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Overview |
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Designed to: |
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Simplify BRENT installations and to provide a more cost effective,
reliable and manageable solution for applications
where multiple BRENTs are required (for videoconferencing, for
example). |
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Enable BRENTs to use more reliable PRI services, which may
also be delivered over fibre to improve security. |
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Ensure more reliable BRENT operation with ISDN in other
countries, including the USA. SPIDs etc are handled and there
are a number of configuration options to help the BRENTs to
function under different conditions and on a huge variety of
networks. BRENT can be troublesome and difficult to
interoperate with non-UK ISDN services. Brent Converter assists
in overcoming these issues. |
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Have many flexible features, such as Number Manipulation,
which often come in useful in the more unusual applications
often associated with BRENTs |
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The BRENT Converter is a powerful and useful tool for many
situations.
Should BRENTs be needed to run over packet networks, either
Private, Public or Satellite, Patapsco’s PacketBand-ISDN has had a
great deal of success and references and referrals are available. |
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Key Additional Features |
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As well as the extensive capabilities of the Liberator “S”, the BRENT
Converter has a number of features specifically for this application.
“ B” Channel Reservation
By way of illustration we have used a real, installed application,
where BRENTs are required for videoconferencing and used with
MCUs (Multi-Conference Units). |
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If the MCU makes an out-going call on the PRI it can utilise any
timeslot. Furthermore, calls to multiple BRENTs may be made at the
same time. If calls to the same remote BRENT converter are not sent
from a single central-site BRENT, calls get “crossed” and fail. Clearly
there needs to be some intelligence to handle, order and route calls
to the appropriate local encryptor.
The BRENT Converter, when it receives a call to a specific
destination number (DDI) on its PRI port routes the call to an
available BRENT. It then reserves the second “B” channel on that
BRENT until it receives another call on the PRI for the same
destination number. In this way the two BRI calls to a remote BRENT
will always originate from a single central BRENT and calls cannot
get crossed. This facility overcomes one of the most troublesome
limitations of the BRENT to provide reliable multi-call sessions. |
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Call Connect Delay |
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When in Secure Mode BRENTs take a period of time to exchange
keys, handle other “handshakes” and “lock”. Once the BRENTs are
locked the attached application/DTE then has end-to-end
communications. |
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However, the BRENT “Red S” interface passes the attached DTE a
Call Connect message as soon as the ISDN call itself is answered
(on the Black interface) - not once there is an actual available data
path for the application when the BRENT is synchronised and no
longer using the ISDN channel for its own purposes.
This means the attached DTE can start to transfer data or try to
communicate with its partner device at the other end of the link
whilst there is no end-to-end circuit available because the BRENT is
still performing its synchronisation exchanges. This can cause data
loss or lead the attached device to give up and close the call so
the application never works. This is common on terrestrial links but
becomes even more obvious on satellite links where the BRENT key
exchange etc takes even longer.
The intelligence in the BRENT Converter means the Call Connect
message from the red “S” bus on the BRENT to the attached
device can be delayed for a user-configurable period of time. This
ensures an end-to-end data path exists for the attached devices as
soon as the call is connected. |
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Call Timers |
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Some internal ISDN state machine call timers have been modified to
better suit the requirements of the BRENT |
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Diagnostics |
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Whilst standard on both the Liberator and the BRENT Converter, the
extensive diagnostics and tools make identifying and resolving
connectivity issues possible and far more simple than with just a
BRENT. For example, traces can capture all low-level ISDN
messaging and these can be forwarded as a file to our experts here
at Patapsco for analysis and advice should that be needed. An
additional small application can convert the ISDN trace data in to a
more human readable format. |
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References |
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Appropriate references as to the capabilities, robustness and
flexibility of the Liberator and BRENT Converter are available, as
are those from organisations experienced in using our fabulous and
fast-reacting Support Services. |
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Support & Training |
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Patapsco provide excellent support for the BRENT Converter and
also know and understand the workings of the BRENT itself. We are
here and available to help.
We have developed and installed ISDN equipment all around the
world, for over 18 years. Our ISDN protocol stacks have been
developed in-house; we really are the experts in this field. Many
organisations have gained access to our knowledge on one of our
training courses. They are typically “hands-on” and focus on ISDN
and BRENTs and cover typical problems in “real world” situations
and applications. |
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