High-level programming of Internet telephony

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High-level programming of Internet telephony

• Luigi Logrippo and group

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Project Objectives Addressed

• Area A To develop the available notations to
  specify requirements (Sincennes)
• Area B To develop innovative methods and tools
  that can be used for the development of correct
  and secure system design models from a given
  specification of the requirements, considering in
  particular the possibilities for automating
  certain parts of the design process (Sincennes)
• Area C To develop innovative formal validation
  methods and tools appropriate for this process
  (Xu)
• Area D To evaluate the notations, methods and
  tools by applying them to realistic examples of
  distributed systems, especially in the area of
  service development in internet telephony (Jiang,
  Sincennes, Xu)

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Main areaProgramming Internet telephonyfor new
and old features

• CPL is proposed, but it is very limited and
  low-level
• Define new languages that are
• Closer to user requirements level
• But still executable or compilable into
  executable
• More appropriate for flexible and general
  features
• Allow VV activities such as Feature Interaction
  detection and resolution

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Project 1 Feature Execution Trees(Jacques
Sincennes) (Areas A,B available and innovative
nots., applics.)

• Initial idea due to Mitel group (Tom Gray,
  others)
• Tuple space is an idealized database where
  pertinent system state information is stored
• In reality, it could be implemented as a number
  of data bases
• Telecom features can be described as decision
  trees that take their input from a tuple space
  and a current trigger, and decide on a sequence
  of actions
• Being developed by Jacques Sincennes as a
  language based on logic programming and Prolog
• Avantages
• Clear logic, probably appropriate for VV based
  on theorem proving
• Executable, because Prolog is executable
• Prolog mechanism is not visible to user, who uses
  high-level primitives

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Project 2 Feature Interaction in CPL(Yiqun Xu)
(Area C formal validation)

• CPL Call Processing Language
• an IETF CFP capable of describing simple
  telephony features
• What kinds of feature interactions are possible
  among features described in CPL?
• Interactions within one script
• shadowing, etc.
• Interactions between scripts
• A call that should be impossible according to the
  policy of one user, or system policies, becames
  possible because of the policy of another
• Global invariants violated

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Project 2 Feature Interaction in CPL(Yiqun Xu)
(Area C)

• Being developed
• Translator from CPL representation in XML into a
  logic-based language
• System to find interactions and flag them for the
  user
• Interesting questions interactions between CPL
  scripts become possible only when CPL scripts
  interwork
• How to detect this possibility in a world where
  there may be as many CPL scripts as there are
  users?

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Project 3CPL extensions(Dongmei Jiang) (Area D
applics)

• CPL extensions for presence
• Use of tuple space that contains presence
  information
• What each user is available for
• in a meeting, in a specific room, wanting to
  receive only certain types of messages
• Availability and notification of presence
  information
• User sets up features by using templates, these
  become programs for agents