007, . [I-D.sivabalan-pce-binding-label-sid] Sivabalan, S., Filsfils, C., Previdi, S., Tantsura, J., Hardwick, J., and M. Nanduri, "Carrying Binding Label/ Segment-ID in PCE-based Networks.", draft-sivabalan-pce- binding-label-sid-01 (work in progress), March 2016. [I-D.ietf-pce-segment-routing] Sivabalan, S., Medved, J., Filsfils, C., Crabbe, E., Lopez, V., Tantsura, J., Henderickx, W., and J. Hardwick, "PCEP Extensions for Segment Routing", draft-ietf-pce- segment-routing-07 (work in progress), March 2016. Anand et al., Expires June 25, 2017 [Page 17] Internet-Draft draft-anand-spring-poi-sr-02 December 22, 2016 13.2 Informative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . Authors' Addresses Madhukar Anand Infinera Corporation 169 W Java Dr, Sunnyvale, CA 94089 Email: manand@infinera.com Sanjoy Bardhan Infinera Corporation 169 W Java Dr, Sunnyvale, CA 94089 Email: sbardhan@infinera.com Ramesh Subrahmaniam Infinera Corporation 169 W Java Dr, Sunnyvale, CA 94089 Email: RSubrahmaniam@infinera.com Jeff Tantsura Email: jefftant.ietf@gmail.com Anand et al., Expires June 25, 2017 [Page 18]