### Answer ## Inbound Call Webhook The Inbound Call Webhook is configured at the phone number level, not the agent level. [(1) ]() To set it up: 1. Go to Phone Numbers in the dashboard 2. Click on the specific number you want to configure 3. Enable the Inbound Webhook option there [(2) ]() The webhook will

POST

to your endpoint when an inbound call is received, allowing you to override agent ID, set dynamic variables, and add metadata before the call connects. ## SIP Configuration For custom telephony/SIP integration: - Retell SIP server URI:

sip:sip.retellai.com

[(3) ]() - IP block for traffic:

18.98.16.120/30

(All regions) ,

143.223.88.0/21

(US only) ,

161.115.160.0/19

(US only) Transport methods supported: TCP (recommended) , UDP, TLS For inbound calls with different transports: - TCP:

sip:sip.retellai.com;transport=tcp

- UDP:

sip:sip.retellai.com;transport=udp

- TLS:

sip:sip.retellai.com;transport=tls

You can integrate via Elastic SIP Trunking (recommended) or Dial to SIP URI depending on your telephony provider setup.

​ To learn more, see the sources I considered: [[1] Inbound call webhook ui not visiable. I only see agent webhook,](https://discord.com/channels/1186424376300679209/1382092411009761310) [[2] Inbound webhook](https://docs.retellai.com/features/inbound-call-webhook) [[3] Custom Telephony Overview](https://docs.retellai.com/deploy/custom-telephony) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.