Issue 066 - WS-Discovery - RelationshipType attribute is notrequired

[Ram Jeyaraman <Ram.Jeyaraman@microsoft.com>]

This issue is assigned the number 066. For further discussions on this issue, please refer to this issue number or use this thread.

 

From: Vipul Modi
Sent: Thursday, September 18, 2008 10:59 AM
To: Ram Jeyaraman
Subject: FW: NEW Issue - WS-Discovery - RelationshipType attribute is not required

 

What issue is this? I cannot find.

 

From: Vipul Modi
Sent: Thursday, September 18, 2008 8:39 AM
To: Ram Jeyaraman
Subject: NEW Issue - WS-Discovery - RelationshipType attribute is not required

 

Please defer discussions on this issue until a time this issue is accepted and is assigned a number.

 

Description:

The current specification requires Probe to include a RelationshipType attribute for sending multicast suppression Hello. This is actually not required, as the value of the RelatesTo header associates the Hello message with the Probe or Resolve message. A Hello message in response of Probe or Resolve indicates that it is a multicast suppression message. Here is the text from the Section 4.1 that clearly indicates that the RelateTo MUST be included if an only if Hello is sent in response to multicast Probe or Resolve.

/s:Envelope/s:Header/a:RelatesTo

MUST be included only by a Discovery Proxy and if and only if Hello is sent unicast in response to a multicast Probe (or Resolve). It MUST be the value of the [message id] property [WS-Addressing] of the multicast Probe (Resolve).

The normal Hello messages do not have RelatesTo header. The presence of RelatesTo header in the Hello message is necessary and sufficient condition to identify it as the multicast suppression message and hence the RelatioshipType attribute is not required. Setting the RelationshipType attribute to be different than the default WS-Addressing value makes it difficult to process the message by general purpose layered web services stack and the default WS-Addressing value correctly characterize this message as in response to the Probe/Resolve message.

 

Proposed Resolution:

Modify the description of the Hello message in Section 4.1 as below”

 

/s:Envelope/s:Header/a:RelatesTo

MUST be included only by a Discovery Proxy and if and only if Hello is sent unicast in response to a multicast Probe (or Resolve). It MUST be the value of the [message id] property [WS-Addressing] of the multicast Probe (Resolve).

/s:Envelope/s:Header/a:RelatesTo/@RelationshipType="d:Suppression"

Indicates this message is a suppression of the multicast Probe (or Resolve).