802.11s Connectivity Test Plan

Test plan for the OLPC 802.11s implementation

This is a first attempt to systematically describe testing procedures for the Marvell/OLPC 802.11s implementation on the XO laptop.

The main concept behind our implementation is that of functional splitting of the networking stack between the WiFi radio and the Host CPU. The ARM processor driving the 88W8388 radio processes Layer-2 frames, while the Host CPU processes packets (IP or any other Layer-3 protocol).

This architecture allows for power savings (since only the Marvell SoC radio is necessary for frame forwarding) and flexibility with upper layer protocols (since it is not depending on any specific Layer-3 protocol - automatically supporting IPv6 for example). It also presents testing challenges in the laptop context since there is no direct user interaction with the ARM processor of the radio.

Testing should concentrate on the following areas:

• Path discovery and management
• Communications integrity
• Performance testing
• Firmware reliability and memory resources management

Given that the implementation is completely distributed, all of the above parameters are stressed as the number of nodes increases. This mandates that test suites are run multiple times with an increasing number of nodes every time.

Path discovery and management

The main purpose of this testing is to ensure proper operation of the core frame forwarding functionality. Assuming a set of nodes with no disconnected members every node should be able to communicate with every other node.

This test can be implemented via a series of any-to-all IP ping sessions with the ping originator mode changing after each set of pings so that all the nodes have the opportunity to originate pings. It is important to have multi-hop topologies during this test so that path discovery and broadcast propagation are exercised. One way to achieve that is to limit the TX power of the radios. Given that the purpose here is to verify frame forwarding, it is desirable that this test is performed in a radio-quiet space so that frame losses due to external radio traffic are minimized. In such an environment, scalability should be tested be gradually increasing the number of nodes (>50).

File:802.11s Connectivity Test Plan.doc - Original document