The following is a look at the code here on GitHub. If you’ve been following my progress so far you will know that I’ve so far managed to run this code, but I am let to take a proper look at the code and how it works.

The top level of the directory contains the following directories/files, typical to an Android project:

1. directory called /res that contains the launcher icon, the xml file describing the layout, and two further xml files which hold the “values” associated with the application
2. directory called /src that containing 4 java files LocalBinder.java, SigcommDemoAndroidActivity.java, SigcommDemoAndroidService.java and TestsSignpost.java and a collection of java files for different data views
3. the AndroidManifest.xml file which highlights that the minimum SDK version is 10
4. the lint.xml file which contains almost nothing
5. the pom.xml file, I’m currently not sure what this does
6. the project.properties file which just re-highlights that the SDK is version 10

I’m now going to take a closer look at the code:

SigcommDemoAndroidActivity.java

Public Methods

• onCreate(Bundle savedInstanceState) – the method that is called when the application is first started
• onDestroy() – the method that is called when the application is closed
• onPause() – the method that is called when the application is paused
• onClick(View v) – the method that is called when either of the two buttons on the application is pressed, v.getId() is then used to determine which button was pressed
• updateTimestampArray (float [] array, float newval) – this method shifts all of the values in the array to the left by one position, disregarding the value at index 0 and inserting newval at the last place in the array. There are also minValBandwidth and maxValBandwidth which are updated according
• updateHistoricValFloat (float [] array, float newval ) – this method shifts all the values in the array to the left by one position, disregarding the value at index 0 and inserting newval at the last place in the array. [Note: the difference between updateTimestampArray and updateHistoricValFloat is that only updateTimestampArray updates the minValBandwidth and maxValBandwidth ]
• plotLatencyPairs (float [] timestampsDownstream, float [] arrayLatencyDownstream, float[] timestampsUpstream, float[] arrayLatencyUpstream) – this method plots latency pairs
• plotBandwidthPairs (float [] timestampsDownstream, float [] arrayBandwidthDownstream, float[] timestampsUpstream, float[] arrayBandwidthUpstream) – this method plots bandwidth pairs
• printVals(int [] array) – this method takes an array of integers, turns them into a string with the values separated by commas and sends them to the INFO log file [Note: API on the log output for android is available here and further information is here]
• updateHistoricValInt (int [] array, int newval ) – this method shifts all the values in the array to the left by one position, disregarding the value at index 0 and inserting newval at the last place in the array.  [Note: the difference between updateHistoricValInt and updateHistoricValFloat is that updateHistoricValFloat takes a float array and updateHistoricValInt takes a int array]

SigcommDemoAndroidService.java


Public Methods

• setMainActivity(SigcommDemoAndroidActivity activity, int [] server, int tcpPort) – this method is how SigcommDemoAndroidActivity.java calls this java file. SigcommDemoAndroidActivity.java calls this method when the user click on the start test button on the UI. This method using the data from SigcommDemoAndroidActivity to initialise some of the variables in SigcommDemoAndroidService such as server ip address and port number

•  stopThread() – this method simply just re-sets the boolean flag testAlive
•  onBind(Intent arg0) – this method calls the constructor of LocalBinder.java and passes the current instance of SigcommDemoAndroidService to LocalBinder.java
• onUnbind(Intent intent) – this method seems to do nothing :S
• onDestroy () – this method calls the onDestroy() on the class Service that SgcommDemoAndroidService inherits from
• onCreate() – this method calls the onCreate() on the class Service that SgcommDemoAndroidService inherits from and creates a new thread called th
• callFinalize() – this method calls System.exit(0)
• notifyActivity (int value, int caseId) – this method refreshs values
• run () – this method connects to the server and measures the time for packets to be transported between client and server

This is blog post number 4, on try to run Iperf on Android, my previous attempts were:

• Method 1 – getting the Google Play Store on a CyanogenMod phone and downloading the Iperf for Android application
• Method 2 – SSHing into an Android phone and trying to run Iperf from the command line
• Method 3 – repeating method 1 & 2 on another Android phone and trying a different application called Aperf
• Method 4 – trying to run a cross-compiled version of Iperf on the Android phone
• Potential Method 5 – cross-compile Iperf myself and try to run that version
• Potential Method 6 – install Linux on android, following instructions here.
• Potential Method 7 – write my own version of Iperf

THE PLAN

1. Get to grips with the basics of Android Debug Bridge (adb)
2. Download the cross compiled Iperf and push it onto SD card
3. Copy Iperf over the correct location in the system

THE REALITY

1
Android Debug bridge (adb) is a command line tool for communicating with an android device via USB or an emulator instance. adb is not installed in the machine so it must be ran from the correct location, for me this was android-sdk-linux/platform-tools/.

I connect my android phone via USB and run ./adb devices to test that the device is connected. If multiple emulators/device instances are running then I will need to specify with device to use when using adb so for simplicity, I close all running emulators so that I have only my android phone running.

(* starts a remote shell on the android device, the command prompt becomes #   *)

mount -o rw,remount /system
(* remount the /system filesystem so that its now read-write *)

cp /sdcard/iperf /system/bin
(*copy the iperf code over to newly remounted /system filesystem *)

mount -o ro,remount /system
(* remount the /system filesystem so that its now read-only *)

Now I try iperf, from the remote shell and IT WORKS !
Yes, that’s right, it works perfectly. This time it was 4th time lucky.

And this right here, is the reason that I’m a computer scientist. For the high, that you get when something finally works and you know that it works because you made it work. Looking back over the past few days, I feel like I’ve learned so much about Android and given the opportunity I would definitely do it all over again but now its time for a coffee.

My current aim is to get Iperf running on an Android phone so that I can collect “accurate” network data to compare to the network data produced by Signpost Demo Application that I’m currently trying to test.

The problem is that I can’t get the Iperf for Android application to run on any of the available android phones. I have also tried SSHing into the phone and running Iperf, this also did not work.

I need to get Iperf working on android to collect the data for comparison to data produced by the demo code. The back up plan will be to write my own application to collect the required network data, but I would like to have Iperf working so that I can test my own application.

If anyone has suggestions of tools to collect network data like bandwidth, latency, goodput and jitter, that work on linux and android using a client server architecture, then comment below.

So, I’ve got my hands on yet another android phone, I think this is phone number 6 or something like that. It is a HTC Magic, that is currently not rooted. I boot it up, get it going and download the Iperf for Android application and …

…. it still will not work

So, I do some research and I come across another application that claims to also act as an Iperf cleint, this one is called Aperf. I install it on two different android phones, test and …

…. it still will not work

Repeating the tests, changing Wi-Fi networks and finally it works, The following results are from the Iperf server

[ ID] Interval       Transfer     Bandwidth

[  4] local port 5001 connected with port 58204
[  4]  0.0- 8.9 sec  30.0 KBytes  27.6 Kbits/sec
[  5] local port 5001 connected with port 37831
[  5]  0.0- 6.0 sec  47.0 KBytes  64.3 Kbits/sec
[  4] local port 5001 connected with port 43876
[  4]  0.0- 6.6 sec   132 KBytes   164 Kbits/sec
[  5] local port 5001 connected with port 56253
[  5]  0.0- 6.6 sec   400 KBytes   496 Kbits/sec
[  4] local port 5001 connected with port 55373
[  4]  0.0- 6.5 sec   103 KBytes   131 Kbits/sec
[  5] local port 5001 connected with port 50778
[  5]  0.0- 8.6 sec   697 KBytes   662 Kbits/sec
[  4] local port 5001 connected with port 42511
[  4]  0.0- 5.1 sec  59.0 KBytes  94.3 Kbits/sec
[  5] local port 5001 connected with port 42474
[  5]  0.0- 5.9 sec   386 KBytes   539 Kbits/sec
[  4] local port 5001 connected with port 38663
[  4]  0.0- 8.6 sec  35.0 KBytes  33.3 Kbits/sec
[  5] local port 5001 connected with port 38036
[  5]  0.0- 8.2 sec   332 KBytes   331 Kbits/sec

The information above dose not show the complete picture. This data was collected from the server, in each case the client has only transmitted data for 5 seconds, this means that the bandwidth values above as incorrect. To calculate the correct bandwidth values I need to take amount of data transferred and divide by 5 seconds.

The client dose not seem to output any data except that required to calculate bandwidth. Using UDP instead of TCP dose not seem to allow me to collect any more information.

Ironically the network statistics collected by the Signpost diagnosis android app are latency, goodput and jitter but the only network statistics that I am able to collect is bandwidth.

I do not know where to go forward from here, I need accurate network statistics between a android client and Linux server so I can test the code. I could write my own application to collect the data, but then I will have the same problem again as I need accurate network statistics to check my application is working correctly

Any suggestions ??

Due to the issues with the Iperf application for android and part of the touch screen on my andriod phone not working properly, I’ve decided that it would be best to set up SSH to remote access on android phone, to make working with the phone easier.

To application that I decided to use to help get my SSH running on as quickly as possible was SSHDroid. This is an excellent application that I would highly recommend. The steps in setting up SSH access where:

• Install SSHDroid and launch application
• Change the password from its default which is “admin”
• Install OpenSSH on your linux computer
• run ssh root@
• Enter password when requested

Now I have the command line of the android phone, I downloaded iperf and extracted the contains of the .tar.gz file to the SD card. The next stage in my plan was to use ./configure then make then make install as per usual.

But as ever, thing are never that straight forward.

• on doing ./configure, I get permission denied
• on doing sudo ./configure, I get sudo: not found
• on doing echo $USER, I get root
• on doing ls -l | grep configure, I get —xrwxr-x

so why will it not work ?

UPDATE:

I’ve managed to deal with the “Permission Denied” error despite having root access and the correct permission by prefixing ./configure with sh. This then fails to compile due to the lack of a C++ compiler