[Sis-dtn] IPN URI Scheme Service Numbers

[Birrane, Edward J.]

I would encourage any observations on the need for standard service numbers (and that they are not port numbers) to be also made to the DTNWG mailing list. It would help inform the discussion that is occurring there.

-Ed

Edward J. Birrane, III, Ph.D. (he/him/his)
Chief Engineer, Space Constellation Networking
Supervisor, Embedded Applications Group 
Space Exploration Sector
Johns Hopkins Applied Physics Laboratory
(W) 443-778-7423 / (C) 443-690-8272


> -----Original Message-----
> From: Felix Flentge <Felix.Flentge at esa.int>
> Sent: Monday, May 22, 2023 11:50 AM
> To: Birrane, Edward J. <Edward.Birrane at jhuapl.edu>; sis-
> dtn at mailman.ccsds.org
> Subject: [EXT] RE: IPN URI Scheme Service Numbers
> 
> APL external email warning: Verify sender Felix.Flentge at esa.int before
> clicking links or attachments
> 
> Hi,
> 
> Seems to be a very sensible proposal to me. For the more immediate future,
> I assume that there will be only limited need for interoperable use of service
> numbers (ie, an application of one agency communicating to an application
> of another agency) and I would expect missions to pick the low service
> numbers for their (private) M&C and payload needs anyway. What we might
> want to agree on are service numbers used for network management and
> diagnostic needs (e.g., bpecho).
> 
> Regards,
> Felix
> 
> -----Original Message-----
> From: SIS-DTN <sis-dtn-bounces at mailman.ccsds.org> On Behalf Of Birrane,
> Edward J. via SIS-DTN
> Sent: Monday, May 22, 2023 2:38 PM
> To: sis-dtn at mailman.ccsds.org
> Subject: [Sis-dtn] IPN URI Scheme Service Numbers
> 
> WG,
> 
>   Last week at the SIS-DTN weekly meeting we had a good discussion on
> allocation strategies for IPN service numbers.
> 
>   IIRC, there were three major areas of discussion related to these numbers:
> encoding size, allocation policy, and registry ownership.
> 
>   The encoding size discussion noted that the CBOR encoding of service
> numbers creates a very small allocation of 1-byte encodings (0-23), a small
> allocation of 2-byte encodings (24-155), a moderate size allocation of 3-byte
> encodings (256-65,535), and then 4+ byte encodings that give us the
> remainder of the 64bit service number space.
> 
>   The allocation policy discussion noted that there was a good case for
> "private use" service numbers for mission-specific use cases (commanding,
> telemetry) that do not otherwise map to a standardized protocol. These
> mission specific service numbers should not be standardized (they are
> mission specific) and there should be some allowance for them in the small
> encoding space since they will be used by missions often (perhaps most
> often).
> 
>   The registry ownership discussion noted that IANA is creating (updating
> really..) a registry for service numbers and should there be a SANA allocation
> in that registry.
> 
>   At the end of the discussion the following proposal was put forward:
> 
> 1 byte service numbers (1-23) will be private use .
> 2 byte service numbers (24-255) will be expert review with a 64-id chunk
> allocated to SANA.
> 3 byte service numbers (256-65k) will be cut 1/3 private use, 1/3 IANA
> managed and 1/3 IANA managed but given to SANA.
> 4 byte will have a chunk of experimental.
> 4+bytes is unassigned.
> 
>   This continues to be an area of active discussion in the IETF mailing list.
> Some IETF participants are proposing that all service numbers be private-use
> and there be no standard service numbers since service discovery is better
> done today independent of port numbers. I disagree with this position -
> service numbers are not port numbers - but that case needs to be made, for
> those interested in following the discussion on the IETF mailing list.
> 
> -Ed
> 
> ---
> Edward J. Birrane, III, Ph.D. (he/him/his) Chief Engineer, Space Constellation
> Networking Supervisor, Embedded Applications Group Space Exploration
> Sector Johns Hopkins Applied Physics Laboratory
> (W) 443-778-7423 / (F) 443-228-3839
> 
> 
> 
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