Enterprise Functional Overview
Customer expectations have changed in todays' business
environment. Corporate-Customer relationships are more
complex and as a result, companies are providing an ever
increasing array of products and services to accommodate
them. The task of managing the vast amount of data across
heterogeneous systems and networks has become a challenge.
Organizations are also under pressure to differentiate and
maximize the profitability of their services while
increasing market penetration through effective
cross-selling. The foundation for this activity is
understanding customer relationships across all lines of
their business consistently, regardless of geography.
Getting data from all sources, including legacy systems, in
real time to an integrated enterprise-wide information
management system has proven extremely difficult.
In addition to this, working in a global economy, the
business day is now twenty-four hours long, seven days a
week. To service this need, systems must now be integrated
around the world and provide virtually zero down-time.
Oasis' and Digital's' 'Enterprise' represents the
first and foremost solution to these complex business
The only long term, scaleable solution is to implement a
unified, consistent, yet flexible approach to handling
transactions and other messaging data across the entire
organization - regardless of the source or destination. To
this end, Digital and Oasis have jointly created
'Enterprise'. This is an integrated software environment
allowing fault resilient transaction processing and
delivery, real time and batch, between virtually any end
points within your organization.
is composed of Digital's Reliable Transaction Router
(RTR) technology working in harmony with Oasis
Information Switching Technology / Message Services
Enterprise into existing business systems is
possible with Enterprise's Open Systems Architecture that
can operate on your existing platforms and interface with
existing transaction and message protocols. Data in legacy
applications can be accessed to support improved account
management and new business opportunities.
Enterprise, transaction and data integrity is
insured by using techniques such as message timers, two
phase commit, disk shadowing, site shadowing and journaling.
By automatically managing system failures, lost or
duplicated data is avoided. Data can now be collected from
all lines of business and across all geographies in
accordance to the data model established.
With the Enterprise solution; in conjunction with
other data mapping, modeling and integration services;
Digital and Oasis help organizations avoid such problems as
a lack of data integrity across multiple data-stores,
inaccessible data or information relationship-blindness.
Inconsistent views of data can now be eliminated.
Consistent and reliable support is provided for a full array
of information management tools by focusing on the key
ingredient - data - and insuring this data flows reliably
and uniformly across the entire enterprise in real time or
provides the means for managing organizational data
effectively in order to deliver higher quality services with
increased cross-selling; ultimately allowing improved
profitability and customer loyalty.
IST/MSI is an integrated real time and batch
transaction switching and processing environment, designed
specifically to handle distributed data across heterogeneous
systems and networks. IST/MSI provides virtually
unlimited message formats and message translation.
backbone architecture is IST/Foundation, thereby
taking advantage of the rich transaction processing
functionality available within that Oasis product. IST/MSI
also provides software for Session Management and
high-performance database access.
One of the main features of IST/MSI is its
flexibility and scalability. It can run on hundreds of
small-end platforms residing in branches or customer call
centers, for example; or it could also run on one large
installation sitting in a datacentre; or any configuration
In addition to the transaction processing power IST/MSI
provides, many special features were built to enable the
IST/MSI software to work hand-in-hand with Digital's'
RTR (Reliable Transaction Router) product in order
to provide the true 7/24 operations our customers' demand.
is just as flexible and scaleable. Where necessary, it can
accompany IST/MSI into whatever configuration is
required by our customers.
The DIGITAL Reliable Transaction Router (RTR) is
disaster-tolerant, middleware for business applications that
require the reliable execution of transactions in real time
and without any interruptions of service across widely
distributed systems. RTR provides reliable transactional
messaging, with ACID properties, between distributed client,
router and server systems. RTR takes responsibility for
detecting failures in a distributed environment and
providing transparent fail-over and transaction integrity
for uninterrupted service. RTR insulates applications from
software, network and site failures.
allows the application designer to decide where to place
the application data. RTR allows data to be partitioned over
as many nodes and disks as the performance or business
requirements dictate. The location of the application data
is transparent to the applications, allowing for
easier system reconfiguration and horizontal
applications may perform transactions, which access more
than one database. RTR insures (in cooperation with the
application) that transaction operations are either all
applied to the databases or are all rolled back. This is
known as all or nothing transaction semantics (2
lets the application designer concentrate on the
application, rather than the problems of handling the
network. RTR simplifies the design of applications that are
distributed across the network, and preserves
data-consistency even if components of the system fail
(including the application themselves).
provides a high degree of failure resilience and allows
continued system operation in case of node or link failures.
RTR supports shadow and standby operations to protect
against entire site failures. RTR guarantees transaction
integrity against many kinds of failures by using a
RTR and IST/MSI comprise Enterprise.
The ability to process financial and non-financial
transactions over large heterogeneous networks;
The ability to process an unlimited number of message
The ability to handle an unlimited number of devices;
The ability to process messages up to 4 gigabyte in
High performance transaction switching;
Open API's so that customers can build their own
Plug and play capabilities with other Oasis IST
Parallelism; the ability to have multiple Enterprise
environments operating within one hardware platform;
Open-systems architecture running under Unix and NT;
A comprehensive Data Base Management layer allowing you
to connect to a range of databases (i.e. Oracle, Sybase,
'Transaction Spawning' (one-to-many) provides you a
unique solution for highly complex transactions;
Proven quality and reliability;
Provide automated and instantaneous fail-over
capabilities to allow for a true 7 by 24 operating
Comply with disaster recovery strategies that call for
geographically separated datacentres;
Ensure commit order integrity across distributed and/or
Ability to work in a lights-out datacentre paradigm;
is based on proven technology and available products.
IST provides financial transaction and messaging
services at over 120 sites in more than 40 countries.
Citibank, MasterCard, Visa, Diners Club, Europay, Bejing
Golden Card and many others are using Oasis' Information
Switching Technology to route financial messages from ATMs
and POS terminals, provide EFT transaction routing, provide
full or partial authorizations, transaction reporting and
electronic draft capture (EDC), and store-and-forward
processing all in a completely secure, encrypted
environment. It supports many shared-cash networks, such as
VISA and MasterCard. It has been distributed across multiple
machines on both Local and Wide-Area Networks.
is used worldwide by some of the world's most demanding
clients to provide a distributed fault-tolerant
infrastructure for their transaction systems. Many of the
world's stock and option exchanges use RTR; Swiss Electronic
Bourse, American Stock Exchange, Hong Kong Futures Exchange,
Amsterdam Stock Exchange, Australian Stock Exchange, Ced
Borsa (Milan) and others. RTR can be found where transaction
integrity is a must; Banking, Citibank, Bank Austria;
Transportation, Polish Railways (PKP), India Railway and
Information Services, Reuters. At over 250 customers RTR
provides transaction reliability, every day, all day for
Meeting Your Business Needs
is ideally suited to help your organization integrate
their transaction based systems and data; on a regional or
global basis. Some typical uses for the product are :
Customer Relationship Management
Distributed Data Management
Financial Transaction Processing & Electronic Commerce
can work hand-in-hand with the entire Oasis family of
products. As such, customers have the flexibility of taking
advantage of these plug-and-play systems :
- to handle all ATM, POS, Credit and Debit Card
- is a fully integrated Clearing and Settlement Package;
- is a back-end Card Processing system for issuers and
The Oasis Family of Products is illustrated in the following
Digital RTR is a licensed product of the Digital Equipment
The transaction processing engine of Enterprise resides
within IST/MSI component. IST/MSI uses four conceptual
layers to perform processing: the Communications Driver, the
Agent, the Transaction Managed Processor (TMAP) and the
Gateway(s). The communication driver forms the link between
outside networks and IST/MSI. The Agent(s) work as
translators converting data from some external format into
the IST/MSI internal format. The TMAP processes and routes
the transactions. The Gateways allow MSI to interact
seamlessly with Digital's Reliable Transaction Router (RTR)
Conceptual Enterprise Architecture
IST/MSI communicates between all processes using ELF
(Elementized Format) messages (based on the ASN.1 Standard).
ELF is a series of containers that can hold arbitrary data
fields, or groups of data fields. The result can be a simple
linear set of data fields to a complex hierarchical
structure. IST/MSI uses only ELF messages to communicate
internally, both for transaction processing and process
The following diagram shows a typical Enterprise
configuration, allowing for 7/24 operation.
Conceptual Enterprise Configuration
provides for the concept of 'Spawned Transactions'. This
means that a single transaction initiated at some end-point
(super-transaction), may automatically spawn multiple
sub-transactions within Enterprise.
Why is this an advantage? Here is an example. A customer
enters a bank branch and wishes to have a complete profile
of all the business that they do with this bank. This would
mean all the household information, account information,
brokerage information, insurance information, etc. available
on that individual.
This would be a very large transaction that may have to go
to multiple host and local databases in order to retrieve
the desired data. By splitting the transaction into
sub-transactions, the bank representative is not forced to
wait for the entire transaction to complete before being
able to begin serving this customers needs. As the
sub-transactions complete, the representative will be able
to see more and more profile information on that customer.
If one sub-transaction fails, it does not mean that the
entire query would fail. A diagrammatic representation of
this can be found in the following section entitled "Example
Example Enterprise Application
In the above example, a client terminal initiates a request
(1) to Enterprise. That request goes to a local database and
retrieves some information (1a) and returns it back to
Enterprise. Based on some of the information returned,
Enterprise automatically spawns another transaction (2)
which is sent to Host 1. Simultaneous to this, response 1a
is sent back to the requester.
Host 1 responds with response 2a. Based on data within this
reply, two additional transactions are generated (3 and 4).
These are sent to Host 2 and Host 3, respectively. The first
host response (2a) waits in Enterprise until a 'More'
request is initiated by the client. A 'More' request is
asking if there is any further data to the original request.
At this point, the 2a reply is sent back to the requester.
At some point in time, Host 2 and Host 3 reply back to
Enterprise. Their respective replies (3a and 4a) are
suspended (held) within the system. When an additional
'More' request is initiated, those replies are sent back to
the client. In this example, that original transaction is
The fault resilient capability of Enterprise is achieved
through the RTR components. RTR divides the transaction
system into clients (requesters), servers and the
interconnection between them, the router. The client
component of RTR manages the interface between the user and
The RTR Server component manages the interface between the
server and RTR router; the router manages the integrity of
the interconnection between the client and the server.
Together they isolate the user and the server from failures,
in the network and the servers and the need to know when a
client or server has moved or been added.
RTR architecture considers each RTR component as running on
a node; front-end nodes, back-end nodes and
router nodes as shown above.
The RTR client processes run on the front-end nodes. This
layer allows computing power to be provided locally at the
end-user site for transaction acquisition and presentation.
The RTR server processes run on the back-end nodes. This
layer allows the application (and database) to be
distributed geographically, and permit fault tolerant
systems to be constructed which cope with either node or
The RTR router normally contains no application software.
This layer reduces the number of logical network links
required on front-end and back-end nodes. It also de-couples
the back-end layer from the front-end layer so that
configuration changes in the (often rapidly changing) user
environment have little influence on the transaction
processing and database (back-end) environment.
Although RTR is based on a three-node model, it is not
necessary for all three nodes to be physically present. For
systems with few front-ends, the router and front-end layers
can be combined. The physical locations of the front-end,
router and back-end nodes are specified using RTR
When configuring and managing RTR to provide the level of
fault tolerance desired the user can specify a server to
have a specific role.
Shadow servers are separate back-ends, which handle the
same transactions in parallel on identical copies of the
database. The databases are mirrors. In Figure 5 the main
server (Smain) is at site 1 and the shadow server (Sshdw)
are at site 2 both receive every transaction. Should site 1
fail, site 2 continues to operate, and the service is
uninterrupted. When the failed back-end node restarts, the
transactions, which had not been committed by the servers at
the time of the back-end failure, are replayed to the
servers from a disk journal.
are "spare" servers, which automatically take over from
the main back-end if it fails. This take-over is transparent
to the application. The above diagram shows a possible RTR
configuration. The main server (Smain) runs on one node
while the standby server (Ssby) runs on the other node (both
have access to the same database). The standby server is
active, but RTR does not pass transactions to it. Should the
first node fail, RTR starts passing transactions to the
standby server. Concurrent servers are servers
running on the same node. This is useful for increasing
throughput, especially when the database only allows one
active transaction per process.
Since the RTR Router is the heart of the fault management,
multiple routers are usually configured. Front-end nodes
will automatically find another router if the one being used
fails. This reconnection is transparent to the application.
Front-ends may also be configured to choose routers with the
least loading. If the original router coordinating a
transaction fails, the back-end nodes select another router
that can ensure correct transaction completion.
IST/MSI Architectural Services
architectural services consist of five elements:
A mailbox is a basic resource that all IST applications use
to communicate with other applications. It is essentially an
address, or a location on the network, where processes may
send and receive messages.
The mailbox manager provides the run-time message
communications environment for IST/MSI applications,
employing mailboxes that use semaphores and shared memory to
allow inter-process communication. The IST/MSI
communications components responsible for routing
transaction messages through the system all utilize the
mailbox system. These components each possess an inbound and
outbound mailbox to simplify the direction of message
traffic within the system.
Mailboxes are unique to the applications that use them. Each
application may have one or more mailbox sub-systems
operating on their behalf. By analyzing mailbox attributes,
the Mailbox Manager will determine the appropriate message
routing within the system.
A task is any process that is running or will be run within
The Task Manager creates and monitors tasks (processes)
within the system and ensures that they execute properly. If
a task should fail, the Task Manager will attempt to
A message port is an intermediary between a communications
driver in IST/MSI and a physical communications link to an
external network or device. It provides the actual link to
The port manager starts and monitors system tasks associated
with message ports. For example, it starts each
communication driver in the system. The port manager is
responsible for establishing, maintaining, monitoring, and
shutting down the connections between tasks and the
communication drivers; it is not involved in the actual
transfer of transaction messages throughout the system.
The port manager also permits multi-port management and
The event manager is an IST/MSI service that handles timer
events for the system as a whole. Applications responsible
for message routing call upon the event manager to time
transaction responses from devices, other IST/MSI
applications, and hosts or external networks. Once an event
is created, the event manager monitors it and notifies the
requesting application, through its mailbox, when and if the
event expires before the transaction processing is complete.
Application Manager (APM)
The Application Manager (APM) tracks the
initialization/state of each process according to run-level.
A run-level is a global stage of IST/MSI's initialization.
To prevent data sharing problems, IST/MSI processes are
started, run, and terminated according to run-levels, which
the APM manages. The APM also receives manual requests from
a command level interface, allowing the management of higher
General Platform Services (GPS)
General Platform Services (GPS) is a layer within IST/MSI
that provides key services to other components of IST/MSI,
such as the mailbox subsystem, task management, application
management, and file service handling.
A communications driver is responsible for sending a message
to the Agent. It strips the header information from the
message and performs a parity check to verify the integrity
of the data. Similarly, the Agent sends messages directly to
a specific communications driver that has been written for a
specific network. The communications driver sends the
message to a network through its port.
The communications driver is programmed to handle a specific
networking protocol. A switch handling multiple protocols
will have multiple communications drivers. Typical examples
of communication drivers would be X.25 and TCP/IP.
The IST/MSI Agent is a data normalizer. It functions as a
translator between message formats. It determines a
message's type, source, and destination. The Agent then
creates a destination message from this information and
sends it to the appropriate process, via the mailbox
The Agent transmits messages between the Communications
Driver and the TMAP. Each Agent is configured to translate a
specific message format and to communicate with a specific
Communications Driver. However, the Agent is not limited to
a specific TMAP process, and may send messages to any TMAP
process. Typical examples of Agents are ISO8583 translators,
CGMS translators, Visa agents, Mastercard agents, etc.
Transaction Managed Processor (TMAP)
The Transaction Managed Processor (TMAP) provides the
application functionality for transaction processing. The
TMAP processes transactions by following scripts contained
in the Transaction Document (TDOC). The TMAP reads the
instructions contained in the script and executes the
Application Units (AUs) specified.
The TMAP exists in memory as a combination of the TMAP
modules, which use a series of resources to process
transactions. The TMAP consists of the TMAP driver, the
Classifier, the Parser, and the Script Executor.
The Classifier determines message types. It looks at an ELF
message, reads its data elements, and determines which
script the TMAP will use to process the transaction. The
Classifier then returns the ID of the script to the TMAP.
Transaction Document (TDOC)
The TDOC contains scripts that describe how to complete an
application process. Each script consists of several steps.
The steps of a script direct the TMAP to call Application
Units (AUs) to evaluate or calculate data for the
transaction being processed.
The following diagram represents a TDOC as seen in a
theoretical two-dimensional view.
IST-RTR Client & Server Gateways
These processes provide the interfaces between the IST/MSI
and the Digital RTR product. These gateways link the IST/MSI
transaction id's to RTR channels. They also provide for
parts of the protocol used for transaction execution.
TMAPR is a specialized TMAP which interfaces with the RTR
channel model. It provides a tightly coupled scheme for
ensuring that RTR transactions are equivalent to database
transactions. This is because RTR considers the activity on
the RTR channel to be directly indicative of the state of
the database transaction.
In order to fully implement the IST/MSI Two Phase Commit
protocol, a standard application skeleton is employed within
Elfsql-SP is usually used within TMAPR. It provides a high
performance interface to database systems that support
stored procedures. It translates the IST/MSI internal
message format (ELF) directly into stored procedure
arguments, and vise-versa. All execution is pre-parsed where
possible to insure optimum database performance.
The Application Unit (AU) is the code that is executed under
the direction of the TDOC script, and performs all of the
transaction-related application processing for the TMAP.
Oasis Technology Ltd. and Digital Equipment Corporation
provide a complete solution for your enterprise-wide
transaction integration, switching and messaging business
needs. A full range of services, including support,
education, publications, and project management accompany
the Enterprise solution.
IST suite of products is a highly adaptable set of
switching software and application 'building blocks'. It can
be modified to suit any business based transaction
processing requirement. There are no limitations to the
number of devices it can control and it can operate on any
UNIX or NT platform. The architecture is scaleable from
small branch or regional applications to global enterprise
solutions. Many of IST's features are user-configurable,
allowing users to personalize and customize the product to
suit specific needs.
provides a geography independent delivery mechanism for
fault resilient transaction processing over heterogeneous
is a 'Universal Message Integrator', allowing our
customers to integrate, process and communicate data from
many disparate sources regardless of where the data is in
allows them to do it every minute of every day.
Citibank, one of the largest banks in the United States
found this to be true. So will you.
to make it work for you?
Digital and Oasis offer a range of services to help you be
successful with Enterprise. Digital brings solid
experience in managing large complex integration projects.
As a Digital partner Oasis Technology has proven product,
technical and support expertise in the field of transaction
processing. As a team Digital and Oasis have a proven track
record of success.
Digital and Oasis have the experienced staff to help you
select the features of Enterprise you need, design
the distributed Enterprise environment required to service
your organization, and install your systems.
We can help you develop the applications and build your
Digital has technology migration services to help you move
existing applications to Enterprise.
Digital and Oasis offer educational seminars, self-paced
training and classes to develop the skills of your staff to
fully exploit the features of Enterprise.
from Digital and Oasis, a solid foundation for the next