[Olsr-dev] [PATCH v1 0/3] Use bandwidth during gateway selection

[Ferry Huberts]

On 27-07-12 15:35, Teco Boot wrote:
> Me, as dummy, get easily confused.
>   - Factors should be multipliers.
>   - Lower data rate links would have high influence, in a balanced way.
>
> My proposal:
>    Config option:                   Recommended value:   Default:
>    ==============================   ==================   ========
>    SmartGatewayWeightEtx            1.00                 1.00
>    SmartGatewayWeightExitLinkUp     1.00                 0.00
>    SmartGatewayWeightExitLinkDown   1.00                 0.00
>
> And calculate such as:
>
>    SmartGatewayWeightExitLinkUp
>   ------------------------------
>
>                          SmartGatewayWeightExitLinkUp
>     costExitLinkUp = -----------------------------------
>                      SmartGatewaySpeed(upstream) *  1000

   SmartGatewaySpeed(upstream) *  1000
gives you bps

I think you want
   SmartGatewaySpeed(upstream) / 1000
right?

>
>                          SmartGatewayWeightExitLinkDown
>     costExitLinkDown = -----------------------------------
>                        SmartGatewaySpeed(upstream) *  1000
>

same here

>     costEtx = SmartGatewayWeightEtx * PathEtxCost / 4

what's with the magic constant 4?
how about
   costEtx=(SmartGatewayWeightEtx/SmartGatewayDividerEtx)*PathEtxCost

>
>
>     gw_cost =  costExitLinkUp + costExitLinkDown + costEtx
>
>
> Teco
>
>
> Op 27 jul. 2012, om 14:06 heeft Ferry Huberts het volgende geschreven:
>
>>
>>
>> On 27-07-12 13:59, Daniel Nitzpon wrote:
>>> Hi!
>>>
>>> Am 27.07.2012 13:21, schrieb Teco Boot:
>>>> I also want to see comments. Maybe also:
>>>>   - not interest in SmartGW at all
>>>>   - interested, but not tried yet
>>>
>>>>
>>>> Op 27 jul. 2012, om 12:50 heeft Henning Rogge het volgende geschreven:
>>>>
>>>>> I would like to hear some comments about this from someone who has
>>>>> USED the SmartGW system.
>>>
>>> Haven't used it yet, sorry..
>>> But still a comment:
>>>
>>>>> On 07/26/2012 04:23 PM, Ferry Huberts wrote:
>>>>>> - We calculate a new path cost of
>>>>>>
>>>>>>      new_path_cost = (1 / (uplink + downlink)) + (tc_path_cost / 4)
>>>>>>
>>>>>>    (uplink and downlink in Mbps)
>>>>>>    (the 1 and 4 are weighing factors and we can make then configurable)
>>>
>>> Freifunk experience here tells that in shared gateways via ADSL the
>>> uplink is usually a much more limiting factor than the downlink. So I
>>> would propose something along the lines of
>>>
>>> new_path_cost = (1 / 2*(min (uplink*4, downlink))) + (tc_path_cost / 4)
>>>
>>> (without having a real opinion on the weighting factors, just introduced
>>> 1/2 to preserve the magnitude of the original suggestion)
>>>
>>
>> Interesting point.
>> I did think about this a few days ago, but wanted to propose the simple scenario first ;-)
>>
>> How about scaling the combined bandwidth back with an asymmetry factor, something like:
>>
>>
>> asym = (uplink > downlink) ? (downlink/uplink) : (uplink/downlink)
>> new_path_cost = (1 / (asym * (uplink + downlink))) + (tc_path_cost / 4)
>>
>>> Daniel
>>>
>>
>> --
>> Ferry Huberts
>>
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>

-- 
Ferry Huberts