Subject: Re: Tiny ant vs big Mammoths, was RE: [Simple] Using MSRP for real time text conversation

From: Dean Willis <[email-masked]>
Date: Thu, 01 Jul 2004 11:03:56 -0500

A vWijk wrote:
> My comment marked with ***
> *** The discussion about MSRP is only to play with the idea of using MSRP for interactive text.
> The idea to lift with the instant messaging revolution on terminals is apealing.
> But we stay with t140/rtp as described in RFC 2793( bis-07).
> But introducing new interactive text formats raises the danger of incompatibilities. So that is why I am negative about just using MSRP for interactive text.
> 
> So... t140/RTP is a great solution and the redundancy usage of 2 generations are indeed sent by the next packet that would be sent anyway. So there is hardly any load increase at all.
> And I had yesterday a call with interactive text (t140/RTP) along with audio and video, the connection was not so good, 20% packets drop with peaks to about 40% lost packets. Sound was bad (according the hearing person, video was also bad with blocks in it..but the interactive text worked just flawlessly. When disabling the interactive text, the audio and video staryed just as crappy as they were.
> We talk about 2-3 kbit/sec out of 384 kbit total bandwidth used!!! THAT is now we are talking about (yes with redundancy on!)..a tiny little ant along the Mammoths.
> 
> Just to bring it into the right perspective. :-)
> 
> So, there is nothing wrong with RFC2793 interactive text. Except perhaps that a device that does not support RTP cannot use T140/RTP.
> 

No, let's put it in the right perspective.

Assume real-time text drives 2kb/s of bandwidth, or approximately 3 
packets per second.

Assume 20,000,000 users are running real-time-text sessions 
concurrently. This is approximately peak load for a really big mobile 
operator, and well below peak load for the Internet as a whole.

Assume that real-time text continues to operate without the sort of 
congestion control that forces it to "back off" in the event of network 
congestion.

We now have 40 billion (40E9) bits per second of 
non-bandwidth-controlled traffic out there, or approximately 60E6 
packets per second.

Will any of this ever traverse a link that is also trying to carry nice 
friendly TCP traffic? Will that link ever get congested? Will the 
real-time text "starve out" the TCP traffic when it does? The answers 
here are most likely "yes" . . .

How can you assure us that this will never happen? Are operators going 
to build dedicated networks for real-time text? Are we going to use 
DS-markings to make real-time text low priority and discardable?

Or, otherwise said, what gives real-time-text the "right" to cheat the 
rules and unfairly consume scarce network resources? Does any 
application have that right?

--
Dean

_______________________________________________
Simple mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/simple

---

From: "Arnoud van Wijk" <[email-masked]>
Date: Thu, 1 Jul 2004 19:23:34 +0200

Dean,

I said this to indicate that the method Interactive text is using for
redundancy will only slightly increase the bandwidth. There are generally no
more packets per second being sent with redundancy, the redundant generation
is sent with the normal next batch of typed characters in the following
packet! 
Think of a bus with 10 characters in it or a bus with 20 characters in it.
It is then the same bus.

It is not 1 packet per character! Unless you t  y  p  e   s  o    s  l  o  w
that there is a second or more between every character or so. :-)

And if there is a congestion like you described with so many Interactive
text streams. Normal congestion mechnism that are used for other RTP traffic
will also apply for Interactive text.
Also as stated in the 07 version of the RFC 2793 bis draft, if there is a
good mechanism that prevents dropped packets..then that can be used instead
of the 2 generations redundancy.

So, I do not see the problem.

Greetz

Arnoud

-----Original Message-----
From: Dean Willis [mailto:[email-masked]] 
Sent: donderdag 1 juli 2004 18:04
To: A vWijk
Cc: [email-masked]; [email-masked];
[email-masked]; [email-masked]; [email-masked];
[email-masked]; [email-masked]
Subject: Re: Tiny ant vs big Mammoths, was RE: [Simple] Using MSRP for real
time text conversation

A vWijk wrote:
> But introducing new interactive text formats raises the danger of
incompatibilities. So that is why I am negative about just using MSRP for
interactive text.
> 
> So... t140/RTP is a great solution and the redundancy usage of 2
generations are indeed sent by the next packet that would be sent anyway. So
there is hardly any load increase at all.
> And I had yesterday a call with interactive text (t140/RTP) along with
audio and video, the connection was not so good, 20% packets drop with peaks
to about 40% lost packets. Sound was bad (according the hearing person,
video was also bad with blocks in it..but the interactive text worked just
flawlessly. When disabling the interactive text, the audio and video staryed
just as crappy as they were.
> We talk about 2-3 kbit/sec out of 384 kbit total bandwidth used!!! THAT is
now we are talking about (yes with redundancy on!)..a tiny little ant along
the Mammoths.
> So, there is nothing wrong with RFC2793 interactive text. Except perhaps
that a device that does not support RTP cannot use T140/RTP.

--
Dean

---

From: "Arnoud van Wijk" <[email-masked]>
Date: Thu, 1 Jul 2004 23:37:31 +0200

Henry,
Do you know what the danger is?
I already see it emerging.

Here at the IETF many are wonderful and quite supporters for Interactive
text. But their bosses..higher up pointed haired bosses are just dumb and
only see what they know.

Interactive text is scary for them. They do not believe that many will use
it under condition that it is available in as many phones as possible!
All mobile phones offer SMS (Europe, Asia). But most do not use it. But a
significant group does. Even though text input is very clumsy using
numerical key combinations.

Too many say right now EXACT the same thing as with Interactive text.
SMS/Interactive text? Hardly anybody is interested in it. Why send text
while you can just as quickly place a voice call? There is no need for
SMS/Interactive text. People won't use it Don't like it.

(sounds familiar?)

My message to the vendors is simple: implement interactive text. Text/t140.
If you have a phone with IM capabilities, add interactive text!
Try interactive text in as many phones you produce! People will be grateful
for it and buy your products.
I am not saying that every phone must have it. But in every price range,
have enough models with text/t140.
It is cheap to implement, it adds value to your phone for the buyers. And
those who don't care, will likely later appreciate interactive text as soon
they discover it. And keep buying your IP phones for their kids, family
members..new phone etc etc.

We, the IETF cannot mandate this. But we are a bunch of smart people. So, we
do know what we do.

Greetz

Arnoud

-----Original Message-----
From: Henry Sinnreich [mailto:[email-masked]] 
Sent: donderdag 1 juli 2004 21:53
To: 'Arnoud van Wijk'; 'Dean Willis'
Cc: [email-masked]; [email-masked];
[email-masked]; [email-masked]; [email-masked];
[email-masked]; [email-masked]
Subject: RE: Tiny ant vs big Mammoths, was RE: [Simple] Using MSRP for real
time text conversation

Arnoud,

I have to agree with Dean's arguments and add that in dealing with real
vendors and program managers, even what is 100% consensus in the IETF is "in
the next generation" (in a next life probably) under consideration for them.

So let's do a reality check and come back with these issues after we had a
couple of months to check with vendors and program managers, so we don't
spin our wheels here in the list.

Henry

Henry Sinnreich
MCI
400 International Parkway
Richardson, Texas 75081
USA
 
-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf
Of Arnoud van Wijk
Sent: Thursday, July 01, 2004 12:24 PM
To: 'Dean Willis'
Cc: [email-masked]; [email-masked];
[email-masked]; [email-masked]; [email-masked];
[email-masked]; [email-masked]
Subject: RE: Tiny ant vs big Mammoths, was RE: [Simple] Using MSRP for real
time text conversation

Dean,

Greetz

Arnoud

-----Original Message-----
From: Dean Willis [mailto:[email-masked]] 
Sent: donderdag 1 juli 2004 18:04
To: A vWijk
Cc: [email-masked]; [email-masked];

--
Dean

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---

From: Henry Sinnreich <[email-masked]>
Date: Thu, 01 Jul 2004 14:53:17 -0500

Arnoud,

Henry

Henry Sinnreich
MCI
 
-----Original Message-----

Dean,

Greetz

Arnoud

-----Original Message-----
From: Dean Willis [mailto:[email-masked]] 
Sent: donderdag 1 juli 2004 18:04
To: A vWijk
Cc: [email-masked]; [email-masked];

--
Dean

-