![](/images/new-backgrounds/1174427/17442721x1.webp)
Caller ID on Cisco 2600 and 3600 Series Routers and Cisco MC3810 Multiservice Concentrators
Caller ID Configuration Task List
| Command | Purpose |
Step 4 |
|
|
(FXO ports, only when | ||
| ||
|
| on the FXO port when the incoming subscriber |
|
| telephone line uses line polarity reversal to signal |
|
| the start of |
|
| The Cisco FXO interface cannot detect |
|
| |
|
| reason, DSPs must be |
|
| Type 1 caller ID information when it arrives. |
|
| Preallocating the DSPs enables the DSP to |
|
| continuously monitor for the arrival of |
|
| information. |
Step 5 |
|
|
(FXS ports only) Configure this setting only when | ||
|
| the attached telephone device requires the |
|
| (immediate ring) method to signal the start of a |
|
| caller ID information. The command activates a |
|
| |
|
|
|
Cisco IOS Voice, Video, and Fax Configuration Guide