Trunks

Navigation: Admin → Telephony → Trunks (or Admin → Telephony → BYOC Cloud → Trunks)
 Last verified: Genesys Cloud Resource Center — March 2026 
 
 What Are Trunks? 
 A trunk is the SIP communications link between Genesys Cloud and an external carrier or PBX. Trunks carry inbound and outbound SIP signaling and are consumed by Sites via Outbound Routes to send calls to the PSTN or connected telephony infrastructure. 
 
 Trunk Types 
 
 
 
 Trunk Type 
 Deployment Model 
 Used For 
 
 
 
 
 BYOC Carrier 
 BYOC Cloud 
 Third-party SIP carrier connectivity over the public internet 
 
 
 BYOC PBX 
 BYOC Cloud 
 SIP interconnect with an existing IP-PBX over the public internet 
 
 
 External SIP 
 BYOC Premises 
 On-premises SIP carrier or PBX connectivity through an Edge 
 
 
 
 
 ℹ️ BYOC Carrier and BYOC PBX are for BYOC Cloud. External SIP is for BYOC Premises. Do not mix deployment models. 
 
 
 Navigation 
 
 
 
 Task 
 Path 
 
 
 
 
 Open trunks 
 Admin → Telephony → Trunks 
 
 
 Open BYOC Cloud trunks 
 Admin → Telephony → BYOC Cloud → Trunks 
 
 
 Create a trunk 
 Trunks → Create Trunk 
 
 
 Edit a trunk 
 Trunks → select trunk → Edit 
 
 
 Use trunk in routing 
 Admin → Telephony → Sites → [Site] → Outbound Routes 
 
 
 
 
 Creating a BYOC Carrier Trunk — Field Reference 
 
 
 
 Field 
 Description 
 Notes 
 
 
 
 
 Name 
 Trunk name 
 Use a descriptive, consistent naming convention 
 
 
 Type 
 BYOC Carrier / BYOC PBX / External SIP 
 Determined by your deployment model 
 
 
 Subtype 
 Vendor/carrier profile where applicable 
 Optional 
 
 
 State 
 Operational state 
 Set to In Service when ready for production 
 
 
 Transport Protocol 
 SIP transport used to send calls 
 UDP / TCP / TLS — does not control inbound protocol 
 
 
 Inbound SIP Termination Identifier 
 Regionally unique ID for inbound SIP routing 
 Required for BYOC Carrier; confirm with carrier 
 
 
 Outbound Request URI 
 Controls SIP request routing for outbound calls 
 Carrier-specific 
 
 
 SIP Servers / Proxies 
 Remote SIP server or proxy addresses 
 Carrier-provided 
 
 
 Digest Authentication 
 SIP authentication 
 Enable if required by the carrier or PBX 
 
 
 Caller Address / Caller ID 
 Outbound caller number 
 E.164 format 
 
 
 Caller Name 
 Outbound caller name 
 Text 
 
 
 SIP Access Control 
 IP allowlist for inbound SIP signaling 
 Restrict to carrier signaling IPs only 
 
 
 PBX Passthrough 
 Enables PBX passthrough where supported 
 Optional 
 
 
 Custom SIP Headers 
 Additional SIP header configuration 
 Optional 
 
 
 
 
 Transport Protocol Behaviour 
 
 
 
 Protocol 
 Notes 
 
 
 
 
 UDP 
 Standard, connectionless — widely supported 
 
 
 TCP 
 Connection-oriented, more reliable for SIP 
 
 
 TLS 
 Encrypted SIP signaling; pairs with SRTP for full call security 
 
 
 
 
 ⚠️ For BYOC Cloud, the transport protocol setting controls how Genesys sends calls on the trunk. It is not enforced on calls received on that trunk. 
 
 
 Step-by-Step: Create a BYOC Carrier Trunk 
 
 
 
 Step 
 Action 
 
 
 
 
 Step 1 
 Navigate to Admin → Telephony → BYOC Cloud → Trunks 
 
 
 Step 2 
 Click Create Trunk 
 
 
 Step 3 
 Select BYOC Carrier as the trunk type 
 
 
 Step 4 
 Enter the trunk Name 
 
 
 Step 5 
 Set State to In Service 
 
 
 Step 6 
 Select Transport Protocol 
 
 
 Step 7 
 Enter the Inbound SIP Termination Identifier 
 
 
 Step 8 
 Configure Outbound Request URI 
 
 
 Step 9 
 Enter SIP Servers / Proxies 
 
 
 Step 10 
 Enable Digest Authentication if required 
 
 
 Step 11 
 Under Calling, set Caller ID and Caller Name 
 
 
 Step 12 
 Configure SIP Access Control IP rules 
 
 
 Step 13 
 Save the trunk 
 
 
 Step 14 
 Add the trunk to a Site → Outbound Route 
 
 
 Step 15 
 Validate with test calls or Simulate Call 
 
 
 
 
 Dependencies 
 
 
 
 Component 
 Purpose 
 
 
 
 
 Sites 
 Outbound routes on sites reference external trunks 
 
 
 Number Plans 
 Classify dialed numbers before route/trunk selection 
 
 
 Outbound Routes 
 Select one or more trunks with Sequential or Random distribution 
 
 
 Carrier / PBX 
 Remote SIP endpoint the trunk connects to 
 
 
 Certificate Authorities 
 Required when using TLS trunks (BYOC Premises) 
 
 
 
 
 Troubleshooting 
 
 
 
 Issue 
 Cause 
 Resolution 
 
 
 
 
 Trunk not sending calls 
 Wrong transport protocol or routing config 
 Recheck protocol, URI, and remote endpoint requirements 
 
 
 Inbound calls fail 
 Incorrect inbound SIP identifier 
 Validate inbound SIP termination identifier with carrier 
 
 
 Secure calls fail 
 TLS/certificate mismatch 
 Validate TLS support and certificate/trust configuration 
 
 
 Unauthorized SIP traffic 
 SIP ACL not configured 
 Restrict signaling IPs using SIP Access Control 
 
 
 Wrong outbound identity 
 Caller ID/name misconfigured 
 Recheck Calling section values 
 
 
 Route not selecting trunk 
 Number plan or outbound route misconfiguration 
 Validate number plans, route classification, trunk selection 
 
 
 
 
 Quick Reference 
 
 
 
 Question 
 Answer 
 
 
 
 
 What trunk types exist? 
 BYOC Carrier, BYOC PBX, External SIP 
 
 
 Which are for BYOC Cloud? 
 BYOC Carrier and BYOC PBX 
 
 
 Which is for BYOC Premises? 
 External SIP 
 
 
 What transport protocols are supported? 
 UDP, TCP, TLS 
 
 
 What does SIP Access Control do? 
 Permits signaling only from specific IP addresses 
 
 
 What is the Inbound SIP Termination Identifier? 
 A regionally unique ID used for inbound SIP routing on BYOC Carrier 
 
 
 
 
 Naming Convention 
 
 
 
 Resource 
 Example 
 
 
 
 
 Carrier trunk 
 CarrierA_BYOCCarrier_Prod 
 
 
 PBX trunk 
 CorpPBX_BYOCPBX_Test 
 
 
 Premises SIP trunk 
 HQ_ExternalSIP_Primary 
 
 
 
 Pattern: <Provider>_<TrunkType>_<Environment> 
 
 See Also 
 
 Sites — outbound routes are configured here and reference trunks 
 Certificate Authorities — required for TLS trunk trust (BYOC Premises) 
 Edges & Edge Groups — BYOC Premises trunks attach to Edges 
 Architectural Build Order — trunks are built in Phase 2 
 
 
 Screenshots