What works
- Calls from Five9 to your agent
- Transfers from your agent back to Five9
- Call data passed to Five9 in SIP headers
- DTMF (RFC 2833)
Prerequisites
- A Five9 contact center (VCC) account, and your Five9 account team
- A Bland account with SIP trunking enabled. If there is no SIP tab under Phone numbers, contact Bland support
- A Bland agent ready to answer, so the interop test exercises the real conversation
How the call flows
INVITE to Five9 over the same trunk and bridges the audio.
Signaling uses TLS on port 5061 and audio uses SRTP. Five9 recommends TLS, and Bland accepts TLS only.
Order and configure Five9
Order AI Agent Connect
Give Five9 the Bland connection details
- Endpoint: your Bland region, for example
us2.sip.bland.ai. The other regions are under Connection endpoints - Transport: TLS 1.2 or higher, port 5061
- Media: SRTP (
AES_CM_128_HMAC_SHA1_80), UDP 16384 to 32768 - Trusted peers: all six Bland IPs for your region, signaling and media
- Certificate: Let’s Encrypt. The ISRG Root X1 CA must be trusted
- Number format: E.164 or 10-digit. Bland accepts both
Route calls to Bland in Five9
Tell Bland which numbers to use
Configure Bland
Assign an agent
Add the transfer back to Five9
Pass call data to the Five9 agent
Test before go-live
Five9 requires a successful interop test before it allows go-live. Plan for:- Real test numbers, labeled for the Bland trunk on your Five9 domain. Five9 doesn’t accept Twilio numbers or Five9-owned numbers as test numbers
- Every call path. When Five9 assigns a primary and a secondary SBC, test through both
- The whole call: two-way audio, DTMF, hold, and a transfer back to a live Five9 agent
- A Five9 user logged in as an agent, so transfers back to Five9 have someone to land on
Common failures
Five9's SIP OPTIONS ping to Bland times out
Five9's SIP OPTIONS ping to Bland times out
Calls are rejected with 603 Decline
Calls are rejected with 603 Decline
Calls go to Five9 voicemail or stay inside Five9
Calls go to Five9 voicemail or stay inside Five9
Test calls go over the phone network instead of the trunk
Test calls go over the phone network instead of the trunk
Calls drop mid-call with 481 Call/Transaction Does Not Exist
Calls drop mid-call with 481 Call/Transaction Does Not Exist
The call connects with no audio
The call connects with no audio
The transfer back to Five9 fails or lands in the wrong queue
The transfer back to Five9 fails or lands in the wrong queue