![](/images/new-backgrounds/1237012/23701299x1.webp)
2.2Making Calls
2.2.7Integrated Services Digital Network (ISDN) Service Access
You can reach the ISDN Key Pad Protocol Service from your extension. The service depends on the contract with your telephone company.
If your telephone has an ISDN SERVICE button.
DPT
(CO)
OR
9
OR
| 8 | 1 | (ISDN SERVICE) |
|
| to |
|
| 8 | 3 |
|
Seize an external line | Press “ISDN SERVICE” button. | ||
| (CO, 9 or |
|
If your telephone does not have an ISDN SERVICE button.
DPT
(CO)
OR
9
|
| OR | FWD/DND | ISDN Service no. | FWD/DND |
| 8 | 1 |
| ||
|
|
|
| ||
|
| to |
|
|
|
| 8 | 3 |
|
|
|
Seize an external line | Press FWD/DND | Enter ISDN Service | Press FWD/DND | ||
| (CO, 9 or | button. | number (max. 32 digits). | button. |
DPT/SLT
| 7 2 9 | ISDN Port no. | ISDN Service no. |
|
Dial 729 . | Enter ISDN Port | Enter ISDN Service | Wait for | |
|
| number (1, 2 or 3). | number (max. 32 digits). | 5 seconds. |
• At the end of the procedure, a voice prompt tells you that the acceptance of the service is completed depending on each Integrated Digital Services Network.
50 | Operation |