Re: RE: Hardware shaping

["Ronnie Lindgren" <ronnie@radiolan.se>]

Thanks!
That means that the PCA200E may not work with our ISP. In this case, if I understand it right (i'm a newbe), the PCA200E fills up the stream with idle cells up to 155 Mbps? That should explain why it don't work. 

Is an idle cell equal to an empty cell? What size is an idle cell?

Are there any other NICs that work without transmitting idle cells when shaping? Are there a way to filter these idle cells away? 

/Ronnie


-----Ursprungligt meddelande-----
Från: Gianluca Insolvibile <g.insolvibile@cpr.it>
Till: Ronnie Lindgren <ronnie@radiolan.se>
Kopia: linux-atm@lrc.di.epfl.ch <linux-atm@lrc.di.epfl.ch>; Linux Fore 200E list <pca200e-linux@os.inf.tu-dresden.de>
Datum: den 21 maj 1999 09:45
Ämne: Re: Hardware shaping


>Hi,
>as far as I know, the PCA200E performs hardware shaping by inserting "idle" cells in the output cell stream, which is always transmitted at 155 Mbps (i.e., if you want to transmit cells at 100 Mbps, the NIC will alternate sending 2 "normal" data cells and 1
>idle cell, with a constant rate of 155 Mbps).
>If I'm not wrong, the idle/good cells ratio is controlled by the driver, which has no other means to lower to transmit rate.
>
>Regards,
>    Gianluca
>
>Ronnie Lindgren wrote:
>
>> Hi all,
>>
>> Question:
>> Exactly, how does the hardware shaping work on the PCA200E with Linux ATM?
>>
>> Our config:
>> atmarp -s 195.163.xx.yy  0.0.33 qos cbr:pcr=166cps
>>
>> Problem:
>> In this case, our ISP's ATM-switch cuts our traffic when it is heavy loaded. Small packages can get through (5 bytes). Big packages don't.
>>
>> It seems that the Linux-ATM shaping is different than the switch (unknown brand). When our ISP configures their switch to 80-90 Mbits/s everything works ok. But, when shaping is set to 2.5Mbit/s on the switch (same as our shaping above?) it don't work. Why?
>>
>> /Ronnie
>>
>> kernel - linux-2.0.29
>> atm    - atm-0.31
>> pca_200e - pca_200e-0.2
>>
>> ____________________________________________
>> ronnie@radiolan.se
>> ____________________________________________
>
>
>
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>| Gianluca Insolvibile                                       |
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