Hello Thomas, As summarized in table 1 in RFC9232, gRPC is an application protocol, which can be used to export all the telemetry metrics for Management Plane, Control Plane, Forwarding Plane and External Data. By using GPB encoding, gRPC is widely used to export real time performace metrics, such as link delay, jitter, packet loss measured by TWAMP or STAMP. Almost all our vendors support this way to export passport iOAM metrics and the test results in our lab are good. We have plan to deploy it in our field network soon.
In my understanding, the aggregation benifit of IPFIX is not applicable for iOAM metrics, such as delay and packet loss, because iOAM metrics are different for different flows. Neither sampling, how can you insure that the flow you want its iOAM metrics will be sampled? The iOAM metrics, especially the delay and packet loss, should be exported in time, for example in one second. I don't think IPFIX is the right protocol. I do not object this doc to move forward if we can reach this consensus. Best Regards, Zhenqiang Li li_zhenqi...@hotmail.com 发件人： thomas.g...@swisscom.com 发送时间： 2023-01-04 00:20 收件人： li_zhenqi...@hotmail.com; zhoutianran=40huawei....@dmarc.ietf.org; i...@ietf.org 抄送： opsawg@ietf.org 主题： RE: [ippm] 回复: FW: WG Adoption Call for draft-tgraf-opsawg-ipfix-on-path-telemetry-01 Dear Zhenqiang, Thanks a lot for your feedback. I presume with gRPC you are referring to YANG push (RFC 8639, RFC 8641, draft-ietf-netconf-udp-notif, draft-ietf-netconf-https-notif). gNMI (gRPC is the transport of gNMI) has been proposed (draft-openconfig-rtgwg-gnmi-spec) in 2018 but not standardized within IETF as a transport protocol for YANG push. It did not find enough traction. A good overview about the state of the union about YANG push in the industry is a presentation I gave at the IEPG, slide 3-6, http://www.iepg.org/2022-11-06-ietf115/slides-115-iepg-sessa-network-operator-challenges-in-network-telemetry-data-mesh-integration-thomas-graf-00.pdf. RFC 9232 gives a good overview about Network Telemetry. In section 3.1.3 (https://datatracker.ietf.org/doc/html/rfc9232#section-3.1.3) is a summary of the protocols for forwarding plane data collection. As you pointed out, it makes sense to use one common Network Telemetry protocol. However today we have 3, IPFIX for data plane, BMP for BGP routing control-plane and YANG push for management-plane. These 3 protocols have different unique mandatory characteristics. IPFIX allows data reduction with sampling (RFC5476) an aggregation (RFC7015). While BMP allows to mirror BGP PDU's (lightweight) and add device dimensions such as peering, RIB and route-policy (context). And YANG push allows through its sophisticated data modelling to have configurational and operational metrics within a single data model. In OPSAWG presentation of IETF 115 (https://datatracker.ietf.org/meeting/115/materials/slides-115-opsawg-export-of-on-path-delay-in-ipfix-00.pdf) I described in slide 2 and 3 the benefit of adding the delay measurements to IPFIX. Having one single protocol for data-plane data collection. The ability to perform data correlation and aggregation with an existing proven IPFIX protocol. Does that resonate with you? The use cases are described in section 5 of the draft (https://datatracker.ietf.org/doc/html/draft-tgraf-opsawg-ipfix-on-path-telemetry-01#section-5). Able to see for a given egress interface, BGP next-hop or SRv6 traffic engineered path or active segment how much delay at which node we accumulate. With YANG push this would be rather difficult and expensive to achieve. This was also confirmed by large network operators in their first on-path delay measurement deployments. Best wishes Thomas From: ippm <ippm-boun...@ietf.org> On Behalf Of li_zhenqi...@hotmail.com Sent: Tuesday, January 3, 2023 4:51 PM To: Tianran Zhou <zhoutianran=40huawei....@dmarc.ietf.org>; ippm <i...@ietf.org> Cc: opsawg@ietf.org Subject: [ippm] 回复: FW: WG Adoption Call for draft-tgraf-opsawg-ipfix-on-path-telemetry-01 Hi Tianran and all, Why not use one protocol, such as grpc, to export all the iOAM metrics? It is ok to export one way delay in IPFIX. If other metrics, such as queue depth, buffer occupancy, etc, have to be exported in grpc, it is not necessory to export one way delay in IPFIX. Best Regards, Zhenqiang Li li_zhenqi...@hotmail.com 发件人： Tianran Zhou 发送时间： 2022-12-22 10:40 收件人： 'IETF IPPM WG' 抄送： opsawg@ietf.org 主题： [ippm] FW: WG Adoption Call for draft-tgraf-opsawg-ipfix-on-path-telemetry-01 Hi IPPM, The OPSAWG just started a WG adoption call for draft-tgraf-opsawg-ipfix-on-path-telemetry-01. https://datatracker.ietf.org/doc/draft-tgraf-opsawg-ipfix-on-path-telemetry/ There are performance metrics registrations within this draft. We would really appreciate your comments from IPPM. Thanks, Tianran 发件人: OPSAWG [mailto:opsawg-boun...@ietf.org] 代表 Tianran Zhou 发送时间: 2022年12月22日 10:26 收件人: opsawg@ietf.org 抄送: draft-tgraf-opsawg-ipfix-on-path-teleme...@ietf.org 主题: [OPSAWG] WG Adoption Call for draft-tgraf-opsawg-ipfix-on-path-telemetry-01 Hi WG, This mail starts a WG Adoption Call for draft-tgraf-opsawg-ipfix-on-path-telemetry-01. https://datatracker.ietf.org/doc/draft-tgraf-opsawg-ipfix-on-path-telemetry/ Please reply your supports or objections. We would really appreciate your comments. Since there are holidays, this call will last for 3 weeks, and end on Thursday, Jan 12, 2023. Cheers, Tianran (as co-chairs)
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