MBSF Feature: Packet mode

[davidjwbbc]

This accompanies 5G-MAG/rt-mbs-transport-function#64 and is the MBSF changes to support the PACKET distribution method.

This also includes the fix from rt-mbs-transport-function for incorrectly applied Read-Only and Write-Only property attributes in the generated model code for the MbStfIngestAddr type to ensure consistent interpretation of data types between the MBSF and MBSTF.

[davidjwbbc]

I've tested this using the rt-mbs-transport-function/tests/packet_stream_gen.py script and Insomnia.

For the Insomnia entry I duplicated an Object mode User Data Ingest Session creation entry and changed the body to:

{
  "mbsUserServId": "{{ _.mbs_user_service_id }}",
  "mbsDisSessInfos": {
    "AP_MBS_SESSION_1": {
      "mbsSessionId": {
        "ssm": {
          "sourceIpAddr": {
            "ipv4Addr": "127.0.0.5"
          },
          "destIpAddr": {
            "ipv4Addr": "232.10.0.7"
          }
        }
      },
      "mbsDistSessState": "ACTIVE",
      "maxContBitRate": "10 Mbps",
      "distrMethod": "PACKET",
      "pckDistrInfo": {
        "operatingMode": "PACKET_FORWARD_ONLY",
        "pckIngMethod": "UNICAST",
        "ingEndpointAddrs": {
          "afEgressTunAddr": {
            "ipv4Addr": "127.0.0.1",
            "portNumber": 3000
          }
        }
      }
    }
  },
  "suppFeat": "3"
}

I then ran the packet_stream_gen.py script to generate the stream and caught the packets using wireshark:

~/rt-mbs-transport-function/tests/packet_stream_gen.py 127.0.0.1:3000 127.0.0.1:35371 232.10.0.7:5555 127.0.0.5:6666

Note: Address 127.0.0.1:35371 came from the mbStfIngressTunAddr value in the response to Insomnia from the MBSF.

The packets sent using the script look like:

These packet go from the address specified in the afEgressTunAddr property in the original request and go to the address given by the mbStfIngessAddr property from the creation request response. These packets contain encapsulated multicast packets using the source and destination addresses from the MBS session ID SSM in the original creation request and uses source port 6666 and destination port 5555.

This is then forwarded from the MBSTF to the MB-UPF UDP tunnel (as requested by the MBSF when creating the MBS Session with the MB-SMF):

This is sent from an ephemeral port on the MBSTF to the MB-UPF UDP tunnel that has been created for the MBS Session. The packet contains the encapsulated packet as sent by the generator script to the MBSTF.

The MB-UPF then passes the encapsulated packet to the gNodeB via the GTP-U protocol for transmission to any subscribed UE's:

[rjb1000]

Thanks, @davidjwbbc.

Updates to copyright years are needed in some source files.

[dsilhavy]

Thanks @davidjwbbc I fidnt find any issues when reviewing the code. On our end we will try to replicate your setup now.