Q1: What is OpenRDMA?
A1: OpenRDMA is an industry open source effort.  The primary focus of this effort is to enable RDMA (Remote Direct Memory Access) technology to operate over high-speed I/O interconnects such as Ethernet and InfiniBand.  RDMA technology may be implemented through a combination of hardware and software or entirely in software.


Q2: What specifications does OpenRDMA support?
A2: OpenRDMA utilizes specifications from the IETF, DAT, and the OpenGroup Interconnect Software Consortium (ICSC).  
        
The IETF specifications (aka iWARP) cover:
* RDMA version 1.0 RFC <TBD> Protocol
* Direct Data Placement Protocol version 1.0 RFC <TBD> (DDP)
* MPA version 1.0 RFC <TBD> (Marker PDU Aligned Framing).

Additional upper layer protocols (ULP) are being considered within the IETF: 
* iSER version 1.0 RFC <TBD> (iSCSI Extensions for RDMA)
* SDP version 1.0a (Sockets Direct Protocol) from the RDMA Consortium

OpenGroup Interconnect Software Consortium ICSC specifications cover:
* IT API version 1.0 - Interconnect Transport API (superset of uDAPL) 
* IT API version 2.0 - Extensions for iWARP / InfiniBand 1.2 Verbs and kernel-space 
* RNIC PI version 1.0 - RDMA NIC Provider Interface (direct access to RDMA hardware) 
* Sockets and Sockets Extensions version 1.0 - Required POSIX / Unix branding compliant Sockets API specifications

DAT specifications cover:
* uDAPL version 1.1 - User-space Direct Access Provider Library
* kDAPL version 1.0 - Kernel-space Direct Access Provider Library

Using these specifications, OpenRDMA will be capable of supporting a wide-range of applications, API, and kernel subsystems: MPI (Message Passing Interface), traditional Berkeley Sockets as well as the new OpenGroup Sockets Extensions which add asynchronous and explicit memory management support (requires use of the Sockets Direct Protocol), NFS RDMA Extensions, iSCSI Extensions for RDMA (iSER) over iWARP as well as potentially InfiniBand, SRP (SCSI RDMA Protocol), Lustre, distributed database, GRID computing, etc.  


Q3: Where is OpenRDMA source repository?
A3: OpenRDMA is hosted on http://sourceforge.net/projects/rdma 


Q4: What is the initial set of components to be developed?
A4: The initial focus will be on the RNIC PI, IT API, and DAPL interfaces.  This will enable RDMA-based user and kernel applications to be quickly ported.  As this effort evolves, new RDMA-based applications will be enabled. 


Q5: Where can I find more information about OpenRDMA and its architecture?
A5: All documentation, architecture overview, etc. can be found at <insert URL>


Q6 Can anyone participate in the OpenRDMA effort?
A6: Yes.  OpenRDMA is an open source effort open to any who wish to contribute their time and energy to developing software.  This is an open source community effort thus does not require a membership agreement or similar legal documentation to participate.  All are welcomed to contribute.  To join, see the following URL http://sourceforge.net/projects/rdma. 


Q7: What open-source licensing will be used?
A7: OpenRDMA will support both GPL and MIT licensing to enable the broadest adoption of this software.


Q8: How will IHV (independent hardware vendor) integrate their products into this open source architecture?
A8: The RNIC PI provides an abstract yet high-speed interface to enable easy integration of IHV hardware without permuting the rest of the OpenRDMA architecture. OpenRDMA-based subsystems, e.g. IT API or DAPL, use the RNIC PI entry points to communicate to IHV hardware.  The IHV provides libraries with the associated entry points to be linked into the OpenRDMA stack.  This enables OpenRDMA to simultaneously support multiple IHV implementations and interconnect types.

Q9: What is the relationship of OpenRDMA and OpenIB.org?
A9: While there is functional overlap and architectural similarities between OpenRDMA and OpenIB.org, the two efforts differ in their focus.  OpenRDMA is focused on creating a complete ecosystem based on open, industry standards interfaces that will easily operate over any industry-standard RDMA-capable solution.  This will allow the OpenRDMA architecture to operate over a wide-range of implementation options and interconnects, e.g. software-based or hardware-based RDMA over the IP protocol suite (aka iWARP) and InfiniBand (hardware-based industry standard RDMA interconnect).  The objective is to enable the broadest set of applications and kernel subsystems to be cleanly layered on top of this RDMA infrastructure without sacrificing performance, modularity, or quality.  This will enable faster adoption of RDMA-based solutions without requiring the entire solution space to be re-implemented whenever something changes in the RDMA infrastructure or associated specification suite.  OpenIB.org is focused on creating an InfiniBand-based open source environment.


Q10: Will OpenRDMA and OpenIB.org merge in the future?
A10: Given these two efforts are relatively nascent in terms of development, anything is possible however there are currently no discussions occurring on this topic.


Q11: What e-mail reflectors are available for those that want to participate in this effort?
A11: There are three reflectors available:
        (1) rdma-developers     - used for source development discussions
        (2) rdma-general        - used for general RDMA technology, questions, etc. discussions
        (3) rdma-arch-wg        - used for OpenRDMA architecture discussions

Individuals may subscribe to these reflectors at: http://sourceforge.net/projects/rdma.  Go to the bottom of the page and click on mailing lists for subscription.


Q12: How does one obtain help with OpenRDMA?
A12: The OpenRDMA website contains all relevant documentation and e-mail reflectors required to obtain help.  Use of the reflectors is strongly encouraged as this will provide a real-time answer as well as allow others who may not have thought of a particular issue to become aware.


Q13: How is the source maintained and how are patches submitted?
A13: See the <insert document name> for complete details on the associated processes.


Q14: What processor architectures does OpenRDMA support?
A14: OpenRDMA will target: x86, x86-64 (AMD Opteron and Intel EMT64), Itanium, PowerPC 32 and 64-bit


Q15: What is the target version of the Linux kernel to be supported?
A15: OpenRDMA will be built on top of the 2.6 Linux kernel.


November 11, 2004 Draft openrdma_faq.txt