Enhanced Messaging System Scenarios
Thomas A. Alspaugh, Annie I. Antón, and Abdi Modarressi
24 July 2001
(HTML representation revised 15 Jan 2004, 11 Dec 2006)

Corresponding to the EMS requirements of 19 June 2001. 

Table of contents

0.  The form of a scenario
1.  Glossaries
1.1.  Defined terms
1.1.  Primitive conditions
1.1.  Actors
1.1.  Episodes
1.1.  Menu trees
2.  Scenarios

S0.  EMS startup
S1.  EMS shutdown
S2.  Subscriber authentication
S3.  Subscriber authentication from unsubscribed telephone
S4.  Subscriber authentication from another subscriber's telephone
S5.  Subscriber changes his/her passcode
S6.  Subscriber configures his/her announcement
S7.  Subscriber sets up a group of phone numbers as a recipient
S8.  Subscriber checks for new messages
S9.  New message notification by stuttered dial tone
S10.  New message notification, by indicator
S11.  No new message notification, by indicator
S12.  Subscriber listens to a message
S13.  Subscriber has no more messages to listen to
S14.  Subscriber skips to next message
S15.  Subscriber would skip to next message but has no more messages
S16.  Subscriber skips around in a message while listening to it
S17.  Subscriber listens to the time a message was received
S18.  Subscriber erases a message
S19.  Subscriber erases the last message
S20.  Subscriber archives a message
S21.  Subscriber archives the last message
S22.  Subscriber forwards a message
S23.  Subscriber forwards a message with a preface
S24.  Subscriber replies to a message
S25.  Confidential
S26.  Subscriber records a message and sends it to someone
S27.  Subscriber takes no action for a long time
S28.  Subscriber is prompted about old held messages
S29.  Subscriber is prompted about old archived messages
S30.  Subscriber disconnects from EMS
S31.  Caller calls subscriber and leaves a message
S32.  Caller reviews his/her message
S33.  Caller reviews and re-records his/her message
S34.  Caller distinguishes his/her message as urgent
S35.  Caller distinguishes his/her message as private
S36.  Caller decides he/she needs to speak to a receptionist
S37.  Caller doesn't want to listen to the subscriber's announcement
S38.  Caller calls EMS directly and leaves a message
S39.  Caller takes no action for a long time
S40.  Caller disconnects from EMS

0.  The form of a scenario

Each scenario has 0 or more preconditions which must be true when the scenario is initiated, and 0 or more postconditions which will be true when the scenario terminates.

The events in each scenario occur beginning with the first and continuing through the last. An event may be

The choice of whether an iteration continues, or between alternatives, is expressed in terms of an action of an agent external to the system, or in terms of the external state of the system.

1.  Glossaries

1.0  Defined terms

Terms used in this document are defined here or in the EMS requirements.

current message   The subscriber's newest urgent new message, if any; else the subscriber's newest message, if any; else the subscribe has no current message.

next message   Relative to the current message, the subscriber's next newest urgent new message (if any), or next newest message (if any); if not, then the subscribe has no next message. (Compare the less detailed next message.)

1.1  Primitive conditions used in pre- and post-conditions

The conditions are predicates on a subscriber, caller, or message. In these scenarios it is clear which subscriber, caller, or message is intended, so no explicit notation is used to identify each predicate's parameter.

Announcement Bypassable   The subscriber has configured his/her announcement so that it can be bypassed (R2.2.5, R4.6).

Archived   The subscriber is processing a message that hasn't been archived (R3.2.8).

Authenticated   The subscriber is connected to EMS and is authenticated (R1.4).

Connected   The caller is connected to the EMS.

Has (m) More   The subscriber has m messages not listened to or otherwise processed in this call, and m≥0.

Has (m>0) More   The subscriber has m messages not listened to or otherwise processed in this call, and m>0.

Has (m) New   The subscriber has m new messages and m≥0.

Has (m>0) New   The subscriber has m new messages and m>0.

Has Current   The subscriber is processing a message that hasn't been erased or archived (R3.2.7, R3.2.8).

Has New Message Indicator   The subscriber' phone has a new message indicator (R3.1.5).

Has Old Held   The subscriber has one or more old held messages.

Left Message   The caller has left a message but has not yet hung up (R4.2).

Played   EMS has just played a message.

Subscribed   The caller is a subscriber of EMS (R1.5).

1.2  Actors

  1. EMS
  2. A subscriber
  3. A caller
  4. Central office
  5. An EMS administrator

1.3  Named Episodes

E2.  MakeRecording

Used in:  S23, S24, S26.

1.  Iteration with explicit exit:
1.1.  EMS tells the subscriber to begin recording.
1.2.  The subscriber says what he/she wants, then presses the "stop recording" command.
1.3.  EMS plays back the recording and asks for a confirmation or rejection.
1.4.  Alternatives:
1.4.1.  The subscriber dials the confirmation command. - Exit from iteration.
1.4.2.  The subscriber dials the rejection command.

These trees in the form of outlines summarize a possible set of menu choices of the actions used in the scenarios for subscriber actions.

1.4.1  Access

A subscriber or caller has these choices only when EMS first answers.

1.  Subscriber authentication for the telephone called from. If authentication is successful, the subscriber goes to the "subscriber actions" menu tree.
2.  Subscriber authentication for another telephone number. (same as above)
3.  Caller leaves a message for a single EMS subscriber . The caller goes to the "Caller actions" menu tree.

1.4.2.  Subscriber actions

1.  Configuration
1.1.  Change passcode.
1.2.  Configure announcement.
1.3.  Set up group of phone numbers.
1.4.  Up to parent menu.
2.  Check for new messages.
3.  Process messages
3.1.  Play the first message.
3.1.1.  Skip around in the current message.
3.2.  Play the next message (a.k.a. "skip").
3.2.1.  Skip around in the current message.
3.3.  Play the time the current message was received.
3.4.  Erase the current message, and move to the next one.
3.5.  Archive the current (new or held) message, and move the next one (not available if the current message is an archived message).
3.6.  Reply to the current message.
3.7.  Forward the current message.
3.8.  Forward the current message with a preface. (Suggest this should become an alternative within "forward the current message")
3.9.  Call the person who left the current message.
3.10.  Record a message and send it to a phone number.
3.11.  Up to parent menu.

It is assumed that some actions can take place at almost any point:

  1. Move up to the next higher level in the menu tree.
  2. Abandon the current action.

When processing old held or archived messages, the "skip" menu item is not available.

1.7.3.  Caller actions

The tree for caller actions is much simpler. This tree is available in two situations: to someone who has called a subscriber's number if the subscriber doesn't answer, and to someone who has called EMS directly to leave a message without the possibility of speaking to the subscriber.

It is assumed that the action of leaving a message doesn't require making any menu choice.

1.  Skip announcement. This choice is only available while the announcement is playing.
2.  Review message.
3.  Re-record message.
4.  Mark message as urgent.
5.  Mark message as private.
6.  Speak to receptionist.

2.  Scenarios

S0.  EMS startup

Requirements:  (none).
Postcondition:  (none).

1.  The administrator starts up the EMS.

This is the initial scenario for the system.

S1.  EMS shutdown

Requirements:  (none).
Precondition:   (none).

1.  The administrator gives the command to shut down the EMS.
2.  The EMS stops accepting new calls.
3.  When all calls have terminated, the EMS shuts down.

This is the terminal scenario for the system.

S2.  Subscriber authentication

Requirements:  R1.1, R1.3, R1.4.
Precondition:   Subscribed.
Postcondition:  Authenticated.
Equivalent to:  S2, S3, S4.

1.  The subscriber dials EMS on his or her telephone.
2.  EMS answers and announces the subscriber's name.
3.  The subscriber dials his or her passcode.
4.  EMS authenticates the passcode.

An initial scenario for subscriber narrative

S3.  Subscriber authentication from unsubscribed telephone

Requirements:  R1.1, R1.2, R1.3, R1.4.
Precondition:   Subscribed.
Postcondition:  Authenticated.
Equivalent to:  S2, S3, S4.

1.  The subscriber dials EMS from some unsubscribed telephone.
2.  EMS answers with some announcement.
3.  The subscriber dials his or her telephone number.
4.  EMS announces the subscriber's name.
5.  The subscriber dials his or her passcode.
6.  EMS authenticates the passcode.

An initial scenario for subscriber narrative

S4.  Subscriber authentication from another subscriber's telephone

Requirements:  R1.1, R1.2, R1.3, R1.4.
Precondition:   Subscribed.
Postcondition:  Authenticated.
Equivalent to:  S2, S3, S4.

1.  The subscriber dials EMS from some other subscriber's telephone.
2.  EMS answers and announces the other subscriber's name.
3.  The subscriber dials his or her telephone number.
4.  EMS announces the subscriber's name.
5.  The subscriber dials his or her passcode.
6.  EMS authenticates the passcode.

An initial scenario for subscriber narrative

S5.  Subscriber changes his/her passcode

Requirements:  R2.1.
Precondition:   Authenticated.
Postcondition:  Authenticated.
Can follow:  S2, S3, S4.
Equivalent to:  S5, S6, S7.

1.  The subscriber dials the "new passcode" command.
2.  EMS asks for the new passcode.
3.  The subscriber dials the new passcode.
4.  EMS asks for the new passcode again.
5.  The subscriber dials the new passcode again.
6.  EMS changes the subscriber's passcode and announces that the passcode has been changed.

S6.  Subscriber configures his/her announcement

Requirements:  R2.2.
Precondition:   Authenticated.
Postcondition:  Authenticated.
Can follow:  S2, S3, S4.
Equivalent to:  S5, S6, S7.

1.  Iteration:
1.1.  The subscriber dials the "configure announcement" command.
1.2.  EMS asks the subscriber to say the new announcement or press the "choose default announcement" command.
1.3.  Alternatives:
1.3.1.  The subscriber says his/her new announcement and presses the "end of announcement" command;
1.3.2.  or the subscriber presses the "choose default announcement" command.
1.4.  EMS plays back the chosen announcement and asks the subscriber to dial a command to accept it or the "configure announcement" command to try again.
2.  The subscriber dials the command to accept the chosen announcement.
3.  EMS uses that announcement as the subscriber's announcement.

S7.  Subscriber sets up a group of phone numbers as a recipient

Requirements:  R2.3.
Precondition:   Authenticated.
Postcondition:  Authenticated.
Can follow:  S2, S3, S4.
Equivalent to:  S5, S6, S7.

1.  The subscriber dials the command to set up a group of phone numbers as a recipient.
2.  Iteration with explicit exit:
2.1.  EMS announces that the subscriber can enter a phone number followed by a non-numeric number-ending command (for example "#"), or can enter a non-numeric sequence-ending command (for example "*").
2.2.  Alternatives:
2.2.1.  Sequence:
2.2.1.1.  The subscriber dials a telephone number followed by the number-ending command.
2.2.1.2.  EMS reads the number back, and asks for a confirmation command or a rejection command.
2.2.1.3.  Alternatives:
2.2.1.3.1.  The subscriber dials the confirmation command, and the telephone number is added to the group.
2.2.1.3.2.  The subscriber dials the rejection command.
2.2.2.  The subscriber dials the sequence-ending command - Exit from iteration.
3.  EMS asks for the two-digit number that will stand for this group.
4.  The subscriber dials the two-digit number.
5.  EMS reads the number back, and asks for a confirmation command.
6.  The subscriber dials the confirmation command.
7.  EMS stores the group and announces that the group has been created.

S8.  Subscriber checks for new messages

Requirements:  R3.1.1, R3.1.2.
Precondition:   Authenticated.
Postcondition:  Authenticated.
Can follow:  S2, S3, S4.
Follow-equivalent to (can follow same scenarios as):  S5, S6, S7.

1.  The subscriber dials the "check for new messages" command.
2.  EMS announces how many new messages the subscriber has.

S9.  New message notification by stuttered dial tone

Requirements:  R3.1.1, R3.1.4.
Precondition:   (None).
Postcondition:  (None).
Equivalent to:  (None).

1.  The subscriber's phone needs to produce a dial tone (because the phone was picked up, or a new connection is opened with call waiting).
2.  The central office sends a message to EMS asking if this phone has new messages.
3.  Alternatives:
3.1.  Sequence:
3.1.1.  EMS sends a message to the central office saying there are new messages.
3.1.2.  The central office sends a stuttered dial tone to the subscriber's phone.
3.2.  Sequence:
3.2.1.  EMS sends a message to the central office saying there are no new messages.
3.2.2.  The central office sends a normal dial tone to the subscriber's phone.

Compare S9, S10, S11. Not synchronized with any of the main narratives.

S10.  New message notification

Requirements:  R3.1.1, R3.1.5.
Precondition:   Has (0) New, Has New Message Indicator.
Postcondition:  Has (1) New, Has New Message Indicator.
Equivalent to:  (None).

1.  A caller leaves a new message for the subscriber.
2.  EMS sends a "new message" notification to the subscriber's phone.
3.  The new message indicator on the subscriber's phone turns on.

Compare S9, S10, S11. Can follow S31 if subscriber has new message indicator.

S11.  No new message notification

Requirements:  R3.1.1, R3.1.5.
Precondition:   Has (1) New, Has New Message Indicator.
Postcondition:  Has (0) New, Has New Message Indicator.
Equivalent to:  (None).

1.  The subscriber processes all his/her new messages.
2.  EMS sends a "no new message" notification to the subscriber's phone.
3.  The new message indicator on the subscriber's phone turns off.

Compare S9, S10, S11. Should potentially follow S12, S13 if subscriber has new message indicator.

S12.  Subscriber listens to a message

Requirements:  R3.2.1, R3.2.2.
Precondition:   Authenticated, Has (n>0) More.
Postcondition:  Authenticated, Has (n-1) More, Has Current.
Equivalent to:  (None).

1.  The subscriber dials the "listen to message" command.
2.  If the current message is a new message, EMS changes its state to "held".
3.  EMS plays the next message, and that message becomes the current message.

Compare S13, S14

S13.  Subscriber has no more messages to listen to

Requirements:  R3.2.1, R3.2.2.
Precondition:   Authenticated, Has (0) More.
Postcondition:  Authenticated, Has (0) More, ¬Has Current.
Equivalent to:  (None).

1.  The subscriber dials the "listen to message" command.
2.  EMS announces that there are no more messages.

Compare S12, S15

S14.  Subscriber skips to next message

Requirements:  R3.2.1, R3.2.2.
Precondition:   Authenticated, Has (n>0) More, Has Current.
Postcondition:  Authenticated, Has (n-1) More, Has Current.
Equivalent to:  (None).

1.  The subscriber dials the "next message" command.
2.  If the next message is a new message, EMS changes its state to "held".
3.  EMS plays the next message, and that message becomes the current message.

Compare S12, S15

S15.  Subscriber would skip to next message but has no more messages

Requirements:  R3.2.1, R3.2.2.
Precondition:   Authenticated, Has (0) More.
Postcondition:  Authenticated, Has (0) More, ¬Has Current.
Equivalent to:  (None).

1.  The subscriber dials the "next message" command.
2.  EMS announces that there are no more messages.

Compare S13, S14

S16.  Subscriber skips around in a message while listening to it

Requirements:  R3.2.5.
Precondition:   Authenticated, Has Current.
Postcondition:  Authenticated, Has Current.
Equivalent to:  (None).

1.  While listening to a message, or after listening to a message, the subscriber enters a command to skip around in the message (such as "go back to the beginning of the message", "go back 5 seconds", "skip ahead 5 seconds", "skip to the end of the message").
2.  EMS continues playing the message from the point the subscriber selects (or stops playing the message if the subscriber selected the end or a point that would be after the end). If the command to go back was entered after the message had ended, the point selected is taken to be relative to the end of the message.

S17.  Subscriber listens to the time a message was received

Requirements:  R3.2.6.
Precondition:   Authenticated, Has Current.
Postcondition:  (no change).
Equivalent to:  (None).

1.  The subscriber dials the "listen to info" command.
2.  EMS plays the date and time the message was received, and the caller's phone number if it is known.

S18.  Subscriber erases a message

Requirements:  R3.2.4, R3.2.7.
Precondition:   Authenticated, Has (n>0) More, Has Current.
Postcondition:  Authenticated, Has (n-1) More, Has Current.
Equivalent to:  S20.

1.  The subscriber dials the "erase current message" command.
2.  EMS erases the current message, and that message is no longer accessible.
3.  EMS plays the next message, and that message becomes the current message.

S19.  Subscriber erases the last message

Requirements:  R3.2.4, R3.2.7.
Precondition:   Authenticated, Has (0) More, Has Current.
Postcondition:  Authenticated, Has (0) More.
Equivalent to:  (None).

1.  The subscriber dials the "erase current message" command.
2.  EMS erases the current message, and that message is no longer accessible.
3.  EMS announces that there are no more messages.

S20.  Subscriber archives a message

Requirements:  R3.2.4.
Precondition:   Authenticated, Has (n>0) More, Has Current, ¬Archived.
Postcondition:  Authenticated, Has (n-1) More, Has Current.
Equivalent to:  S17.

1.  The subscriber dials the "archive current message" command.
2.  EMS changes the current message's state to "archived".
3.  EMS plays the next message, and that message becomes the current message.

S21.  Subscriber archives the last message

Requirements:  R3.2.8.
Precondition:   Authenticated, Has (0) More, Has Current, ¬Archived.
Postcondition:  Authenticated, Has (0) More, ¬Has Current.
Equivalent to:  S17.

1.  The subscriber dials the "archive current message" command.
2.  EMS changes the current message's state to "archived".
3.  EMS announces that there are no more messages.

S22.  Subscriber forwards a message

Requirements:  R3.2.10.
Precondition:   Authenticated.
Postcondition:  Authenticated.
Equivalent to:  S22, S23, S24, S26.

1.  The subscriber dials the "forward current message" command.
2.  Alternatives:
2.1.  If the message is private, EMS announces that it can't be forwarded for that reason.
2.2.  Sequence:
2.2.1.  Iteration with explicit exit:
2.2.1.1.  EMS asks for the phone number to which to forward the message.
2.2.1.2.  The subscriber enters the phone number followed by a number-ending command (such as "#").
2.2.1.3.  EMS repeats the number and asks for confirmation.
2.2.1.4.  Alternatives:
2.2.1.4.1.  The subscriber dials the confirmation command - Exit from iteration.
2.2.1.4.2.  The subscriber dials the rejection command.
2.2.2.  EMS forwards the message.

S23.  Subscriber forwards a message with a preface

Requirements:  R3.2.10.
Precondition:   Authenticated.
Postcondition:  Authenticated.
Equivalent to:  S22, S23, S24, S26.

1.  The subscriber dials the "forward current message with preface" command.
2.  Alternatives:
2.1.  If the message is private, EMS announces that it can't be forwarded for that reason.
2.2.  Sequence:
2.2.1.  Iteration with explicit exit:
2.2.1.1.  EMS asks for the phone number to which to forward the message.
2.2.1.2.  The subscriber enters the phone number followed by a number-ending command (such as "#").
2.2.1.3.  EMS repeats the number and asks for confirmation.
2.2.1.4.  Alternatives:
2.2.1.4.1.  The subscriber dials the confirmation command - Exit from iteration.
2.2.1.4.2.  The subscriber dials the rejection command.
2.2.2.  EMS asks for the preface to be forwarded with the message.
2.2.3.  Alternatives:
2.2.3.1.  Episode: MakeRecording
2.2.3.2.  The subscriber dials the rejection command.
2.2.4.  EMS forwards the message and preface.

S24.  Subscriber replies to a message

Requirements:  R3.2.9.
Precondition:   Authenticated.
Postcondition:  Authenticated.
Equivalent to:  S22, S23, S24, S26.

1.  The subscriber dials the "reply to current message" command.
2.  Episode: MakeRecording.
3.  EMS sends the recording to the sender of the current message.

S25.  Confidential

This scenario is excluded from public versions of the scenarios.

S26.  Subscriber records a message and sends it to someone

Requirements:  R3.2.14.
Precondition:   Authenticated.
Postcondition:  Authenticated.
Equivalent to:  S22, S23, S24, S26.

1.  The subscriber dials the "record message" command.
2.  Iteration with explicit exit:
2.1.  EMS asks for the telephone phone number to which the message will be sent.
2.2.  The subscriber dials the telephone number, followed by a non-numeric number-ending command (such as '#').
2.3.  EMS says the telephone number and asks the subscriber to confirm or reject it.
2.4.  Alternatives:
2.4.1.  The subscriber dials the confirmation command. Exit from iteration
2.4.2.  The subscriber dials the rejection command.
3.  Episode: MakeRecording.
4.  EMS sends the recorded message to the telephone number.

S27.  Subscriber takes no action for a long time

Requirements:  R3.2.15.
Precondition:   Authenticated.
Postcondition:  ¬Authenticated.
Equivalent to:  S27, S30.

1.  The subscriber doesn't take any action for more than a certain length of time.
2.  EMS disconnects and hangs up.

S28.  Subscriber is prompted about old held messages

Requirements:  R3.2.15.
Precondition:   Authenticated.
Postcondition:  Authenticated.

1.  EMS announces that the subscriber has one or more old held messages, and won't be allowed to process any other message until all the old held messages are handled.
2.  Iteration while condition remains true: Has Old Held
2.1.  EMS plays an old held message and asks the subscriber to take an action.
2.2.  Iteration with explicit exit:
2.2.1.  Alternatives:
2.2.1.1.  The subscriber erases the message. Exit from iteration.
2.2.1.2.  The subscriber archives the message. Exit from iteration.
2.2.1.3.  The subscriber forwards the message.

S29.  Subscriber is prompted about old archived messages

Requirements:  R3.2.16.
This scenario is identical with scenario S28 for old held messages, with "archived" substituted for "held" and without the alternative of archiving the already-archived message.

S30.  Subscriber disconnects from EMS

Requirements:  (No individual requirement).
Precondition:   Authenticated.
Postcondition:  ¬Authenticated.
Equivalent to:  S27, S30.

1.  The subscriber hangs up.
2.  EMS terminates the call.

S31.  Caller calls subscriber and leaves a message

Requirements:  R4.1.
Precondition:   Has (n) New.
Postcondition:  Has (n+1) New, Left Message, Connected.
Equivalent to:  S31, S38.

1.  A caller calls the subscriber's telephone while it is busy.
2.  EMS plays the subscriber's name and announcement.
3.  The caller leaves a message.

S32.  Caller reviews his/her message

Requirements:  R4.3.
Precondition:   Left Message, Connected.
Postcondition:  Left Message, Connected.
Equivalent to:  S32, S33, S34, S35.

1.  The caller presses the "review message" command.
2.  EMS plays the message the caller just left.

S33.  Caller reviews and re-records his/her message

Requirements:  R4.3.
Precondition:   Left Message, Connected.
Postcondition:  (unchanged).
Equivalent to:  S32, S33, S34, S35.

1.  The caller presses the "re-record message" command.
2.  The caller leaves a message.

S34.  Caller distinguishes his/her message as urgent

Requirements:  R4.4.
Precondition:   Left Message, Connected.
Postcondition:  (unchanged).
Equivalent to:  S32, S33, S34, S35.

1.  The caller presses the "urgent" command.
2.  EMS marks the message as urgent.

S35.  Caller distinguishes his/her message as private

Requirements:  R4.4.
Identical to S34, with "urgent" replaced by "private" everywhere.

S36.  Caller decides he/she needs to speak to a receptionist

Requirements:  R4.5.
Precondition:   Connected.
Postcondition:  (No change).

1.  The caller presses the "receptionist" command.
2.  EMS connects the caller to the receptionist.

Can occur virtually anywhere in a caller's call.

S37.  Caller doesn't want to listen to the subscriber's announcement

Requirements:  R4.6.
Precondition:   Announcement Bypassable, Connected.
Postcondition:  (No change).

1.  A caller calls the subscriber's telephone while it is busy.
2.  EMS begins to play the subscriber's name and announcement.
3.  Before the name and announcement are complete, the caller presses the "skip announcement" command.
4.  EMS stops playing the name and announcement.
5.  The caller leaves a message.

Can occur anywhere during the subscriber's announcement.

S38.  Caller calls EMS directly and leaves a message

Requirements:  R4.7.
Precondition:   Has (n) New, Connected.
Postcondition:  Has (n+1) New, Left Message, Connected.
Equivalent to:  S31, S38.

1.  A caller calls EMS directly and chooses the "Leave message" menu item.
2.  EMS asks the caller to enter a subscriber's telephone number.
3.  The caller dials the subscriber's telephone number.
4.  EMS plays the subscriber's name and announcement.
5.  The caller leaves a message.

S39.  Caller takes no action for a long time

Requirements:  R3.2.15.
Precondition:   Connected.
Postcondition:  ¬Connected.
Equivalent to:  S39, S40.

1.  The caller doesn't take any action for more than a certain length of time.
2.  EMS disconnects and hangs up.

S40.  Caller disconnects from EMS

Requirements:  (No individual requirement).
Precondition:   Connected.
Postcondition:  ¬Connected.
Equivalent to:  S39, S40.

1.  The caller hangs up.
2.  EMS terminates the call.