# Check SMPP SMSC trunk connection status

Check whether DIDWW is bound to your SMSC with an SMPP SMSC trunk. In an SMPP
SMSC trunk, DIDWW connects and binds to your SMSC as an ESME. The status shows
each session that DIDWW opens to your SMSC. Checking it does not reconnect the
trunk.

## Before you begin

- An active DIDWW account is required. [Sign in to DIDWW](https://my.didww.com/users/sign_in).
- An SMPP SMSC trunk is required. If you do not have one, see [Create an
  SMPP SMSC trunk](create-smpp-smsc-trunk.html).
- Your SMSC must accept the bind requests from DIDWW. See [Accept SMPP
  SMSC bind requests](accept-smpp-smsc-bind-requests.html).

## Step 1: Open the status window

1. In the DIDWW User Panel, go to **SMS > SMS Trunks**.
2. Locate the SMPP SMSC trunk and click the **Actions** button next to it.
3. Select **Check Status**.

[![Actions menu of an SMPP SMSC trunk on the SMS Trunks page with Check Status highlighted](../../../../_images/fig434.png)](../../../../_images/fig434.png)


**Fig. 1.** Open the status window

## Step 2: Review the connection status

The **Status Information** window shows one entry for each session that DIDWW
opens to your SMSC. When **Transceiver mode** is off, it shows a transmitter
session (**Type** `TX`) and a receiver session (**Type** `RX`). When
**Transceiver mode** is on, it shows one transceiver session (**Type**
`TRX`).

| Field | Description |
| --- | --- |
| Status | While DIDWW is bound, the bind type, for example `BIND_TRX` for a transceiver bind. While DIDWW cannot connect or bind to your SMSC, `CONNECTING`. |
| Sent, Received, Pending | Message counters for the session. |
| Type | Session type: `TX` (transmitter), `RX` (receiver), or `TRX` (transceiver). |
| System ID | System ID that DIDWW binds with, as entered in the trunk. |
| Connected | Date and time when the current bind was established. Shown while DIDWW is bound. |
| Online | How long the current bind has been active. Shown while DIDWW is bound. |
| Connection | IP addresses and ports of the DIDWW SMPP server and your SMSC. |
| Last Error | Reason for the last failed connection attempt, for example `Connection timed out`. Shown while DIDWW cannot connect or bind. |

[![Status Information window of an SMPP SMSC trunk showing Status BIND_TRX, Sent, Received, Pending, Type TRX, System ID, Connected, Online, and Connection](../../../../_images/status_information1.webp)](../../../../_images/status_information1.webp)


**Fig. 2.** Review the connection status

## Next steps

- If **Status** shows `CONNECTING`, check the **Last Error**, the trunk's
  connection details and credentials, and your firewall. See [Accept SMPP
  SMSC bind requests](accept-smpp-smsc-bind-requests.html).
- To receive SMS, [assign the trunk](../../../../phone-numbers/my-numbers/how-to-guides/assign-sms-trunk.html#assigning-sms-trunk) to one or more
  DIDs that support inbound SMS.

## Related resources

- [Accept SMPP SMSC bind requests](accept-smpp-smsc-bind-requests.html) -
  Prepare your SMSC and firewall for the bind from DIDWW.
- [Manage SMPP SMSC trunks](manage-smpp-smsc-trunk.html) - Edit the
  connection settings and credentials of the trunk.
- [Server locations and IP addresses](../../technical-data/smpp-specification.html#smpp-endpoints) - Look up the IP
  address of each DIDWW SMPP server location.
- [Inbound SMS logs](../../../../logs-analytics/sms-logs/inbound-logs.html#inbound-logs) - Review inbound SMS delivered
  through your SMS trunks.
- [Outbound SMS logs](../../../../logs-analytics/sms-logs/outbound-logs.html#outbound-logs) - Review outbound SMS sent from
  your account.
- [SMPP SMSC trunk](../smpp-smsc-trunk.html) - Understand how DIDWW connects
  and binds to your SMSC.