Operational Expenses (OPEX)

Operational Expenses (OPEX) 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 Operational Expenses (OPEX) in the wider telecom-security picture, review CAPEX, Red Team Exercise, GTP-U Smuggling, Lateral Movement (Telecom), FS.20 and FS.21: each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

• CAPEX
• Red Team Exercise
• GTP-U Smuggling
• Lateral Movement (Telecom)
• FS.20
• FS.21
• I-CSCF
• FS.07

Related topic hubs

• Roaming Security IPX/GRX interconnect risk, home-routed vs local-breakout, SEPP.
• SS7 Security SS7/MAP/CAP/SCCP attacks and defenses across 2G/3G interconnect.
• Diameter Security 4G/LTE Diameter threats across IPX/roaming and DEA defenses.
• Signaling Firewall Unified SS7/Diameter/GTP/SMS signaling firewall framework.

More from the TelcoSec Glossary

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