  X25router 2000, Version 1.1                             SPD 28.86.01         
  (Formerly X25router)                                                         
                                                                               
  DESCRIPTION                                                                  
                                                                               
  The X25router 2000 is a communications product that provides routing and     
  X.25 communications services for a Local Area Network (LAN). It allows       
  communications with nodes outside the LAN within a Wide Area Network (WAN).  
  By using an X25router 2000, the routing load on other nodes on the LAN is    
  reduced, releasing resources for other applications.                         
                                                                               
  Note:    The X25router 2000 software product runs on the DEC MicroServer     
           (DEMSA) hardware unit or the DEC MicroServer-SP (DEMSB) hardware    
           unit. The X25router 2000 software license is available as part of   
           two packages:                                                       
                                                                               
           oo    The X25router 2000 package includes the X25router 2000       
                software license and the DEC MicroServer (DEMSA) hardware      
                unit.                                                          
                                                                               
           oo    The X25router 100 package include the X25router 2000 software
                license and the DEC MicroServer-SP (DEMSB) hardware unit.      
                                                                               
  Overview                                                                     
                                                                               
  The X25router 2000 software running on the DEC MicroServer (DEMSA) or DEC    
  MicroServer-SP (DEMSB) provides the following services to Phase IV DECnet    
  nodes on a IEEE 802.3 or ISO 8802/3 Local Area Network (LAN):                
                                                                               
  oo   DECnet routing services                                                
                                                                               
  oo   X.25 communications services                                           
  DECnet Routing Services                                                      
                                                                               
  For DECnet routing purposes, Phase IV DECnet networks consist of a number    
  of linked areas. Each area is not limited to a specific geographic region,   
  but is often localized (such as a LAN in a building). DECnet routing is      
  handled by specified routing nodes which may have to do this task in         
  addition to providing services to users. DECnet routing works on two         
  levels:                                                                      
                                                                               
  oo   Level 1 routers provide routing services between nodes within an area. 
      This is called intra-area routing.                                       
                                                                               
  oo   Level 2 routers provide routing services between areas.  This is called
      inter-area routing.                                                      
                                                                               
  The X25router 2000 running on the DEC MicroServer is a routing system that   
  can act as a level 1 and/or a level 2 router. The system routes data over a  
  LAN (Ethernet) circuit, synchronous DDCMP circuits, and DECnet circuits      
  established across X.25 PSDNs. This gives other DECnet nodes on the LAN      
  access to remote nodes, and also relieves them of the routing overhead.      
                                                                               
  The X25router 2000 running on the DEC MicroServer-SP is a routing system     
  that can act only as a level 1 router. The system routes data over a LAN     
  (Ethernet) circuit and DECnet circuits established across X.25 PSDNs. This   
  gives other DECnet nodes on the Ethernet access to remote nodes, and also    
  relieves them of the routing overhead. If required, the system can also      
  route data over a single synchronous DDCMP circuit.                          
                                                                               
  X25 Communication Services                                                   
                                                                               
  For X.25 communications purposes, the X25router 2000 allows DECnet users to  
  reach remote DECnet nodes across a supported PSDN. This facility is called   
  Data Link Mapping (DLM). The X25router 2000 also acts as a connector node    
  to provide access to supported PSDNs for any system on the LAN running a     
  supported VAX P.S.I. Access product. (Note that VAX P.S.I. Access is         
  available only on VMS or MicroVMS systems.)                                  
                                                                               
  The X25router 2000 can be used in several different ways. For example,       
  running on the DEC MicroServer, the X25router 2000 can:                      
                                                                               
  oo   Act as a level 1 router to route data to nodes in the same area        
                                                                               
  oo   Act as a level 2 router to route data to nodes in other areas          
                                                                               
  oo   Connect to a DECnet node in another area via DDCMP                     
                                                                               
  oo   Act as an access point to a PSDN for nodes on a LAN                    
                                                                               
  oo   Connect to remote DECnet nodes in other areas via a public PSDN        
                                                                               
  oo   Connect to remote DECnet nodes by means of a private PSDN              
                                                                               
  oo   Provide a point-to-point ISO 8208 connection                           
                                                                               
  System Overview                                                              
                                                                               
  The X25router 2000 system is a combination of hardware and software. The     
  X25router 2000 software runs on either the DEC MicroServer (DEMSA) or the    
  DEC MicroServer-SP (DEMSB) communications  server.                           
                                                                               
  The major features of the X25router 2000 software running on the DEC         
  MicroServer (DEMSA) are:                                                     
                                                                               
  oo   Physical Characteristics                                               
                                                                               
      -    A table top unit which can also be rack or wall mounted.            
                                                                               
      -    Status display.                                                     
                                                                               
      -    Ethernet and four synchronous ports.                                
                                                                               
      -    The four synchronous ports can be used as either DECnet DDCMP       
           connections or X.25 connections.                                    
                                                                              
  oo   Synchronous Line Capabilities                                          
                                                                               
      -    Line speeds of up to 384K bits per second                           
                                                                               
      -    Supports the following interchange circuits and electrical          
           interfaces:                                                         
                                                                               
           CCITT - V.24, V.28, V.35, V.36, V.11, V.10                          
                                                                               
           EIA   - RS232-C, RS232-D, RS449, RS422, RS423                       
                                                                               
      -    Supports CCITT (1980) X.21 for leased line services only            
                                                                               
      -    Full modem control on all synchronous lines                         
                                                                               
  oo   DECnet Routing Capabilities                                            
                                                                               
      -    DECnet Phase IV Level 1 and/or level 2 routing.                     
                                                                               
      -    Provides routing services between 63 areas, each of up to 1023      
           nodes. These are the maximum values permitted by Digital Equipment  
           Corporation's Network Architecture. Note that satisfactory          
           operation in large networks requires proper network planning.       
                                                                               
      -    Adaptive routing to and from the LAN, and using up to 63 other      
           routing circuits (DDCMP or DLM) over the synchronous links.         
                                                                               
      -    Communicates with remote Phase III nodes in the same DECnet area.   
                                                                               
      -    Path splitting, where there are two or more equal-cost paths        
           between the X25router 2000 and the destination DECnet node. For     
           this feature, all the destination nodes must support out-of-order   
           packet caching.                                                     
                                                                               
  oo   DDCMP Capabilities                                                     
                                                                               
      -    Communicates with all supported synchronous Digital DDCMP           
           products, excluding the DMC11.                                      
                                                                               
      -    Works on point-to-point or multipoint links. However, on DDCMP      
           multipoint links, the X25router 2000 can act only as a tributary.   
                                                                               
      -    Full- or half-duplex communications.                                
                                                                               
  oo   X.25 Capabilities                                                      
                                                                               
      -    Connects to multiple supported PSDN(s) on a per-line basis.         
                                                                               
      -    Can have more than one connection to a PSDN. Each connection must   
           have a unique DTE address. The X25router 2000 can share outgoing    
           calls between all the DTEs connected to a PSDN.                     
                                                                               
      -    Supports both Permanent Virtual Circuits (PVCs) and Switched        
           Virtual Circuits (SVCs). PVCs and SVCs can be used either as DLM    
           circuits (VMS and ULTRIX hosts) or as virtual circuits with VAX     
           P.S.I. Access nodes.                                                
                                                                              
      -    Supports a maximum of 512 PVCs and/or SVCs, of which a maximum of   
           63 can be DLM circuits.                                             
                                                                               
  The major features of the X25router 2000 software running on the DEC         
  MicroServer-SP (DEMSB) are:                                                  
                                                                               
  oo   Physical Characteristics                                               
                                                                               
      -    A table top unit which can also be rack or wall mounted.            
                                                                               
      -    Status display.                                                     
                                                                               
      -    Ethernet and a single synchronous port.                             
                                                                               
      -    The synchronous port can be used as either a DECnet DDCMP           
           connection or an X.25 connection.                                   
                                                                               
  oo   Synchronous Line Capabilities                                          
                                                                               
      -    Line speeds of up to 19.2K bits per second                          
                                                                               
      -    Supports the following interchange circuits and electrical          
           interfaces:                                                         
                                                                               
           CCITT - V.24, V.28, V.35, V.36, V.11, V.10                          
                                                                               
           EIA   - RS232-C, RS232-D, RS449, RS422, RS423                       
                                                                               
      -    Supports CCITT (1980) X.21 for leased line services only            
                                                                               
      -    Full modem control on the synchronous line                          
                                                                               
  oo   DECnet Routing Capabilities                                            
                                                                               
      -    DECnet Phase IV Level 1 routing only                                
                                                                               
      -    Provides routing services for up to 16 end nodes within its own     
           area                                                                
                                                                               
      -    Adaptive routing to and from the LAN, and using up to 2 other       
           routing circuits (2 DLM or 1 DDCMP) over the synchronous link       
                                                                               
      -    Communicates with remote Phase III nodes in the same DECnet area    
                                                                               
  oo   DDCMP Capabilities                                                     
                                                                               
      -    Communicates with all supported synchronous Digital DDCMP           
           products, excluding the DMC11.                                      
                                                                               
      -    Works on point-to-point or multipoint links. However, on DDCMP      
           multipoint links, the X25router 2000 can act only as a tributary.   
                                                                               
      -    Full- or half-duplex communications.                                
                                                                               
  oo   X.25 Capabilities                                                      
                                                                               
      -    Connects to a single supported PSDN.                                
                                                                               
      -    Supports both Permanent Virtual Circuits (PVCs) and Switched        
           Virtual Circuits (SVCs). PVCs and SVCs can be used either as DLM    
           circuits (VMS and ULTRIX hosts) or as virtual circuits with VAX     
           P.S.I. Access nodes.                                                
                                                                               
                                                                              
      -    Supports a maximum of 16 PVCs and/or SVCs, of which a maximum of 2  
           can be DLM circuits.                                                
                                                                               
  The X25router 2000 running on either the DEC MicroServer (DEMSA) or DEC      
  MicroServer-SP (DEMSB) has the following management capabilities and tools:  
                                                                               
      -    Configuration from a VMS or ULTRIX load host using a configuration  
           program.                                                            
                                                                               
      -    Dynamic reconfiguration while the system is running from any        
           suitable VMS node or ULTRIX load host using the DECnet Network 
           Control Program (NCP).
                                                                               
      -    Remote management from any suitable VMS node or ULTRIX load host    
           using the DECnet Network Control Program (NCP).                     
                                                                               
      -    Remote problem diagnosis from any suitable VMS node using the       
           TRACE utility.                                                      
                                                                               
      -    Automatic dumping and reloading from a VMS or ULTRIX load host      
           following a system failure.                                         
                                                                               
      -    Event logging to any suitable VMS or ULTRIX node.                   
                                                                               
  X.25 Capabilities                                                            
                                                                               
  Some of the major X.25 capabilities of the X25router 2000 are:               
                                                                               
  oo   Can be used as a packet-mode DTE connected to a supported PSDN (refer  
      to Table II at the end of this SPD).                                     
                                                                               
  oo   Can be used as one end of a point-to-point connection that uses ISO    
      7776 and 8208 standard protocols. The X25router can act as either the    
      DTE or DCE.                                                              
                                                                               
      Note that the X25router does not provide any packet-switching exchange   
      facilities.                                                              
                                                                               
  oo   Conforms to CCITT recommendations X.25 (1978, 1980, 1984) and to ISO   
      standards 3309, 7776, and 8208 (refer to the Conformance to Standards    
      section for more information).                                           
                                                                               
  oo   Uses LAPB or LAPBE as the frame-level data link protocol.              
                                                                               
  oo   Can split and recombine messages that are longer than the packet size  
      of a DECnet DLM circuit.                                                 
                                                                               
  oo   Routes non-DECnet traffic from a PSDN to one or more VAX P.S.I. Access 
      nodes on the Ethernet. The network manager has full control over which   
      node the incoming call is routed to.                                     
                                                                               
  Supported Public Networks                                                    
                                                                               
  Table II lists the public PSDNs that are supported by the X25router 2000.    
  The product is supported only on the public PSDNs in the countries shown.    
  Connections to public networks not listed in Table II are not supported by   
  Digital at the time of publication of this SPD. Please consult your local    
  Digital office for any questions you have concerning other public PSDNs.     
                                                                               
  In addition to the public PSDNs listed in Table II, certain private PSDNs    
  are supported by the X25router 2000, and the appropriate profiles are        
  included in the X25router 2000 product.                                      
                                                                               
                                                                              
  Conformance To Standards                                                     
                                                                               
  The X25router 2000 conforms to the following international standards:        
                                                                               
  oo   CCITT recommendation X.25 (1978, 1980, or 1984) using the LAPB or LAPBE
      variants of the data link and X.25 packet protocols.                     
                                                                               
  oo   ISO standards 7776 and 8208.                                           
                                                                               
  oo   ISO standard 3309 for HDLC frame generation and recognition (BSC       
      framing is not supported) on the X.25 ports.                             
                                                                               
  The hardware can operate with a number of electrical interface standards     
  (refer to the Line Support section). The X25router 2000 provides only the    
  electrical interface of a DTE rather than a DCE and does not provide clock   
  signals. An external clock source (such as a modem) is required for any      
  X.25 or DDCMP synchronous port.                                              
                                                                               
  Optional X.25 Facilities Supported by the X25router 2000                     
                                                                               
  The X.25 recommendation covers a wide range of optional facilities. Table    
  III (located at the end of this SPD) lists these facilities and indicates    
  which of these facilities the X25router 2000 supports. The central column    
  in Table III indicates the paragraph number in the X.25 recommendation       
  (1984) that defines the facility.                                            
                                                                               
  The features in Table III are those that the X25router 2000 is capable of    
  supporting when used with a VAX P.S.I. Access product that also supports     
  that feature. However, individual PSDNs may not support all of these         
  features. The product documentation specifies the facilities available on    
  each supported public PSDN.                                                  
                                                                               
  Line Support                                                                 
                                                                               
  The DEC MicroServer (DEMSA) and the DEC MicroServer-SP (DEMSB) hardware      
  units are packaged in LANbridge 100-type enclosures that contain an          
  Ethernet interface port (IEEE 802.3 compatible). The DEC MicroServer has 4   
  synchronous communications ports, while the DEC MicroServer-SP has a single  
  synchronous port. Both hardware units are supplied as table-top units, but   
  can also be wall or rack mounted in a standard 19 inch rack.                 
                                                                               
  The  DEC MicroServer and DEC MicroServer-SP support the following            
  interchange circuits and electrical interfaces:                              
                                                                               
  oo   CCITT - V.24, V.28, V.35, V.36, V.11, V.10                             
                                                                               
  oo   CCITT - X.21 (1980) for leased line services only                      
                                                                               
  oo   EIA   - RS232-C, RS232-D, RS449, RS422, RS423                          
                                                                               
  The number of lines supported depends on the hardware unit, the electrical   
  interface type, and the maximum line speed in use:                           
                                                                               
                                    TABLE I                                    
                                                                               
         DEC MicroServer                      Maximum Line Speed (Kbps)        
                                                                               
          Interface Type                      19.2   64    256    384          
                                                                               
          V.28/V.24       RS232-C/D             4     -     -      -           
          V.36/V.11       RS422/RS449           4     4     3      2           
          V.10            RS423                 4     4     -      -           
          V.35                                  4     4     3      2           
          X.21 leased line                      4     4     3      2           
                                                                              
         DEC MicroServer-SP                   Maximum Line Speed (Kbps)        
                                                                               
          Interface Type                                19.2                   
                                                                               
          V.28/V.24       RS232-C/D                     1                      
          V.36/V.11       RS422/RS449                   1
          V.10            RS423                         1                      
          V.35                                          1                      
          X.21 leased line                              1                      
                                                                               
  Adapter cables provide the necessary interchange circuits for each           
  synchronous line. Refer to the System Support Addendum (SSA 28.86.01-x) for  
  further information on the required adapter cables.                          
                                                                               
  Note that an external clock source, such as a modem, is always required.     
                                                                               
  Installation and Configuration                                               
                                                                               
  The X25router 2000 has no file storage of its own and relies on a host       
  system (load host) to load the software on the DEC MicroServer or DEC        
  MicroServer-SP.                                                              
                                                                               
  The minimum requirement is for one load host. However, the X25router 2000    
  software can be installed on a number of load hosts. This helps to protect   
  against loss of service if a single load host is unavailable, or unable to   
  load the system for any other reason.                                        
                                                                               
  The X25router 2000 software image is installed and configured on an ULTRIX,  
  VMS or MicroVMS load host on the same LAN as the DEC MicroServer or DEC      
  MicroServer-SP hardware unit. During system initialization, this software    
  image is down-line loaded to the hardware unit from the load host.           
                                                                               
  The load host and configuration databases contain information that defines   
  the X25router 2000 configuration. The network manager can create and modify  
  these databases by using utilities that are part of the load host software.  
  The configuration database is down-line loaded to the X25router 2000 during  
  system initialization.                                                       
                                                                               
  Network Management                                                           
                                                                               
  The network manager controls the system when it is running by using the      
  DECnet Network Control Program (NCP) from any DECnet Phase IV node. For      
  example, the manager can use the NCP utility from one of the systems on the  
  LAN. Management of the X.25 part of this product is restricted to ULTRIX     
  load host, VMS or MicroVMS systems.                                          
                                                                               
  The NCP utility provides three basic functions:                              
                                                                               
  oo   Control the X25router 2000 (for example, starting and stopping lines,  
      setting parameters, and loading the software)                            
                                                                               
  oo   Display statistics and error information for the X25router 2000 (for   
      example, statistics on line usage or errors)                             
                                                                               
  oo   Test the components of the network (for example, loop messages through 
      all or part of a communications path to isolate a defective component)   
                                                                               
  Accounting and Security                                                      
                                                                               
  Each VAX P.S.I. Access node using the X25router 2000 can maintain            
  accounting information for each virtual circuit in use. The X25router 2000   
  does not collect any additional accounting information.                      
                                                                              
                                                                               
  The X25router 2000 can provide basic security mechanisms for all inbound     
  calls. However, each VAX P.S.I. Access node can also provide further         
  security checks for both inbound and outbound calls.                         
                                                                               
  Problem Solving                                                              
                                                                               
  The TRACE utility, which is available on VMS or MicroVMS systems only,       
  assists problem-solving by tracing information at various stages in its      
  path through the X25router 2000.                                             
                                                                               
  Event logging allows the network manager to monitor events generated  by     
  the X25router 2000 and also assists problem solving.                         
                                                                               
  The X25router 2000 will attempt to dump to and automatically reload from a   
  suitable load host following a system failure.                               
                                                                               
  Path Splitting (DECnet routing only)                                         
                                                                               
  The X25router 2000 running on the DEC MicroServer performs path splitting    
  provided the routing costs are set appropriately. Note that routing cost is  
  an arbitrary network management parameter set by the network manager to      
  control network traffic flow. If the cost between the X25router 2000 and     
  the destination node is the same on multiple synchronous ports, then the     
  X25router 2000 splits the traffic across the ports. As a result, the         
  X25router 2000 provides higher data transfer rates and higher reliability    
  due to redundant paths.                                                      
                                                                               
  Performance                                                                  
                                                                               
  The actual packet rate will be less than that indicated by the aggregate     
  synchronous line speed, and is determined by such factors as:                
                                                                               
  oo   Type of traffic (routing updates or data packets) and data rates       
                                                                               
  oo   Proportion of DDCMP to X.25 traffic, and the packet-sizes and ratio of 
      DLM to non-DLM traffic for X.25 links                                    
                                                                               
  oo   The path of DDCMP messages through the X25router 2000 (LAN-to-LAN,     
      synchronous-to-LAN, or synchronous-to-synchronous)                       
                                                                               
  oo   Communications line characteristics                                    
                                                                               
  oo    Frequency and type of errors on the synchronous links                 
                                                                               
  oo    Network topology                                                      
                                                                               
  oo   Applications                                                           
                                                                               
  oo   Protocol overhead                                                      
                                                                               
  PREREQUISITE SUPPORT                                                         
                                                                               
  A Network Profile and DECnet Customer Support Plan covering all intended     
  network nodes and their support may be required by your Digital office.      
                                                                               
                                                                              
  INSTALLATION                                                                 
                                                                               
  Digital requires that a customer's first purchase of the product includes    
  Digital Installation Services. These services provide for installation of    
  the software product by an experienced Digital Software Specialist.          
                                                                               
  Only customers experienced with Digital's X.25 products should attempt       
  second or subsequent installations. Digital recommends that all other        
  customers purchase Digital's Installation Services.                          
                                                                               
  The Digital installation service consists of:                                
                                                                               
  oo   Installation of the X25router 2000 software on one load host.          
                                                                               
  oo   Configuration of one X25router 2000 unit on that load host.            
                                                                               
  oo   Installation verification using one connection to one supported PSDN.  
                                                                               
  Customer Responsibilities                                                    
                                                                               
  In some cases, the X.25 network supplier (or PTT) may impose restrictions,   
  limitations, or requirements on the proposed Digital network configuration.  
  The customer must ensure that they understand and adhere to these controls   
  for each and every network.                                                  
                                                                               
  Before the software is installed, the customer must:                         
                                                                               
  oo   Previously have installed all requisite software and hardware          
      (including terminals needed for the installation).                       
                                                                               
  oo   Obtain, install, and demonstrate as operational any modems and other   
      equipment and facilities necessary to interface to Digital's             
      communication equipment.                                                 
                                                                               
  oo   Demonstrate where necessary that the modems used meet the appropriate  
      interface standards.                                                     
                                                                               
  oo   Designate one adjacent node to verify connectivity for any synchronous 
      DDCMP circuits.                                                          
                                                                               
  oo   Subscribe to the Open User Group and to at least two SVCs to be able to
      complete the product's installation checkout (this test loops            
      information from the X25router 2000 to the PSDN and back to the          
      X25router 2000). Systems that use PVCs or Closed User Groups only, or    
      where the PSDN does not support calls to the same DTE address, require   
      specially negotiated arrangements for Digital installation of the        
      product.                                                                 
                                                                               
  oo   Make available for a reasonable period of time all the hardware        
      (including terminals), software, and communications facilities needed    
      during the installation. This period of time is mutually agreed between  
      the customer and Digital.                                                
                                                                               
  Delays caused by failure to fulfill any of these responsibilities will be    
  charged at the then prevailing rate for time and materials.                  
                                                                               
                                                                              
  HARDWARE REQUIREMENTS                                                        
                                                                               
  VAX, MicroVAX or VAXstation configurations as specified in the System        
  Support Addendum (SSA 28.86.01-x).                                           
                                                                                
  DEC MicroServer or DEC MicroServer-SP as specified in the System Support     
  Addendum (SSA 28.86.01-x).                                                   
                                                                               
  SOFTWARE REQUIREMENTS                                                        
                                                                               
  For each VMS or MicroVMS system acting as a load host or dump receiver:      
                                                                               
  oo   VMS Operating System or MicroVMS Operating System                      
                                                                               
  oo   DECnet-VAX                                                             
                                                                               
  For each ULTRIX system acting as a load host or dump receiver:               
                                                                               
  oo   ULTRIX-32 Operating System or ULTRIX Worksystem Software including the 
      ULTMOP subset                                                            
                                                                               
  oo   DECnet-ULTRIX                                                          
                                                                               
  Refer to the System Support Addendum (SSA 28.86.01-x) for availability and   
  required versions of prerequisite/optional software.                         
                                                                               
  ORDERING INFORMATION                                                         
                                                                               
  For VMS and MicroVMS Load Hosts:                                             
                                                                               
  Software Licenses: QL-VIAA*-**                                               
  Software Media: QA-VIAA*-**                                                  
  Software Documentation: QA-VIAAA-GZ                                          
  Software Product Services: QT-VIAA*-**                                       
                                                                               
  For ULTRIX Load Hosts:                                                       
                                                                               
  Software Licenses: QL-VIAA*-**                                               
  Software Media: QA-VIAA*-**                                                  
  Software Documentation: QA-VIAAB-GZ                                          
  Software Product Services: QT-VIAA*-**                                       
                                                                               
  *   Denotes variant fields. For additional information on available          
      licenses, services and media, refer to the appropriate price book.       
                                                                               
  SOFTWARE LICENSING                                                           
                                                                               
  You will need a separate license for each DEC MicroServer or DEC             
  MicroServer-SP unit on which you will be using the software product (except  
  as otherwise specified by Digital).                                          
                                                                               
  The licensing provisions of Digital's Standard Terms and Conditions provide  
  in part that the software and any part thereof (but excluding those parts    
  specific to the load hosts) may be used only on the single DEC MicroServer   
  hardware unit on which the software is operated, but may be copied, in       
  whole or in part (with the proper inclusion of Digital's copyright notice    
  and any proprietary notices on the software) between multiple load hosts on  
  the same LAN.                                                                
                                                                              
  SOFTWARE LICENSING                                                           
                                                                               
  This software is furnished under the licensing provisions of Digital         
  Equipment Corporation's Standard Terms and Conditions. For more information  
  about Digital's licensing terms and policies, contact your local Digital     
  office.                                                                      
                                                                               
  License Management Facility Support (VMS Systems Only)                       
                                                                               
  This layered product supports the VMS License Management Facility. License   
  units for this product are allocated on a per-CPU basis and are not          
  dependent on CPU-capacity or User/Activity.                                  
                                                                               
  For more information on the License Management Facility, refer to the VMS    
  Operating System Software Product Description (SPD 25.01.xx) or the License  
  Management Facility manual of the VMS Operating System documentation set.    
                                                                               
  SOFTWARE PRODUCT SERVICES                                                    
                                                                               
  A variety of service options are available. For more information on these    
  or other services, please contact your local Digital office.                 
                                                                               
  SOFTWARE WARRANTY                                                            
                                                                               
  The X25router 2000 is warranted for use only with supported Phase III and    
  Phase IV DECnet products supplied by Digital. Any system connected to one    
  of the X25router's synchronous DDCMP links, or attempting DECnet             
  communication via a PSDN, must run a current version of a DECnet Phase       
  III/IV product using any supported synchronous interface, but excluding a    
  DMC11 device.                                                                
                                                                               
  Digital has designed or adapted the X.25 portion of this product to operate  
  with:                                                                        
                                                                               
  oo   Equipment conforming to ISO standards 7776 and 8208                    
                                                                               
  oo   The public networks in the appropriate countries listed in Table II    
                                                                               
  oo   Certain private PSDNs, for which Digital has included specific PSDN    
      profiles in this product                                                 
                                                                               
  Digital cannot offer its standard warranty for this product unless it has    
  been configured appropriately for the PSDN. If the product has not been      
  configured appropriately, the product will not be supported by Digital.      
                                                                               
  Each PSDN listed in Table II indicates Digital's commitment to supporting    
  the X25router 2000 for that public service. However, it does not imply that  
  the appropriate networking authority has granted network certification for   
  the X25router 2000. Please contact your Digital sales office for up-to-date  
  information on certification status.                                         
                                                                               
  Warranty for this software product is provided by Digital with the purchase  
  of a license for the product as defined in the Software Warranty Addendum    
  of this SPD.                                                                 
                                                                               
                                                                              
                                   TABLE II                                    
                                                                               
                 Public PSDNs Supported By The X25router 2000                  
                                                                               
  Country                      Public Network and            Comments and      
                               CCITT Revisions               Restrictions      
                                                                               
  Argentina                         Arpac                                      
  Australia                         Austpac                                    
  Austria                           Datex-P                                    
  Belgium                           DCS                                        
  Brazil                            Renpac                                     
  Canada                            Datapac (1976 or 1980)                     
                                    Infoswitch                                 
  Denmark                           Datapak                                    
  Eire                              Eirpac (1980)                              
  Finland                           Datapak                                    
  France                            Transpac                                   
  Hong Kong                         Datapak                                    
                                    Intelpak                                   
  Indonesia                         SKDP                                       
  Italy                             Itapac                                     
  Japan                             DDX (1976, 1980)         (See Note 1)      
                                    Venus-P (1980)                             
                                    Tymnet                                     
  Luxemburg                         LUXPAC                                     
  Malaysia                          Maypac                                     
  Mexico                            Telepac                                    
  Netherlands                       Datanet 1                                  
  New Zealand                       Pacnet                                     
  Norway                            Datapak                                    
  Portugal                          Telepac                                    
  Singapore                         Telepac                                    
  South Korea                       Dacomnet                                   
  Spain                             Iberpac                                    
  Sweden                            Datapak                                    
  Switzerland                       Telepac (1978, 1980)                       
  Taiwan                            Pacnet                                     
  United Kingdom                    PSS                                        
  United States                     Accunet                                    
                                    Autonet                                    
                                    Bell Atlantic                              
                                    Compuserve                                 
                                    ConnNet                                    
                                    IMPACS                                     
                                    Infonet                                    
                                    Mark*Net Extended Service                  
                                    Pulselink                                  
                                    Telenet                                    
                                    Tymnet                                     
                                    Western Union PTN-1                        
                                    Worldnet                                   
  West Germany                      Datex-P                                    
                                                                              
  Note:                                                                        
                                                                               
  1.  Digital offices in Japan can supply the mandatory additional             
      information that explains the special use of the X25router 2000 with     
      the DDX PSDN.                                                            
                                                                               
  Unless otherwise acknowledged within the product's documentation, the        
  trademarks under which services are offered are proprietary to the           
  respective national PTT, the owning or operating companies, or equivalent    
  organization.                                                                
                                                                               
                                   TABLE III                                   
                                                                               
           Optional X.25 Facilities Supported by the X25router 2000            
                                                                               
        Optional Facility                     Paragraph      Supported         
                                              Number                           
                                              in CCITTX.25                     
                                              (1984)                           
                                                                               
    1.  Extended packet sequence numbering        6.2          Yes             
    2.  Non-standard default window size          6.10         Yes             
    3.  Default throughput class assignment       6.11         n/a             
    4.  Packet re-transmission                    6.4          (See Note 1)    
    5.  Incoming calls barred                     6.5          n/a             
    6.  Outgoing calls barred                     6.6          n/a             
    7.  One-way logical channel outgoing          6.7          n/a             
    8.  One-way logical channel incoming          6.8          Yes             
    9.  Closed user group (CUG)                   6.14.1       Yes             
   10   CUG with outgoing access                  6.14.2       Yes             
   11.  CUG with incoming access                  6.14.3       Yes             
   12.  Incoming calls barred within CUG          6.14.4       Yes             
   13.  Outgoing calls barred within CUG          6.14.5       Yes             
   14.  CUG selection                             6.14.6       Yes             
   15.  CUG with outgoing access selection        6.14.7       No              
   16.  Absence of both CUG selection facilities  6.14.8       Yes             
   17.  Bilateral CUG                             6.15.1       Yes             
   18.  Bilateral CUG with outgoing access        6.15.2       Yes             
   19.  Bilateral CUG selection                   6.15.3       Yes             
   20.  Reverse charging                          6.18         Yes             
   21.  Reverse charging acceptance               6.19         Yes             
   22.  Local charge prevention                   6.20         n/a             
   23.  Network user identification               6.21         Yes             
   24.  Charging information                      6.22         Yes             
   25.  RPOA selection                            6.23         Yes             
   26.  Hunt group                                6.24         (See Note 2)    
   27.  Call redirection                          6.25         n/a             
   28.  Called line address modified notification 6.26         Yes             
   29.  Call redirection notification             6.27         Yes             
   30.  Transit delay selection and indication    6.28         Yes             
   31.  On-line facility registration             6.1          No              
   32.  Non-standard packet size                  6.9          Yes             
   33.  Flow control parameter negotiation        6.12         Yes             
   34.  Throughput class negotiation              6.13         Yes             
   35.  Fast select                               6.16         Yes             
   36.  Fast select acceptance                    6.17         Yes             
   37.  D-bit modification                        6.3          No              
   38.  Abbreviated address                       ---          n/a             
   39.  Datagram queue length selection           ---          No              
   40.  Datagram service signal logical channel   ---          No              
   41.  Datagram non-delivery indication          ---          No              
   42.  Datagram delivery confirmation            ---          No              
   43.  Call statistics (non-X.25)                ---          (See Note 3)    
                                                                               
  Notes:                                                                       
                                                                               
  1.  This is not applicable to a DTE. This product does not support the       
      reception of a level 3 Reject packet, and will not generate one.         
                                                                               
  2.  Each DTE must be assigned a unique addresses independent of the hunt     
      group address. The X25router 2000 can then ignore the hunt group.        
      Alternatively, each line can be configured as if it were connected to a  
      separate PSDN with each line having the same DTE address. In either      
      case, all the lines must be connected to the same X25router 2000.        
                                                                               
  3.  This product does not generate these statistics. However, a VAX P.S.I.   
      Access node can obtain statistics supplied by the PSDN through the       
      programming interface.                                                   
                                                                               
  4.  The X25router 2000 does not support the following items of the CCITT     
      X.25 recommendation:                                                     
                                                                               
      -    Multi-link protocol                                                 
                                                                               
      -    Use of the D-bit in outgoing packets                                
                                                                               
  November 1989                                                                
  BH-KP96B-TN                                                                  
                                                                               
  (R)  The DIGITAL Logo is a registered trademark of Digital Equipment         
       Corporation.                                                            
  (TM) ULTRIX, DECstation, DECsystem, VAX, MicroVAX, VAXstation, and VAXserver 
       are trademarks of Digital Equipment Corporation.                        
                                                                               
