--- title: Connect Exotel SIP trunking with Vocallabs (Superflow B2B API)(Alpha) slug: exotel-agentstream/connect-exotel-sip-trunking-with-vocallabs-superflow-b2b-apialpha createdAt: 2026-04-01T16:44:16.969Z --- This guide links **Exotel SIP trunking** and your **Exotel DID** to **Vocallabs**. Vocallabs publishes a **B2B REST API** on **https\://api.superflow\.run/b2b/** — including **createSIPCall** with did, phone\_number, websocket\_url, and webhook\_url — not the same **dashboard BYO SIP trunk** pattern as Vapi or ElevenLabs. Use this article for **API + telephony alignment**; confirm **inbound SIP URIs** and **static egress IPs** with Vocallabs if you need classic trunk **destination-uris** / **whitelisted-ips**. **GitHub repo (reference):** https\://github.com/exotel/AgentStream-VoiceAIEcosystem :::BlockQuote **Applicability:** **API-driven** (token + createSIPCall / websockets / webhooks). SIP trunk routing is optional and only applies if Vocallabs provides a stable SIP target. ::: :::BlockQuote **Docs:** Vocallabs API documentation (hosted API reference and samples). ::: :::BlockQuote **Engineering detail:** vocallabs/integrations/exotel-vsip/vocallabs-exotel-voice-ai-connector.md ::: :::BlockQuote **Quickstart:** vocallabs/integrations/exotel-vsip/QUICKSTART.md ::: ## Vocallabs API (from official docs) | Topic | Detail | | -------------------- | ---------------------------------------------------------------------------------------------------- | | Base | https\://api.superflow\.run/b2b/ | | Auth | POST …/createAuthToken/ — JSON clientId, clientSecret → **Bearer** token for subsequent calls (docs) | | SIP call | POST …/vocallabs/createSIPCall — phone\_number, did, websocket\_url, webhook\_url, sample\_rate | | Outbound-style calls | POST …/vocallabs/initiateVocallabsCall — agentId, prospect\_id | | Webhook dial | POST …/vocallabs/initiateCallWebhook — from (DID), number (destination) | | Websocket URL | GET …/vocallabs/getWebsocketUrl — query agent\_id, prospect\_id | **Wallet / usage:** GET …/getGreenBalance, transaction history — see Vocallabs docs for billing context. ## How this maps to Exotel | Concept | Exotel side | Vocallabs side | | --------------------- | ------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **DID** | Exophone on SIP trunk (snippets) | Use the same E.164 as **did** (or from in webhook flows) where the API expects your caller / rented number | | **PSTN termination** | Exotel edge **IP\:port** + digest (POST …/credentials) | **Not** fully specified in the public reference as a single “SIP gateway hostname” like other providers — **coordinate with Vocallabs** for SIP leg details if createSIPCall is meant to drive traffic to Exotel | | **Inbound PSTN → AI** | Trunk **destination-uris** + Flow **Connect** **sip:\** | Requires a **SIP origination target** from Vocallabs. If their team only documents **REST + websocket**, implement that path first; add **destination-uris** when they provide a stable SIP URI | ## Part A — Vocallabs (auth + SIP call) ### 1. Create token :::BlockQuote curl -s -X POST 'https\://api.superflow\.run/b2b/createAuthToken/' \\ -H 'Content-Type: application/json' \\ -d '\{"clientId":"CLIENT\_ID","clientSecret":"CLIENT\_SECRET"}' ::: Use the returned token as **Authorization: Bearer \**. ### 2. Create SIP call (example shape) Per [Vocallabs API docs](https://docs.vocallabs.ai/vocallabs): :::BlockQuote curl -s -X POST 'https\://api.superflow\.run/b2b/vocallabs/createSIPCall' \\ -H 'Content-Type: application/json' \\ -H 'Authorization: Bearer AUTH\_TOKEN' \\ -d '\{ "phone\_number": "+91XXXXXXXXXX", "did": "+91YYYYYYYYYY", "websocket\_url": "wss\://your-bridge.example.com/media", "webhook\_url": "https\://your-app.example.com/vocallabs/webhook", "sample\_rate": "16000" }' ::: Replace **did** with your **Exotel number** in E.164 when that number is the identity Vocallabs should use for the session. **websocket\_url** / **webhook\_url** must be **your** endpoints as required by Vocallabs — see their latest field definitions. ### 3. Other flows - **initiateVocallabsCall** — agent + prospect (docs). - **initiateCallWebhook** — from / number for click-to-call style flows. - **getWebsocketUrl** — retrieve media URL for agent\_id + prospect\_id. ## Part B — Exotel (SIP trunk + DID) When you use Exotel as the **Indian PSTN carrier** for the same DID you pass to Vocallabs: 1. **Create trunk** → **map DID** → **POST …/credentials** (if your design uses SIP digest toward Exotel). 2. Templates: \_exotel-trunk-api-snippets.md. 3. **Optional:** POST …/whitelisted-ips **only** if Vocallabs publishes **fixed static egress IPs** (mask: 32 per IP). 4. **Inbound** (only if Vocallabs gives you a **SIP URI** to send calls to): POST …/destination-uris toward that URI → **Flow → Connect** → **sip:\** ([Detailed SIP Trunking API Reference](docId:2OdDTEDmmf64scwjhGVkT). ## Troubleshooting | Symptom | What to check | | ---------------------- | ---------------------------------------------------------------------------------------------- | | **401** on Superflow | Valid **createAuthToken** + **Bearer** header | | Call fails / wrong CLI | **did** / **from** match **E.164** Exotel number you own | | No media | **websocket\_url**, **getWebsocketUrl**, firewall to Vocallabs / your bridge | | SIP vs API mismatch | Vocallabs may be **API-first** — confirm with their team before assuming full SIP trunk parity | ## References | Resource | URL | | ------------------------- | --------------------------------------------------------------------------------- | | Vocallabs API docs | https\://docs.vocallabs.ai/vocallabs | | Exotel SIP API | https\://docs.exotel.com/dynamic-sip-trunking/detailed-sip-trunking-api-reference | | Exotel network / firewall | https\://docs.exotel.com/dynamic-sip-trunking/network-and-firewall-configuration |