4 Protocol Examples

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This section describes example operations that are used in common scenarios to illustrate the function of the Proximity Service Discovery Protocol.

Examples showing computation of format identifiers from namespace URIs:

 String:  "http://schemas.xmlsoaps.org/ws/2004/10/discovery"

First (leftmost) 4 octets of HMAC–SHA256 (format id) of the previous string: 0xF8 0xCB 0x35 0x15.

 String:  "http://schemas.microsoft.com/networking/discoveryformat/v2"

First (leftmost) 4 octets of HMAC–SHA256 (format id) of the previous string: 0xCF 0xF1 0x64 0x17.

Note The transmission order is: The first (leftmost) octet is transmitted first.

If the "shatest" program as specified in [RFC4634] is used to produce the format identifier from a string, the procedure is as follows:

  1. Create a testfile containing the string in UTF-16 little endian format.

  2. Call shatest: shatest -h 2 -f testfile -k ""

The following is an example of the vendor extension IE conveyed in a Beacon or Probe Response frame for the format identifier string "test" (without quotes) and 8 octets data in the payload.

Example of the vendor extension IE

Figure 7: Example of the vendor extension IE