Re: Refs or no refs, 1 frame/10 minutes

Rolf Hemmerling (hemmerling@geocities.com)
Mon, 27 Oct 1997 23:25:08 +0100


By now, with WP Cu-SEEME 2.1.1x, I had configured the client to allow
"up to 8 clients", even if I did not want to see 8 videos at the same
time, and auto-opening and closing was activated (because these are the
default values

Now I changed that to "up to 3 clients" for my 28.8 K connection,
minimum transmission and reception rate is 10, maximum transmission and
reception rate is 28, and I disabled auto-opening and auto-closing.
To get rid of the common Closing-Video-Window bug of WP 2.1.1x, I close
*all* windows by the "close eye" button and reopen the corresponding
windows again immediately afterwards, from time to time and if I would
like to select a new video by a different user.

So instead of clicking away "new" windows opened automatically by the
client, I just allow 3 clients, and I select the ones that I want. In
the past, I clicked away freshly automatically opened windows very often
and with a rather high frequency. So it was really a task to keeep all
unwanted windows closed.

This change in the configuration seeems to help much.

If I meant 1 frame/10 minutes I mean that if there are 10..20 users,
and if I click on the window, even after a few minutes the picture is
not filled by the video pictue, and especially that the picture is not
moving (updating) properly. There is a certain mechanism in the CU
transfer protocol so that only "new" informations are transfered. This
causes the well-known effect of several (dark) shapes of the moving
object (face, body) on a video picture so that after all nothing can be
recognized properly !!

I never had problems with video transmission as long as there are just 3
or 4 other users on a ref !!! Nevertheless, if some of the users have
bandwidth limitations by itself, their video doesn=B4t appear on my
screen even after a minute. Then I press the close-eye button, reopen
the already successfully connected videos and try again.

>=20
> v2.* does not turn off the received video stream from vid-windows th=
at
> you close by closing the window directly or by using the participant=
s
> list. The only way to turn off the video stream is to use the
> "close-all-windows" command/button (closed eye on the button bar).
> This is a bug that causes the majority of complaints about bad/broke=
n
> vid, this is also why it's strongly suggested to turn off auto-open =
of
> remote video. This bug also seems to be an extention of the old
> Cornell "null-assertion" problem with the participants list.
>=20
Thanks for that quotation, I didn=B4t read that before. So I ran into thi=
s
trap:
Auto-opening of up to 8 windows, and I closed many windows manually
again and again during a session... maybe I even had 30 pseudo-closed
channels open, so that there is not even the limit to 8 open channels,
or ?

> Not that I know of..Actually, if you have a 28.8kbps modem and are send=
ing
> around 15kbps, you can't receive the full rate that the others are send=
ing
> at (assuming they are sending at 15kbps as well)
> Total sending for you =3D 15kbps
> Total receive for you =3D 15kbps X 2 vids =3D 30kbps.
> -------------------------------------------------
> 45kbps total required...neglecting the overhead=
of
> the reflector (The overhead of Cornell reflectors is much more than tha=
t
> of WP or Enhanced Reflectors).
>=20
> Assuming the others are sending around 15kbps, you can get all of their
> vid if you keep one window open and are sending around 15kbps. I've
> always had problems with CU in opening up more than 2 windows. The
> problem is made even worse if the people you are trying to see are usin=
g
> color. Even with 2 windows open, the color window may never update.
Hmmm.. modem connections are bidirectional: So I may send with 15 kbps
and receive 28.8 kbps. Just the ref must handle 45 kbps. I hope that the
ref does not send me back my 15 kbps, or ???? That would be a great
fault, from my pov.=20

> How about if his whole ISP was on a 128K line? :)
My very-first commercial ISP had a single 64K line (or two single 64K
lines, I don=B4t remember) in January 1996, and asked for 19 DM (=3D $10)
per month for an **unlimited** account (no volume,no time limit, no
homepage, no newsserver). The ISP server was the home of the "biggest
german Internet database for classified adds", though, additionally. At
that time, I did not think about iphoning or even video phoning.=20

The database is also published on paper two times a week, and it is
really one of the big newspapers for classified ads in Germany. So just
the connection, not the database was the fake, but just from the pov of
today. Nevertheless, it worked, I never complained. Especially in whole
1996 until early 1997, the database was *free*, so because all was on
the same server, quick and cheap reading of the newspaper was possible
without pain with this account !! Today, of course, they have a 2 MBit
line, but the database is not free anymore.

> Or the routers between him and the rest of the world were constantly
> congested?
As I said, I am surfing in the calm times of the Internet day, at=20
6.00-8.00 a.m local time (CET with daylight savings) =3D 5.00-7.00 a.m GM=
T
with daylight savings. There is not congestion at that time, neither in
Germany / Europe nor in USA !
>=20
> It seems to me more like a problem with the local internet service and =
his
> link to outside of his country that's the problem. If he has slowness
> problems on virtually every reflector, then you can't say it's the
> reflector that's slow. Getting another service provider won't fix a th=
ing
> if there's only one, already overcrowded, pipe leaving the country. It=
's
> nice to be in America where that problem doesn't exist on such a widesc=
ale
> basis. (ie: don't think your ISP has enough bandwidth to support its
> users, get another one that does).
Again.. at busy times, there is a breakdown with some providers
(DEUTSCHE TELEKOM). At calm times.. this all does not really matter.
>=20
> In America, we seem to believe if you have the money, you can get as mu=
ch
> bandwidth as you want. If you can afford it, you can have a T1/T3 runn=
ing
> to your home. Unfortunately, for other countries it doesn't sound like
> that can happen. Of course, I'm only guessing here.
Again, tell me please the kbps values of T1 and T3. ISDN has 64 KBit,
channel bundeling (=3D 128 KBit) is not usual for accessing ISP accounts.
Analog lines
allow 33.6 Kbit, and with the new 56K-FLEX technology by US-ROBOTICS, we
may download with 56 KBit and upload with 33.6 KBit.
>=20
> As an aside...I have seen someone offering $5/month dialup accounts on =
his
> 128Kbps ISDN system. So it HAS been done. :)
Yes, in Germany too, see above.
> The latest thing I've heard about are cable modem users reselling their
> bandwidth to make a profit.
The real problem with cable modems in Germany is that the backchannel
must be opened by the telephone line with its expensive time rates,
because our European / German cable systems are not bidirectional by the
transmission amplifiers !!! lol (or not lol)!!!

Sincerely
Rolf
--=20
/ / / Alone on the data highway...
/ / like on an allee in Hannover-Herrenhausen
/ / / Rolf Hemmerling, Germany
/ / http://home.pages.de/~rolf.hemmerling/