[ofw] some WinOF questions

[Diego Guella]

----- Original Message ----- 
>From: "Tzachi Dar" <tzachid at mellanox.co.il>
>
>> -----Original Message-----
>> From: Smith, Stan [mailto:stan.smith at intel.com]
>> Microsoft requires those who distribute SDP to sign a license
>> with MS concerning IP rights of SDP.
>> Since WinOF is open-source MS has declined to offer an SDP
>> licensing option, therefore SDP is not part of WinOF (Windows
>> OpenFabrics which is based on the openib-windows src tree).
>
>[I'm an Engineer not a lawyer, so here is how I understand this, I might
>be very wrong about this]
>Microsoft indeed requires a license to distribute SDP in source code.
>As a result it can not be an open source program. Still, one can use
>binaries that it receives from Mellanox in order to use SDP with the
>open fabrics software.
>In order to get the source code of SDP in order to be able to contribute
>one has to sign an agreement with MS. This is indeed a barrier, but it
>can be passed, and was already passed twice.
>So, on the practical reason, one can use SDP (binaries) with the open
>fabrics code.

I don't follow you. Do you mean I can install WinOF 1.0, then manually copy 
some files from WinIB, execute some commands and I have SDP enabled and 
working on WinOF?
What advantages will I have over WinIB 1.3, which has SDP bundled in?

>Please note that WSD has many drawbacks, which makes it practically
>useless:
>1) No support for XP or Vista.
>2) No interoperability with Linux or any other OS.
>
>Both 1,2 are MS design that doesn't seem to change soon. This removes a
>big part of the market.
>3) Very low performance (compared for GE for example):
>a - BW for small messages is around GE. Only for messages
>          that are bigger than 500K we start to see the real advantages
>of it.
>b - High latency, almost double the latency of SDP. (~12us on
>WSD compared to 7us on SDP).
>c - Connection rate of around 100 CPS compared to more than 2000
>CPS on GE.
>
>4) No support for UDP or Multicast.
>Looking at the spec, SDP doesn't support multicast or
>      UDP as well, but they can be added relatively easily.

The cost of Windows Server 2003 and the missing interoperability with Linux 
are enough for me to not consider WSD.