Export of Gigabit Passive Optical Network Encapsulation Mode in IP Flow Information Export (IPFIX)

The G-PON Encapsulation Method (GEM) data plane header defined in Section 8.3.1 of facilitates the framing, error control, payload type identification and payload separation in the Optical Distribution Network. It is being used in the Optical Distribution Network between the Optical Line Termination (OLT) at the network operator and the Optical Network Unit (ONU), Optical Network Terminal (ONT) at the end user in the passive optical transport within the broadband access domain. IPFIX is widely applied in the broadband access domain to gain visibility into the forwarding and data plane. However, that visibility is today constraint to the ethernet, IP and application transport properties of the data plane. This document specifies two IPFIX Information Elements (IEs) to facilitate visibility in the GEM data plane. Figure 1 shows the GEM frame, the GEM header and its properties.

| | | +--------------+-----------------------------------------+ | GEM Header | GEM Payload | +--------------+-----------------------------------------+ / | / --------------\ / --------------\ / -----------\ v v +----------------+----------------+---------+------------------+ | PLI | Port-ID | PTI | HEC | | (12-bits) | (12-bits) | (3-bits)| (13-bits) | +----------------+----------------+---------+------------------+ Figure 1: G.984.3 GEM header and frame structure ]]> These IEs are used to export the GEM Port-ID and PTI to enable the distinction between user service and user and OAM application frames. Some examples are provided in Appendix A.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here. This document makes use of the terms defined in , and . The following terms are used as defined in : IPFIX IPFIX Information Elements Template Template Record Options Template Options Template Record Data Record Data Set The following terms are used as defined in : Optical Access Network (OAN) Optical Distribution Network (ODN) Optical Line Termination (OLT) Optical Network Termination (ONT) Optical Network Unit (ONU) The following terms are used as defined in : G-PON Encapsulation Method (GEM) GEM Port Gigabit-capable Passive Optical Network (G-PON)

This section specifies the new IPFIX G-PON GEM IEs. 3-bit GEM PTI content type field defined in Section 8.3.1 of associated with ingress interface. The values are encoded in the 3 least significant bits of the IE. 3-bit GEM PTI content type field defined in Section 8.3.1 of associated with egress interface. The values are encoded in the 3 least significant bits of the IE. 12-bit GEM Port-ID field defined in Section 8.3.1 of associated with ingress interface. The values are encoded in the 12 least significant bits of the IE. 12-bit GEM Port-ID field defined in Section 8.3.1 of associated with egress interface. The values are encoded in the 12 least significant bits of the IE.

The IPFIX IEs ingressGponGemPti (TBD1), egressGponGemPti (TBD2), ingressGponGemPortId (TBD3), egressGponGemPortId (TBD4), sourceMacAddress (56), destinationMacAddress (80), ingressInterface (10), egressInterface (14) and forwardingStatus (89) , and some existing counter information providing answers to the following questions (among others): How many user or OAM data fragments are forwarded or dropped to which ONU on which egress interface and GEM Port-ID? If dropped, for which reasons? The received ONU frames on an OLT are mapped and forwarded depending on GEM Port-ID to a dot1qVlanId (243) and dot1qPriority (244) upstream to the provider network.

Note to the RFC-Editor: Please replace TBD1 - TBD4 with the values allocated by IANA Please replace the [RFC-to-be] with the RFC number assigned to this document

This document requests IANA to add new IEs () to the "IPFIX Information Elements" registry available at . Table 1 lists the new G-PON GEM IEs:

Name:: ingressGponGemPti

ElementID:: TBD1

Description:: Values for this Information Element are listed in the "G-PON Encapsulation Method PTI" subregistry, see .

Abstract Data Type:: unsigned8

Data Type Semantics:: flags

Range:: The valid range is 0-7.

Additional Information:: See the assigned types in [IPFIX G-PON Encapsulation Method PTI Subregistry] associated with ingress interface. The values are encoded in the 3 least significant bits of the IE.
Note to IANA:: Please replace [IPFIX G-PON Encapsulation Method PTI Subregistry] with the URL of the IANA subregistry.

Reference:: [RFC-to-be]

Name:: ingressGponGemPti

ElementID:: TBD1

Description:: Values for this Information Element are listed in the "G-PON Encapsulation Method PTI" subregistry, see .

Abstract Data Type:: unsigned8

Data Type Semantics:: flags

Range:: The valid range is 0-7.

Additional Information:: See the assigned types in [IPFIX G-PON Encapsulation Method PTI Subregistry] associated with egress interface. The values are encoded in the 3 least significant bits of the IE.
Note to IANA:: Please replace [IPFIX G-PON Encapsulation Method PTI Subregistry] with the URL of the IANA subregistry.

Reference:: [RFC-to-be]

Name:: ingressGponGemPortId

ElementID:: TBD2

Description:: The 12-bit GEM Port-ID field defined in Section 8.3.1 of associated with an ingress interface.

Abstract Data Type:: unsigned16

Data Type Semantics:: identifier

Additional Information:: The values are encoded in the 12 least significant bits of the IE.

Reference:: [RFC-to-be]

Name:: ingressGponGemPortId

ElementID:: TBD2

Description:: The 12-bit GEM Port-ID field defined in Section 8.3.1 of associated with an egress interface.

Abstract Data Type:: unsigned16

Data Type Semantics:: identifier

Additional Information:: The values are encoded in the 12 least significant bits of the IE.

Reference:: [RFC-to-be]

This document requests IANA to create a new subregistry called "IPFIX G-PON Encapsulation Method PTI" under the "IPFIX Information Elements" registry available at . The allocation policy of this new subregistry is Expert Review (Section 4.5 of ). The designated experts for this registry should be familiar with the G-PON Encapsulation Method. The guidelines that are being followed by the designated experts for the IPFIX registry should be followed for this subregistry. In particular, criteria that should be applied by the designated experts include to monitor the G-PON Encapsulation Method related activities at ITU-T and mirror the GEM PTI content type fields into this registry. Hence, keeping both registries in sync. Initial values in the registry are defined in Table 2 and reflect the 3-bit GEM PTI content type field defined in Section 8.3.1 of .

The authors would like to thank Paul Aitken and Nuno André for their review and valuable comments, and Xiao Chen, Jian Ping Zhang and Jiale Li for the implementation and validation.

Note to the RFC-Editor: Please remove this section before publishing.

Huawei plans to implement the following IEs as part of a production implementation in the VRP based MA5800T-X17 OLT platform: ingressGponGemPortId egressGponGemPortId The implementation will be validated at IETF 125 hackathon.

There exists no extra security considerations regarding allocation of these new IPFIX IEs compared to . The IEs described in this document export provider plane data metrics on how frames are being forwarded within an Optical Access Network. Applications and operators using the IEs described in this document must evaluate the sensitivity of this information in their implementation context, and apply the data-at-rest storage guidance in Section 11.8 of as appropriate.