Source note · SIP trunk capacity and concurrent call planning
In SIP, 486 Busy Here means the callee is busy and cannot take the call now, but the caller may try again later.
Checked 2026-09-24
The callee is busy and cannot take the call at this time, but the caller may try again later.
- Vendor
- IETF
- Product
- SIP
- Subsystem
- response codes
- Deployment
- standard
- Region
- not restricted
- Release range
- RFC 3261
- Checked
- 2026-09-24
Sources
- RFC 3261 — SIP: Session Initiation Protocol — IETF / RFC Editor · tier 1 standards and regulators · Section 21.4.24 '486 Busy Here'
Cite this note
APA
WarmTransfer. (2026, September 24). SIP trunk capacity and concurrent call planning: source note sip-trunk-capacity-planning-rfc3261-486-busy. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-trunk-capacity-planning-rfc3261-486-busy
BibTeX
@misc{warmtransfer-claim-sip-trunk-capacity-planning-rfc3261-486-busy,
title = {SIP trunk capacity and concurrent call planning: source note sip-trunk-capacity-planning-rfc3261-486-busy},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-trunk-capacity-planning-rfc3261-486-busy},
note = {Source note sip-trunk-capacity-planning-rfc3261-486-busy, checked 2026-09-24}
}