What transport is used for RTP in VoLTE?

Interview
1

Q. What transport is used for RTP in VoLTE?

a) SCTP
b) TCP
c) ICMP
d) UDP

Check 🔎

:arrow_right: Correct answer: Letter d.

In a VoLTE call, RTP (Real-time Transport Protocol) carries the actual voice media over the LTE network. Because voice is real-time and cannot tolerate retransmission delays, RTP is transported over UDP, which is a connectionless, low-latency protocol best suited for real-time applications.

Unlike TCP, UDP does not require a handshake or retransmissions, avoiding delays that would degrade voice quality.

Q. What transport is used for RTP in VoLTE?

a) :x: SCTP
→ Incorrect. SCTP is used for signaling transport between MME and eNodeB (S1-MME interface), not for RTP media.

b) :x: TCP
→ Incorrect. TCP is too heavy and retransmission-oriented, making it unsuitable for real-time voice traffic.

c) :x: ICMP
→ Incorrect. ICMP is used for network diagnostic messages (like ping/echo), not media transport.

d) :white_check_mark: UDP
→ Correct. UDP is the standard transport for RTP media streams in VoLTE because it is lightweight and minimizes latency.