Re: [manet] I-D Action: draft-ietf-manet-dlep-03.txt

["Stan Ratliff (sratliff)" <[e-mail]>]

On Sep 4, 2012, at 9:17 AM, Henning Rogge wrote:

> On 09/04/2012 02:17 PM, Mercieca, Victoria wrote:
>> Hi all,
>> 
>> I've also spent some time looking at the new DLEP draft and here are
>> my thoughts. I have divided my comments into notes on DLEP
>> functionality and notes on the document itself.
> 
> Hi,
> 
> triggered by your comment about the credit window system of DLEP I got
> another question.
> 
> If I understand DLEP right it handles a credit window per neighbor. How
> do we handle the common usecase where we have a radio with a "sender
> window", which means we have credits for sending data, but not to a
> specified receiver.

I've never seen, nor dealt with, such a device, and we have the credit windowing of RFC4938/RFC5578 deployed with multiple radios.  What you imply is a credit scheme that would exist from router to modem, and the 03 DLEP specifically precludes that. 

> 
> Lets say our radio (because of some TDMA waveform) has an outgoing
> credit window of 1000 bytes.

Sorry, but I can't envision a TDMA radio that doesn't have a "specified receiver". After all, isn't that the point of TDMA? That being, that *someone* "out there" is listening at the time you're sending? Now, there could be a broadcast/multicast slot, but that would be handled in DLEP by using the correct MAC address (e.g. for the broadcast/multicast) and creating a neighbor.

Regards,
Stan


> 
> Do we set the credit window of every neighbor to 1000 bytes? This would
> mean we might get 1000 bytes for every neighbor, which is too much.
> 
> Do we distribute the 1000 bytes among our neighbors? This would prevent
> any outgoing traffic to use the full 1000 bytes.
> 
> I think this should be considered before we build a Credit Window Scheme into DLEP that is not applicable for this use case.
> 
> Henning Rogge
> 
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