Octopus system1 Moshe Tocker Avihai Mejer

Octopus system2 The Octopus system Goal The system’s primary goal is to Measure performance parameters in real time on an Ethernet LAN. The parameters the system measures are latency, throughput, and reliability. The parameters measured will help analyze the load and utilization of the LAN.

Octopus system3 The elements in the system Manager – An application that runs on any station in the LAN. It’s functionality: –It will let the user choose what tests to run on the Ethernet LAN. –Passes commands to Agents instructing them what tests to perform. The manager will expect back the tests results for allowing the user further analysis.

Octopus system4 The elements in the system (Cont.) Agents – Combined of two parts: –Agent application –Miniport driver Agent application – Communicates with the Manager application & the minioprt driver, passing information between the two. Miniport driver –Kernel mode SW component, operates the Network Adapter. –Carries out the tests.

Octopus system5 The Agents Agent Application Miniport Driver Command/Result Other Agents Manager TCP/IP Other Agents Other Agents HOST

Octopus system6 The Octopus system Layout Manager Agent A Agent B Ethernet LAN NT stations

Octopus system7 Project Implementation steps Part I –infrastructure i.e. Communication & Interaction between different system components. Part II –Designing and implementing the experiments at the mininport level, for actual measurement of the LAN’s performance. –Designing and developing the Manager interface.

Octopus system8 Communication & Interaction The communication & Interaction includes: –User to Manager interface –Manager to Agent app. communication –Agent app. to miniport communication –Agent app. to Agent app. communication –Miniport to miniport communication

Octopus system9 User to Manager interface The manager is a Windows Application that exports a GUI to the user allowing him to choose: –the type of experiment to be done –Relevant parameters: number of tests to run, time interval between consecutive tests. –The Agents addresses and ports. The experiment results are displayed to the user in a visual and textual format.

Octopus system10 Manager to Agent communication Manager & Agent are both user level applications that communicate using standard TCP/IP. The Manager & Agent Pass among themselves: –Commands from Manager to Agent to perform an experiment, or –Results and data back from Agent To Manager. Note: communication between two agent works in a similar way.

Octopus system11 AgentManager TCP/IP WinSock Commands Results

Octopus system12 Agent to miniport communication Agents application order the miniport of what tests to do and what parameters to use Miniport performs the test and sends test results back to Agent application Communication between Agent application and the miniport is by using Files performing a buffer role.

Octopus system13 The Agents Agent Application Miniport Driver “CommFile” HOST “ResFile”

Octopus system14 Miniport to miniport communication The miniports communicate among themselves directly through the LAN, i.e they format Ethernet packets by themselves using the MAC address they received from the agent app.

Octopus system15 The miniport implementation We used an open-source driver for our Network Adapter. The driver was converted to our needs: –It creates a new thread running in kernel mode, dedicated to the Octopus system, always listening for commands from the Agent Application, and ready to perform the requested test. –Because of the multithreaded implementation, the driver’s performance and functionality remains unharmed. –Host can be used normally, even when used as Agent.

Octopus system16 Experiments characterizing (1/3) All experiments are conducted by the miniports on the agents. Basically sending/receiving packets between them and measuring time intervals. Experiments involve large number of packets, in order to achieve accurate expectancy.

Octopus system17 Experiments characterizing (2/3) Latency – measuring round trip time of several small packets. Throughput – measuring the time required for sending large bursts of data. Frame-Train – sending packets over the LAN periodically in constant intervals, and time- stamping the acks. Then compare the intervals between sends and receives. (this is highly important for time-sensitive applications such as voice over IP)

Octopus system18 Experiments characterizing (3/3) We report for each experiment: –The detailed intervals times measured. Manager app also calculates and displays averages over these results. –Statistics gathered by the HW during the tests: # good frames sent/received # collisions detected –We also report of lost packets (or lost acks)

Octopus system19 How does it work?

Octopus system20 MANAGER application miniport application miniport command results ack commfile resfile commfileAgent 1Agent 2 Perform test User requests

Octopus system21 Difficulties encountered Win2K drivers do not support usage of named- pipes. We therefore had to implement ourselves the mechanism by using ordinary files and polling on them. The driver had to be transformed into a multi- function driver, without harming its original goal. Multi-threaded programming was the solution. Upgrading the dialox-box GUI to the current one.

Octopus system22 Possible expansions Support for muliple LAN technologies – only requires a new miniport driver Super manager application – for using Octopus on more complex networks Adding new experiments to meet user’s requirements is very easy with the Octopus system - requires minor changes to the apps, and writing the new experiment in the miniport.

Octopus system23