Re: [Detnet] draft-ietf-detnet-yang-17: IP/MPLS over TSN

[Florian Kauer <[e-mail]>]

Hi all,

On 03.05.23 12:25, Florian Kauer wrote:
> [...]  
> My second question is regarding the use of type inet:ip-prefix in draft-ietf-detnet-yang-17.

I was able to clarify my confusion about the ip-prefix as soon as I understood the first example only describes the configuration/operational state at the ingress node and not the network as a whole - for the ingress locally, the concrete endpoint IP address is of course not relevant and the IP prefix is sufficient for flow mapping. It only got clear to me after watching Don's talk from IETF110 where he talks about how the YANG model is "vertically" on a certain node instead of "horizontally" as the flow model. Maybe it is worth mentioning it more explicitly in the draft and/or providing examples for the other nodes in the network, too, to provide the full picture.

As a step into this direction, I tried to write down the configuration for the egress node for the A-1 example (see below), but I noticed a few things:
- The leaf app-flow->ingress->interface is mandatory in the model, but in my understanding that interface does not exist since the traffic is only incoming from the service layer.
- For the service sub-layer on destination side, I would assume an "incoming forwarding-sub-layer" corresponding to the "outgoing forwarding-sub-layer" on source side.
  I have now specified a "service-id" instead, but it does not contain a reference to the forwarding sub-layer. Have I used it the way it is meant to be?
- In the A-1 example, only eth0 and eth2 are used. Should the others be removed from ietf-interfaces:interfaces for clarity or do I overlook something?

Greetings,
Florian

{
  "ietf-detnet:detnet": {
    "traffic-profile": [
      {
        "name": "pf-1",
        "traffic-requirements": {
          "min-bandwidth": "100000000",
          "max-latency": 100000000,
          "max-latency-variation": 200000000,
          "max-loss": "0.0000001",
          "max-consecutive-loss-tolerance": 5,
          "max-misordering": 0
        },
        "traffic-spec": {
          "interval": 5,
          "max-pkts-per-interval": 10,
          "max-payload-size": 1500,
          "min-payload-size": 100,
          "min-pkts-per-interval": 1
        },
        "member-app": [
          "app-0",
          "app-1"
        ]
      },
      {
        "name": "pf-2",
        "traffic-requirements": {
          "min-bandwidth": "200000000",
          "max-latency": 100000000,
          "max-latency-variation": 200000000,
          "max-loss": "0.000001",
          "max-consecutive-loss-tolerance": 5,
          "max-misordering": 0
        },
        "traffic-spec": {
          "interval": 5,
          "max-pkts-per-interval": 10,
          "max-payload-size": 1500,
          "min-payload-size": 100,
          "min-pkts-per-interval": 1
        },
        "member-service": [
          "ssl-1"
        ]
      },
      {
        "name": "pf-3",
        "traffic-spec": {
          "interval": 5,
          "max-pkts-per-interval": 10,
          "max-payload-size": 1500
        },
        "member-fwd-sublayer": [
          "fsl-1"
        ]
      }
    ],
    "app-flows": {
      "app-flow": [
        {
          "name": "app-0",
          "bidir-congruent": false,
          "incoming-service": "ssl-1",
          "traffic-profile": "pf-1",
          "ingress": {
            "interface": "unused0"
          },
          "egress": {
            "ip-mpls": {
              "outgoing-interface": "eth1",
              "next-hop-address": "2001:db8::8"
            }
          }
        },
        {
          "name": "app-1",
          "bidir-congruent": false,
          "incoming-service": "ssl-1",
          "traffic-profile": "pf-1",
          "ingress": {
            "interface": "unused0"
          },
          "egress": {
            "ip-mpls": {
              "outgoing-interface": "eth1",
              "next-hop-address": "2001:db8::8"
            }
          }
        }
      ]
    },
    "service": {
      "sub-layer": [
        {
          "name": "ssl-1",
          "service-rank": 10,
          "traffic-profile": "pf-2",
          "service-protection": {
            "protection": "none",
            "sequence-number-length": "long-sn"
          },
          "operation": "termination",
          "incoming": {
            "service-id": {
              "mpls-label-stack": {
                "entry": [
                  {
                    "id": 0,
                    "label": 102
                  }
                ]
              }
            }
          },
          "outgoing": {
            "app-flow": {
              "flow": [
                "app-0",
                "app-1"
              ]
            }
          }
        }
      ]
    },
    "forwarding": {
      "sub-layer": [
        {
          "name": "fsl-1",
          "traffic-profile": "pf-3",
          "operation": "pop-and-lookup",
          "incoming": {
            "forwarding-id": {
              "interface": "eth0",
              "mpls-label-stack": {
                "entry": [
                  {
                    "id": 0,
                    "label": 10005
                  }
                ]
              }
            }
          },
          "outgoing": {
            "service-sub-layer": {
              "sub-layer": [
                "ssl-1"
              ]
            }
          }
        }
      ]
    }
  },
  "ietf-interfaces:interfaces": {
    "interface": [
      {
        "name": "eth0",
        "type": "iana-if-type:ethernetCsmacd",
        "oper-status": "up",
        "statistics": {
          "discontinuity-time": "2020-12-18T18:59:00-05:00"
        }
      },
      {
        "name": "eth1",
        "type": "iana-if-type:ethernetCsmacd",
        "oper-status": "up",
        "statistics": {
          "discontinuity-time": "2020-12-18T18:59:00-05:00"
        }
      },
      {
        "name": "unused0",
        "type": "iana-if-type:ethernetCsmacd",
        "oper-status": "up",
        "statistics": {
          "discontinuity-time": "2020-12-18T18:59:00-05:00"
        }
      }
    ]
  }
}