RE: [ws-dd-comment] FW: WS-DD 1.1 2009/01; Issue PR004

Dear Mr. Treptow:

Thank you very much for submitting your comment on WS-Discovery during the current public review period regarding Section 4.1.3, Discovery Proxy. It was assigned issue number PR004 for tracking purposes.

The issue contains two points. The first point suggests adding a statement to clarify that “[H]ello should be sent regardless of any Type or Scopes that might be in the request”. The TC examined the language in the fourth bullet of 4.1.3, and decided that the word “any” in the phrase “In response to any multicast Probe (or multicast Resolve) from a Client” is sufficiently clear and that no additional statement is needed.

The second point suggests adding language to spell out certain specific behaviors of a “discovery proxy” such as responding to multicast Probe messages on behalf of Target Services on other subnets. The TC considered this suggestion, but decided not to add any additional material to the specification. The WS-Discovery specification defines the roles Discovery Proxy and Target Service in terms of their Port Types, focusing on the wire protocol rather than the functionality or features of software implementing these roles. The scenario you describe is certainly valid and can be addressed by the current protocol specification. An application can implement the Target Service role for services in different subnets; it can send multicast announcements on behalf of services in other subnets and respond to multicast Probe and Resolve messages on behalf of those services, as if those services are present on the current subnet. Such an application is using the Target Service port type for such communications, acting as an “agent” of services on other subnets. The same application can also implement the Discovery Proxy role as described in the specification. However, it is beyond the scope of WS-Discovery to fully describe how the various roles described in the specification might be combined to produce a complete product (such as the various ways a proxy application might become aware of services on other subnets). The TC chose not to venture beyond protocol specifications and into writing product specifications, and thus declined to accept this suggestion.

Because neither of the points raised were accepted by the TC, issue PR004 was moved to the Dropped state.

Thanks again for your interest and suggestions.

Best regards,

Toby Nixon

Co-Chair, OASIS WS-DD Technical Committee

From: Jay A. Treptow [mailto:jay@treptows.net]

Sent: Thursday, February 26, 2009 6:43 PM

To: ws-dd-comment@lists.oasis-open.org

Subject: [ws-dd-comment] FW: WS-DD 1.1 2009/01

Below are comments on the Web Services Dynamic Discovery (WS-Discovery) Version 1.1 Public Review Draft 01 28 January 2009.

In section ‘4.1.3 Discovery Proxy’, bullet four, you might consider a statement that clarifies that the hello should be sent regardless of any Type or Scopes that might be in the request. At first I thought that the Hello should only be sent in response to a Probe or Resolve for d:DiscoveryProxy type requests.

Additionally, I can see how the Hello response reduces network traffic for discovery proxy aware clients (Win7), but I think that it misses a use case for non discovery proxy aware clients (Vista). If a target service on subnet A provisions a discovery proxy on subnet B via a managed mode Hello, then any non discovery proxy aware clients on network B will not discover the target service.

You might consider stating that the proxy MAY return ProbeMatch or ResolveMatch elements for target services that were provisioned via managed mode, or for all target services where their XAddrs are on a different subnet from where the Probe was received.

Toby Nixon | Senior Standards Program Manager | Windows Device and Storage Technologies | Microsoft Corporation

toby.nixon@microsoft.com | www.microsoft.com | V: +1 425 706 2792 | M: +1 206 790 6377 | F: +1 425 708 4811

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