Source note · Calls that drop after about 30 seconds
If the side that does not refresh receives no refresh, RFC 4028 says it SHOULD send a BYE slightly before the session expires. The recommended margin is the smaller of 32 seconds and one third of the session interval.
Checked 2026-09-25
The minimum of 32 seconds and one third of the session interval is RECOMMENDED.
- Vendor
- IETF
- Product
- SIP
- Subsystem
- session timers
- Deployment
- any
- Region
- not restricted
- Release range
- RFC 4028
- Checked
- 2026-09-25
Sources
- RFC 4028: Session Timers in the Session Initiation Protocol (SIP) — IETF / RFC Editor · tier 1 standards and regulators · Section 10 (UAS/UAC behaviour on session expiration)
Cite this note
APA
WarmTransfer. (2026, September 25). Calls that drop after about 30 seconds: source note sip-calls-drop-30-seconds-non-refresher-bye. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-calls-drop-30-seconds-non-refresher-bye
BibTeX
@misc{warmtransfer-claim-sip-calls-drop-30-seconds-non-refresher-bye,
title = {Calls that drop after about 30 seconds: source note sip-calls-drop-30-seconds-non-refresher-bye},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-calls-drop-30-seconds-non-refresher-bye},
note = {Source note sip-calls-drop-30-seconds-non-refresher-bye, checked 2026-09-25}
}