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Network Working Group                                       G. MansfieldRequest for Comments: 1609                        AIC Systems LaboratoryCategory: Experimental                                      T. Johannsen                                                      Dresden University                                                              M. Knopper                                                    Merit Networks, Inc.                                                              March 1994Charting Networks in the X.500 DirectoryStatus of this Memo   This memo defines an Experimental Protocol for the Internet   community.  This memo does not specify an Internet standard of any   kind.  Discussion and suggestions for improvement are requested.   Distribution of this memo is unlimited.Abstract   There is a need for a framework wherein the infrastructural and   service related information about communication networks can be made   accessible from all places and at all times in a reasonably efficient   manner and with reasonable accuracy.  This document presents a model   in which a communication network with all its related details and   descriptions can be represented in the X.500 Directory. Schemas of   objects and their attributes which may be used for this purpose are   presented.  The model envisages physical objects and several logical   abstractions of the physical objects.Mansfield, Johannsen & Knopper                                  [Page 1]

RFC 1609        Charting Networks in the X.500 Directory      March 1994Table of Contents      1. Introduction                                       2      2. Infrastructural information requirements           2      3. The Nature of the Network Map - The X.500 Solution 4      4. The hierarchical model of a network                5      4.1 Network maps                                      5      4.2 Representation in the X.500 Directory             6      5. Position in The Directory Information Tree(DIT)    7      6. Proposed Schemes                                   8      6.1 Communication Object Classes                      9      6.2 Physical elements                                10      6.2.1 Network                                        10      6.2.2 Node                                           11      6.2.3 NetworkInterface                               12      6.3 Logical Elements                                 12      6.3.1 Network                                        13      6.3.2 Node                                           13      6.3.3 NetworkInterface                               13      7. Security Considerations                           14      8. Authors' Addresses                                14      9. References                                        151. Introduction   The rapid and widespread use of computer networking has highlighted   the importance of holding and servicing information about the   networking infrastructure itself.  The growing and active interest in   network management, which has concentrated mainly in the areas of   fault and performance management on a local scale, is severely   constrained by the lack of any organized pool of information about   the network infrastructure itself. Some attempts have been made, on a   piecemeal basis, to provide a larger view of some particular aspect   of the network (WHOIS, DNS, .. in the case of the Internet; [1],   [2]).  But to date, little or no effort has been made in setting up   the infrastructural framework, for such an information pool. In this   work we explore the possibility of setting up a framework to hold and   serve the infrastructural information of a network.2. Infrastructural information requirements   Network operation and management requires information about the   structure of the network, the nodes, links and their properties.   Further, with current networks extending literally beyond bounds, the   scope of the information covers networks beyond the span of local   domain of authority or administration.  When the Network was   relatively small and simple the map was already known to the   knowledgable network administrator.  Based on this knowledge theMansfield, Johannsen & Knopper                                  [Page 2]

RFC 1609        Charting Networks in the X.500 Directory      March 1994   course of the packets to different destinations would be charted. But   presently the size of the Network is already beyond such usages. The   current growth of the Network is near explosive. This is giving rise   to the urgent necessity of having infrastructural and service related   information made accessible from all places and at all times in a   reasonably efficient manner and with reasonable accuracy. In the rest   of this work a network is the media for transmitting information.   Network elements are equipment with one or more network interfaces   whereby it is possible to exchange information with the network.   Network elements with multiple interfaces e.g.,   gateways/routers/bridges/repeaters...  may be used to connect   networks.  Network related information, referred to as 'network map'   in the rest of this paper, should   1. Show the interconnection between the various network      elements. This will basically represent the Network as a graph      where vertices represent objects like gateways/workstations/      subnetworks and edges indicate the connections.   2. Show properties and functions of the various network elements      and the interconnections. Attributes of vertices will represent      various properties of the objects e.g., speed, charge, protocol, OS,      etc. Functions include services offered by a network element.   3. Contain various name and address information of the networks      and network elements   4. Contain information about various administrative and management      details related to the networks and network elements.   5. Contain the policy related information, part of which may be      private while the other part may be made public.   Using this map the following services may be provided   1. Configuration management:      - Display the physical configuration of a network,        i.e., nodes and their physical interconnections      - Display the logical configuration of a network,        i.e., nodes and their logical interconnections.   2. Route management:      - Find alternate routes by referring to the physical        and logical configurations.      - Generate routing tables considering local policy and        policy of transit domainsMansfield, Johannsen & Knopper                                  [Page 3]

RFC 1609        Charting Networks in the X.500 Directory      March 1994      - Check routing tables for routing loops,        non-optimality, incorrect paths, etc.   3. Fault management: In case of network failures      alternatives may be found and used to bypass the      problem node or link.   4. Service management: Locate various services and      servers in the Network.   5. Optimization: The information available can be used      to carry out various optimizations, for example cost,      traffic, response-time, etc.   6. Provide mappings between the various names and      addresses of elements   7. Depict administrative/autonomous domains.   8. Network Administration and Management: References to      people responsible for administering and technically      maintaining a network will be useful.   Examples of such usages are described in [3], [4].3. The Nature of the Network Map - The X.500 solution   Implementing and maintaining a detailed map of the network poses a   serious problem.  The scope of the map is global and the network   itself is expanding.  Some of the problems that are peculiar to the   network map are listed below.   o The Network configuration is quasi-static. Nodes,     links and networks are being added,updated and deleted     someplace or the other.   o The Network is huge and geographically distributed.   o The network spans several political and administrative     areas. The related information is also controlled and     maintained in a distributed fashion.   In short, global network configuration information is unwieldy and   growing continuously.  It is impossible to service such information   in a centralized fashion. There is need for a distributed framework   which allows users and applications to access information about   users, services, networks, ... easily and globally.  The OSI X.500   Directory services [5] provides a rich framework to support aMansfield, Johannsen & Knopper                                  [Page 4]

RFC 1609        Charting Networks in the X.500 Directory      March 1994   globally distributed information service system.  The X.500 Directory   is intended to be a very large and highly distributed database. It is   structured hierarchically with entries arranged in the form of a tree   in which each object corresponds to a node or an entry. Information   is stored about an object as a set of attributes.4. The hierarchical model of a network   For representing networks in the Directory we use the following   hierarchical model.   A network is the media for transmitting information with zero or more   network elements each having at least one network interface on the   media. The media may be any kind of a line (physical circuit/virtual   circuit), or a collection of interconnected networks.       <  The postscript version of this document  >       <  has a figure here. However, the figure   >       <is too complex to be drawn in simple ASCII.> Figure 1:  Simple and composite networks and their mapping to the DIT.   The model allows hierarchy of subnetworks.  Network elements with   multiple interfaces may act as external gateways to the attached   network and to networks higher up in the hierarchy.  Thus, a gateway   may be the external gateway of several networks which are either   interconnected or have a hierarchical relationship.   A network may be simple consisting of zero or more network elements   or composite consisting of several sub-networks.  Examples of simple   networks are ethernets, optical fiber/copper cables, free space, .. .4.1 Network Maps   Using the above model it is straight forward to draw the topological   graph of the network where the vertices represent the components of   the network and edges indicate the connections.  For visual   representation the graph may be translated to a more "physical"   illustration (figure 1).   Just as there are several maps of the same geographical domain   (political, natural...)  one can envisage several views of the same   network and its components. A view (called "image" in the remainder)   could pertain to a particular protocol suite (IP/OSI/...), an   administrative domain or purpose.  Using images, several abstractions   of the same object are possible.Mansfield, Johannsen & Knopper                                  [Page 5]

RFC 1609        Charting Networks in the X.500 Directory      March 19944.2 Representation in the X.500 Directory   To represent the various images of networks and its components along   with the real-image relationship among the various objects we   introduce the following classes of objects:   o Communication Object Class (CO): All objects defined     furtheron in this document belong to this class.     Common attributes for all communication objects are     defined insection 6.   o Physical Communication Object Class (PCO): A subclass     of CO-class, this class defines common properties for     all objects representing physical communication objects.   o Image Communication Object Class (ICO): A subclass of     CO-class, this class defines common properties for all     objects representing images of communication objects.   The above classes sort communication objects into physical or image   object.  As is implied in the nomenclature a physical object will   have several attributes describing it physical properties - location,   weight, size, ....  etc.  An image object will have an Image-of   attribute. The Image-of attribute will point to a physical object or   to another image object.   Using this schema it is possible to represent the case of several   logical network systems (running different protocol stacks - IP, XNS,   SNA, OSI, ...) which coexist on the same physical network.   Information related to different types of networks, no matter what   the underlying communication protocol is, will reside in the   Directory in harmony.  Also, their interrelation will be represented   and accessed in a fashion independent of the source/destination   network, namely, using the OSI X.500 protocol.   Schemes for physical networks and logical images of physical networks   are defined insection 6.   All objects are defined insection 6.Mansfield, Johannsen & Knopper                                  [Page 6]

RFC 1609        Charting Networks in the X.500 Directory      March 1994                                              ...............                                             :              :                                             :   IP    OSI  :                                             :  +-+    +-+  :                                             :  |A|    |B|  :                             NetWork  -----> :  +-+    +-+  :                             /    \          :   |      |   :                            /      \         : ============ :                           /        \        :      |       :                          /          \       :     +-+      :                         /            \      :     |C|      :                        /              \     :     +-+      :                   OSI-image        IP-image :   IP + OSI   :                       |                |    +..............+                       V                V                     ........       ........                     :      :      :       :                 IP  : OSI  :      :   IP  : OSI                +-+  : +-+  :      :  +-+  : +-+                |A|  : |B|  :      :  |A|  : |B|                +-+  : +-+  :      :  +-+  : +-+             ....|...:  |   :      :   |   :..|...             : ============ :      : ============ :             :      |       :      :      |       :             :     +-+      :      :     +-+      :             :     |C|      :      :     |C|      :             :     +-+      :      :     +-+      :             :   IP + OSI   :      :   IP + OSI   :             +..............+      +..............+      Figure 2: Several logical views of the same physical network5. Position in the Directory Information Tree (DIT)   Information about networks usually will be contained in the DIT as   subordinate of the organization maintaining the network. The network   model gets mapped into a tree structure for network elements.  There   is one network object giving general descriptions of the network.   Subordinates of this network object are node objects for each node   element present in the network.  Node objects hold networkInterface   objects as subordinates.  A network can be physically or logically   subdivided into several (sub)networks.  In this case, a network entry   will have network objects as subordinates which again build the same   structure.  These entries may be kept as subordinates of   organizationalUnit entries as well, with pointers from the "root"   network.Mansfield, Johannsen & Knopper                                  [Page 7]

RFC 1609        Charting Networks in the X.500 Directory      March 1994   This structure holds for physical and logical elements.  Physical   elements are named network, node and networkInterface, and logical   elements are named networkImage, nodeImage and networkInterfaceImage.                          _root_                         /      \                        /        \                       /          \                  country          \                     /              \                    /            organization                   /             /    |     \                  /             /     |      \                 /             /      |       \                /             /       |        \               /  organizationalUnit* |         \              /   /             \ \   |          \             /   /               \ \__|_________  \            /   /                 \   |         \  \           Person                 Network*<====>NetworkImage*                                      |             |                                      |             |                                     Node      NodeImage                                      |             |                                      |             |                           NetworkInterface   NetworkInterfaceImage           Legends: * the object may recursively contain objects of                    same class as children           Figure 3: Part of the Directory Information Tree,          showing relations of White Pages and network objects6. Proposed Schemes   A physical network comprises of wires and machines. The physical map   of the network will show the interconnections of these nodes by these   circuits.   For each physical network element, one or more images may exist.   Similarly, an image may be attached to one or more physical objects.   The types of images can grow along with the requirements.   Relationship between elements (physical or logical) are expressed by   attributes or the position in the Directory tree.Mansfield, Johannsen & Knopper                                  [Page 8]

RFC 1609        Charting Networks in the X.500 Directory      March 1994   Problems that are addressed in the schema:   1. Avoiding data duplication   2. Preserving administrative boundaries/controls.   3. Simple representation (minimal number of pointers)   4. Security: Though no special emphasis has been placed      in this work we believe the X.500 access control policies      policies will provide a reasonable secure framework for security      and privacy.   Problems that are not addressed:   1. Caching policies, etc.: to be decided locally6.1 Communication Object Classes   The object classes introduced insection 4 are defined as follows:   CommunicationObject OBJECT CLASS    SUBCLASS of top    MAY CONTAIN {     description :: CaseIgnoreStringSyntax,      /* can contain any information about the object,         however, wherever an appropriate attribute         exists, this should be used first to hold         information */     adminContact :: distinguishedNameSyntax,      /* points to the person which is responsible for         the administration of the instance this object         describes;         This refers to the instance only in the context         of the concrete object class */     technContact :: distinguishedNameSyntax,      /* points to the person which is responsible for         the technical maintenance of the instance this         object describes;         This refers to the instance only in the context         of the concrete object class;         Availability (e.g. hours of service) is not         covered by this attribute. */    }   PhysicalCommunicationObject OBJECT CLASS    SUBCLASS of CommunicationObject    MAY CONTAIN{     owner :: distinguishedNameSyntax,      /* refers to organization or person owning the        physical element;Mansfield, Johannsen & Knopper                                  [Page 9]

RFC 1609        Charting Networks in the X.500 Directory      March 1994        Note that more detailed information (like lease,        rental, etc.) can be covered in a specific image        (ownerImage) of this element */     localityName :: CaseIgnoreStringSyntax      /* where the object is located;         can be used freely to "spot" a network element,         e.g. state/city/street/building/floor/room/         desk/... */     ICO :: distinguishedNameSyntax      /* points to image object the physical object         is related to;            might have several values if physical object is            used for several applications at the same time */           }   ImageCommunicationObject OBJECT CLASS    SUBCLASS of CommunicationObject    MAY CONTAIN{     type :: caseIgnoreStringSyntax,      /* expresses the view this object refers to, e.g.         view of provider/user/IP/OSI/...;            Note that this information can be covered by            the object class in some cases            (e.g. ipNetworkImage gives the IP view) */     imageOf :: distinguishedNameSyntax,      /* points to physical/image object the image         is related to;            might have several values if view applies to            several physical objects at the same time */    }6.2 Physical elements   The following objects describe network elements without saying   anything about their usage.  All objects inherit properties of the   PhysicalCommunicationObject class.6.2.1 Network   The network object supplies general descriptions which are common for   a set of nodes and circuits comprising one network.  This includes   information about the type of circuits (medium, broadcast or point-   to- point, etc.) and properties (speed etc.).   network OBJECT CLASS    SUBCLASS of PhysicalCommunicationObject    MUST CONTAIN  {     networkName :: caseIgnoreStringSyntax }Mansfield, Johannsen & Knopper                                 [Page 10]

RFC 1609        Charting Networks in the X.500 Directory      March 1994    MAY CONTAIN {     externalGateway :: distinguishedNameSyntax,      /* points to one or more nodes that connect         this network to neighbor networks;            whether a node actually is used as gateway            for one or the other protocol, is defined            in a related networkImageObject */     nwType :: caseIgnoreStringSyntax,      /* type of this network;         either "composite" (if consisting of subnetworks)         or type of a line:         bus, ring, star, mesh, point-to-point */     media :: caseIgnoreStringSyntax,      /* if network is not composite,         describes physical media:         copper, fiber optic, etc. */     speed :: numericStringSyntax,      /* nominal bandwidth, e.g. 64 kbps */     traffic :: numericStringSyntax      /* (average) use in percent of nominal bandwidth            [ this needs more specification later ] */     configurationDate ::  uTCTimeSyntax,      /* date when network was configured in current            shape */     configurationHistory :: caseIgnoreStringSyntax      /* list of configuration changes, like:            added/removed nodes, lines */     }6.2.2 Node   The node object describes any kind of device that is part of the   network, such as simple nodes, printer, bridges.   node OBJECT CLASS    SUBCLASS of PhysicalCommunicationObject    MUST CONTAIN{     nodeName :: caseIgnoreStringSyntax }    MAY CONTAIN {     machineType :: caseIgnoreStringSyntax,      /* e.g. main frame, work station, PC, printer;         might include manufacturer */     OS :: caseIgnoreStringSyntax,      /* e.g. VM, UNIX, DOS; might include release */    }Mansfield, Johannsen & Knopper                                 [Page 11]

RFC 1609        Charting Networks in the X.500 Directory      March 19946.2.3 NetworkInterface   Each node object will have one or more networkInterface objects as   subordinates.  NetworkInterface objects provide information about   interfaces of the node and connectivity.   networkInterface OBJECT CLASS    SUBCLASS of PhysicalCommunicationObject    MUST CONTAIN {     networkInterfaceName :: caseIgnoreStringSyntax      /* It is suggested that the networkInterface         name is derived from the name of the logical         device this networkInterface represents for         the operating system, e.g. le0, COM1 */     }    MAY CONTAIN {     networkInterfaceAddress  :: caseIgnoreStringSyntax,      /* this should contain a protocol-independent            interface address, e.g. Ethernet board number */     connectedNetwork :: distinguishedNameSyntax,      /* pointer to object of network which this networkInterface is         connected to */     }6.3 Logical Elements   An abstract view of a physical element is called image in this   document.  The word image gets appended to the object type, leading   to the new objects networkImage, nodeImage and networkInterfaceImage.   Images will either build Directory trees of themselves or be stored   as part of the physical network tree (seesection 5).   Image objects inherit properties of the ImageCommunicationObject   class.   Each image object has specific attributes which vary depending on the   point of view (IP, OSI, ...). Also, the user and provider of an image   will view an object differently; further a user of an object may also   be providing the services of the same object to another user.   Therefore, in the following a complete and general list of attributes   cannot be given.  We recommend to define subclasses of Image classes   for each logical view. These subclasses inherit all attributes   defined with the object classes below and add more specific   attributes.  Examples for an IP-view are given in [1].Mansfield, Johannsen & Knopper                                 [Page 12]

RFC 1609        Charting Networks in the X.500 Directory      March 19946.3.1 Network   There may be several network images for one and the same physical   network: one for each protocol, application, etc.   networkImage OBJECT CLASS    SUBCLASS of ImageCommunicationObject    MAY CONTAIN {     externalGateway :: distinguishedNameSyntax,      /* points to one or more nodes that act         as gateway for the protocol application         this images refers to */     speed :: numericStringSyntax,      /* nominal bandwidth for the channel dedicated         to this protocol or application ,         e.g. 64 kbps */     traffic :: numericStringSyntax,      /* (average) use in percent of nominal bandwidth         [this needs more specification later ] */     charge  :: numericStringSyntax      /* amount of money that has to be paid to         service provider for usage;         [it is felt that this needs further definition:          e.g. monetary unit / time unit, monetary unit /          data unit ] */     }6.3.2 Node   Name and functionality within the network might vary for a node from   protocol to protocol considered.  In particular, a node might act as   gateway for one protocol but not for the other. Routing policy is   stored in the case of policy gateways.   nodeImage OBJECT CLASS    SUBCLASS of ImageCommunicationObject     /* no attributes common for all nodeImages have been        defined yet */6.3.3 NetworkInterface   As with physical nodes, nodeImages have networkInterfaces   (networkInterfaceImages) which describe connectivity to other network   elements. NetworkInterfaceImages are only given if the protocol is   establishing connections via this networkInterface.   networkInterfaceImage OBJECT CLASS    SUBCLASS of ImageCommunicationObjectMansfield, Johannsen & Knopper                                 [Page 13]

RFC 1609        Charting Networks in the X.500 Directory      March 1994    MAY CONTAIN {     networkInterfaceAddress :: caseIgnoreStringSyntax,      /* the networkInterface address in the image         context, e.g. IP number, NSAP */     connectedNetwork   :: distinguishedNameSyntax      /* pointer to networkImageObject that describes         the network this networkInterface is attached         to in terms of the protocol or application the         image indicates */     }7. Security Considerations   Security issues are not discussed in this memo.8. Authors' Addresses   Glenn Mansfield   AIC Systems Laboratory   6-6-3 Minami Yoshinari   Aoba-ku, Sendai 989-32   Japan   Phone: +81 22 279-3310   EMail: glenn@aic.co.jp   Thomas Johannsen   Dresden University of Technology   Institute of   Communication Technology   D-01062 Dresden   Germany   Phone: +49 351 463-4621   EMail: Thomas.Johannsen@ifn.et.tu-dresden.de   Mark Knopper   Merit Network, Inc.   1071 Beal Avenue   Ann Arbor, MI 48109   EMail: mak@merit.eduMansfield, Johannsen & Knopper                                 [Page 14]

RFC 1609        Charting Networks in the X.500 Directory      March 19949. References  [1]  Harrenstein, K., Stahl, M., and E. Feinler, "NICNAME/WHOIS",RFC954, SRI, October 1985.  [2]  Mockapetris, P., "Domain Names - Implementation and       Specification", STD 13,RFC 1035, USC/Information Sciences       Institute, November 1987.  [3]  Johannsen, T., Mansfield, G., Kosters, M., and S. Sataluri,       "Representing IP information in the X.500 Directory",RFC 1609,       Dresden University, AIC Systems Laboratory, Network       Solutions,Inc., AT&T Bell Laboratories, March 1994.  [4]  Johannsen, T., and G. Mansfield, "The Soft Pages Project", OSI-DS       WG document, OSI-DS-39, Dresden University, AIC Systems       Laboratory, February 1993.  [5]  CCITT Blue Book, "Data Communication Networks: Directory",       Recommendations X.500-X.521, December 1988.Mansfield, Johannsen & Knopper                                 [Page 15]