# Dynamic Bandwidth Detection (BWCheck) **URL:** \ **Category:** Wowza Streaming Engine\ **Created:** [March 15, 2007, 6:40am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73 "2007-03-15T06:40:15Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![system](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/system/32/447_2.png) [@system](https://community.wowza.com/u/system)\ **Post date:** [March 15, 2007, 6:40am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/1 "2007-03-15T06:40:15Z")
Below is a bandwidth checker from forum contributor Roger. It is a Wowza Pro/Java version of the bandwidth checker discussed in this article: [http://www.adobe.com/devnet/flashcom/articles/flvideo\_bandwidth.html](http://www.adobe.com/devnet/flashcom/articles/flvideo_bandwidth.html) Java code: - Download a built version of this code from [wms-plugin-bwcheck.zip](https://www.wowza.com/downloads/forums/bwcheck/wms-plugin-bwcheck.zip) - Unzip and copy the wms-plugin-bwcheck.jar file (not the entire folder) into the **[install-dir]/lib** folder and restart the server - Create a folder named **[install-dir]/applications/bwcheck** - Create a folder named **[install-dir]/conf/bwcheck** - Copy **[install-dir]/conf/Application.xml** into new **bwcheck** config folder - Edit copied **Application.xml** file and remove the module reference to **ModuleFLVPlayback** and add the module reference below as the last entry in the section (it is important that it is the last entry): ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [March 16, 2007, 8:32am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/2 "2007-03-16T08:32:19Z")
Below is a link to a simple Flash movie for testing the connection speed to the Wowza Pro server from a client machine. If you configure your server as prescribed in the previous post, this tool will just work out of the box. It calls the server side bandwidth detection code every 5 seconds and returns the results. Its very useful for debugging client bandwidth issue like stuttering movies or poor video chat performance. [BWChecker.zip](https://www.wowza.com/downloads/forums/bwcheck/BWChecker.zip) To install, unzip. To run, double click bwchecker.html and change the connection string if needed. The results are returned in kilobits per seconds which is the same units used to determine the bit rate of your media content. So if you are consistently seeing values of 600Kbps or greater, then this connection should be able to support content encoded at combine rate of ~500Kbps (400Kbps video, 96Kbps audio). Enjoy, Charlie ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [March 12, 2008, 9:05am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/3 "2008-03-12T09:05:22Z")
Take a look at the IOPerformanceCounter interface that is attached the IMediaStream interface. You can get the IMediaStream interface by calling: ```auto IApplicationInstance appInstance; MediaStreamMap streams = appInstance.getStreams(); IMediaStream stream = streams.getStream(streamName); IOPerformanceCounter ioPerformance = stream.getMediaIOPerformance(); ``` Through the IOPerformanceCounter you can monitor the bits that travel in and out of the publishing stream. So if you monitor this over time you can calculate the rate. Make sense? Charlie ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [November 19, 2008, 11:40am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/4 "2008-11-19T11:40:39Z")
Because the FLVPlayback module is just a fake bandwidth check that is require by the FLVPlayback component. This interfers with the real bandwidth checker. Charlie ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [June 17, 2009, 9:19am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/5 "2009-06-17T09:19:46Z")
You can certainly modify the code to suit your needs. Remember that this system is testing the end to end bandwidth between your machine and the Wowza Media Server. So you might not get full line speed based on that path. Also, the way that latency is substracted from the calculation can throw off the calculation. If the latency is high I believe it lowers the calculated bandwidth. Charlie ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [December 14, 2009, 4:14am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/6 "2009-12-14T04:14:58Z")
I sent a note to Roger who wrote this code. Charlie ---
**Author:** ![craig\_udit](https://avatars.discourse-cdn.com/v4/letter/c/b5ac83/32.png) [@craig\_udit](https://community.wowza.com/u/craig_udit)\ **Post date:** [April 3, 2008, 7:05pm UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/7 "2008-04-03T19:05:26Z")
Is anyone familiar with a tool that allows me to mimic a slower connection speed on my own computer – in other words, to reduce the actual speed at which I connect so I can test how the bandwidth checking works for various connection speeds? ---
**Author:** ![Joe\_Pritchard](https://avatars.discourse-cdn.com/v4/letter/j/e9bcb4/32.png) [@Joe\_Pritchard](https://community.wowza.com/u/Joe_Pritchard)\ **Post date:** [January 29, 2009, 1:49am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/8 "2009-01-29T01:49:08Z")
Hi, I am testing this bandwidth checker in conjunction with wowza streaming server so that I can automatically give low bandwidth users a lower quality video. The bandwidth values that the checker is giving out seem to be a little sporadic and I can’t work out if this is something to do with my setup or if this is usual. As an example, the first five results that were picked up on one attempt were 783, 2483. 12375, 2774, 3576. I am worried that someone with an acceptable connection will be given the lower quality result due to an unreliable return. I have checked it on a couple of connections and it seems to be the same. As a test I have altered the included app to create a running average on every check. As you can see below, it does find an average of 3777 after a while but I can’t really make the user wait to find this average. Is the module designed to just check once? If someone could advise me as to whether I have made a mistake somewhere, perhaps it could be the wowza server being busy affecting the speed? perhaps there is another method that would be more reliable? , 2483, 2483, 5780.33333333333, 5028.75, 4738.2, 4647, 4494, 4180.875, 3831.33333333333, 5884.5, 5573.81818181818, 5388.16666666667, 5101.84615384615, 4890.85714285714, 4830, 5169.25, 5043.64705882353, 4933.94444444444, 4959.21052631579, 4841.6, 4770.38095238095, 4743.04545454546, 4721.04347826087, 4686.75, 4642.32, 4525.46153846154, 4423.33333333333, 4354.03571428571, 4256.72413793103, 4202.93333333333, 4134.06451612903, 4180.15625, 4304.81818181818, 4207.11764705882, 4125, 4167.33333333333, 4318.08108108108, 4349.94736842105, 4291.64102564103, 4281.8, 4192.73170731707, 4143.07142857143, 4334.51162790698, 4283.11363636364, 4235.4, 4206.32608695652, 4249.53191489362, 4234.16666666667, 4169.57142857143, 4104.7, 4487.45098039216, 4412.05769230769, 4340.94339622641, 4279.7962962963, 4218.23636363636, 4242.35714285714, 4181.68421052632, 4137.06896551724, 4084.52542372881, 4037.06666666667, 4142.67213114754, 4080.17741935484, 4041.85714285714, 3988.125, 3945.49230769231, 3900.42424242424, 3855.98507462687, 3849.13235294118, 3806.65217391304, 3765.47142857143, 3729.2676056338, 3681.68055555556, 3640.72602739726, 3609.44594594595, 3644.61333333333, 3638.35526315789, 3623.66233766234, 3622.84615384615, 3588.48101265823, 3576.4375, 3571.56790123457, 3614.43902439024, 3578.72289156626, 3586.28571428571, 3608.23529411765, 3625.13953488372, 3619.6091954023, 3614.14772727273, 3722.01123595506, 4093.15555555556, 4093.74725274725, 4091.19565217391, 4051.20430107527, 4014.12765957447, 3983.05263157895, 3949.5625, 3930.21649484536, 3909.66326530612, 3878.57575757576, 3859.68, 3841.25742574257, 3834.04901960784, 3806.93203883495, 3792.05769230769, 3804.79047619048, 3782.69811320755, 3755.98130841121, 3730.36111111111, 3713.97247706422, 3758.95454545455, 3776.36036036036, 3799.23214285714, 3795.34513274336, 3771.35964912281, 3777.74782608696, 3776.43965517241, 3767.8717948718, 3765.56779661017, 3773.1512605042, 3764.90833333333, 3747.2479338843, 3733.30327868852, ---
**Author:** ![Thomas\_Neuendorffer](https://avatars.discourse-cdn.com/v4/letter/t/77aa72/32.png) [@Thomas\_Neuendorffer](https://community.wowza.com/u/Thomas_Neuendorffer)\ **Post date:** [June 4, 2007, 10:23am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/9 "2007-06-04T10:23:48Z")
Has anyone made progress on an upload speed test? It doesn’t look that hard, but I have no desire to reinvent the wheel if it can be avoided. Thanks, Tom ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [April 12, 2007, 4:32am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/10 "2007-04-12T04:32:35Z")
We don’t have a BWCheck for that yet. The methodology would be the same. Obviously, the client would be sending data to the server. You could certainly modify the BWCheck code (server and client) above to create a BWCheckUpstream test. I can help support you in doing this. Charlie ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [June 4, 2007, 7:44am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/11 "2007-06-04T07:44:00Z")
No, I don’t think anyone has had a go at extending the BWChecker to test upload performance. Charlie ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [February 27, 2008, 7:50am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/12 "2008-02-27T07:50:38Z")
Also, set the ObjectEndoding to AMF0. Charlie ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [June 6, 2008, 3:19am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/13 "2008-06-06T03:19:47Z")
The getMessagesLossBytes will always be 0 when publishing since the throttling is happening on the client side. Wowza Pro has no idea if packets are being dropped on the server side. Charlie ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [June 6, 2008, 5:36am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/14 "2008-06-06T05:36:06Z")
I don’t know of any way of getting that information. Charlie ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [March 24, 2009, 9:37am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/15 "2009-03-24T09:37:02Z")
There shouldn’t be. Maybe Roger will chime in with more info. Charlie ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [March 7, 2010, 5:16am UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/16 "2010-03-07T05:16:55Z")
I think the problem is obvious isn’t it. Your client-side method is: ```auto public function onBWDone(kbitDown:Number, deltaDown:Number, deltaTime:Number, latency:Number):void ``` It is looking for a version of this method with no parameter. ```auto public function onBWDone():void ``` Charlie ---
**Author:** ![Aaron\_Roberson](https://avatars.discourse-cdn.com/v4/letter/a/8dc957/32.png) [@Aaron\_Roberson](https://community.wowza.com/u/Aaron_Roberson)\ **Post date:** [April 17, 2007, 10:25pm UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/17 "2007-04-17T22:25:39Z")
When I try to use this tool it sits on “testing performance…” indefinitely. ---
**Author:** ![Aaron\_Roberson](https://avatars.discourse-cdn.com/v4/letter/a/8dc957/32.png) [@Aaron\_Roberson](https://community.wowza.com/u/Aaron_Roberson)\ **Post date:** [April 17, 2007, 10:44pm UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/18 "2007-04-17T22:44:00Z")
Sorry, I didn’t see the top post since I was linked directly to the second post. I have it working now. -Aaron ---
**Author:** ![Roger\_Littin](https://avatars.discourse-cdn.com/v4/letter/r/d26b3c/32.png) [@Roger\_Littin](https://community.wowza.com/u/Roger_Littin)\ **Post date:** [April 12, 2007, 5:27pm UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/19 "2007-04-12T17:27:34Z")
I will have a look at it and put something up later. Roger. ---
**Author:** ![Roger\_Littin](https://avatars.discourse-cdn.com/v4/letter/r/d26b3c/32.png) [@Roger\_Littin](https://community.wowza.com/u/Roger_Littin)\ **Post date:** [June 10, 2007, 12:56pm UTC](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73/20 "2007-06-10T12:56:40Z")
I did start to look into it and then got swamped with other things. Will take another look at it. Roger. [Next page](https://community.wowza.com/t/dynamic-bandwidth-detection-bwcheck/73.md?page=2)