SM (Session Manager)

In telecom contexts, SM most often refers to the Session Manager that handles the lifecycle of communication sessions in IMS or in a 5G PDU session managed by the SMF. The same acronym is also used for Short Message in SMS specifications (e.g. MAP MO-ForwardSM) and should be disambiguated by surrounding context.

Categories: Core NetworkSignalingProtocols and Standards

SM in context

The mobile core carries subscriber sessions, mobility and policy. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF.

Signaling protocols carry the control-plane messages that set up calls, register subscribers and route SMS. SS7, Diameter, GTP-C and SIP are the four dominant families, and interconnect exposure of any of them is treated by GSMA as top-tier telecom risk.

To place SM in the wider telecom-security picture, review Conformance Testing, ZIP, NDR, 5G SA, 5G SBA and ACL — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.