Source note · ITU-T Q.850 call clearing cause values
Cause 18 no user responding is used when the called party does not respond to call establishment within the allotted time, while cause 19 no answer from user is used when the called party was alerted and did not answer, so the pair separates a device that never signalled from a device that rang.
Checked 2026-09-15
This cause is used when the called party has been alerted but does not respond with a connect indication within a prescribed period of time.
- Vendor
- ITU-T
- Product
- ITU-T Recommendation Q.850
- Subsystem
- Cause and location
- Deployment
- not restricted
- Region
- not restricted
- Release range
- edition 10/2018
- Checked
- 2026-09-15
Sources
- ITU-T Recommendation Q.850 (10/2018), Usage of cause and location in the Digital Subscriber Signalling System No. 1 and the Signalling System No. 7 ISDN user part — International Telecommunication Union (ITU-T) · tier 1 standards and regulators · clauses 6.2.7.1.13 and 6.2.7.1.14
Cite this note
APA
WarmTransfer. (2026, September 15). ITU-T Q.850 call clearing cause values: source note q850-cause-19-differs-from-18-by-alerting. WarmTransfer. https://warmtransfer.net/knowledge/claims/q850-cause-19-differs-from-18-by-alerting
BibTeX
@misc{warmtransfer-claim-q850-cause-19-differs-from-18-by-alerting,
title = {ITU-T Q.850 call clearing cause values: source note q850-cause-19-differs-from-18-by-alerting},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/q850-cause-19-differs-from-18-by-alerting},
note = {Source note q850-cause-19-differs-from-18-by-alerting, checked 2026-09-15}
}