MGCP requested event vs. detect event

Discussion in 'VOIP' started by Jack, Jan 29, 2005.

  1. Jack

    Jack Guest


    What is the difference between requested event and detect event in MGCP?

    When is an event Quarantined?

    Some example would be of great help.


    Jack, Jan 29, 2005
    1. Advertisements

  2. Jack

    voipguy Guest

    A requested event would be sent in an RQNT message, and might be for
    like "offhook" or "onhook". Once the call agent has sent this to the
    then when it detects such an event, it will send it via a NTFY message.

    If I recall correctly, I think quarantine works like this:
    If multiple events occur on an interface, they must be sent one at a
    time, with
    only one event outstanding in the transmit queue. Let's say the person
    presses a series of digits, and the call agent asked for one digit at a
    time (not GW digit collection).

    Since MGCP sends over UDP, it can't just send them all up to the call
    because some messages could be lost, and would require retransmission.
    The GW can only send one at a time, in FIFO order. It sends the event,
    waits for an ack,
    then sends the next event. Otherwise, some UDP messages would get
    and others might not. Then the CA has no idea what the real digit order
    was supposed
    to have been, even though with retransmission it got all of them.

    The first digit will be sent to the CA in an NTFY, and the GW waits for
    an ACK.
    Subsequent events (while an ACK is outstanding) will go into the
    quarantine buffer, and dequeued and sent as
    events are acknowledged. Same thing goes for something like
    sequences. These have to be naintained and processed in order, or the
    doesn't know what the current hookstate is.

    Hope this is helpful.
    voipguy, Feb 22, 2005
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.