The Sinch Elastic SIP Trunking product hunts through endpoints in order of priority whenever the customer’s infrastructure rejects, or fails to respond to, a SIP Invite request.
4XX: By default, we will not hunt on 4XX errors except for the following codes:
|
Code
|
Reason
|
Default behavior
|
|
403
|
Forbidden
|
Hunt
|
|
404
|
Not Found
|
Hunt
|
|
408
|
Request Timeout
|
Hunt
|
|
415
|
Unsupported Media Type
|
Hunt
|
|
420
|
Bad Extension
|
Hunt
|
|
421
|
Extension Required
|
Hunt
|
|
422
|
Session Interval Too Small
|
Hunt
|
|
423
|
Interval Too Brief
|
Hunt
|
|
436
|
Bad Identity Info
|
Hunt
|
|
437
|
Unsupported Certificate
|
Hunt
|
|
438
|
Invalid Identity Header
|
Hunt
|
|
480
|
Temporarily Unavailable
|
Hunt
|
|
48
|
Request Terminated
|
Hunt
|
|
488
|
Not Acceptable Here
|
Hunt
|
|
491
|
Request Pending
|
Hunt
|
|
493
|
Undecipherable
|
Hunt
|
5XX: We will always continue hunting on a 5XX error
|
Code
|
Reason
|
Default behavior
|
|
500
|
· Internal Server Error
|
Hunt
|
|
503
|
· Service Unavailable
|
Hunt
|
|
504
|
· Server Timeout
|
Hunt
|
6XX: We will not continue hunting after receiving a 6XX error
