Subject: Re: Bandwidth Brokers

From: Raj Yavatkar <[email-masked]>
Date: Mon, 22 Dec 1997 12:14:47 -0800

Juha,

when you say you don't like CL, is it because of a lack of quantitave
measure to verify it. The way I look at it, you are free to define service
profiles for aggregate traffic that takes into account (with some
approximation) a user's per-flow requirement. You can continue to use
intserv model at the host-network boundary or over the last mile before you
go into the ISP's big net.

Raj

At 09:47 PM 12/22/97 +0200, Juha Heinanen wrote:
>   >In summary, I think that we should, for the sake of consistency (and
>    because 
>   >it seems to make sense), continue to apply the intserv model, at least at
>   >the host/network boundary. This means (to me):
>   >
>   >- Using a set of service types.
>   >- Defining our offered traffic (or requested traffic) using the
>   token bucket 
>   >model.
>   >- Providing filterspecs to describe the packets which should be
associated
>   >with the service type and the token bucket model.
>
>i don't like at all the controlled load as a service type and definitely
>don't want to support that in my network nor to constraint my diff-serv
>profiles to those defined by int-serv.  the isps should be given the
>freedom to define their own profiles.  it has been the assumption on
>this mailing list from the very beginning that the profiles are not to
>be standardized and i don't like to change that.  it is enough that the
>semantics of the bits in the packet header are agreed upon.
>
>-- juha
>
>

-----------------------------------------
   Raj Yavatkar                                       
   Communication Architecture Lab           [email-masked]
   Intel Corporation, JF3-206                     voice -- 503-264-9077
   2111 NE 25th Avenue,  Hillsboro, OR 97124

---

From: Juha Heinanen <[email-masked]>
Date: Mon, 22 Dec 1997 22:35:43 +0200

one reason why i don't like cl because it allows best effort packets to
be sent out of order.  also, if i remember correctly, it didn't allow
queueing of packets, but required them to treated as if the user would
be alone on the internet.

i must repeat that i'm very worried about the invasion that int-serv is
trying to make to diff-serv.  we were supposed to be defining very
simple delay and drop semantics (or corresponding mechanisms) for the ip
header bits, but now the trend seems to be how to provide int-serv
services with aggregate flow specs.

i think it would be high time to create the diff-serv working group and
select a chair that has had nothing to do with the (academic) int-serv
effort. isp would have needed the diff-serv bits to be defined
yesterday.

any router vendors willing to go for an experimental rfc with one delay
bit and one drop preference bit in order to get things moving and
something deployable for the isps?

-- juha

---

From: Paul Ferguson <[email-masked]>
Date: Mon, 22 Dec 1997 15:47:49 -0500

>effort. isp would have needed the diff-serv bits to be defined

I echo your concerns here, and *strongly* agree with your second
paragraph.

Having said that (and I've said this before), I don't want to
explicitly preclude interworking with intserv mechanics. We just
have a pretty simple problem that needs to be solved, and trying
to mix intserv & diffserv from the onset is simply muddying the
waters, imho.

- paul

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From: Roch Guerin <[email-masked]>
Date: Mon, 22 Dec 97 18:51:16 -0500

Juha,
>be alone on the internet.

I believe that CL has undergone a number of adjustments since it was first
proposed.  I believe that it now explicit states that preserving packet ordering
is preferred (although not mandated).  Similarly, queueing of packets is 
definitely allowed (I think there was some confusion initially due to the
terminology of service definition which involved comparison to an "unloaded"
network).

>trying to make to diff-serv.

No invasion in sight ;-)  just would like to make sure that the door is open
for some mapping, e.g., a bit combination for the service class.  Diff-serv
wont have to worry about how it's used or how to do aggregation, so I don't
think this will hamper that effort.

Roch

---

From: Wu-chang Feng <[email-masked]>
Date: Tue, 23 Dec 1997 12:14:38 -0500 (EST)

> ....[discussion of controlled-load service deleted]..
> proposed.  I believe that it now explicit states that preserving packet 
> ordering is preferred (although not mandated).  

If this is the case, then compliant and non-compliant packets of the same
flow see similar delay.  How is this any different than protected best-effort
service, then?

It seems peculiar to me that two of the services which are currently
being proposed for diffserv (premium and assured) are minor variants of
intserv services (committed rate and protected best-effort) which were 
already looked at and discarded.  Did the use of priority bits 
somehow change the services we want out of the network?

Wu

---

From: Roch Guerin <[email-masked]>
Date: Tue, 23 Dec 97 13:19:20 -0500

>flow see similar delay.  How is this any different than protected best-effort

Wu,

compliant and non-compliant packets do indeed see the same delay, but assuming
you have a DP bit, they would not see the same loss.

Wrt the difference with pbe, I'd need to go back to Juha's draft to be specific,
but from what I recall, some of the motivations for not introducing new 
services, e.g., pbe or cr, was that it was deemed that CL was already not that 
different.  
Roch

---

From: Juha Heinanen <[email-masked]>
Date: Wed, 24 Dec 1997 12:33:39 +0200

Cc: [email-masked] (Roch Guerin), [email-masked]
   Wrt the difference with pbe, I'd need to go back to Juha's draft to
   be specific, 
   but from what I recall, some of the motivations for not introducing new 
   services, e.g., pbe or cr, was that it was deemed that CL was already
   not that different.  

it was different.  i didn't write if for fun, but because cl didn't meet
my requirements.  if you find the draft somewhere, email me a copy too.
my disk crashed about a year ago and i lost it.  if i rememebr
correctly, the latest version was 01.

-- juha

---

From: Roch Guerin <[email-masked]>
Date: Wed, 24 Dec 97 08:57:28 -0500

Juha,

>my requirements.

Did not say CL was not different at the time.  It was.  However, it has been
modified since then so that the differences are smaller.  I think the view then
was that CL could be evolved to address some of the issues/aspects brought
forward in the PBE and CR drafts.

>if you find the draft somewhere, email me a copy too.

On its way by separate mail.  Btw the last version I had was 02.

Happy Holidays.

Roch