CLCOR Protocols And Endpoints Practice Question
You are monitoring RTP traffic using a protocol analyzer. You observe that the Payload Type field in the RTP header is set to 0. Which codec is currently in use?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
G.711 PCMU
In G.711 PCMU (u-law), the assigned payload type is 0 according to RFC 3551.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
G.729
Why it's wrong here
G.729 usually uses dynamic payload types (e.g., 18).
- ✗
Opus
Why it's wrong here
Opus uses dynamic payload types.
- ✓
G.711 PCMU
Why this is correct
Payload type 0 is reserved for G.711 u-law.
- ✗
G.711 PCMA
Why it's wrong here
G.711 A-law uses payload type 8.
About these practice questions
One of 263 original CLCOR practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official Cisco exam blueprint
This CLCOR practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CLCOR exam.