Subject: Protocol Action: 'Direct Data Placement over Reliable Transports' to Proposed Standard

From: The IESG <[email-masked]>
Date: Mon, 16 Oct 2006 23:39:00 -0400

The IESG has approved the following documents:

- 'Direct Data Placement over Reliable Transports '
   <draft-ietf-rddp-ddp-07.txt> as a Proposed Standard
- 'A Remote Direct Memory Access Protocol Specification '
   <draft-ietf-rddp-rdmap-07.txt> as a Proposed Standard

These documents are products of the Remote Direct Data Placement Working 
Group. 

The IESG contact persons are Lars Eggert and Magnus Westerlund.

A URL of this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-rddp-ddp-07.txt

Technical Summary
 
Direct Data Placement Protocol (DDP) enables an Upper Layer Protocol (ULP)
to send data to a Data Sink without requiring the Data Sink to Place the
data in an intermediate buffer - thus when the data arrives at the Data
Sink, the network interface can Place the data directly into the ULP's
buffer.  This can enable the Data Sink to consume substantially less
memory bandwidth than a buffered model. Additionally, this can also enable
the network protocol to consume substantially fewer CPU cycles than if the
CPU was used to move the data, and removes the bandwidth limitation of
only being able to move data as fast as the CPU can copy the data. DDP
preserves ULP record boundaries (messages) while providing a variety of
data transfer mechanisms and completion mechanisms to be used to transfer
ULP messages. 

The Remote Direct Memory Access Protocol (RDMAP) operates over the Direct
Data Placement Protocol (DDP).  RDMAP provides read and write services
directly to applications and enables data to be transferred directly into
ULP Buffers without intermediate data copies. It also enables a kernel
bypass implementation. 

Working Group Summary
 
DDP provides two mechanisms, a Tagged Buffer mechanism for Remote DMA
transfers where the network communication contains a destination memory
offset, and an Untagged Buffer mechanism that supports socket-like sends
where the receiver chooses the buffer on its own. The WG has strong
consensus that both mechanisms are required in order for an implementation
to exercise control over all memory buffer resources used for network
communication.

RDMAP supports both DMA (direct read/write to identified buffer) style
and message (send, receiver selects buffer) style transfers.  The WG has
strong consensus that both transfer styles are required in order for an
implementation to exercise control over all memory buffer resources used
for network communication, and to appropriately support usage where a DMA
style transfer is followed by a message style transfer whose reception is
used to infer completion of the preceding DMA style transfer. 

Protocol Quality
 
These protocols have been reviewed for the RDDP WG by David Black, who
also acted as PROTO Shepherd.

Francis Dupont ([email-masked]) was the GEN-ART Reviewer for
these documents.

These protocols have been reviewed for the IESG by Lars Eggert and Jon
Peterson.

Note to RFC Editor

Section 1 of draft-ietf-rddp-rdmap, last paragraph:

    this document are to be interpreted as described in [RFC2119]."
                                                                  ^
Note: remove the double-quote after the period.

Section 10.1 of draft-ietf-rddp-rdmap:

Remove the unused [VERBS] reference.

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