TCP (Transmission Control Protocol)

The Transmission Control Protocol, defined in RFC 9293, is the connection-oriented transport that provides reliable, ordered, byte-stream delivery on top of IP. It implements the three-way handshake, sliding-window flow control, congestion control, and retransmission. Most internet traffic, HTTP, TLS, SMTP, SSH, SS7-over-IP variants, Diameter, runs over TCP. Its long-lived connections make it the target of SYN floods and amplification attacks, mitigated by SYN cookies, rate limiting, and DDoS scrubbing.

Categories: Radio Access NetworkSignalingSecurity Controls

TCP in context

The radio access network is where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations and downgrade attacks; defenses rest on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

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 TCP in the wider telecom-security picture, review SIP, Lawful Interception, RTP, RADIUS, TDD and TLS: each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

Related topic hubs

  • Signaling Firewall Unified SS7/Diameter/GTP/SMS signaling firewall framework.
  • 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.
  • Diameter Attacks S6a IDR/PUR/CLR abuse, subscriber tracking, LTE signaling attacks.

More from the TelcoSec Glossary

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