Connection-less Transport

Note

The scenarios in this section require that the Device Under Test has the Connection-mode Echo Test Application installed and accessible under the service name urn:nfc:sn:dta-cl-echo-in.

Connection-less transport provides best effort delivery of service data units between a local and a remote service access point in either direction. An connection-less transport channel is termed a logical data link and implied by a pair of local and remote service access point adress values used in a Unnumbered Information (UI) PDU. No setup or termination procedure exisits for a logical data link.

Due to the Medium Access (MAC) layer guarantees any outbound LLCP PDU, includinga UI PDU, will arrive at the remote LLC layer. However, a local LLC or remote LLC may drop a UI PDU at any point in time without notification.

Start of Test Sequence

The start of test sequence is common to all further test scenarios for connection-less transport mode. Run as a dedicated test scenario, the following steps verify that the Device Under Test has the Connection-less Echo Test Application installed and accessible, and that the Connection-less Echo Test Application attempts to discover the service access point address for returning data packets to the Device In Testmode.

  1. Perform service discovery to learn the remote service access point address value for the service name urn:nfc:sn:dta-cl-echo-in.
  2. Send a service data unit with the ASCII string “SOT” to the Connection-less Echo Test Application to indicate the start of test.
  3. Verify that the Connection-less Echo Test Application performs service discovery to learn the service access point address value for the service name urn:nfc:sn:dta-cl-echo-out on the Device In Testmode.

Guaranteed Information Size

The guaranteed information size for an outbound Unnumbered Information (UI) PDU is 128 octets. Although implementations should support a larger number of information octets, an application designed to work with a variety of peer devices must be able to function even if only the guaranteed information size is available.

  1. Perform the Start of Test Sequence
  2. Send a service data unit with 128 random octets to the Connection-less Echo Test Application.
  3. Verify that the Connection-less Echo Test Application sends the same service data unit to the local service access point bound to urn:nfc:sn:dta-cl-echo-out.

Maximum Information Size

The maximum information size of any outbound Unnumbered Information (UI) PDU is determined by the Link MIU value that the remote device transmitted during LLCP Link Activation. The purpose of this scenario is to verify that the Device Under Test accepts a UI PDU with a number of information octets equal to the device’s Link MIU. Note that in order to run this test the Device In Testmode must have a Link MIU that is equal or greater than the Link MIU of the Device Under Test because otherwise the Connection-less Echo Test Application will not be able to return the service data unit.

  1. Perform the Start of Test Sequence
  2. Send a service data unit with N random octets to the Connection-less Echo Test Application, with the value of N being equal to the Link MIU of the Device Under Test.
  3. Verify that the Connection-less Echo Test Application sends the same service data unit to the local service access point bound to urn:nfc:sn:dta-cl-echo-out.

Packet Loss Stimulation

  1. Determine the echo buffer capacity C and delay D of the Connection-less Echo Test Application running on the Device Under Test.
  2. Perform the Start of Test Sequence
  3. Within D seconds send C + 1 service data units of 128 octets to the Connection-less Echo Test Application.
  4. Verify that the Connection-less Echo Test Application returns the first C service data units to the local service access point at urn:nfc:sn:dta-cl-echo-out.
  5. Send one service data unit of 128 octets to the Connection-less Echo Test Application.
  6. Verify that the Connection-less Echo Test Application returns the service data unit to the local service access point at urn:nfc:sn:dta-cl-echo-out.