CU-SeeMe Rate Settings

All CU-SeeMe software has to be finely set up for optimal performance. Straight out of the box rates settings will give poor viewing results. The rates suggested below are by no means the most authoritative but are based on personal experience gained from having used CU-SeeMe. Setting transmit rates too high can result in very high packet loss. This in turn can make it hard for others to open your video even at low quality settings! Taking the settings below you can then follow the software sections below this for the click-by-click setup guide.

28.8 or      
33.6 k
Transmission Rate:
   Minimum 2 Kbps
   Maximum 15 Kbps
Receive Rate:
   Minimum 2 Kbps
   Maximum 28Kbps
Max Viewable Video Windows:
56K Modem:   Transmission Rate:
   Minimum 2 Kbps
   Maximum 15 Kbps
Receive Rate:
   Minimum 2 Kbps
   Maximum 39 Kbps
Max Viewable Video Windows:
64k ISDN:  Transmission Rate:
   Minimum 2 Kbps
   Maximum 15 Kbps
Receive Rate:
   Minimum 2 Kbps
   Maximum 40-64 Kbps
Max Viewable Video Windows:

128k ISDN
Cable Modem:
Transmission Rate:
   Minimum 2 Kbps
   Maximum 15 Kbps
Receive Rate:
   Minimum 5 Kbps
   128k ISDN Maximum:
      100-128 Kbps
   Cable Modem Max
      100-500 Kbps
Max Viewable Video Windows:
Remember, the transmit rates are the MOST IMPORTANT settings!!! Most reflector will allow more on the Maximum Receive setting, check the MOTD (Message Of The Day) popup at log on to the reflector. These minimum rates are of little functional value other than to prevent you from being excluded from reflectors that enforce minimum rates. also see The Max Receive Myth Explained at the bottom of this page.

Cornell CU-SeeMe version 1.0a

Cornell CU-SeeMe v1.0a does turn off the video stream from closed windows quickly. For quicker turn off the video use the "close-all-windows" command/button (counter clockwise single arrow on the button bar)  . This can cause bad video for many seconds after closing windows.
I strongly suggest un-checking Open Video Windows Automatically under View, Preferences, General tab.

1 ) First select View, Preferences

2) Open the Rates tab. Below is the typical setting for a K56 or X2 or v90 modem

3) Individual reflectors will have to be re-set as well. Click Save for each reflector once all four rates have been changed.

White Pine CU-SeeMe Versions 2.x.x

White Pine Enhanced CU-SeeMe v2.x.x does not turn off the flow of video from the reflector of video-windows that you closed. The only way to turn off this video flow is to use the "close-all-windows" command/button (closed eye on the button bar). This is a longstanding bug that causes the majority of complaints about bad/broken video with this version. When the flow of these videos are still present it causes the same problems that having too many video windows open. Video slows, becomes choppier and motion gets jerky. In extreme cases previously opened windows will "freeze" and the just opened video window will remain black.

I strongly suggest turning off auto-open of remote video windows which will help immensely. Do this by clearing the Open and check box at Edit, Preferences, Conferencing tab, Remote Video Windows section. See the picture below.

NOTE: The Close All button  usually has to be hit multiple times to kill all of the video streams. Watch your local video window to see the actual Receiving:  rate drop as you hit the button. You WILL have to hit it MANY times and wait a while, be patient!! This defect will persist even after performing the settings below.

1) Select Edit, Preferences...

2) Then select the Communications Tab. Below is the suggested rates for a K56, X2 or v90 modem.

White Pine CU-SeeMe version 3.1.x and up

1) Click on Call Options, Profiles...

2) Select the Profiles Tab. With the profile your editing highlighted click the Edit button.

3) Select the Hardware Tab. In the Network Configuration area click on the down arrow . Scroll up to the top and select Custom. Do not be tempted to select your modem speed here! Now click the Customize... button.

4) Below is the area that the maximum rates are set. Don't be concerned about the minimums shown as you can't change them here.

5) Setting the minimum rates globally isn't possible. Please edit each reflector Contact card individually. Do this by right clicking on each of the reflector's Contact Card names in the Contact cards listing. Left click on Properties...

6) this brings up the Contact Card Editor. Select the Network Tab.

7) In the Compatibility section check Enforce Minimum rates settings. Modify the rates and OK all your way out.

The Max Receive Myth Explained

Okay folks, here it is: The last word on those of us with high speed modem/cable/ISDN connections and high receive rates.....This answer is direct from Brian "Spacer" Godette, author of "Godette's Enhanced Reflector"....There are few people with his expertise and knowledge of CU-SeeMe software and it's intricate workings....

At 11:47 PM 3/2/98 -0500, Hidday wrote:
> What is the effect of high RECEIVE rates on bandwidth?...That is, if one
> user is set to high receive rates (say above 28 to 56k) does it affect
> vid reception to others in the reflector, slow vid, degrade vid, etc?
> Transmit rates are obvious, but this seems to be an on-going discussion
> at the moment. With the trend to high speed modems and cable, friction
> seems to be on the increase if somone has high reception rates..Thanks
> Brian..I appreciate your time..AND ALL THE WORK you've put into make CU
> more pleasureable for us all...

High receive rates don't do diddly unless there's one of two conditions.

1) The main connection to the net the reflector can't handle the traffic. (reflectors on cable modems)

2) The backbone network between the reflector and the majority of users is congested. (reflectors outside the US mainly)

In any case Enhanced Reflectors limit the receive rate of the client to the max-max-recv or conf-max-max-recv setting. The next version (1.07 b9) also adjust the values in the OC packets before sending them out to the other clients to put the individual client's actual max receive rate in if it's set higher than what the reflector is set to.

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Last updated: Thursday, August 26, 1999 4:55:43 PM