MTP3:States
From TBwiki
States information, which can be gathered at any time by MTP3, indicates the current state of the software or Service Access Point (SAP). This information indicates the Quality of Service (QoS) parameters and can be used to assist in SS7 software debugging. The collection of status information does not affect any of the information examined.
Link states
General explanation of the link states parameters:
- The Link state parameter indicates the current state of a MTP3 link. Possible values:
| Connection mode | Description |
|---|---|
| Up | Link in UP state (aligned and ready to carry traffic). A link in UP state can carry traffic provided it is not inhibited or blocked. MTP3 chooses an active, unblocked and uninhibited link to carry traffic based on the link priority and the requirements for load sharing. Refer to the SS7 specifications for details on load sharing algorithms. |
| Down | Link in DOWN state. An active link moves to DOWN state when the alignment is lost or when the layer manager deactivates the link or inhibition or blocking is initiated for this link. |
| Not available | MTP3 link is not configured and is waiting for MTP2 link configuration. |
- The Locally inhibited flag indicates whether or not the link is locally inhibited. Possible values are 'True' or 'False'.
- A link under congestion cannot be inhibited. If the link is the only one available for traffic, it cannot be inhibited.
- The Remotely inhibited flag indicates whether or not the link is remotely inhibited. Possible values are True' or 'False'.
- The Locally blocked flag indicates whether or not the link is locally blocked. Possible values are True' or 'False'.
- The Remotely blocked flag indicates whether or not the link is remotely blocked. Possible values are True' or 'False'.
- The Congested flag indicates whether or not the link is in congestion state. Possible values are True' or 'False'.
- The Emergency indication flag indicates we are in emergency condition. Possible values are True' or 'False'.
- The Retransmit queue size field gives the number of messages presents in link retransmit queue. Messages in retransmit queue are present only for a short duration until the buffer retrieval is completed during the changeover procedure.
- The Transmit queue size field gives the number of messages queued in the link transmit queue.
- The Congestion priority field. Allowable values: see Table 19 - MTP3 link prioritiesTable 23 - MTP3 link priorities.
- The current congestion status is updated based on the configured thresholds hit in the link transmit queue after queuing is initiated. For international networks and networks without multiple congestion states (where all Priority X Message Queue Lengths are the same), the CongestionPriority can take only two values: 'Priority 3' (link congested) or 'Priority 0' (no congestion).
Linkset states
General explanation of the linkset states parameters:
- The Active parameter indicates whether or not the linkset is active. Possible values are 'True' or 'False'.
- The Linkset status parameter indicates the current status of a MTP3 linkset. Possible values:
| Linkset state | Description |
|---|---|
| Active | A link set in active state can carry traffic |
| Inactive | A link set in inactive state cannot carry traffic |
NOTE: Link capability state for NTT (JAPAN). This field gives the number of active links in the link set. Possible values:
| Linkset state | Description |
|---|---|
| Abnormal | No links are active |
| Half-normal | Less than half links are active |
| Normal | More than half links are active |
| Full normal | All the links are active |
- The Transmit prohibit state flag is set to 'True' when a transfer prohibit message (TFP) is received from the network on this linkset for the point code represented by the route of the linkset. This flag is reset when a transfer allowed message (TFA) or a transfer restrict message (TFR) is received from the network. Possible values are 'True' or 'False'.
- The Transmit restricted state flag is set to 'True' when a TFR is received from the network on this linkset for the point code represented by the route of the linkset. This flag is reset when a TFA or TFP is received from the network. Possible values are 'True' or 'False'.
