ForCES Model Extension
draft-haleplidis-forces-model-extension-01
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| Document | Type |
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|
|---|---|---|---|
| Author | Evangelos Haleplidis | ||
| Last updated | 2012-10-17 | ||
| RFC stream | (None) | ||
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| Consensus boilerplate | Unknown | ||
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draft-haleplidis-forces-model-extension-01
Internet Engineering Task Force E. Haleplidis
Internet-Draft University of Patras
Intended status: Informational October 17, 2012
Expires: April 20, 2013
ForCES Model Extension
draft-haleplidis-forces-model-extension-01
Abstract
Forwarding and Control Element Separation (ForCES) defines an
architectural framework and associated protocols to standardize
information exchange between the control plane and the forwarding
plane in a ForCES Network Element (ForCES NE). RFC5812 has defined
the ForCES Model provides a formal way to represent the capabilities,
state, and configuration of forwarding elements within the context of
the ForCES protocol, so that control elements (CEs) can control the
FEs accordingly. More specifically, the model describes the logical
functions that are present in an FE, what capabilities these
functions support, and how these functions are or can be
interconnected.
RFC5812 has been around for two years and experience in its use has
shown room for extensions without a need to alter the protocol while
retaining backward compatibility with older xml libraries.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
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."
This Internet-Draft will expire on April 20, 2013.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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described in the Simplified BSD License.
Table of Contents
1. Terminology and Conventions . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
1.2. Definitions . . . . . . . . . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. ForCES Model Extension overview . . . . . . . . . . . . . . . 6
4. Extensions . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. Complex Metadata . . . . . . . . . . . . . . . . . . . . . 7
4.2. DataType Optional Default Value . . . . . . . . . . . . . 9
4.3. Enhancing XML Validation . . . . . . . . . . . . . . . . . 9
5. XML Extension Schema for LFB Class Library Documents . . . . . 11
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 24
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
8. Security Considerations . . . . . . . . . . . . . . . . . . . 26
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 27
9.1. Normative References . . . . . . . . . . . . . . . . . . . 27
9.2. Informative References . . . . . . . . . . . . . . . . . . 27
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 28
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1. Terminology and Conventions
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
1.2. Definitions
This document follows the terminology defined by the ForCES Model in
[RFC5812]. The required definitions are repeated below for clarity.
FE Model - The FE model is designed to model the logical
processing functions of an FE. The FE model proposed in this
document includes three components; the LFB modeling of individual
Logical Functional Block (LFB model), the logical interconnection
between LFBs (LFB topology), and the FE-level attributes,
including FE capabilities. The FE model provides the basis to
define the information elements exchanged between the CE and the
FE in the ForCES protocol [RFC5810].
LFB (Logical Functional Block) Class (or type) - A template that
represents a fine-grained, logically separable aspect of FE
processing. Most LFBs relate to packet processing in the data
path. LFB classes are the basic building blocks of the FE model.
LFB Instance - As a packet flows through an FE along a data path,
it flows through one or multiple LFB instances, where each LFB is
an instance of a specific LFB class. Multiple instances of the
same LFB class can be present in an FE's data path. Note that we
often refer to LFBs without distinguishing between an LFB class
and LFB instance when we believe the implied reference is obvious
for the given context.
LFB Model - The LFB model describes the content and structures in
an LFB, plus the associated data definition. XML is used to
provide a formal definition of the necessary structures for the
modeling. Four types of information are defined in the LFB model.
The core part of the LFB model is the LFB class definitions; the
other three types of information define constructs associated with
and used by the class definition. These are reusable data types,
supported frame (packet) formats, and metadata.
Element - Element is generally used in this document in accordance
with the XML usage of the term. It refers to an XML tagged part
of an XML document. For a precise definition, please see the full
set of XML specifications from the W3C. This term is included in
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this list for completeness because the ForCES formal model uses
XML.
Attribute - Attribute is used in the ForCES formal modeling in
accordance with standard XML usage of the term, i.e., to provide
attribute information included in an XML tag.
LFB Metadata - Metadata is used to communicate per-packet state
from one LFB to another, but is not sent across the network. The
FE model defines how such metadata is identified, produced, and
consumed by the LFBs, but not how the per-packet state is
implemented within actual hardware. Metadata is sent between the
FE and the CE on redirect packets.
ForCES Component - A ForCES Component is a well-defined, uniquely
identifiable and addressable ForCES model building block. A
component has a 32-bit ID, name, type, and an optional synopsis
description. These are often referred to simply as components.
LFB Component - An LFB component is a ForCES component that
defines the Operational parameters of the LFBs that must be
visible to the CEs.
LFB Class Library - The LFB class library is a set of LFB classes
that has been identified as the most common functions found in
most FEs and hence should be defined first by the ForCES Working
Group.
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2. Introduction
The ForCES Model [RFC5812] presents a formal way to define FEs
Logical Function Blocks (LFBs) using XML. [RFC5812] has been
published a litlte more than two years and current experience in its
use has shown some room for adding new and changing existing modeling
concepts.
This document extends the ForCES Model by changing and adding new
concepts. These extensions do not require any changes on the ForCES
protocol [RFC5810] as they are simply changes of the schema
definition. Additionally backward compatibility is ensured as xml
libraries produced with the earlier schema are still valid with the
new one.
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3. ForCES Model Extension overview
The folowing extensions are considered:
1. Allow complex metadata.
2. Allow optional default values for datatypes.
Additionally this document is also enhancing the XML validation.
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4. Extensions
Some of these extensions were product of the work done on the
OpenFlow library [I-D.haleplidis-forces-openflow-lib] document.
4.1. Complex Metadata
Section 4.6. (Element for Metadata Definitions) in the ForCES Model
[RFC5812] limits the datatype use in metadata to only atomic types.
Figure 1 shows the xml schema excerpt where ony typeRef and atomic
are allowed for a metadata definition.
With this extension (Figure 2), complex data types are also allowed,
specifically structs and arrays as metadata. The key declarations
are required to check for validity of content keys in arrays and
componentIDs in structs.
<xsd:complexType name="metadataDefsType">
<xsd:sequence>
<xsd:element name="metadataDef" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN"/>
<xsd:element ref="synopsis"/>
<xsd:element name="metadataID" type="xsd:integer"/>
<xsd:element ref="description" minOccurs="0"/>
<xsd:choice>
<xsd:element name="typeRef" type="typeRefNMTOKEN"/>
<xsd:element name="atomic" type="atomicType"/>
</xsd:choice>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
Figure 1: Initial MetadataDefType Defintion in the schema
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<xsd:complexType name="metadataDefsType">
<xsd:sequence>
<xsd:element name="metadataDef" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN"/>
<xsd:element ref="synopsis"/>
<xsd:element name="metadataID" type="xsd:integer"/>
<xsd:element ref="description" minOccurs="0"/>
<xsd:choice>
<xsd:element name="typeRef" type="typeRefNMTOKEN"/>
<xsd:element name="atomic" type="atomicType"/>
<xsd:element name="array" type="arrayType">
<xsd:key name="contentKeyID1">
<xsd:selector xpath="lfb:contentKey"/>
<xsd:field xpath="@contentKeyID"/>
</xsd:key>
</xsd:element>
<xsd:element name="struct" type="structType">
<xsd:key name="structComponentID1">
<xsd:selector xpath="lfb:component"/>
<xsd:field xpath="@componentID"/>
</xsd:key>
</xsd:element>
</xsd:choice>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
Figure 2: New MetadataDefType Defintion for the schema
Two simple use cases can be seen in the OpenFlow switch
[OpenFlowSpec1.1]:
1. The Action Set metadata follows a packet inside the Flow Tables.
The Action Set metadata is an array of actions to be performed at
the end of the pipeline.
2. When a packet is received from a controller it may be accompanied
by a list of actions to be performed on it prior to be sent on
the flow table pipeline which is also an array.
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4.2. DataType Optional Default Value
In the original schema, default values can be defined only in
datatypes defined inside LFB components. However when it's a complex
datatype or it's a refered datatype, using the default value field is
difficult to be used. Additionally there is no option in a complex
datatype to use the default value field for only one component in the
complex datatype.
This extension allows optionally to add default values to atomic and
typeref types, whether they are as simple or complex datatypes. A
simple use case would be to have a struct component where one of the
components is a counter which the default value would be zero.
This extension alters the definition of the typeDeclarationGroup in
the xml schema from Figure 3 to Figure 4 to allow default values to
TypeRef.
<xsd:element name="typeRef" type="typeRefNMTOKEN"/>
Figure 3: Initial Excerpt of typeDeclarationGroup Defintion in the
schema
<xsd:sequence>
<xsd:element name="typeRef" type="typeRefNMTOKEN"/>
<xsd:element name="DefaultValue" type="xsd:token"
minOccurs="0"/>
</xsd:sequence>
Figure 4: New Excerpt of typeDeclarationGroup Defintion in the schema
Additionally it appends to the declaration of the AtomicType this xml
(Figure 5) to allow default values to Atomic datatypes.
<xsd:element name="defaultValue" type="xsd:token" minOccurs="0"/>
Figure 5: Appending xml in of AtomicType Defintion in the schema
4.3. Enhancing XML Validation
As specified earlier this is not an extension but an enhancement of
the schema to provide additional validation rules. This includes
adding new key declarations to provide uniqueness as deinfed by the
ForCES Model [RFC5812]. Such validations work only on within the
same xml file.
The following validation rules have been appended in the original
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schema in [RFC5812]:
1. Each metadata ID must be unique.
2. LFB Class IDs must be unique.
3. Component ID, Capability ID and Event Base ID must be unique per
LFB.
4. Event IDs must be unique per LFB.
5. Special Values in Atomic datatypes must be unique per atomic
datatype.
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5. XML Extension Schema for LFB Class Library Documents
<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns="urn:ietf:params:xml:ns:forces:lfbmodel:1.0"
xmlns:lfb="urn:ietf:params:xml:ns:forces:lfbmodel:1.0"
targetNamespace="urn:ietf:params:xml:ns:forces:lfbmodel:1.0"
elementFormDefault="qualified" attributeFormDefault="unqualified">
<xsd:annotation>
<xsd:documentation xml:lang="en">
Schema for Defining LFB Classes and associated types (frames,
data types for LFB attributes, and metadata).
</xsd:documentation>
</xsd:annotation>
<xsd:element name="description" type="xsd:string" />
<xsd:element name="synopsis" type="xsd:string" />
<!-- Document root element: LFBLibrary -->
<xsd:element name="LFBLibrary">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="description" minOccurs="0" />
<xsd:element name="load" type="loadType"
minOccurs="0" maxOccurs="unbounded" />
<xsd:element name="frameDefs" type="frameDefsType"
minOccurs="0" />
<xsd:element name="dataTypeDefs" type="dataTypeDefsType"
minOccurs="0" />
<xsd:element name="metadataDefs" type="metadataDefsType"
minOccurs="0" />
<xsd:element name="LFBClassDefs" type="LFBClassDefsType"
minOccurs="0" />
</xsd:sequence>
<xsd:attribute name="provides" type="xsd:Name"
use="required" />
</xsd:complexType>
<!-- Uniqueness constraints -->
<xsd:key name="frame">
<xsd:selector xpath="lfb:frameDefs/lfb:frameDef" />
<xsd:field xpath="lfb:name" />
</xsd:key>
<xsd:key name="dataType">
<xsd:selector xpath="lfb:dataTypeDefs/lfb:dataTypeDef" />
<xsd:field xpath="lfb:name" />
</xsd:key>
<xsd:key name="metadataDef">
<xsd:selector xpath="lfb:metadataDefs/lfb:metadataDef" />
<xsd:field xpath="lfb:name" />
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</xsd:key>
<xsd:key name="metadataDefID">
<xsd:selector xpath="lfb:metadataDefs/lfb:metadataDef" />
<xsd:field xpath="lfb:metadataID" />
</xsd:key>
<xsd:key name="LFBClassDef">
<xsd:selector xpath="lfb:LFBClassDefs/lfb:LFBClassDef" />
<xsd:field xpath="lfb:name" />
</xsd:key>
<xsd:key name="LFBClassDefID">
<xsd:selector xpath="lfb:LFBClassDefs/lfb:LFBClassDef" />
<xsd:field xpath="@LFBClassID" />
</xsd:key>
</xsd:element>
<xsd:complexType name="loadType">
<xsd:attribute name="library" type="xsd:Name" use="required" />
<xsd:attribute name="location" type="xsd:anyURI"
use="optional" />
</xsd:complexType>
<xsd:complexType name="frameDefsType">
<xsd:sequence>
<xsd:element name="frameDef" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN" />
<xsd:element ref="synopsis" />
<xsd:element ref="description"
minOccurs="0" />
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="dataTypeDefsType">
<xsd:sequence>
<xsd:element name="dataTypeDef" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN" />
<xsd:element name="derivedFrom" type="xsd:NMTOKEN"
minOccurs="0" />
<xsd:element ref="synopsis" />
<xsd:element ref="description"
minOccurs="0" />
<xsd:group ref="typeDeclarationGroup" />
</xsd:sequence>
</xsd:complexType>
</xsd:element>
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</xsd:sequence>
</xsd:complexType>
<!-- Predefined (built-in) atomic data-types are: char, uchar,
int16, uint16, int32, uint32, int64, uint64, string[N], string,
byte[N], boolean, octetstring[N], float32, float64 -->
<xsd:group name="typeDeclarationGroup">
<xsd:choice>
<!-- Extension -->
<xsd:sequence>
<!-- /Extension -->
<xsd:element name="typeRef" type="typeRefNMTOKEN" />
<!-- Extension -->
<xsd:element name="DefaultValue" type="xsd:token"
minOccurs="0" />
</xsd:sequence>
<!-- /Extension -->
<xsd:element name="atomic" type="atomicType" />
<xsd:element name="array" type="arrayType">
<!-- Extension -->
<!--declare keys to have unique IDs -->
<xsd:key name="contentKeyID">
<xsd:selector xpath="lfb:contentKey" />
<xsd:field xpath="@contentKeyID" />
</xsd:key>
<!-- /Extension -->
</xsd:element>
<xsd:element name="struct" type="structType">
<!-- Extension -->
<!-- key for componentIDs uniqueness in a struct -->
<xsd:key name="structComponentID">
<xsd:selector xpath="lfb:component" />
<xsd:field xpath="@componentID" />
</xsd:key>
<!-- /Extension -->
</xsd:element>
<xsd:element name="union" type="structType" />
<xsd:element name="alias" type="typeRefNMTOKEN" />
</xsd:choice>
</xsd:group>
<xsd:simpleType name="typeRefNMTOKEN">
<xsd:restriction base="xsd:token">
<xsd:pattern value="\c+" />
<xsd:pattern value="string\[\d+\]" />
<xsd:pattern value="byte\[\d+\]" />
<xsd:pattern value="octetstring\[\d+\]" />
</xsd:restriction>
</xsd:simpleType>
<xsd:complexType name="atomicType">
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<xsd:sequence>
<xsd:element name="baseType" type="typeRefNMTOKEN" />
<xsd:element name="rangeRestriction"
type="rangeRestrictionType" minOccurs="0" />
<xsd:element name="specialValues" type="specialValuesType"
minOccurs="0">
<!-- Extension -->
<xsd:key name="SpecialValue">
<xsd:selector xpath="specialValue" />
<xsd:field xpath="@value" />
</xsd:key>
<!-- /Extension -->
</xsd:element>
<!-- Extension -->
<xsd:element name="defaultValue" type="xsd:token"
minOccurs="0" />
<!-- /Extension -->
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="rangeRestrictionType">
<xsd:sequence>
<xsd:element name="allowedRange" maxOccurs="unbounded">
<xsd:complexType>
<xsd:attribute name="min" type="xsd:integer"
use="required" />
<xsd:attribute name="max" type="xsd:integer"
use="required" />
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="specialValuesType">
<xsd:sequence>
<xsd:element name="specialValue" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN" />
<xsd:element ref="synopsis" />
</xsd:sequence>
<xsd:attribute name="value" type="xsd:token" />
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="arrayType">
<xsd:sequence>
<xsd:group ref="typeDeclarationGroup" />
<xsd:element name="contentKey" minOccurs="0"
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maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="contentKeyField"
type="xsd:string" maxOccurs="unbounded" />
</xsd:sequence>
<xsd:attribute name="contentKeyID" type="xsd:integer"
use="required" />
</xsd:complexType>
</xsd:element>
</xsd:sequence>
<xsd:attribute name="type" use="optional"
default="variable-size">
<xsd:simpleType>
<xsd:restriction base="xsd:string">
<xsd:enumeration value="fixed-size" />
<xsd:enumeration value="variable-size" />
</xsd:restriction>
</xsd:simpleType>
</xsd:attribute>
<xsd:attribute name="length" type="xsd:integer"
use="optional" />
<xsd:attribute name="maxLength" type="xsd:integer"
use="optional" />
</xsd:complexType>
<xsd:complexType name="structType">
<xsd:sequence>
<xsd:element name="derivedFrom" type="typeRefNMTOKEN"
minOccurs="0" />
<xsd:element name="component" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN" />
<xsd:element ref="synopsis" />
<xsd:element ref="description"
minOccurs="0" />
<xsd:element name="optional" minOccurs="0" />
<xsd:group ref="typeDeclarationGroup" />
</xsd:sequence>
<xsd:attribute name="componentID"
type="xsd:unsignedInt" use="required" />
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="metadataDefsType">
<xsd:sequence>
<xsd:element name="metadataDef" maxOccurs="unbounded">
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<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN" />
<xsd:element ref="synopsis" />
<xsd:element name="metadataID" type="xsd:integer"/>
<xsd:element ref="description"
minOccurs="0" />
<xsd:choice>
<xsd:element name="typeRef"
type="typeRefNMTOKEN" />
<xsd:element name="atomic" type="atomicType" />
<!-- Extension -->
<xsd:element name="array" type="arrayType">
<!--declare keys to have unique IDs -->
<xsd:key name="contentKeyID1">
<xsd:selector xpath="lfb:contentKey" />
<xsd:field xpath="@contentKeyID" />
</xsd:key>
<!-- /Extension -->
</xsd:element>
<xsd:element name="struct" type="structType">
<!-- Extension -->
<!-- key declaration to make componentIDs
unique in a struct -->
<xsd:key name="structComponentID1">
<xsd:selector xpath="lfb:component" />
<xsd:field xpath="@componentID" />
</xsd:key>
<!-- /Extension -->
</xsd:element>
</xsd:choice>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="LFBClassDefsType">
<xsd:sequence>
<xsd:element name="LFBClassDef" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN" />
<xsd:element ref="synopsis" />
<xsd:element name="version" type="versionType" />
<xsd:element name="derivedFrom" type="xsd:NMTOKEN"
minOccurs="0" />
<xsd:element name="inputPorts"
type="inputPortsType"
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minOccurs="0" />
<xsd:element name="outputPorts"
type="outputPortsType"
minOccurs="0" />
<xsd:element name="components"
type="LFBComponentsType"
minOccurs="0" />
<xsd:element name="capabilities"
type="LFBCapabilitiesType"
minOccurs="0" />
<xsd:element name="events" type="eventsType"
minOccurs="0" />
<xsd:element ref="description"
minOccurs="0" />
</xsd:sequence>
<xsd:attribute name="LFBClassID" type="xsd:unsignedInt"
use="required" />
</xsd:complexType>
<!-- Key constraint to ensure unique attribute names
within a class: -->
<xsd:key name="components">
<xsd:selector xpath="lfb:components/lfb:component" />
<xsd:field xpath="lfb:name" />
</xsd:key>
<xsd:key name="capabilities">
<xsd:selector xpath="lfb:capabilities/lfb:capability"/>
<xsd:field xpath="lfb:name" />
</xsd:key>
<xsd:key name="events">
<xsd:selector xpath="lfb:events/lfb:event" />
<xsd:field xpath="lfb:name" />
</xsd:key>
<xsd:key name="eventsIDs">
<xsd:selector xpath="lfb:events/lfb:event" />
<xsd:field xpath="@eventID" />
</xsd:key>
<xsd:key name="componentIDs">
<xsd:selector xpath="lfb:components/lfb:component" />
<xsd:field xpath="@componentID" />
</xsd:key>
<xsd:key name="capabilityIDs">
<xsd:selector xpath="lfb:capabilities/lfb:capability"/>
<xsd:field xpath="@componentID" />
</xsd:key>
<xsd:key name="ComponentCapabilityComponentIDUniqueness">
<xsd:selector
xpath="lfb:components/lfb:component|
lfb:capabilities/lfb:capability|lfb:events" />
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<xsd:field xpath="@componentID|@baseID" />
</xsd:key>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<xsd:simpleType name="versionType">
<xsd:restriction base="xsd:NMTOKEN">
<xsd:pattern value="[1-9][0-9]*\.([1-9][0-9]*|0)" />
</xsd:restriction>
</xsd:simpleType>
<xsd:complexType name="inputPortsType">
<xsd:sequence>
<xsd:element name="inputPort" type="inputPortType"
maxOccurs="unbounded" />
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="inputPortType">
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN" />
<xsd:element ref="synopsis" />
<xsd:element name="expectation" type="portExpectationType"/>
<xsd:element ref="description" minOccurs="0" />
</xsd:sequence>
<xsd:attribute name="group" type="xsd:boolean"
use="optional" default="0" />
</xsd:complexType>
<xsd:complexType name="portExpectationType">
<xsd:sequence>
<xsd:element name="frameExpected" minOccurs="0">
<xsd:complexType>
<xsd:sequence>
<!-- ref must refer to a name of a defined
frame type -->
<xsd:element name="ref" type="xsd:string"
maxOccurs="unbounded" />
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="metadataExpected" minOccurs="0">
<xsd:complexType>
<xsd:choice maxOccurs="unbounded">
<!-- ref must refer to a name of a defined
metadata -->
<xsd:element name="ref"
type="metadataInputRefType" />
<xsd:element name="one-of"
type="metadataInputChoiceType" />
</xsd:choice>
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</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="metadataInputChoiceType">
<xsd:choice minOccurs="2" maxOccurs="unbounded">
<!-- ref must refer to a name of a defined metadata -->
<xsd:element name="ref" type="xsd:NMTOKEN" />
<xsd:element name="one-of" type="metadataInputChoiceType" />
<xsd:element name="metadataSet" type="metadataInputSetType"/>
</xsd:choice>
</xsd:complexType>
<xsd:complexType name="metadataInputSetType">
<xsd:choice minOccurs="2" maxOccurs="unbounded">
<!-- ref must refer to a name of a defined metadata -->
<xsd:element name="ref" type="metadataInputRefType" />
<xsd:element name="one-of" type="metadataInputChoiceType"/>
</xsd:choice>
</xsd:complexType>
<xsd:complexType name="metadataInputRefType">
<xsd:simpleContent>
<xsd:extension base="xsd:NMTOKEN">
<xsd:attribute name="dependency" use="optional"
default="required">
<xsd:simpleType>
<xsd:restriction base="xsd:string">
<xsd:enumeration value="required" />
<xsd:enumeration value="optional" />
</xsd:restriction>
</xsd:simpleType>
</xsd:attribute>
<xsd:attribute name="defaultValue" type="xsd:token"
use="optional" />
</xsd:extension>
</xsd:simpleContent>
</xsd:complexType>
<xsd:complexType name="outputPortsType">
<xsd:sequence>
<xsd:element name="outputPort" type="outputPortType"
maxOccurs="unbounded" />
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="outputPortType">
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN" />
<xsd:element ref="synopsis" />
<xsd:element name="product" type="portProductType" />
<xsd:element ref="description" minOccurs="0" />
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</xsd:sequence>
<xsd:attribute name="group" type="xsd:boolean"
use="optional" default="0" />
</xsd:complexType>
<xsd:complexType name="portProductType">
<xsd:sequence>
<xsd:element name="frameProduced" minOccurs="0">
<xsd:complexType>
<xsd:sequence>
<!-- ref must refer to a name of a defined
frame type -->
<xsd:element name="ref" type="xsd:NMTOKEN"
maxOccurs="unbounded" />
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="metadataProduced" minOccurs="0">
<xsd:complexType>
<xsd:choice maxOccurs="unbounded">
<!-- ref must refer to a name of a defined
metadata -->
<xsd:element name="ref"
type="metadataOutputRefType" />
<xsd:element name="one-of"
type="metadataOutputChoiceType" />
</xsd:choice>
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="metadataOutputChoiceType">
<xsd:choice minOccurs="2" maxOccurs="unbounded">
<!-- ref must refer to a name of a defined metadata -->
<xsd:element name="ref" type="xsd:NMTOKEN" />
<xsd:element name="one-of" type="metadataOutputChoiceType" />
<xsd:element name="metadataSet"
type="metadataOutputSetType" />
</xsd:choice>
</xsd:complexType>
<xsd:complexType name="metadataOutputSetType">
<xsd:choice minOccurs="2" maxOccurs="unbounded">
<!-- ref must refer to a name of a defined metadata -->
<xsd:element name="ref" type="metadataOutputRefType" />
<xsd:element name="one-of"
type="metadataOutputChoiceType" />
</xsd:choice>
</xsd:complexType>
<xsd:complexType name="metadataOutputRefType">
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<xsd:simpleContent>
<xsd:extension base="xsd:NMTOKEN">
<xsd:attribute name="availability" use="optional"
default="unconditional">
<xsd:simpleType>
<xsd:restriction base="xsd:string">
<xsd:enumeration value="unconditional" />
<xsd:enumeration value="conditional" />
</xsd:restriction>
</xsd:simpleType>
</xsd:attribute>
</xsd:extension>
</xsd:simpleContent>
</xsd:complexType>
<xsd:complexType name="LFBComponentsType">
<xsd:sequence>
<xsd:element name="component" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN" />
<xsd:element ref="synopsis" />
<xsd:element ref="description"
minOccurs="0" />
<xsd:element name="optional" minOccurs="0" />
<xsd:group ref="typeDeclarationGroup" />
<xsd:element name="defaultValue" type="xsd:token"
minOccurs="0" />
</xsd:sequence>
<xsd:attribute name="access" use="optional"
default="read-write">
<xsd:simpleType>
<xsd:list itemType="accessModeType" />
</xsd:simpleType>
</xsd:attribute>
<xsd:attribute name="componentID"
type="xsd:unsignedInt" use="required" />
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<xsd:simpleType name="accessModeType">
<xsd:restriction base="xsd:NMTOKEN">
<xsd:enumeration value="read-only" />
<xsd:enumeration value="read-write" />
<xsd:enumeration value="write-only" />
<xsd:enumeration value="read-reset" />
<xsd:enumeration value="trigger-only" />
</xsd:restriction>
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</xsd:simpleType>
<xsd:complexType name="LFBCapabilitiesType">
<xsd:sequence>
<xsd:element name="capability" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN" />
<xsd:element ref="synopsis" />
<xsd:element ref="description"
minOccurs="0" />
<xsd:element name="optional" minOccurs="0" />
<xsd:group ref="typeDeclarationGroup" />
</xsd:sequence>
<xsd:attribute name="componentID" type="xsd:integer"
use="required" />
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="eventsType">
<xsd:sequence>
<xsd:element name="event" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:NMTOKEN" />
<xsd:element ref="synopsis" />
<xsd:element name="eventTarget"
type="eventPathType" />
<xsd:element ref="eventCondition" />
<xsd:element name="eventReports"
type="eventReportsType" minOccurs="0" />
<xsd:element ref="description"
minOccurs="0" />
</xsd:sequence>
<xsd:attribute name="eventID" type="xsd:integer"
use="required" />
</xsd:complexType>
</xsd:element>
</xsd:sequence>
<xsd:attribute name="baseID" type="xsd:integer"
use="optional" />
</xsd:complexType>
<!-- the substitution group for the event conditions -->
<xsd:element name="eventCondition" abstract="true" />
<xsd:element name="eventCreated"
substitutionGroup="eventCondition" />
<xsd:element name="eventDeleted"
substitutionGroup="eventCondition" />
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<xsd:element name="eventChanged"
substitutionGroup="eventCondition" />
<xsd:element name="eventGreaterThan"
substitutionGroup="eventCondition" />
<xsd:element name="eventLessThan"
substitutionGroup="eventCondition" />
<xsd:complexType name="eventPathType">
<xsd:sequence>
<xsd:element ref="eventPathPart" maxOccurs="unbounded" />
</xsd:sequence>
</xsd:complexType>
<!-- the substitution group for the event path parts -->
<xsd:element name="eventPathPart" type="xsd:string"
abstract="true" />
<xsd:element name="eventField" type="xsd:string"
substitutionGroup="eventPathPart" />
<xsd:element name="eventSubscript" type="xsd:string"
substitutionGroup="eventPathPart" />
<xsd:complexType name="eventReportsType">
<xsd:sequence>
<xsd:element name="eventReport" type="eventPathType"
maxOccurs="unbounded" />
</xsd:sequence>
</xsd:complexType>
<xsd:simpleType name="booleanType">
<xsd:restriction base="xsd:string">
<xsd:enumeration value="0" />
<xsd:enumeration value="1" />
</xsd:restriction>
</xsd:simpleType>
</xsd:schema>
OpenFlow XML Library
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6. Acknowledgements
TBD
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7. IANA Considerations
This memo includes no request to IANA.
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8. Security Considerations
TBD
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9. References
9.1. Normative References
[I-D.haleplidis-forces-openflow-lib]
Haleplidis, E., Cherkaoui, O., Hares, S., and W. Wang,
"Forwarding and Control Element Separation (ForCES)
OpenFlow Model Library",
draft-haleplidis-forces-openflow-lib-01 (work in
progress), July 2012.
[OpenFlowSpec1.1]
http://www.OpenFlow.org/, "The OpenFlow 1.1
Specification.", <http://www.OpenFlow.org/documents/
OpenFlow-spec-v1.1.0.pdf>.
[RFC5810] Doria, A., Hadi Salim, J., Haas, R., Khosravi, H., Wang,
W., Dong, L., Gopal, R., and J. Halpern, "Forwarding and
Control Element Separation (ForCES) Protocol
Specification", RFC 5810, March 2010.
[RFC5812] Halpern, J. and J. Hadi Salim, "Forwarding and Control
Element Separation (ForCES) Forwarding Element Model",
RFC 5812, March 2010.
9.2. Informative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
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Author's Address
Evangelos Haleplidis
University of Patras
Department of Electrical and Computer Engineering
Patras, 26500
Greece
Email: ehalep@ece.upatras.gr
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