> ## Documentation Index > Fetch the complete documentation index at: https://docs.poly.ai/llms.txt > Use this file to discover all available pages before exploring further. # Get a SIP Trunk ## OpenAPI ````yaml GET /v1/accounts/{account_id}/telephony/sip-trunks/{trunk_id} openapi: 3.0.3 info: title: PolyAI SIP Trunking API version: 1.0.0 description: Management API for PolyAI SIP Trunks and their Extensions. servers: - url: https://api.us.poly.ai description: US region - url: https://api.eu.poly.ai description: EU region - url: https://api.uk.poly.ai description: UK region security: - polyApiKey: [] tags: - name: SIP Trunks description: >- A SIP Trunk is a virtual connection between your telephony platform and PolyAI. It authenticates callers, accepts inbound calls, and holds the list of Extensions that map a dialed number to a PolyAI agent. - name: SIP Trunk Extensions description: >- An Extension binds a dialed number on a trunk to a PolyAI agent. When a call reaches a trunk, the dialed user part is matched against that trunk's extensions to pick the agent. - name: Outbound Calls description: Place and query outbound calls that route over a SIP Trunk. paths: /v1/accounts/{account_id}/telephony/sip-trunks/{trunk_id}: parameters: - $ref: '#/components/parameters/account_id' - $ref: '#/components/parameters/trunk_id' get: tags: - SIP Trunks summary: Get a SIP Trunk operationId: getSipTrunk responses: '200': description: The SIP Trunk. content: application/json: schema: $ref: '#/components/schemas/SipTrunk' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' components: parameters: account_id: name: account_id in: path required: true description: ID of the account that owns the SIP Trunk. schema: type: string trunk_id: name: trunk_id in: path required: true description: The SIP Trunk ID. schema: type: string schemas: SipTrunk: type: object description: A SIP Trunk. properties: id: type: string description: PolyAI-generated SIP Trunk ID, e.g. `tr-0123456789abcdefghijklmn`. account_id: type: string description: The PolyAI account that owns the SIP Trunk. sip_cidr: type: array description: The IPv4 CIDR blocks of your SIP servers. items: type: string rtp_cidr: type: array description: The IPv4 CIDR blocks of your RTP / media servers. items: type: string name: type: string description: A friendly name to help identify your SIP Trunk. encrypted: type: boolean description: >- Whether this SIP Trunk will handle encrypted (true; SIP over TCP/TLS, media over UDP/SRTP) or unencrypted (false; SIP over UDP, media over UDP/RTP) calls. inbound: $ref: '#/components/schemas/SipTrunkInbound' outbound: $ref: '#/components/schemas/SipTrunkOutbound' created_at: type: string format: date-time description: RFC 3339 timestamp of when the SIP Trunk was created. updated_at: type: string format: date-time description: RFC 3339 timestamp of when the SIP Trunk was last updated. required: - id - account_id - sip_cidr - rtp_cidr - name - encrypted - inbound - created_at - updated_at SipTrunkInbound: type: object description: Configuration for inbound calls. properties: hostname: type: string description: Hostname that uniquely identifies this SIP Trunk. sip_auth: $ref: '#/components/schemas/SipAuth' sip_token_auth: $ref: '#/components/schemas/SipTokenAuth' default_route: $ref: '#/components/schemas/DefaultRoute' required: - hostname - sip_auth - sip_token_auth SipTrunkOutbound: type: object description: Configuration for outbound calls leaving PolyAI. properties: sip_addresses: type: array description: The SIP addresses of your SIP servers to send outbound calls to. example: - sip:my-sbc.example.com:5060 - sip:my-sbc.example.com:5061;transport=tls items: type: string default_caller_id: type: string description: Default caller ID to use on outbound calls. Error: type: object description: Error response body. properties: success: type: boolean error: type: string message: type: string required: - success - error - message SipAuth: type: object description: SIP digest auth state. properties: enabled: type: boolean description: Whether SIP digest auth is enabled for this SIP Trunk. username: type: string description: SIP digest auth username. Present when enabled. realm: type: string description: SIP digest auth realm. Present when enabled. required: - enabled SipTokenAuth: type: object description: SIP token auth state. properties: enabled: type: boolean description: Whether SIP token auth is enabled for this SIP Trunk. required: - enabled DefaultRoute: type: object description: >- The agent that receives inbound calls whose dialed number has no extension on the trunk. Omitted when the trunk has no default route, in which case such calls are rejected. properties: agent: $ref: '#/components/schemas/Agent' required: - agent Agent: type: object description: The PolyAI agent an extension routes calls to. properties: agent_id: type: string description: PolyAI Agent / Project ID to route to. client_env: type: string description: One of sandbox, pre-release, live. enum: - sandbox - pre-release - live variant_id: type: string description: Agent variant to route to. required: - agent_id - client_env - variant_id responses: Unauthorized: description: Missing or invalid credential. content: application/json: schema: $ref: '#/components/schemas/Error' Forbidden: description: Caller is not a telephony admin on the account. content: application/json: schema: $ref: '#/components/schemas/Error' NotFound: description: Resource not found. content: application/json: schema: $ref: '#/components/schemas/Error' securitySchemes: polyApiKey: type: apiKey in: header name: X-API-Key ````