VTP 2.0 Proposed Recommendation: Request for Comments

Public discussion page for the IVOA VTP 2.0 Proposed Recommendation.

The latest version of the VTP Specification can be found at:

• http://www.ivoa.net/documents/VOEventTransport/20160503/index.html

Reference Interoperable Implementations

• Comet (Python)
• Dakota VOEVent Tools (C#/.NET)
• PyGCN (Python; only implements subscription)
• GCN client demo (C; only implements subscription

Comments from the IVOA Community and TCG members during RFC period: 2016-05-31 - 2016-07-16

Comments from TCG members during the TCG Review Period: 2016-05-31 - 2016-07-16

WG chairs or vice chairs must read the Document, provide comments if any and formally indicate if they approve or do not approve of the Standard.

IG chairs or vice chairs are also encouraged to do the same, although their inputs are not compulsory.

TCG Chair & Vice Chair ( _Matthew Graham, Pat Dowler )

Applications Working Group ( _Pierre Fernique, Tom Donaldson )

Data Access Layer Working Group ( François Bonnarel, Marco Molinaro )

Data Model Working Group ( _Mark Cresitello-Dittmar, Laurent Michel )

Grid & Web Services Working Group ( Brian Major, Giuliano Taffoni )

Registry Working Group ( _Markus Demleitner, Theresa Dower )

Sect. 6.1f use the term IVORN, which was deemed hopelessly ambiguous during the creation of Identifiers 2.0 (which had attempted to properly define it). So, we've deprecated it -- just call it IVOA Identifier or IVOID and be done with it (*).

Also in 6.1, you say "should normally include a timezone". You've probably seen the discussions about timestamp fromats in the context of UWS and DALI -- perhaps you could prevent future inconsistencies with the rest of the VO by saying "This [time and date] should include a ``Z'' timezone indicator. If the timezone indicator is missing, clients should assume UTC. The use of other timezone indicators (and, hence, timezones) is severely discouraged." (and similar in the following sections).

Still in 6.1, the sample document references a non IVOA-namespace and schema location. I realize it's probably too late to change the namespace. Perhaps you could still comment on this and at least use the ivoa.net schema location (http://ivoa.net/xml/Transport-v1.1.xsd, I think)?

I'm not terribly happy about 9.2, as the authentication scheme proposed isn't mentioned in the SSO document that we're reviewing almost simulataneously. If this wasn't advertised as "finished tech just being codified", I'd say it's a bit embarrassing to, in effect, have conflicting recommendations (SSO: "Auth schemes approved are..."; VTP: "...something we don't particularly care about."). Things being what they are: if this is deployed and implemented, so be it (except that then I think you should say what XML signature scheme actually is used). If it's not, however, can't you just put in "to be specified in 2.1"? [All this leaves aside the question of what kind of security is achieved by the protocol proposed -- over a plain TCP connection with all its susceptability to eavesdropping and hijacking, that's probably limited in the first place].

Typos and similar

p. 4 "...set of brokers which subscribe/r/ to each other's" (*)

"The Transport Protocol, hereafter VTP" -- perhaps actually put a "VOEvent" in front of "Transport" so the acronym matches? (*)

Provided at least the points marked with (*) are somehow addressed, we approve.

Semantics Working Group ( _Mireille Louys, Alberto Accomazzi )

Education Interest Group ( _Massimo Ramella, Sudhanshu Barway )

Time Domain Interest Group ( _John Swinbank, Dave Morris )

Data Curation & Preservation Interest Group ( Françoise Genova )

Operations Interest Group ( _Tom McGlynn, Mark Taylor )

Knowledge Discovery Interest Group ( Kaï Polsterer )

Theory Interest Group ( _Carlos Rodrigo )

Standards and Processes Committee ( Françoise Genova)