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Protocol MIC-0 - The interface to the CCS

The syntax of MIC-0 is defined in Appendix 3.

MIC-0 is the interface between the Conference Control System and the CHannel Server. The Conference Control System does not have to know anything about codecs, networks, different types of multiplexors and so forth. All it needs to know about video streams is that there is a particular set of endpoints, and that a subset of these endpoints want multiplexing together, and the resultant multiplexed stream be distributed to another subset of endpoints.

MIC-0CNF is defined as being the set of requests that can be sent to the Channel Server from the Conference Server.

MIC-0CH is the set replies that can be sent to the Conference Server from the Channel Server.

MIC-0CNF requests can be of the following types:

• Request Endpoint Name List
• Request Assignment of a Multiplexor

  This request can either contain either:

  • a proposed list of Endpoint Names, or
  • a Booking Ticket (this can either be a genuine ticket obtained from the booking system, or a ticket requesting a special class of mux to allow us to deal with special cases)
• A mux release request

  This is an order from the Channel Server to give up a multiplexor. The mux will be de-assigned anyway (due to a prior booking or similar event), but this gives the Conference Server the possibility to report the event.

• Add source to mux
  • input number
  • endpoint name
• Remove source from mux
• Add sink to mux
• Remove sink from mux

MIC-0CH responses are:

• Endpoint list
  • A list of endpoint names
  Generated in response to a request, or in response to a new endpoint codec controller connecting to the Channel Server
• Multiplexor Assignment
  • Multiplexor name
  • number of inputs
• Multiplexor Released
  • Mux name
  Generated in response to a "Release Mux" request, or when the Mux is no longer required.
• Mux State
  • A list of:
    • mux input number
    • source endpoint name
  • A list of sink endpoint names
  • A human readable error message (if needed)

Note that one-to-one links are simply special multiplexors. As the channel server knows there is only one source, it can choose to optimise the link, but the Conference Server know nothing of this.