[ofw] Hello there

[Hefty, Sean]

> Our needs are: program at user mode level, right now we are interested in
> XP/2003, and in the future maybe move to 2008. We really want to get the
> maximum of the card for low latency. We need to handle multicast traffic
> (UDP), as well as TCP traffic. I went through the Mellanox webpage, and
> couldn't find any place where you guys provide documentation/apis to
> download. Should I keep looking there or this mailing list is going to help
> me to get where I want?

The text below is from an interfaces.txt file found in the windows source tree.  Based on your requirements, I believe that only the Microsoft defined API, NetworkDirect, will NOT meet your needs.  It does not support UD or multicast.  The other APIs support RDMA and UD communication.  Note that these APIs support channel based communication over queue pairs.  These are not socket based interfaces and do not provide TCP or UDP offload directly.  Other possibilities include using a Winsock Direct provider (WDP) and Socket Direct provider (SDP).  These support the winsock interfaces, but you will give up latency in both of those cases.

The OFA source tree is available from SVN and also mirrored to a git tree on the OFA server (http://git.openfabrics.org/git?p=~shefty/rdma-win.git;a=summary).

- Sean
 
WinOF provides several userspace interfaces.  The main application
interfaces are given below, along with a brief description of each.


libibverbs
OFA interface available on windows and linux
	This is the only linux verbs interface, which was ported to
	windows to support portability.  This sits over winverbs.
	It provides low abstraction to the hardware, but does not
	expose windows specific	features, like overlapped operations
	for asynchronous control.  This is a good choice for low-level
	access, with portability between windows and linux.

WinVerbs
OFA windows interface
	Lowest level windows verbs interface for applications.  Most
	of the other interfaces sit over this interface.  This provides
	the lowest abstraction to the hardware, while also exposing
	windows specific features.  This is a good choice for
	low-level access on windows.

DAPL (Direct Access Programming Library)
Industry standard RDMA interface for multiple OS's
	Hardware providers may support this interface, even if not
	part of OFA.  This sits over libibverbs and ibal.  This provides a
	higher level of abstraction, but provides the most portability.

Network Direct (ND)
Microsoft defined interface for windows
	Hardware providers may support this interface, even if not
	part of OFA.  This sits over winverbs and ibal.  This provides
	a higher level of abstraction, but may provide access to the
	most hardware on Windows platforms.

IBAL (InfiniBand Access Layer)
OFA windows interface
	Older windows interface.  This is currently a peer to winverbs,
	with a longer term goal of moving it over winverbs.  The
	interface will be supported going forward.  This provides low
	level abstraction, but does not expose windows specific features.