# Configuring Egress Trunk

The Stir/Shaken in the egress trunk defines whether to sign a call or not when passing the calls to Egress trunk. 

![](https://4102392624-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MXPCJcszvw7MAuHjiRr%2Fuploads%2FW9EkqSXD6nmkSxQkHeFQ%2Fimage.png?alt=media\&token=acd8d421-acaa-49c7-b9c7-e4d49adb52d4)

| Verification Policy                   | Description                                                                                                                       |
| ------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------- |
| Disable Stir/Shaken                   | This option means the switch will ignore Stir/Shaken for this egress trunk.                                                       |
| Require Signature or Block Call       | This option means Class 4 will not send call to this egress trunk if it does not has an Identity header.                          |
| Require Valid Signature or Block Call | This option means Class 4 will not send call to this egress trunk if it does not has a valid Identity header.                     |
| Passthur or Sign Call if no signature | This options means Class 4 will attempt to sign calls according to the attestation defined in the ingress trunk to sign the call. |

## P-header setting

By default, Class 4 does not do anything to P-header.  Class 4 supports 2 different p-asserted identity header setting as shown her:

![](https://4102392624-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MXPCJcszvw7MAuHjiRr%2Fuploads%2FdeGCq4JuvZHNAJnZOkav%2Fimage.png?alt=media\&token=2dd321e4-6f7b-4f56-8674-5b8a58073346)