[Nsi-wg] Issues for next NSI call

[Henrik Thostrup Jensen]

Hi.

As promised, here a number of issues, which I think we need to decide on. 
Please read them and understand the subject, so we don't have to spend 
most of the call explaining the issue itself. Please write if you would 
like to explain something before the meeting.


* NML format decision

We need to decide on a format for topology exchange (note that the model for
all these are NML, is is just about the specific format).

Options are: XML, OWL, N3 (unless we want to invent something).

OWL and N3 are RDF based, where as the XML is a direct NML representation in
XML. See the NML spec for XML and OWL examples. OWL and N3 examples can be seen
in the autogole-topology repository at:
https://github.com/jeroenh/AutoGOLE-Topologies/tree/nsiv2/goles

All of the formats need to be augmented slightly for describing NSAs, but that
is more or less trivial in all of them (and roughly the same procedure).

Personally I like the XML representation is it the one most close to the actual
mode, and seems easy to generate and parse.


* Do we allow one NSA (by URL) to act for multiple networks

This isn't clear and does affect some things in the protocol design.

Personally I think this is way more trouble than it is worth, and it is easy to
create different URLs for each NSA even if they are hosted within the same daemon.


* Do we allow multiple NSAs for a single network

Could potentially be used for redundancy.

In case we allow them, should the NSAs have different identity or the same?


* WSDL clean up

Remove superflourous NetworkIdType and saml import ogf_nsi_connection_types_v2_0.xsd

I don't expect any objections here.


* Decide on SOAP 1.1 or SOAP 1.2 for NSI2

This affects requests (slightly), processing and SOAP Faults.

It appears that most are on SOAP 1.1 (at least from the faults I have seen).


* ServiceExceptionType variables

ServiceExceptionType has the following variables decleration:

<xsd:element name="variables"           type="tns:VariablesType" />

Could we get minOccurs="0" on this, as not all exceptions are necessarely
related to a variable.


* Orientation

In the WSDL we allow STPs to be specified without an orientation.

What is the semantics for an STP without orientation?


* Connection Identifier

We currently have no good way of making an identifier for a connection (it is
scoped within the requester identity). This means that there is no way for one
entity to pass a connection reference to another.

The easiest way to get this it allow NSAs to scope connection ids independently
of requester identity, which means that a connection id at an NSA is always the
same. This should allow us to create a URN for it at least.

The real solution is to have a URL, but since we don't use a protocol where
URLs are first-grade citizens that would require a major re-design.



     Best regards, Henrik

  Henrik Thostrup Jensen <htj at nordu.net>
  Software Developer, NORDUnet