Network Working Group                                          T. Iijima
Internet-Draft                                               Y. Atarashi
Intended status: Informational                                 H. Kimura
Expires: October 23, 2008                                      M. Kitani
                                                  Alaxala Networks Corp.
                                                                H. Okita
                                                           Hitachi, Ltd.
                                                          April 21, 2008


              Experience of implementing NETCONF over SOAP
              draft-iijima-netconf-soap-implementation-07

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
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   This Internet-Draft will expire on October 23, 2008.














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Abstract

   This document describes how the authors developed a SOAP (Simple
   Object Access Protocol)-based NETCONF client and server.  In the case
   that SOAP is used as a transport protocol for NETCONF, various kinds
   of development tools are available.  By making full use of these
   tools, developers can significantly reduce their workload.  The
   authors developed an NMS (Network Management System) and network
   equipment that can deal with NETCONF messages sent over SOAP.  This
   document aims to provide NETCONF development guidelines gained from
   the experience of implementing a SOAP-based NETCONF client and
   server.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  NETCONF over SOAP  . . . . . . . . . . . . . . . . . . . .  3
     1.2.  Motivation . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  NETCONF Development on Web Services Framework  . . . . . . . .  4
     2.1.  WSDL as an Interface Description Language  . . . . . . . .  4
     2.2.  Generation of APIs . . . . . . . . . . . . . . . . . . . .  5
   3.  Architecture of the NETCONF over SOAP Implementation . . . . .  6
     3.1.  SOAP Implementation in NMS . . . . . . . . . . . . . . . .  7
       3.1.1.  SOAP Parser in NMS . . . . . . . . . . . . . . . . . .  7
       3.1.2.  Session Maintenance in NMS . . . . . . . . . . . . . .  7
     3.2.  SOAP Implementation in the Network Equipment . . . . . . .  8
       3.2.1.  SOAP Parser in the Network Equipment . . . . . . . . .  8
       3.2.2.  Session Maintenance in the Network Equipment . . . . .  8
   4.  Guidelines for Developing NETCONF Clients and Servers  . . . .  9
     4.1.  Procedures of Development of NETCONF Clients . . . . . . .  9
       4.1.1.  Developing NETCONF Clients without Eclipse . . . . . . 10
       4.1.2.  Developing NETCONF Clients using Eclipse . . . . . . . 12
     4.2.  Procedures of Development of NETCONF Servers . . . . . . . 14
       4.2.1.  Developing NETCONF Servers without Eclipse . . . . . . 15
       4.2.2.  Developing NETCONF Servers using Eclipse . . . . . . . 16
       4.2.3.  Developing NETCONF Servers by C Language
               Programming  . . . . . . . . . . . . . . . . . . . . . 18
   5.  Security Considerations  . . . . . . . . . . . . . . . . . . . 20
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 21
   7.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 22
     7.1.  Normative References . . . . . . . . . . . . . . . . . . . 22
     7.2.  Informative References . . . . . . . . . . . . . . . . . . 22
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23
   Intellectual Property and Copyright Statements . . . . . . . . . . 25






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1.  Introduction

1.1.  NETCONF over SOAP

   This document is not a product from the NETCONF WG but a report on
   the experience acquired by individual developers.

   SOAP (Simple Object Access Protocol) was specified in [RFC4743] as
   one of the transport protocols for NETCONF.  It is designed to use
   XML (eXtensible Markup Language) as its description language, which
   is a fundamental messaging technology for Web services.  For this
   reason, SOAP is well suited to the NETCONF protocol and could be
   deployed widely.

   To develop a SOAP-based NETCONF client and server, several
   development tools are available as open-source software.  The authors
   developed a SOAP-based NETCONF client and server by using available
   development tools.  The SOAP-based NETCONF client was developed by
   utilizing Java APIs (Application Programming Interface) that are
   automatically generated from the XSD file and WSDL (Web Services
   Description Language) file obtained from [RFC4741] and [RFC4743],
   respectively.  The SOAP-based NETCONF client that the authors
   developed acts as an NMS (Network Management System).  And the SOAP-
   based NETCONF server that the authors developed runs on network
   equipment and accepts NETCONF messages sent from the NETCONF client.

1.2.  Motivation

   The aim of this document is to describe why the authors believe SOAP
   is practical as a transport protocol for NETCONF when an NMS is
   developed.  When developing an NMS that uses SOAP as its transport
   protocol, development tools and procedures could be used according to
   Web Services framework.  This document also describes the experience
   of implementing NETCONF over SOAP so that even those who have little
   knowledge of SOAP can start developing a SOAP-based NETCONF client
   and server.















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2.  NETCONF Development on Web Services Framework

   SOAP is a fundamental messaging technology for Web Services.
   Therefore, if SOAP is used as a transport protocol for NETCONF,
   network configuration performed by NETCONF is achieved on the Web
   Services framework.  In this section, the overall architecture of Web
   Services is described.


   +---+ +----------+ +-----------+ +-------------+ +--------+
   |XML| | Security | | Reliable  | | Transaction | | Search |
   |   | |          | | Message   | |             | |        |
   |   | |          | |           | |             | |  UDDI  |22
   |   | |    WS-   | |    WS-    | |     WS-     | +--------+
   |   | | Security | |Reliability| | Transaction | +--------+ +-------+
   |   | |          | |           | |             | |Language| |  API  |
   |   | |          | |           | |             | |        | |       |
   |   | |          | |           | |             | |  WSDL  | | JAXM  |
   |   | +----------+ +-----------+ +-------------+ +--------+ |JAX-RPC|
   |   | +---------------------------------------------------+ | .NET  |
   |   | |              Fundamental Messaging                | |       |
   |   | |                                                   | |       |
   |   | |                       SOAP                        | |       |
   +---+ +---------------------------------------------------+ +-------+
         +---------------------------------------------------+
         |                    Transport                      |
         |                                                   |
         |                   HTTP, HTTPS...                  |
         +---------------------------------------------------+


              Figure 1: Overall architecture of Web Services

   As depicted in Figure 1, peripheral technologies around SOAP/HTTP are
   well developed.  Therefore, if SOAP/HTTP is chosen as a transport
   layer for the NETCONF protocol, each surrounding technology does not
   have to be developed from scratch.  Hence, the development of a
   NETCONF-based NMS is relatively easy when SOAP is chosen as a
   transport protocol for NETCONF.

2.1.  WSDL as an Interface Description Language

   WSDL [WSDL] defines how SOAP messages are exchanged among Web
   Services entities.  Interfaces of Web Services entities are
   automatically generated by development tools when importing a WSDL
   file.  Interfaces generated in this manner act as APIs.  For the
   development of an NMS only these APIs are necessary; there is no need
   to use SOAP directly.



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   Useful tools that can import a WSDL file are available with SOAP.
   For instance, Apache Axis [Axis] generates an interface from a WSDL
   file and acts as a widely used SOAP implementation middleware.

2.2.  Generation of APIs

   As described in the previous section, APIs are generated from a WSDL
   file by development tools such as Apache Axis.  Such APIs are in the
   form of a Java library and act as programming interfaces for an NMS.
   By using these APIs an NMS can send SOAP messages to Web Services
   entities.








































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3.  Architecture of the NETCONF over SOAP Implementation

   The architecture of the NETCONF over SOAP implementation is shown in
   Figure 2.  A NETCONF implementation residing in an NMS works as a
   NETCONF client while network equipment acts as a NETCONF server.  In
   this document, we call NETCONF-client and NETCONF-server
   implementations a NETCONF application and a NETCONF service provider,
   respectively.  A SOAP implementation needs to be installed on both,
   NMS and network equipment.  Each instance of the SOAP implementations
   exchanges SOAP messages based on WSDL, as described in [RFC4743].  If
   Java libraries generated from the WSDL are provided in the NMS,
   engineers can develop a NETCONF application, which configures network
   equipment via the NETCONF protocol, by utilizing the Java library.
   There is no need for engineers to use XML or SOAP directly.


    +---------------------------+   +---------------------------+
    |      NETCONF Client       |   |       NETCONF Server      |
    |           (NMS)           |   |     (Network Equipment)   |
    |  +---------------------+  |   |  +---------------------+  |
    |  | NETCONF application |  |   |  |    NETCONF service  |  |
    |  |                     |  |   |  |       provider      |  |
    |  +---------------------+  |   |  +---------------------+  |
    |  +---------------------+  |   |                           |
    |  |    Java library     |  |   |                           |
    |  +---------------------+  |   |                           |
    |  +---------------------+  |   |  +---------------------+  |
    |  | SOAP Implementation |  |   |  | SOAP Implementation |  |
    |  |    (Apache Axis)    |  |   |  |                     |  |
    |  +---------------------+  |   |  +---------------------+  |
    +-------^----------|--------+   +-------^----------|--------+
            |          |     rpc-request    |          |
            |          +-----  /SOAP    ----+          |
            |                  / HTTP(S)               |
            |                                          |
            |                 rpc-reply                |
            +----------------  /SOAP    ---------------+
                               / HTTP(S)


        Figure 2: Architecture of NETCONF implementation using SOAP

   The SOAP implementation in both the NMS and network equipment is
   explained in detail in the following sections.







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3.1.  SOAP Implementation in NMS

   Several SOAP implementations capable for an NMS are available today.
   As one such free SOAP implementation, Apache Axis is the widely used.

   Axis works as a SOAP implementation and an NMS-development tool.  For
   instance, WSDL2Java, one of Axis's tools, generates Java-class files
   from a WSDL file.  Another tool called Java2WSDL does the opposite:
   it generates a WSDL file from Java-class files.  Consequently,
   various kinds of benefits can be acquired if Axis is introduced as a
   SOAP implementation.

   To develop a NETCONF application that is capable of various functions
   such as releasing log messages, Java-class files generated by the
   Axis tool need to be extended by adding more functions.  By utilizing
   these Java libraries, engineers can easily develop NETCONF
   applications.

3.1.1.  SOAP Parser in NMS

   The SOAP Parser function is completely performed by a SOAP
   implementation such as Apache Axis.

3.1.2.  Session Maintenance in NMS

   When exchanging NETCONF messages between an NMS and network
   equipment, implementation of a session-maintenance function is
   necessary on both sides.

   HTTP is a stateless protocol that is used as an underlying transport
   protocol for SOAP.  HTTP creates and terminates a TCP session at
   every request.  Therefore, when using HTTP as a transport protocol
   for SOAP messages, session maintenance at the TCP level as well as at
   the NETCONF level is necessary.  Unless a session is maintained at
   the TCP level, a different NETCONF service provider is invoked every
   time the NETCONF client sends a NETCONF message to the NETCONF
   server.  We used a cookie field inside a HTTP header as a session
   identifier for the session on TCP level.

   The session-maintenance function at the TCP level has to be
   incorporated as follows.  After the NETCONF application sends a
   NETCONF hello message to a NETCONF service provider, the application
   receives a newly allocated session identifier written in the cookie
   field of a replying hello message.  The NETCONF application preserves
   the cookie paired with the network equipment's MAC address and uses
   it as a session identifier for subsequent NETCONF message exchanges.
   When an NMS sets the cookie for subsequent NETCONF messages, the
   network equipment recognizes the session and maintains it.  The



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   stored cookie is erased when the NMS sends a close-session message
   and a response message is received from the network equipment.

3.2.  SOAP Implementation in the Network Equipment

   To accept SOAP messages sent from the NMS, it is also necessary to
   provide SOAP in the network equipment.  As in the case of the NMS,
   some free SOAP implementations to be installed on network equipment
   are available today.  However, in the case of network equipment, the
   capacity of the memory might be limited.  Therefore, a SOAP
   implementation has to be chosen while memory capacity is taken into
   consideration.  In some cases, a memory-saving method will be
   required when implementing SOAP in the network equipment.

3.2.1.  SOAP Parser in the Network Equipment

   When using HTTP as an underlying protocol of SOAP, a SOAP message
   consists of an HTTP header and a SOAP envelope.  The SOAP envelope is
   a mandatory part of every SOAP message.  However, the SOAP
   encodingStyle attribute inside the envelope elements does not need to
   be specified.  If the encodingStyle attribute is not specified, the
   default of "http://schemas.xmlsoap.org/soap/encoding" is applied.  If
   there is a memory constraint, we can omit a parsing function of the
   encodingStyle attribute.

   Similarly, a SOAP header inside the SOAP envelope is defined as
   optional.  Therefore, the module that processes the SOAP header can
   be omitted if the memory capacity in the network equipment is
   insufficient.  In this case, a SOAP parser in the network equipment
   is allowed to parse only mandatory parts of a SOAP envelope.

3.2.2.  Session Maintenance in the Network Equipment

   To maintain sessions with the NMS, the SOAP implementation in network
   equipment must provide a session identifier to the NMS.

   The session-maintenance function that we implemented works as
   follows.  When network equipment receives a NETCONF hello message
   from the NMS, the SOAP implementation in the network equipment sets a
   session identifier paired with the network equipment's MAC address in
   the cookie field inside the HTTP header and sends a response message
   to the network equipment.  When the network equipment receives a
   NETCONF close message from the NMS, it erases the stored session
   identifier.







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4.  Guidelines for Developing NETCONF Clients and Servers

   In the case of SOAP transport mapping, sharing what kinds of
   development tools are available would help developers start
   developing SOAP-based NETCONF clients and servers.  That would
   contribute to the rapid deployment of SOAP-based NETCONF clients and
   servers.

4.1.  Procedures of Development of NETCONF Clients

   To develop a SOAP-based NETCONF client, a stub code needs to be
   generated.  A stub is a library generated automatically from WSDL by
   a Web Services tool and acts as a group of APIs.  In the case of
   using Apache Axis as a Web Services tool, a generated stub is in the
   form of Java APIs.  These Java APIs display interfaces of a Web
   Service as if they are methods capable of configuring a local
   machine.

   The WSDL file named "netconf-soap_1.0.wsdl", which is selected from
   [RFC4743], specifies NETCONF messages to be exchanged between the
   NETCONF client and server.  These NETCONF messages are the "hello"
   message and "rpc" message.  Therefore, stub codes for creating the
   "hello" message and "rpc" message are generated from "netconf-
   soap_1.0.wsdl".  However, the file "netconf- soap_1.0.wsdl" is not
   sufficient because no service element is specified.

   In "myNetconfService.wsdl", which is also selected from [RFC4743], a
   service element is specified and "netconf-soap_1.0.wsdl" is imported.
   Stub codes generated from those WSDL files are found in files such as
   "Netconf.java", "NetconfLocator.java", and "NetconfBindingStub.java".

   When interfaces are used to operate the NETCONF protocol in the
   manner of "get-config" and "edit-config", for example, an XML schema
   file named "netconf.xsd", which is selected from [RFC4741], is used
   by being imported into "netconf-soap_1.0.wsdl".  Using the XML
   schema, methods of operating the NETCONF protocol are generated in
   files such as "GetConfigType.java" and "EditConfigType.java".

   When interfaces are used to configure network functions at network
   equipment, a data model of each network function has to be defined in
   the style of an XML schema.  The XML schema is required to be
   imported into "netconf-soap_1.0.wsdl" in the same manner as that of
   the XML schema in [RFC4741].

   The connection between the NETCONF schema and a data model should be
   made by inserting the following attribute into elements of each data
   model.  This attribute is defined in the XML schema in [RFC4741].




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   <xs:attribute name="operation" type="editOperationType"
   default="merge"/>

   Consequently, using "myNetconfService.wsdl" to import "netconf-
   soap_1.0.wsdl", NETCONF schema, and the data model makes it possible
   to generate stub files containing interfaces to configure network
   equipment.

   When stub codes are generated, the development environment needs to
   be arranged as well.  The development of a Java-based NETCONF client
   needs JDK (Java Development Kit) [JDK] and Apache Axis.  In addition,
   using some IDE (Integrated Development Environment) such as Eclipse
   [Eclipse] with Apache Ant [Ant] and NetBeans [NetBeans] would reduce
   the developer workload significantly.  When Eclipse is used as an
   IDE, first, the library (*.jar files) of Axis has to be added to the
   development project's build path as an external library.  The library
   of Axis acts as a SOAP library, so there is no need to be concerned
   about SOAP messaging when programming a NETCONF client using the
   library of Axis.

4.1.1.  Developing NETCONF Clients without Eclipse

   Given that development of a NETCONF client is carried out in the
   environment of a Windows computer without Eclipse and
   "myNetconfService.wsdl" is placed in the "C:\NetconfClient"
   directory, a stub is generated by executing the following command in
   the command prompt.

   C:\NetconfClient>java -classpath .;%AXIS_HOME%\lib\axis.jar;%
   AXIS_HOME%\lib\jaxrpc.jar;%AXIS_HOME%\lib\saaj.jar;%AXIS_HOME%
   \lib\commons-logging-1.0.4.jar;%AXIS_HOME%\lib\commons-discovery-
   0.2.jar;%AXIS_HOME%\lib\wsdl4j-1.5.1.jar
   org.apache.axis.wsdl.WSDL2Java -p stub myNetconfService.wsdl

   In the directory where the WSDL file is located, the WSDL2Java
   command is executed.  Locations of each Axis library have to be
   specified.  The environment variable of "AXIS_HOME" is the directory
   where Axis is installed.  By executing the above command, files with
   an extension of "*.java" are generated in the "stub" directory, which
   is specified by the above command.  Inside the stub directory, we can
   find files such as "NetconfBindingStub.java", "Hello.java", and
   "GetConfigType.java".

   Next, it is necessary to compile these files by executing the
   following command in the command prompt.

   C:\NetconfClient>javac -classpath .;%AXIS_HOME%\lib\axis.jar;%
   AXIS_HOME%\lib\jaxrpc.jar stub/*.java



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   After the compilation of those java files, "*.class" files are
   generated.  At the time of compiling, we need to be careful about the
   encoding style.  After the compiling is done, the source code of the
   NETCONF client has to be written.  Sample source code of the NETCONF
   client is shown in Figure 3.  This NETCONF client is written by
   utilizing stub classes and interfaces, which are imported into the
   local package and referenced.


   import org.apache.axis.types.UnsignedInt;
   import org.apache.axis.types.*;

   public class NetconfClient {
           /**
            * @param args
            */
           public static void main(String[] args) {
                   // TODO Auto-generated method stub
                   try{
                           NetconfClient client = new NetconfClient();
                           java.net.URL url = new java.net.URL(args[0]);
                           stub.Netconf netconf =
                                   new stub.NetconfLocator();
                           stub.NetconfPortType stubNetconf =
                                   netconf.getnetconfPort(url);

                           URI[] uri = new URI[1];
                           stub.holders.HelloCapabilitiesHolder
                           capability = new
                           stub.holders.HelloCapabilitiesHolder(uri);

                           UnsignedInt id = new UnsignedInt();
                           id.setValue(1);
                           org.apache.axis.holders.UnsignedIntHolder
                           holder = new
                           org.apache.axis.holders.UnsignedIntHolder(id)
                           ;
                           stubNetconf.hello(capability, holder);
                   }catch(Exception e){
                           e.printStackTrace();
                   }
           }
   }


              Figure 3: Sample source code of NETCONF clients

   To add functions such as release of log messages, these functions



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   have to be incorporated at this stage.  Again, the NETCONF client is
   developed by compiling its source codes.

4.1.2.  Developing NETCONF Clients using Eclipse

   When we use Eclipse and Apache Ant, the procedures described in the
   previous section are significantly simplified and executed at once.
   In this case, files named "build.xml" and "build.properties" are
   required for Apache Ant.

   The file named "build.xml" is written in XML and seen by Apache Ant
   when Apache Ant is running on Eclipse.  The file specifies how Apache
   Ant behaves.  According to the descriptions of the file, Apache Ant
   compiles source codes, generates JAR (Java ARchive) file, and so on.
   On the other hand, the file named "build.properties" specifies
   properties of the development environment where Apache Ant runs.  And
   the file is referred to by the "build.xml" file.

   Examples of "build.xml" and "build.properties" are shown in Figure 4
   and Figure 5, respectively.































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   <?xml version="1.0"?>
   <project name="NetconfClient" default="all" basedir=".">
           <property file="build.properties"/>
           <path id="axis-classpath">
                   <fileset dir="${axis.libdir}">
                           <include name="*.jar"/>
                   </fileset>
           </path>
           <target name="prepare">
                   <mkdir dir="${destdir}"/>
           </target>
           <target name="stub" depends="prepare">
                   <java classname="org.apache.axis.wsdl.WSDL2Java" fork
                           ="Yes">
                           <arg value="-o"/>
                           <arg value="${srcdir}"/>
                           <arg value="-p"/>
                           <arg value="${stub.stubdir}"/>
                           <arg value="${stub.wsdlpath}"/>
                           <classpath refid="axis-classpath"/>
                   </java>
           </target>
           <target name="compile" depends="stub">
                   <javac srcdir="${srcdir}" destdir="${destdir}"
                           encoding="UTF-8">
                           <classpath refid="axis-classpath"/>
                   </javac>
           </target>
           <target name="stub-jar" depends="compile">
                   <jar jarfile="${stub.jar}" basedir="${destdir}"/>
           </target>
           <target name="all" depends="stub-jar"/>
   </project>


                  Figure 4: build.xml of NETCONF clients



   axis.libdir=C:/axis-1_4/lib
   srcdir=src
   destdir=classes
   stub.stubdir=stub
   stub.wsdlpath=myNetconfService.wsdl
   stub.jar=NETCONF.jar


               Figure 5: build.properties of NETCONF clients



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   The location of the WSDL file has to be specified in the
   "build.properties" file.  In the case shown in Figure 5, the location
   of the WSDL file is specified as being under the current directory.

   By running Apache Ant on Eclipse, the steps specified in Figure 4 are
   taken.  First, stub codes are generated.  Then, compiling those stub
   codes is executed.  After the compilation, Apache Ant will generate a
   JAR file, which is the output that compresses all stub files
   (*.class) and acts as a library.  In this example, the name
   "NETCONF.jar" is specified in Figure 5.  The "NETCONF.jar" file also
   has to be added to the build path of the development project as an
   external library.

   After the "NETCONF.jar" file is added to the build path of the
   development project, source codes of the NETCONF client can be
   written by utilizing stub classes and interfaces.  Source codes like
   the one shown in Figure 3 can be written.  By running Apache Ant
   again, the source code of the NETCONF client is compiled.  The
   NETCONF client is developed in this manner.

4.2.  Procedures of Development of NETCONF Servers

   In the Web Services framework, there are two approaches for
   developing a Web Services provider, namely a NETCONF server.  One is
   called the top-down approach, and the other is called the bottom-up
   approach.  The top-down approach is carried out by first designing a
   WSDL file.  A skeleton source code from the WSDL file is then
   generated by using a Web Services tool such as Apache Axis.  The
   generated skeleton code is just a template of the Web Services
   provider's source code.  Therefore, even though the Web Services
   provider's skeleton code works on its own, if additional functions
   were necessary, the generated skeleton code would require additional
   source codes.  This approach is superior to the bottom-up approach in
   terms of interoperability because the specification is already
   defined in the WSDL file.  All vendors have to be compliant with the
   WSDL file.

   In contrast, the bottom-up approach is carried out by first creating
   Web Services from source code (e.g., Java bean) and then generating a
   WSDL file from the source code by using a Web Services tool such as
   Axis.  This approach is faster and easier than the top-down approach.
   However, in the case of the bottom-up approach, ensuring
   interoperability becomes difficult, since implementation of a Web
   Services becomes vendor specific.

   In the case of developing a NETCONF server, the WSDL file is already
   defined in [RFC4743], so there is no choice but to develop the
   NETCONF server using the top-down approach.  The remainder of the



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   section describes the top-down approach for developing a NETCONF
   server.

   To develop a SOAP-based NETCONF server using the top-down approach, a
   skeleton code is necessary.  A skeleton is a library, which is also
   generated automatically from WSDL by a Web Services tool.  In the
   case of using Axis as a Web Services tool, the generated skeleton is
   in the form of a Java library.  From the same WSDL file as that being
   used for generating the stub code, skeleton codes are generated in
   files such as "NetconfBindingSkeleton.java", "Hello.java", and
   "GetConfigType.java".

   When skeleton codes are being generated, the development environment
   needs to be arranged as well.  Moreover, when a Java-based NETCONF
   server is being developed, in addition to JDK and Axis, a servlet
   container such as Apache Tomcat [Tomcat] is necessary.  The
   "webapps\axis" directory under the Axis directory has to be copied to
   the "webapps" directory under the Tomcat directory.

4.2.1.  Developing NETCONF Servers without Eclipse

   Given that the development environment of a NETCONF server is created
   in the environment of a Windows computer without Eclipse and
   "myNetconfService.wsdl" is placed in the "C:\NetconfServer"
   directory, a skeleton is generated by executing the following command
   in the command prompt.

   C:\NetconfServer>java -classpath .;%AXIS_HOME%\lib\axis.jar;%
   AXIS_HOME%\lib\jaxrpc.jar;%AXIS_HOME%\lib\saaj.jar;%AXIS_HOME%
   \lib\commons-logging-1.0.4.jar;%AXIS_HOME%\lib\commons-discovery-
   0.2.jar;%AXIS_HOME%\lib\wsdl4j-1.5.1.jar
   org.apache.axis.wsdl.WSDL2Java -p skeleton -s -S true -d Session
   myNetconfService.wsdl

   In the directory where the WSDL file is located, a WSDL2Java command
   is executed.  Locations of each Axis library have to be specified.
   The environment variable of "AXIS_HOME" is a directory where Axis is
   installed.  By executing the above command, files with an extension
   of "*.java" are generated in the "skeleton" directory, which is
   specified in the above command.  Inside the skeleton directory, files
   such as "NetconfBindingSkeleton.java", "Hello.java", and
   "GetConfigType.java" exist.  Furthermore, files named "deploy.wsdd"
   and "undeploy.wsdd" are found.  "Deploy.wsdd" and "undeploy.wsdd" are
   used when deploying a NETCONF server in a servlet container and
   undeploying a NETCONF server from a servlet container, respectively.

   Adding source codes of NETCONF server functions to skeleton codes
   such as "NetconfBindingImpl.java" is required as the need arises.



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   Functions such as release of log messages have to be added at this
   stage.  After that, by executing the following command in the command
   prompt, compilation of java files is carried out.  Doing so will
   generate "*.class" files.

   C:\NetconfServer>javac -classpath .;%AXIS_HOME%\lib\axis.jar;%
   AXIS_HOME%\lib\jaxrpc.jar skeleton/*.java

   A NETCONF server can be developed by following the above-described
   procedures.  Copying these class files into the directory
   "webapps\axis\WEB- INFO\classes" of the Apache Tomcat directory is
   required.  Finally, deploying the NETCONF server by executing the
   following command is required.

   C:\NetconfServer>java -classpath .;%AXIS_HOME%\lib\axis.jar;%
   AXIS_HOME%\lib\jaxrpc.jar;%AXIS_HOME%\lib\saaj.jar;%AXIS_HOME%
   \lib\commons-logging-1.0.4.jar;%AXIS_HOME%\lib\commons-discovery-
   0.2.jar org.apache.axis.client.AdminClient -p 832 depoy.wsdd

   The command is executed in the directory where "deploy.wsdd" is
   located.  The file, "deploy.wsdd", is generated at the same time as
   the skeleton code is generated.  After deployment, the NETCONF server
   receives NETCONF messages sent from the NETCONF client.

4.2.2.  Developing NETCONF Servers using Eclipse

   When Eclipse and Apache Ant are used, the procedures followed in the
   previous section are significantly simplified and executed at one
   time.  Files named "build.xml" and "build.properties" are required
   for Apache Ant. Examples of "build.xml" and "build.properties" are
   shown in Figure 6 and Figure 7, respectively.


   <?xml version="1.0"?>
   <project name="NetconfService" default="all" basedir=".">
           <property file="build.properties"/>
           <path id="axis-classpath">
                   <fileset dir="${axis.libdir}">
                           <include name="*.jar"/>
                   </fileset>
           </path>
           <target name="prepare">
                   <mkdir dir="${srcdir}"/>
                   <mkdir dir="${destdir}"/>
           </target>
           <target name="skeleton" depends="prepare">
                   <java classname="org.apache.axis.wsdl.WSDL2Java" fork
                           ="Yes">



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                           <arg value="-p"/>
                           <arg value="${skeletondir}"/>
                           <arg value="-o"/>
                           <arg value="${srcdir}"/>
                           <arg value="-s"/>
                           <arg value="-S"/>
                           <arg value="true"/>
                           <arg value="-d"/>
                           <arg value="Session"/>
                           <arg value="${wsdlpath}"/>
                           <classpath refid="axis-classpath"/>
                   </java>
           </target>
           <target name="compile" depends="skeleton">
                   <javac srcdir="${srcdir}" destdir="${destdir}"
                           encoding="UTF-8">
                           <classpath refid="axis-classpath"/>
                   </javac>
           </target>
           <target name="copy2axis" depends="compile">
                   <copy todir="${tomcat.axis.classesdir}" overwrite=
                           "true">
                           <fileset dir="${destdir}">
                                   <include name="*.class"/>
                                   <include name="*/*.class"/>
                                   <include name="*/*/*.class"/>
                           </fileset>
                   </copy>
           </target>
           <target name="deploy" depends="copy2axis">
                   <java classname="org.apache.axis.client.AdminClient"
                           fork="Yes">
                           <arg value="-p"/>
                           <arg value="${deploy.port}"/>
                           <arg value="${deploy.ddname}"/>
                           <classpath refid="axis-classpath"/>
                   </java>
           </target>
           <target name="all" depends="deploy"/>
   </project>


                  Figure 6: build.xml of NETCONF servers








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   axis.libdir=C:/axis-1_4/lib
   tomcat.axis.classesdir=
   C:/Program Files/Apache Software Foundation/Tomcat 6.0/
   webapps/axis/WEB-INF/classes
   srcdir=src
   destdir=classes
   skeletondir=skeleton
   wsdlpath=myNetconfService.wsdl
   deploy.port=832
   deploy.ddname=src/skeleton/deploy.wsdd


               Figure 7: build.properties of NETCONF servers

   The locations of the WSDL file and "deploy.wsdd" file have to be
   specified in the "build.properties" file.  In Figure 7, the location
   of the WSDL file and "deploy.wsdd" file are specified as being under
   the current directory.

   By running Apache Ant on Eclipse, the steps shown in Figure 6 are
   followed.  First, skeleton codes have to be generated.  After the
   skeleton codes are generated, source codes of the NETCONF server
   functions must be added to the skeleton codes according to the
   function that developers intend to add.

   Then, by running Apache Ant again, compiling the skeleton codes is
   executed.  As a result, class files of the NETCONF server are
   generated.  Apache Ant copies these class files to the directory of
   Tomcat and deploys the NETCONF server.  After that, the NETCONF
   server becomes accessible from the NETCONF client.  The NETCONF
   server is developed in this manner.

4.2.3.  Developing NETCONF Servers by C Language Programming

   When the NETCONF server for network equipment is being implemented,
   memory capacity might be limited, so installing a Java environment on
   the network equipment might not be attainable.  The network-equipment
   platform might not support a Web Services tool.  In that case, it may
   be necessary to implement SOAP as well as the NETCONF server by using
   C programming on the network equipment.

   To develop a NETCONF server capable of receiving NETCONF messages
   sent over SOAP/HTTP, the network equipment needs a HTTP daemon and a
   NETCONF service provider.  A commonly used HTTP daemon can be used.
   A SOAP module needs to be added to the HTTP daemon as a connector
   between the HTTP daemon and the NETCONF service provider.  The
   NETCONF service provider for parsing NETCONF messages sent from the
   NETCONF client and sending reply NETCONF messages toward the NETCONF



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   client has to be developed.

   When an HTTP daemon receives a SOAP message that is sent over HTTP,
   the message is handed over to the SOAP module incorporated in the
   HTTP daemon.  Then, the SOAP module removes the SOAP header and
   passes NETCONF messages to the NETCONF service provider.  After that,
   the NETCONF service provider parses the NETCONF messages and
   configures the network equipment accordingly.











































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5.  Security Considerations

   The security considerations of [RFC4741] and [RFC4743] are applicable
   to this document.  Implementers or users of SOAP-based NETCONF
   clients and servers should take these considerations into account.

   As specified in the security considerations section of [RFC4743],
   transport-level security, such as authentication of users and
   encryption of transport protocol, has to be ensured by TLS (Transport
   Layer Security) in the case of NETCONF SOAP binding.  That is,
   security has to be provided in the form of NETCONF/SOAP/HTTPS.








































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6.  IANA Considerations

   This document has no actions for IANA.
















































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7.  References

7.1.  Normative References

   [RFC4741]  Enns, R., "NETCONF Configuration Protocol", RFC 4741,
              December 2006.

   [RFC4743]  Goddard, T., "Using NETCONF over the Simple Object Access
              Protocol (SOAP)", RFC 4743, December 2006.

 7.2.   Informative References

    [Ant]       "Apache Ant" .

              <http://ant.apache.org/>

   [Axis]     "Web Services - Axis".

              <http://ws.apache.org/axis/>

   [Eclipse]  "Eclipse".

              <http://www.eclipse.org/>

   [JDK]      "Java SE".

              <http://java.sun.com/javase/index.jsp>

   [NetBeans]
              "NetBeans".

              <http://www.netbeans.org/index.html>

   [Tomcat]   "Apache Tomcat".

              <http://tomcat.apache.org/>

   [WSDL]     "Web Service Description Language (WSDL) 1.1".

              <http://www.w3.org/TR/wsdl/>











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Authors' Addresses

   Iijima Tomoyuki
   Alaxala Networks Corp.
   Shin-Kawasaki Mitsui Bldg.
   890 Saiwai-ku Kashimada
   Kawasaki, Kanagawa  212-0058
   Japan

   Phone: +81-44-549-1735
   Fax:   +81-44-549-1272
   Email: tomoyuki.iijima@alaxala.com


   Yoshifumi Atarashi
   Alaxala Networks Corp.
   Shin-Kawasaki Mitsui Bldg.
   890 Saiwai-ku Kashimada
   Kawasaki, Kanagawa  212-0058
   Japan

   Phone: +81-44-549-1735
   Fax:   +81-44-549-1272
   Email: atarashi@alaxala.net


   Hiroyasu Kimura
   Alaxala Networks Corp.
   Shin-Kawasaki Mitsui Bldg.
   890 Saiwai-ku Kashimada
   Kawasaki, Kanagawa  212-0058
   Japan

   Phone: +81-44-549-1735
   Fax:   +81-44-549-1272
   Email: h-kimura@alaxala.net















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   Makoto Kitani
   Alaxala Networks Corp.
   Shin-Kawasaki Mitsui Bldg.
   890 Saiwai-ku Kashimada
   Kawasaki, Kanagawa  212-0058
   Japan

   Phone: +81-44-549-1735
   Fax:   +81-44-549-1272
   Email: makoto.kitani@alaxala.com


   Hideki Okita
   Hitachi, Ltd.
   1-280 Higashi-Koigakubo
   Kokubunji, Tokyo  185-8601
   Japan

   Phone: +81-42-323-1111
   Fax:   +81-42-327-7868
   Email: hideki.okita.pf@hitachi.com






























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Full Copyright Statement

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