Remote Direct Data Placement R. Stewart
Working Group Cisco Systems, Inc.
Internet-Draft C. Bestler
Expires: March 15, 2004 Consultant
J. Pinkerton
Microsoft
S. Ganguly
Iomega Corp, Inc.
H. Shah
Intel Corporation
V. Kashyap
IBM
September 15, 2003
Stream Control Transmission Protocol (SCTP) Remote Direct Memory
Access (RDMA) Direct Data Placement (DDP) Adaptation
draft-ietf-rddp-sctp-00.txt
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that other
groups may also distribute working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at http://
www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on March 15, 2004.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
This document describes a method to adapt Direct Data Placement (DDP)
and Remote Direct Memory Access (RDMA) to Stream Control Transmission
Stewart, et al. Expires March 15, 2004 [Page 1]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
Protocol (SCTP) RFC2960 [2] using a generic description found in
[RDMA-Draft] [4] and [DDP-Draft] [3].
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Conventions . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Data Formats . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Adaptation Layer Indicator . . . . . . . . . . . . . . . . . 5
2.2 Payload Data Chunks . . . . . . . . . . . . . . . . . . . . 5
2.2.1 DDP Source Sequence Number (DDP-SSN) . . . . . . . . . . . . 6
2.2.2 DDP Segment . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2.3 DDP Stream Session Control . . . . . . . . . . . . . . . . . 6
3. DDP Stream Sessions . . . . . . . . . . . . . . . . . . . . 8
3.1 Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2 Legal Sequence: Active/Passive Session Accepted . . . . . . 8
3.3 Legal Sequence: Negotiation-only . . . . . . . . . . . . . . 9
3.4 Legal Sequence: Active/Passive Session Rejected . . . . . . 9
3.5 Legal Sequence: Active/Active Session Accepted . . . . . . . 9
3.6 Other Sequencing Rules . . . . . . . . . . . . . . . . . . . 10
4. SCTP Endpoints . . . . . . . . . . . . . . . . . . . . . . . 11
4.1 Adaptation Layer Indication Restriction . . . . . . . . . . 11
4.2 Multihoming Implications . . . . . . . . . . . . . . . . . . 11
5. Number of Streams . . . . . . . . . . . . . . . . . . . . . 12
6. Fragmentation . . . . . . . . . . . . . . . . . . . . . . . 13
7. Sequenced Unordered Operation . . . . . . . . . . . . . . . 14
8. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 15
8.1 Association Initialization . . . . . . . . . . . . . . . . . 15
8.2 Chunk Bundling . . . . . . . . . . . . . . . . . . . . . . . 15
8.3 Association Termination . . . . . . . . . . . . . . . . . . 16
9. IANA considerations . . . . . . . . . . . . . . . . . . . . 17
10. Security Considerations . . . . . . . . . . . . . . . . . . 18
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 19
References . . . . . . . . . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 20
Intellectual Property and Copyright Statements . . . . . . . 22
Stewart, et al. Expires March 15, 2004 [Page 2]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
1. Introduction
This document describes a method to adapt Direct Data Placement (DDP)
and Remote Direct Memory Access (RDMA) to Stream Control Transmission
Protocol (SCTP) RFC2960 [2] using a generic description found in
[RDMA-Draft] [4] and [DDP-Draft] [3] This adaption provides a method
for two peers to know that each side is performing DDP or RDMA thus
enabling hardware acceleration if available.
Some implementations may include this adaptation layer within their
SCTP implementations to obtain maximum performance but the behavior
of SCTP will be unaffected. In order to accomplish this we specify
the use of the new adaptation layer indication as defined in
[ADDIP-Draft] [6]
1.1 Definitions
DDP Endpoint - The logical sender/receiver of DDP Segments. An SCTP
Stream pair is not assumed to have a DDP Endpoint. DDP Segments
may only be sent once a DDP Endpoint has been assigned to an SCTP
Stream pair by a local interface.
DDP Source Stream Sequence (DDP-SSN) - A stream specific sequence
number assigned by the DDP layer for each SCTP Data Chunk sent.
Use of the SCTP Stream Sequence Number (SSN) could result in
ordered delivery at the receiving end. Use of unordered Data
Chunks indicates that the receiving SCTP layer is to deliver them
without delay. The DDP-SSN retains the original order the Data
Chunks were generated in, no matter what order they were actually
sent or received.
DDP Stream - A bi-directional pair of SCTP streams which have the
same SCTP stream identifier.
DDP Stream Session - A single pairing of DDP Endpoints over a DDP
Stream that lasts from a Initiation message through the
Termination message(s).
DDP Stream Session Control - DDP Stream Session Control messages are
used to control the association of the DDP Endpoint with the DDP
Stream.
RDMA - Remote Direct Memory Access.
RNIC - RDMA Network Interface Card.
Stewart, et al. Expires March 15, 2004 [Page 3]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
SCTP association - A protocol relationship between two SCTP
endpoints. An SCTP association supports multiple SCTP streams.
SCTP Data Chunk - An SCTP Chunk used to convey Payload Data. There
can be multiple Chunks within each SCTP packet. Other Chunks are
used to control the SCTP Association.
SCTP endpoint - The logical sender/receiver of SCTP packets. On a
multi-homed host, an SCTP endpoint is represented to its peers as
a combination of a SCTP port number and a set of eligible
destination transport addresses to which SCTP packets can be sent.
SCTP Stream - A uni-directional logical channel established from one
to another associated SCTP endpoint. There can be multiple SCTP
Streams within each SCTP association. An SCTP Stream is used to
form one direction of a DDP stream.
Transmission Sequence Number (TSN) - A 32-bit sequence number used
internally by SCTP. One TSN is attached to each chunk containing
user data to permit the receiving SCTP endpoint to acknowledge its
receipt and detect duplicate deliveries.
1.2 Conventions
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
SHOULD NOT, RECOMMENDED, NOT RECOMMENDED, MAY, and OPTIONAL, when
they appear in this document, are to be interpreted as described in
RFC2119 [1].
Stewart, et al. Expires March 15, 2004 [Page 4]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
2. Data Formats
2.1 Adaptation Layer Indicator
This mapping places an entire SCTP association into a specific DDP
mode: DDP or DDP+RDMA. It is presumed that the handling of incoming
data chunks for DDP enabled associations is sufficiently different
than for routine SCTP associations that it is undesirable to mix DDP
and non-DDP streams in a single association. An application that
needs to mix DDP and non-DDP traffic must use use more than a single
association.
We define a adaption indication which MUST appear in the INIT or
INIT-ACK with the following format as defined in [ADDIP-Draft] [6]
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type =0xC006 | Length = Variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Adaptation Indication |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Adaptation Indication:
The following values are defined for DDP in this document:
DDP - 0x00000001
DDP+RDMA - 0x00000002
2.2 Payload Data Chunks
After the SCTP association has been established, all DDP relevant
messages are encoded as Payload Data Chunks. Each includes a SCTP
Stream identifier, a Transmissions Sequence Number (TSN), a Payload
Protocol Identifier, the chunk length and the payload data bytes.
The DDP SCTP adaptation uses two types of Payload Data Chunks,
differentiated by the Payload Protocol Identifier:
DDP Segments are use to for messages send between DDP Endpoints.
DDP Stream Session messages are used to control the binding of DDP
endpoints with SCTP streams.
Stewart, et al. Expires March 15, 2004 [Page 5]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
Payload Protocol Identifier:
The following value are defined for DDP in this document:
DDP Segment - 0x00000001
DDP Stream Session Control - 0x00000002
2.2.1 DDP Source Sequence Number (DDP-SSN)
All Payload Data Chunks include a DDP Source Sequence Number
(DDP-SSN) that tracks the sequence the messages were submitted to the
SCTP layer. It is initialized to 1 for each stream at the beginning
of each DDP Stream Session. It wraps to zero after 65535.
The SCTP Stream Sequence Number (SSN) is not suitable for this
purpose, because all messages defined by this document use unordered
Payload Data Chunks to ensure prompt delivery from the receiving SCTP
layer.
The SCTP Transmission Sequence Number (TSN) is not suitable for
determine the original order of Data Chunks within a stream. The
sending SCTP layer is allowed to optimize the transmission sequence
of unordered Data Chunks to encourage Chunk Bundling, or other
purposes.
2.2.2 DDP Segment
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DDP-SSN | DDP Segment |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
DDP Segments are as defined in [DDP-Draft].
2.2.3 DDP Stream Session Control
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DDP-SSN | Function Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Stewart, et al. Expires March 15, 2004 [Page 6]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
| Private Data (Dependent on Function Code) |
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The following function code values are defined for DDP in
this document:
DDP Stream Session Negotiate - 0x001
DDP Stream Session Initiate - 0x002
DDP Stream Session Accept - 0x003
DDP Stream Session Terminate - 0x004
ULP supplied Private Data MUST be included for DDP Stream Session
Negotiate, DDP Stream Session Initiate and DDP Stream Session Accept
messages. However, the ULP supplied Private DATA MAY be of zero
length. Private Data MUST NOT be included for the DDP Stream Session
Termiante message.
Received DDP Stream Session Control messages MUST be reported to the
ULP. Any supplied Private Data MUST be available for the ULP.
Stewart, et al. Expires March 15, 2004 [Page 7]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
3. DDP Stream Sessions
A DDP Endpoint is the logical sender/receiver of DDP Segments. A DDP
Stream connects two DDP Endpoints using a matched pair of SCTP
Streams.
A DDP Stream Session defines the sequence of Data Chunks exchanged
between two DDP Endpoints over a DDP Stream that has a distinct
beginning and end. Data Chunks from one DDP Stream Session are never
carried over to the next session.
The local interface MAY associate a DDP Endpoint with the DDP Stream
based upon the initial exchanges of a DDP Session, and terminate that
association at the session's end.
A DDP Stream is associated with at most one Protection Domain during
a single DDP Stream Session.
3.1 Sequencing
The DDP Source Sequence Number(DDP-SSN) is reset to one at the
beginning of each DDP Stream Session.
The Payload Data Chunks for a given session, when sequenced by their
DDP-SSN, MUST follow one of the patterns defined in this section.
If the adaptation layer receives a Payload Data Chunk that conforms
to none of the enumerated legal patterns the DDP Stream Session MUST
be terminated.
3.2 Legal Sequence: Active/Passive Session Accepted
In this DDP Stream Session sequence one DDP Endpoint assumes the
active role in requesting a DDP Stream Session, which the other side
accepts.
Either the Active or Passive side may send zero or more DDP Stream
Session Negotiate messages.
Active Side sends a DDP Stream Session Initiate message.
Passive Side sends a DDP Stream Session Accept mesage.
Each side may then send zero or more DDP Segments with increasing
DDP-SSNs, subject to various layers of flow control.
The final DDP Segment for each side MAY be a DDP Stream Terminate.
At least one side MUST send a DDP Stream Terminate.
Stewart, et al. Expires March 15, 2004 [Page 8]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
3.3 Legal Sequence: Negotiation-only
Either the Active or Passive side may send zero or more DDP Stream
Session Negotiate messages. The session does not have to proceed
further if the ULPs so desire.
3.4 Legal Sequence: Active/Passive Session Rejected
DDP Stream Sessions allow each party to send a single non-negotiation
message before the other end commits specific resources to the
session. This allow each end to determine which resources are to be
used, and how they are to be configured, or even if the session
should be granted.
These decision MAY be influenced by the need to assign a specific
Protection Domain, to determine how many RDMA Read Credits are
required, or to determine now many receive operations the ULP should
enable.
Because of these, or other, factors the Passive side MAY choose to
reject a DDP Stream Session Request. This results in the following
legal sequence:
Either the Active or Passive side MAY send zero or more DDP Stream
Session Negotiate messages. However, if the result of these
negotiations allow the ULP to determine that a session is not to
be set up, the ULP SHOULD simply refrain from sending the DDP
Stream Initiate message.
Active Side sends a DDP Stream Session Initiate message.
Passive Side sends a DDP Stream Session Terminate mesage.
3.5 Legal Sequence: Active/Active Session Accepted
In this DDP Stream Session sequence both ends seek to establish the
session concurrently, after any negotiation messages required.
Active/Active session establishment MAY require different support
from the local interface than for Active/Passive session
establishment.
The following legal sequence is defined:
Each side may send zero or more DDP Stream Session Negotiate
messages.
Each Side, viewing itself as active, sends a DDP Stream Session
Stewart, et al. Expires March 15, 2004 [Page 9]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
Initiate message.
Each side may then send zero or more DDP Segments with increasing
DDP-SSNs, subject to various layers of flow control.
The final DDP Segment for each side MAY be a DDP Stream Terminate.
At least one side MUST send a DDP Stream Terminate.
3.6 Other Sequencing Rules
A DDP Stream Session Control message MUST NOT be sent if it may be
received before a prior DDP Stream Session Control message within the
same DDP Stream Session.
An active side of a DDP Stream Session MUST NOT send a DDP Segment
that might be received before the DDP Stream Session Initiate
message.
This MAY be determined by SCTP acking of the Data Chunk used to carry
the DDP Stream Session Initiate message, or by receipt of a
responsive DDP Stream Session Control message.
A DDP Stream MUST NOT be re-used for another DDP Stream Session while
any Data Chunk from a prior session might be outstanding.
Unless explicitly allowed for by the Upper Layer Protocol, there may
be no more than one outstanding DDP Stream Session Negotiate message
per side. Multiple messages are intended to support rounds of
negotiations between the potential peers.
Stewart, et al. Expires March 15, 2004 [Page 10]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
4. SCTP Endpoints
4.1 Adaptation Layer Indication Restriction
The local interface MUST allow the ULP to specify an SCTP endpoint to
use a specific Adaptation Indication. It MAY require the ULP to do
so.
Once an endpoint decides on its acceptable Adaptation Indication(s),
it SHOULD terminate all requests to establish an association with any
different Adaptation Indication.
An SCTP implementation MAY choose to accept association requests for
a given SCTP endpoint only until one association for the endpoint has
been established. At that point it MAY choose to restrict all further
associations for the same endpoint to use the same Adaptation
Indication.
4.2 Multihoming Implications
SCTP allows an SCTP endpoint to be associated with multiple IP
addresses, potentially representing different interface devices.
Distribution of the logic for a single DDP stream across multiple
input devices can be very undesirable, resulting in complex cache
coherency challenges. Therefore the local interface MAY restrict
DDP-enabled SCTP endpoints to a single IP address, or to a set of IP
addresses that are all assigned to the same input device ("RNIC").
The default binding of a DDP enabled SCTP endpoint SHOULD NOT cover
more than a single IP address unless doing so results in no
additional bus traffic or duplication of memory registration
resources. This will frequently result in a different default than
for SCTP endpoints that are not DDP enabled.
Even when multi-homing is supported, ULPs are cautioned that they
SHOULD NOT use ULP control of the source address in attempt to
load-balance a stream across multiple paths. A receiving DDP/SCTP
implementation that chooses to support multi-homing SHOULD optimize
its design on the assumption that multi-homing will be used for
network fault tolerance, and not to load-balance between paths. This
is consistent with recommended SCTP practices.
Stewart, et al. Expires March 15, 2004 [Page 11]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
5. Number of Streams
DDP Streams are bidirectional. They are always composed by pairing
the inbound and outbound SCTP streams with the same SCTP Stream
Identifier.
DDP should request the maximum number of SCTP stream it will wish to
use over the lifetime of the association. SCTP streams must still be
bound to DDP Endpoints, and a DDP or DDP+RDMA enabled SCTP
association does not support ordered Data Chunks. Therefore the mere
existence of an SCTP stream is unlikely to require signifigant
supporting resources.
This mapping uses an SCTP association to carry one or more DDP
Steams. Each DDP Stream will be mapped to a pair of SCTP streams with
the same SCTP stream number. DDP MUST initialize all of its SCTP
associations with the same number of inbound and outbound streams.
Stewart, et al. Expires March 15, 2004 [Page 12]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
6. Fragmentation
A DDP/SCTP Receiver already must deal with fragementation at both the
IP and DDP Layers. Therefore the sending DDP layer MUST disable SCTP
layer segmenting of data chunks. If the DDP layer presents messages
that are too large, the result will be IP fragmentation. While SCTP
layer fragmentation is theoretically preferable, virtually all
fragmentation will be done at the DDP layer. Because SCTP layer
fragmentation would only be invoked under corner conditions, its
benefits do not justify the complexity of its inclusion.
When disabling SCTP fragmentation, SCTP will reject messages that are
known to be larger than the MTU size. This means that the DDP layer
MUST be prepared to handle this error case.
Stewart, et al. Expires March 15, 2004 [Page 13]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
7. Sequenced Unordered Operation
DDP MUST use the Unordered option on all Data Chunks (U Flag set to
one). The SCTP Layer is expected to deliver Data Chunks to the DDP
layer without delay.
Because DDP employs unordered SCTP delivery, the receiver MUST NOT
rely upon the SCTP Transmission Sequence Number (TSN) to imply
ordering of DDP Segments. The fact that the SCTP Data Chunk for a DDP
Segment is prior the cumulative ack point does not guarantee that all
prior DDP segments have been placed. The SCTP sender is not obligated
to transmit unordered Data Chunks in the order presented.
The DDP-SSN can be used without special logic to determine the
submission sequence when the maximum number of in-flight messages is
less than 32768. This also applies if the sending SCTP accepts no
more than 32767 Data Chunks for a single stream without assigning
TSNs.
If SCTP does accept more than 32768 Data chunks for a single stream
without assigning TSNs, the sending DDP must simply refrain from
sending more than 32767 Data Chunks for a single stream without
acknowledgement. Note that it MUST NOT rely upon ULP flow control
for this purpose. Typical ULP flow control will deal exclusively with
tagged messages, not with DDP segments.
The receiving DDP implementation MAY perform a validity check on
received DDP-SSNs to ensure that any gap could be accounted for by
unreceived Data Chunks. Implementations are advised against
allocating resources on the assumption that DDP-SSNs are valid
without first performing such a validtity check. An invalid DDP-SSN
MAY result in termination of the DDP Stream.
Stewart, et al. Expires March 15, 2004 [Page 14]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
8. Procedures
8.1 Association Initialization
At the startup of an association, an endpoint wishing to perform DDP,
RDMA, or DDP+RDMA placement MUST include an adaptation layer
indication in its INIT or INIT-ACK (as defined in Section 2.1. After
the exchange of the initial first two SCTP chunks (INIT and
INIT-ACK), an endpoint MUST verify and inspect the adaptation
indication and compare it to the following table to determine proper
action.
Indication | Action
type |
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| This indicates that the peer DOES NOT
NONE | support ANY DDP or RDMA adaption and thus
| RDMA and DDP procedures MUST NOT be
| performed upon this association.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| This indicates that the peer DOES support
DDP | DDP (but not RDMA). Procedures outlined in
| [DDP-Draft] MUST be followed.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| This indicates that the peer supports BOTH
DDP+RDMA | RDMA and DDP. If the receiving endpoint
| indicated the same, then the procedures in
| both [RDMA-Draft] and [DDP-Draft]
| MUST be followed. If the local endpoint
| only indicated DDP, then ONLY the
| procedures in [DDP-Draft] MUST be followed.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| This indicates that the peer DOES NOT
ANY-OTHER | support ANY DDP or RDMA adaption and thus
Indication | RDMA and DDP procedures MUST NOT be
| performed upon this association.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
An implementation MAY require that all associations for a given SCTP
endpoint be placed in the same mode.
The local interface MAY allow the ULP to accept only requests to
establish an association in a specified mode.
8.2 Chunk Bundling
Stewart, et al. Expires March 15, 2004 [Page 15]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
SCTP allows multiple Data Chunks to be bundled in a single SCTP
packet. Data chunks containing DDP Segments with untagged messages
SHOULD NOT be delayed to facilitate bundling. Data chunks containing
DDP Segments with tagged messages will generally be full sized, and
hence not subject to bundling. However partial size tagged messages
MAY be delayed, as that they are frequently followed by a short
untagged message.
8.3 Association Termination
Termination of an SCTP Association due to errors should be handled at
the SCTP layer. The RDMAP defined RDMAP Terminate Message SHOULD NOT
be sent on each DDP Stream when a determination has been made to
terminate an SCTP association. Sending that message on each SCTP
stream could severely delay the termination of the association.
The local interface SHOULD notify all consumers of DDP streams when
the underlying SCTP stream has been terminated.
Other RDMAP defined Terminate Messages MUST be generated as specified
when a DDP Stream is terminated. Note that with the SCTP mapping,
termination of a DDP Stream does not mandate termination of the
Association.
Stewart, et al. Expires March 15, 2004 [Page 16]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
9. IANA considerations
This document defines two new Adaptation Layer Indication codepoints:
DDP - 0x00000001
DDP+RDMA - 0x00000002
This document also defines two new Payload Protocol Identifier
(PPIDs):
DDP Segment - 0x00000001
DDP Stream Session Control - 0x00000002
Stewart, et al. Expires March 15, 2004 [Page 17]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
10. Security Considerations
Any direct placement of memory could pose a significant security risk
if adequate local controls are not provided. These threats should be
addressed in the appropriate DDP [DDP-Draft] [3] or RDMA [RDMA-Draft]
[4] drafts. This document does not add any additional security risks
over those found in RFC2960 [2].
Stewart, et al. Expires March 15, 2004 [Page 18]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
11. Acknowledgments
The authors would like to thank the following people that have
provided comments and input: Stephen Bailey, David Black, Douglas
Otis, Allyn Romanow and Jim Williams.
Stewart, et al. Expires March 15, 2004 [Page 19]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
References
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[2] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer,
H., Taylor, T., Rytina, I., Kalla, M., Zhang, L. and V. Paxson,
"Stream Control Transmission Protocol", RFC 2960, October 2000.
[3] Shah, H., "Direct Data Placement over Reliable Transports",
draft-ietf-rddp-ddp-00 (work in progress), February 2003.
[4] Recio, R., "An RDMA Protocol Specification",
draft-ietf-rddp-rdmap-00 (work in progress), February 2003.
[5] Stewart, R., "Sockets API Extensions for Stream Control
Transmission Protocol", draft-ietf-tsvwg-sctpsocket-05 (work in
progress), September 2002.
[6] Stewart, R., "Stream Control Transmission Protocol (SCTP)
Dynamic Address Reconfiguration",
draft-ietf-tsvwg-addip-sctp-06 (work in progress), September
2002.
Authors' Addresses
Randall R. Stewart
Cisco Systems, Inc.
8725 West Higgins Road
Suite 300
Chicago, IL 60631
USA
Phone: +1-815-477-2127
EMail: rrs@cisco.com
Caitlin Bestler
Consultant
1241 W. North Shore
# 2G
Chicago, IL 60626
USA
Phone: +1-773-743-1594
EMail: cait@asomi.com
Stewart, et al. Expires March 15, 2004 [Page 20]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
Jim Pinkerton
Microsoft
One Microsoft Way
Redmond, WA 98052
USA
Phone: +1-425-705-5442
EMail: jpink@microsoft.com
Sukanta Ganguly
Iomega Corp, Inc.
10955 Vista Sorrento Parkway
San Diego, CA
USA
Phone: +1-858-314-7026
EMail: ganguly@iomega.com
Hemal V. Shah
Intel Corporation
Mailstop: PTL1
1501 S. Mopac Expressway, #400
Austin, TX 78746
USA
Phone: +1-512-732-3963
EMail: hemal.shah@intel.com
Vivek Kashyap
IBM
15450 SW Koll Parkway
Beaverton, OR 57006
USA
Phone: +1-503-578-3422
EMail: vivk@us.ibm.com
Stewart, et al. Expires March 15, 2004 [Page 21]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in BCP-11. Copies of
claims of rights made available for publication and any assurances of
licenses to be made available, or the result of an attempt made to
obtain a general license or permission for the use of such
proprietary rights by implementors or users of this specification can
be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive
Director.
Full Copyright Statement
Copyright (C) The Internet Society (2003). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assignees.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
Stewart, et al. Expires March 15, 2004 [Page 22]
Internet-Draft SCTP RDMA/DDP Adaptation September 2003
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
Stewart, et al. Expires March 15, 2004 [Page 23]
