Requirements for the XCON-DCON Synchronization Protocol
draft-romano-dcon-xdsp-reqs-09

Abstract

The Distributed Conferencing (DCON) framework provides the means to distribute Centralized Conference (XCON) information by appropriately orchestrating a number of centralized focus entities (clouds). The mechanism we propose to make each XCON cloud communicate with its related DCON peer is based on the use of some kind of XCON-DCON Synchronization Protocol (XDSP). This document gives the requirements for XDSP.

Status of this Memo

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This Internet-Draft will expire on December 22, 2011.

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Table of Contents

• 1. Introduction
• 2. Conventions
• 3. Terminology
• 4. XDSP Requirements
• 4.1. General Protocol Requirements
• 4.2. Requests and responses
• 4.3. Updates and asynchronous notifications
• 4.4. Centralized protocols routing and dispatching
• 5. Security Considerations
• 6. Acknowledgements
• 7. References
• Authors' Addresses

1. Introduction

The Distributed Conferencing framework [I-D.romano-dcon-requirements] describes the requirements for the overall architecture, terminology, and protocol components needed for distribuited conferencing. DCON is based on the idea that a distributed conference can be setup and accessed by appropriately orchestrating the operation of a number of XCON "focus" elements, each in charge of managing a certain number of participants. Each pair composed of a centralized focus entity (XCON) and its related distributed counterpart (namely, a DCON focus) is called "island", or "cloud". These islands are then made part of an overlay network composed of several inter-communicating clouds.

Interaction between each participant and the corresponding conference focus is based on the standard XCON framework [RFC5239], whereas inter-focus interaction is based on a peer-to-peer paradigm. The interaction between the centralized conference focus and the distributed conference focus, instead, has requirements that are defined in this document.

2. Conventions

In this document, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as described in BCP 14, RFC 2119 [RFC2119] and indicate requirement levels for compliant implementations.

3. Terminology

Distributed conferencing uses, when appropriate, and expands on the terminology introduced in the both the SIPPING [RFC4353] and XCON [RFC5239] conferencing frameworks. The following additional terms are defined for specific use within the distributed conferencing work.

4. XDSP Requirements

This section describes requirements for the XCON-DCON synchronization protocol (XDSP).

4.1. General Protocol Requirements

4.2. Requests and responses

4.3. Updates and asynchronous notifications

4.4. Centralized protocols routing and dispatching

5. Security Considerations

The communication between each DCON focus entity and its related XCON entity contains sensitive information, since it envisages the possibility to spread important information that only authorized entities should be aware of (e.g. the full internal state of the centralized conference objects and relevant privacy information about users authenticated by the system).

Hence it is very important that protocol messages be protected because otherwise an attacker might spoof the legitimate identity of the DCON focus entity and/or inject messages on his behalf. Many obvious consequences could come out of such an undesirable situation.

To mitigate the above threats, both the DCON focus entity and the XCON focus entity SHOULD be authenticated upon initial contact. All protocol messages SHOULD be authenticated and integrity-protected to prevent third-party intervention and MITM (Man-In-The-Middle) attacks. All messages SHOULD be encrypted to prevent eavesdropping.

6. Acknowledgements

7. References

Authors' Addresses