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Wide Area Network Support for OpenVMS Clusters

HIGHLIGHTS

o  WAN technology using GIGAswitch and FDDI systems provides OpenVMS
   Clusters with DS3 (T3) support

o  New capability supported by OpenVMS Cluster software for AXP and VAX
   systems

o  DS3 technology provides eight times bandwidth of Ethernet

PRODUCT DESCRIPTION

Many users with operations that span multiple sites have not yet optimized
key aspects of their business: Expensive resources and dedicated staffs may
be duplicated at each site. Each regional headquarters may have its own set
of facilities, or data entry points may be at one location and centralized
systems at another. Unique or expensive resources, such as tape libraries or
optical disk archives, may be at one site but needed as well at another
site. Each site may not have access to the latest data.

Moreover, users often transmit business data between their sites in a "batch
oriented" style. Orders, inventory, and delivery information are often sent
in daily transmissions. If a system is down because of a system failure or a
natural disaster, batched or queued data can be lost forever, making it
impossible to reconcile business records.

Business can be more efficient if operated in a "realtime" style. If systems
in two sites run as a single OpenVMS Cluster configuration, critical
information can be instantly available between salesroom and warehouse,
between factory and office, or between data entry point and computer center.

Multisite OpenVMS Cluster configurations, a new feature of both VMScluster
and VAXcluster software, enable users to operate systems as far apart as 150
miles as a single OpenVMS Cluster unit. The support of DS3 technology --
commonly called T3 -- makes this possible. Users at one site have immediate
local access to the latest data, even if it has just been updated by users
at another site. Multisite technology enables users to build an OpenVMS
Cluster system spanning greater distances than previously possible and thus
to optimize their operations across regional locations. With DS3, users also
have eight times the bandwidth of Ethernet, giving them higher performance.
Additionally, with volume shadowing, storage devices at multiple sites can
be members of the same shadow set.

This new cluster enhancement involves the use of a DS3 link, available from
most telephone service carriers, between the two sites. At each end of this
link is a DEFGT WAN option card inside a GIGAswitch device. This establishes
the site-to-site link at distances up to 150 miles, delivering a bandwidth
of 45 Mbits per second in each direction. At each site, the GIGAswitch
device is part of the local FDDI link or dual FDDI ring.

Users can install a multisite OpenVMS Cluster system at locations linked by
up to 150 miles of T3 cable, by following the recommended procedures in the
"DS3 Multisite OpenVMS Cluster Technical Brochure" (AA-QA4KA-TE). This
brochure also specifies the characteristics of the DS3 line leased from the
carrier.

This new feature is an enhancement of the VMScluster Software for OpenVMS
AXP (SPD 42.28) and VAXcluster Software for OpenVMS VAX (SPD 2978) products.
It is not a new product requiring a separate license. Each installed OpenVMS
Cluster system can take advantage of this capability. Users with installed
OpenVMS Cluster systems can determine whether clustering with another part
of their organization within a 150 mile radius would increase their
efficiency.

BENEFITS

o  Multisite OpenVMS Cluster systems bring the well-established benefits of
   clustering -- such as high availability, consistent system management,
   and transparent access to data -- into a new business environment. The
   combination of cluster functionality and WAN distances gives users a more
   cost effective way to run their business. This is the most tightly
   coupled wide area system architecture in the industry, with 100 percent
   data integrity at each site at the completion of each individual
   transaction.

o  Instead of requiring support staff at multiple locations, users will need
   fewer staff to manage their multisite OpenVMS Cluster system. Their
   personnel can be deployed on other MIS activities and deliver other
   end-user services.

o  Users wishing to have data replicated at remote sites with 100 percent
   accuracy and realtime availability can make these sites part of their
   OpenVMS Cluster system without requiring new network operational
   procedures.

o  Previously, users could connect sites up to 25 miles apart with FDDI
   technology. Sites that exceeded the 25 mile limitation typically used
   Ethernet technology with its 10 Mbit per second bandwidth. DS3 technology
   delivers the best of both technologies: eight times the bandwidth of
   Ethernet at distances up to six times the FDDI limit.

o  DS3 technology may have the added benefits of using existing wiring and
   being available in more areas than FDDI.

AVAILABILITY AND ORDERING

The WAN support for OpenVMS Clusters described in this article is available
now.

Digital recommends that if users are combining datacenters for disaster
tolerance, they should use the Business Recovery Server to ensure successful
implementation. (See the accompanying article in this issue)

Users making use of GIGAswitch and FDDI technology need the following
components:

DEFGT-AA	 GIGAswitch 2 port linecard (motherboard) for DS3/SONET/ATM
DEFGE-AA	 DS3 45 Mbit per second card (daughterboard) for DEFGT-AA

TECHNICAL DATA

Software Prerequisites

o  For Alpha AXP systems: OpenVMS AXP operating system and the VMScluster
   Software for OpenVMS AXP product.
o  For VAX systems: OpenVMS VAX operating system and the VAXcluster Software
   for OpenVMS VAX product.

Optional Software

o  Volume Shadowing for OpenVMS VAX systems.
o  Volume Shadowing for OpenVMS AXP systems.

Restrictions

o  Support for DS3 described in this article is limited to areas in which
   DS3 is available. The E3 service available in Europe is not supported by
   the hardware described here.