Subject: [MIPSHOP-MIH-DT] [transport] Next steps

From: Telemaco Melia <[email-masked]>
Date: Wed, 01 Aug 2007 19:40:47 +0200

Nada,

Here is a brief summary of the discussions we had last week with Gorry. 
Please provide your feedback as soon as possible.

After the Thursday meeting, we agreed to adopt the following approach. 
First of all we should consider plain vanilla UDP (without any mechanism 
for ACK and congestion) and evaluate performance. This should help in 
getting a reference (worse case) scenario. These results should be then 
compared respectively with TCP and UDP + .21 ACK. By doing this we 
should get an idea of how the two approaches work and what is the best. 
It may turn out that there is not an optimal choice which could actually 
depend on the selected scenario. It is also a possibility that the .21 
ACK mechanism as specified in the draft needs to be modified/updated.
The list of issues identified today:
-- transport scenarios for IS,CS,ES focusing on the RTT between MIH peers
-- co-located or not co-located services (is there a requirement on the 
transport?)
-- rate (handover related?) and size of message exchange
-- what is the application layer retransmission mechanism including 
timers (.21 ACK)
-- concerns for large information transfer (fragmentation at MIH layer 
or transport, MIH data transmission rate control)
-- implication of the message exchange over congested links
-- queuing of messages with different priority (related to transport)

The identified metrics:
-- congestion on the link
-- latency
-- TCP over wireless and link diversity
-- TCP setup time
-- location of the MoS(RTT)
-- Fragmentation

Please let us know what you think and what is /is not achievable.

regards,
Telemaco

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From: Nada Golmie <[email-masked]>
Date: Mon, 06 Aug 2007 13:04:43 -0400

Hello All,

Thank You for compiling the list of issues that you'd like us to 
investigate. In fact we have started working on the next round of 
results and we are using this list to guide the simulation model 
extensions and the performance analysis. Given the current status of the 
model and the extensions we have in mind, we are looking at the 
following schedule for the results.

1) In the short term, we will focus on:
- transport scenarios for IS/CS/ES
- service co-location
- MIH message rate and size
- transport over congested links
- MIH ACK and retransmission timers

2) Then we will look at:
- MIH fragmentation
- MIH congestion control
- MIH priority queueing

Basically, the issues listed under "short term" will be investigated 
first and we should have results by the end of the month or in early 
September. In fact, we will provide results frequently and as soon as we 
have them in order to allow for frequent feedback and more fluid 
interactions. In the next week or so I will be sending detailed 
descriptions for the scenarios planned including network topology, 
parameters, etc.

Let me know if you have any questions or comments. Any feedback is 
always very appreciated.

Best wishes,

-Nada

Telemaco Melia wrote:
> Nada,
>
> Here is a brief summary of the discussions we had last week with 
> Gorry. Please provide your feedback as soon as possible.
>
> First of all we should consider plain vanilla UDP (without any 
> mechanism for ACK and congestion) and evaluate performance. This 
> should help in getting a reference (worse case) scenario. These 
> results should be then compared respectively with TCP and UDP + .21 
> ACK. By doing this we should get an idea of how the two approaches 
> work and what is the best. It may turn out that there is not an 
> optimal choice which could actually depend on the selected scenario. 
> It is also a possibility that the .21 ACK mechanism as specified in 
> the draft needs to be modified/updated.
> -- co-located or not co-located services (is there a requirement on 
> the transport?)

-- 
Nada Golmie, Ph.D. 
Manager, High Speed Network Technologies Group
National Institute of Standards and Technology
100 Bureau Dr. Stop 8920
Gaithersburg, MD 20899
Email: [email-masked]
Phone: (301) 975-4190
Fax:   (301) 590-0932
Web: http://w3.antd.nist.gov

---

From: Telemaco Melia <[email-masked]>
Date: Tue, 07 Aug 2007 11:27:14 +0200

Nada, all,

The list looks good to me. As soon as you have the simulation framework 
description available let's discuss it
on the mailing list to get an agreement also from the others, especially 
Gorry and Subir.

Thanks for your support and co-operation.

regards,
telemaco

Nada Golmie wrote:
> extensions and the performance analysis. Given the current status of 
> the model and the extensions we have in mind, we are looking at the 
> September. In fact, we will provide results frequently and as soon as 
> we have them in order to allow for frequent feedback and more fluid 
>> After the Thursday meeting, we agreed to adopt the following 
>> approach. First of all we should consider plain vanilla UDP (without 
>> any mechanism for ACK and congestion) and evaluate performance. This 
>> -- concerns for large information transfer (fragmentation at MIH 
>> layer or transport, MIH data transmission rate control)

---

From: Subir Das <[email-masked]>
Date: Wed, 08 Aug 2007 19:36:50 -0400

Nada,
Thanks for updating the status. It looks good to me.  Is it possible to
add transport security as well (in the next round)?

regards,
-Subir