DECrouter 2000, Version 1.2					SPD 28.85.03

DESCRIPTION

The DECrouter 2000 is a communications product that provides a routing service 
for the Local Area Network (LAN). This allows communication with nodes outside 
the LAN within a Wide Area Network (WAN). By using a DECrouter 2000, the 
routing load on the other Ethernet nodes can be reduced, releasing these 
resources for other applications. 

Overview

The DECrouter 2000 provides access to and from Phase IV DECnet nodes on a Local 
Area Network (LAN) to Phase III or Phase IV DECnet nodes over synchronous 
lines. These nodes may be located either locally, via dedicated wiring, or 
remotely via modem connections. Note that LAN refers to any Local Area Network 
that conforms with the Ethernet, IEEE 802.3, or ISO 8802/3 standards.

The DECrouter 2000 software product runs on the DEC MicroServer (DEMSA) and DEC 
MicroServer-SP (DEMSB) hardware units. These units contain an Ethernet 
interface port (IEEE 802.3 compatible); the DEC MicroServer has four 
synchronous communications ports, and the DEC MicroServer-SP has a single 
synchronous port.

Note:	 The DECrouter 2000 software license is available as part of two 
         packages - the DECrouter 2000 package includes the DEC 
         MicroServer hardware and the DECrouter 2000 software license; 
         the DECrouter 100 package includes the DEC MicroServer-SP 
         hardware and DECrouter 2000 software license 

The DECrouter 2000, on the DEC MicroServer, supports the four synchronous lines 
at speeds up to 64K bits per second, two synchronous lines at speeds up to 384K 
bits per second, or one synchronous line at speeds up to 2.048M bits per 
second. The DECrouter 2000, on the DEC MicroServer-SP, supports the single 
synchronous line at speeds up to 64K bits per second. Communication over the 
synchronous lines is full- or half-duplex, and full modem control is supplied 
on all synchronous line(s). The synchronous port(s) can operate as DDCMP 
point-to-point or multipoint links, and can communicate with all supported 
synchronous Digital DDCMP products, excluding the DMC11. On DDCMP multipoint 
links, the DECrouter 2000 can act only as a tributary.

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The DECrouter 2000 software image is installed and configured on a VMS, 
MicroVMS, ULTRIX (VAX or RISC) or MS-DOS RO system (termed a load host) on the 
same LAN as the DEC MicroServer or DEC MicroServer-SP; this software image is 
then down-line loaded to the unit from this load host. The installation process 
enables the manager of the load host to define the Ethernet address, routing 
characteristics, and DDCMP circuits to be used by the DECrouter 2000. The 
configuration databases can be created and modified by using utilities that are 
on the load host.

The DECrouter 2000 is fully integrated into Digital's Network Management 
strategy. Management is through the DECnet Network Control Program (NCP) from 
any DECnet Phase IV node, allowing the system manager to control the DECrouter 
2000, display statistics and error information, and test the components of the 
network. A separate TRACE utility (available on VMS or MicroVMS load hosts) 
assists problem-solving by tracing information within the DECrouter 2000.

Path splitting, where there are two or more equal-cost paths between the 
DECrouter 2000 and the destination DECnet node, is supported.  For this 
feature, all the destination nodes on the network must support out-of-order 
packet caching.

Routing and DECnet Phase IV Areas

The DECrouter 2000 implements Phase IV (with extended functionality) DECnet 
DDCMP routing and network management. Phase IV DECnet networks are hierarchical 
networks that can be segmented into up to 63 areas, each containing up to 1023 
nodes. Note that these are maximum values permitted by the Digital Network 
Architecture, and that satisfactory operation in large networks requires proper 
network planning.

Level 1 Routers route directly towards nodes within their own area, and route 
towards a Level 2 Router when the destination node is in a different area. 
Level 2 Routers act as Level 1 Routers within their own area, but in addition 
route to other areas.

The DECrouter 2000, on the DEC MicroServer, is a dedicated routing system that 
supports both the intra-area routing (Level 1) and inter-area routing (Level 2) 
for Phase IV nodes on a Local Area Network, or Phase III or Phase IV remote 
nodes connected to one of the four synchronous lines.

The DECrouter 2000, on the DEC MicroServer-SP, is a dedicated routing system 
that supports only intra-area routing (Level 1) routing for Phase IV nodes on a 
Local Area Network, or Phase III or Phase IV remote nodes connected to the 
single synchronous line.

Line Support

The DECrouter 2000 software product runs on the DEC MicroServer (DEMSA) and DEC 
MicroServer-SP (DEMSB) hardware units. These are LANbridge 100-type enclosures 
that contain an Ethernet interface port (IEEE 802.3 compatible); the DEC 
MicroServer has four synchronous communications ports, and the DEC 
MicroServer-SP has a single synchronous port. Both hardware units are supplied 
as table-top units, but also can be wall or rack mounted in a standard 19 inch 
rack.

The DECrouter 2000 supports V.24 interchange circuits, the following electrical 
interfaces: V.28 (RS232-D), RS232-C, V.36/V.11 (RS449/RS422), V.10 
(RS449/RS423), and V.35, and CCITT (1980) X.21 for leased line services only. 
The number of lines supported depends on the hardware unit, the electrical 
interface type, and the maximum line speed in use, as follows:

   DEC MicroServer		  Maximum Line Speed (Kbps)

      Interface Type	     19.2    64	   256	 384   1544  2048

      V.28/V.24 (RS232-C/D    4	      -	     -	   -	 -     -
      V.36/V.11 (RS422/RS449) 4	      4	     3	   2	 1     1
      V.10 (RS423)	      4	      4	     -	   -	 -     -
      V.35		      4	      4	     3	   2	 1     1
      X.21 leased line	      4	      4	     3	   2	 1     1

   DEC MicroServer-SP             Maximum Line Speed (Kbps)

      Interface Type	       19.2  64

      V.28/V.24 (RS232-C/D)	1     -
      V.36/V.11 (RS422/RS449)	1     1
      V.10 (RS423)		1     1
      V.35			1     1
      X.21 leased line		1     1

Adapter cables provide the necessary interchange circuits for each 
synchronous line. Refer to the System Support Addendum (SSA 28.85.03-x) 
for further information on the required adapter cables.

The DECrouter 2000 always requires an external clock source (such as a 
modem). The additional requirements for operation of the DEC MicroServer 
with T1 and G.703 lines are as follows:

oo     The DEC MicroServer only supports clear channel interfaces. 
      Connection to a T1 or G.703 line requires a V.35/RS422 to T1/G.703 
      DSU/CSU converter to provide framing to meet CCITT G.704. The DEC 
      MicroServer does not provide either T1 framing pulses or separate 
      channels for 64K bits per second control data for G.703. 

      Note also that the DEC MicroServer does not guarantee line 
      density. T1 links can offer only 1.536M bits per second or 1.344M 
      bits per second data rates. 1.536M bits per second rates require 
      the DSU/CSU converter to offer B8ZS and the line to accept bipolar 
      violations. 1.334M bits per second rates require the DSU/CSU 
      converter to offer B7.

oo     Transmit clocking should be provided by the DCE, CCITT 114. The 
      DEC MicroServer uses CCITT 114 to clock data out of the DTE, and 
      will source a CCITT 113 transmit clock. CCITT 113 should be used 
      by the DCE to receive the transmit data. The DEC MicroServer 
      implements CCITT 113 as a buffered version of CCITT 114. This 
      clocking scheme ensures both network synchronization and minimized 
      skew between the clock and data for a range of cable lengths and 
      parameters.

      If the above transmit clocking mechanism is not provided by the 
      DCE, this DCE must provide a method of adjusting the phase of the 
      clock used to sample the data with respect to that supplied to the 
      DTE. This requires that the DCE provide test points to allow 
      analysis of the clock and data waveforms and that this adjustment 
      is performed on installation, and after any subsequent alteration 
      of the connection cable. This alternative method is required also 
      for DCEs utilizing the X.21 interface.

Installation and Configuration

The DECrouter 2000 has no file storage of its own, and so relies on host 
systems to load the software.

The minimum requirement is for one host to load the DEC MicroServer or 
DEC MicroServer-SP. The DECrouter 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. Each load host must be on the same LAN and preferably in 
the same DECnet area as the DECrouter 2000.

The network manager can create and modify the configuration databases by 
using utilities on the load host. The configuration database is loaded 
into the DECrouter 2000 during system initialization.

System Management

The manager controls the running system by using the DECnet Network 
Control Program from any DECnet Phase IV node. For example, the manager 
can use the utility from one of the systems on the LAN.

The utility provides three basic functions:

oo     Display statistics and error information for the DECrouter 2000 
      (for example, statistics on line usage or errors)

oo     Control the DECrouter 2000 (for example, starting and stopping 
      lines, setting parameters, and loading the software)

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)

In addition, a separate utility available on VMS or MicroVMS load hosts, 
assists problem-solving by tracing information at various stages in its 
path through the DECrouter 2000.

Event-logging and dump reception facilities can be used at the 
discretion of the customer. The product will attempt to dump to a Phase 
IV node on the same LAN and reload automatically following a system 
failure. 

Path Splitting

If the costs are set appropriately, the DECrouter 2000, on the DEC 
MicroServer, performs path splitting. 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 DECrouter 2000 and 
the destination node is the same on multiple synchronous ports, then the 
DECrouter 2000 splits the traffic across the ports.  As a result, higher 
data transfer rates and higher reliability due to redundant paths are 
provided with the DECrouter 2000.

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     The path of messages through the DECrouter 2000 system 
      (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     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. 

HARDWARE REQUIREMENTS

VAX, MicroVAX, VAXstation, VAXserver, DECstation, DECsystem or IBMRO 
PC-compatible configuration as specified in the System  Support Addendum 
(SSA 28.85.03-x)

DEC MicroServer or DEC MicroServer-SP as specified in the System Support 
Addendum.

SOFTWARE REQUIREMENTS

For each VAX system acting as a load host or dump receiver:

VMS Operating System or
MicroVMS Operating System or
ULTRIX-32 Operating System

DECnet-VAX or
DECnet-ULTRIX

For each DECstation or DECsystem acting as a load host or dump receiver:

ULTRIX-32 Operating System

DECnet-ULTRIX

For each IBM PC-compatible system acting as a load host or dump 
receiver:

MS-DOS Operating System or
PC-DOS Operating System

DECnet-DOS

Refer to the System Support Addendum for availability and required 
versions of prerequisite/optional software (SSA 28.85.03-x).

ORDERING INFORMATION

Software Licenses:  QL-VI8A*-**
Software Media for VMS and MicroVMS Operating Systems: QA-VI8AA-**
Software Media for ULTRIX-32 Operating Systems: QA-VI8AB-**
Software Media for MS-DOS Operating Systems: QA-VI8AC-**
Software Documentation: QA-VI8AA-GZ
Software Product Services:  QT-VI8A*-**

*     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.

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. 

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 DECrouter 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 DECrouter 2000's synchronous link(s) must run a current 
version of a DECnet Phase III/IV product using any supported synchronous 
interface, but excluding a DMC11 device.

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.

January 1990
BH-KP97D-TN

(R) The DIGITAL Logo is a registered trademark of Digital Equipment 
Corporation.

(TM)   DECrouter, VAX, VMS, MicroVAX, VAXstation, VAXserver, VAXcluster, DECnet, 
MicroServer and ULTRIX are trademarks of Digital Equipment Corporation.

