Table of Contents - E.371 (02/2026) - Deemed impermissible traffic

1	Scope
2	References
3	Definitions
	3.1	Terms defined elsewhere
	3.2	Terms defined in this Recommendation
4	Abbreviations and acronyms
5	Conventions
6	Types of deemed impermissible traffic
	6.1	Call refiling
	6.2	Call masking
	6.3	SIMbox
	6.4	OTT bypass
	6.5	Premium rate services deemed impermissible traffic
	6.6	Wangiri
	6.7	International call-back
	6.8	Sender ID spoofing
	6.9	Incoming international unknown CLI
	6.10	Flash calls
7	Use cases
8	Impacts of deemed impermissible traffic
	8.1	Impact on operators
	8.2	Impact on quality of service (QoS)
	8.3	Impact on Member States
	8.4	Impact on users
9	Guidelines for stakeholders on mitigating the negative impact of deemed impermissible traffic
	9.1	Operators
	9.2	Member States
	9.3	Users
Annex A  Suggested guidelines for mitigating the negative impact for some deemed impermissible traffic
	A.1	Call masking and refiling
	A.2	OTT bypass
	A.3	PRS deemed impermissible traffic
	A.4	Wangiri
	A.5	Sender ID spoofing
	A.6	Incoming international unknown CLI
Bibliography