MTP 2 message summary

The following table lists the MTP 2 task messages. Messages also contain a message type and a link ID.

Message

Direction

Parameters

Description

Bind request

MTP3 -> MTP2

Service Provider ID

Service User ID

Source Entity ID

Source Instance ID

Binds user application as sole user of MTP 2 link.

Connect request

MTP3 -> MTP2

Service Provider ID

Status

Requests MTP 2 to bring up a physical link. Use the status parameter to specify status to bring link up in (for example, normal, emergency, or power on only).

Connect confirmation

MTP2 -> MTP3

Service User ID

Notifies application that link connection successfully completed (link is aligned).

Data request

MTP3 -> MTP2

Service Provider ID

Data

Requests MTP 2 to transmit an MSU (message signal unit) on a particular link.

Data confirmation

MTP2 -> MTP3

Service User ID

Status

Data

Sends transmitted messages that have not been acknowledged by the far exchange when the application is performing a changeover.

Data indication

MTP2 -> MTP3

Service User ID

Data

Notifies the application of an incoming data packet.

Disconnect request

MTP3 -> MTP2

Service Provider ID

Reason

Requests MTP 2 to disconnect a link.

Disconnect confirmation

MTP2 -> MTP3

Service User ID

Notifies the application that the disconnect request was received.

Disconnect indication

MTP2 -> MTP3

Service User ID

Reason

Notifies the application that a link disconnected.

Disconnect response

MTP3 -> MTP2

Service User ID

Notifies MTP 2 that the application received the disconnect indication.

Flow control request

MTP3 -> MTP2

Service Provider ID

Action

Deprecated.

Flow control indication

MTP2 -> MTP3

Service User ID

Action

FlcLevel

Deprecated.

Flow control response

MTP3 -> MTP2

Service User ID

Action

FlcLevel

Deprecated.

Status request

MTP3 -> MTP2

Service Provider ID

Action

Status

Requests a special status or control function.

Status confirmation

MTP2 -> MTP3

Service User ID

Action

Status

Notifies the application that the status request was received.

Status indication

MTP2 -> MTP3

Service User ID

Status

Value

Notifies the application that a link has gone up or come down or that level 1 buffer depletion occurred.

Status response

MTP3 -> MTP2

Service User ID

Status

Confirms that MTP 3 received a status indication.