In WebRTC, what is the role of a signaling server?
WebRTC media flows peer-to-peer, but the two peers first need to discover and agree on how to connect. The signaling server is the out-of-band channel (often WebSocket) that relays this setup metadata: the SDP offer and answer describing media capabilities, plus ICE candidates describing network paths. Crucially, WebRTC does not specify the signaling protocol — you build it. Once signaling completes the handshake, media flows directly between peers and the signaling server is no longer in the media path.
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What is the difference between a STUN server and a TURN server?
Both address NAT traversal. STUN (Session Traversal Utilities for NAT) lets a peer find out its public-facing IP and port so it can advertise a reachable address — cheap and enables a direct peer-to-peer path in most cases. But some restrictive NATs/firewalls block direct connections entirely. TURN (Traversal Using Relays around NAT) is the fallback: it relays media through a server, guaranteeing connectivity at the cost of bandwidth and latency. ICE tries the cheapest option first (direct/STUN) and falls back to TURN only when necessary.
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What is the ICE framework in WebRTC?
ICE (Interactive Connectivity Establishment) is the process of finding a working network path between peers that may be behind NATs and firewalls. Each peer gathers candidates — possible addresses: its local IP (host candidate), its public IP via STUN (server-reflexive), and a relay address via TURN. The peers exchange candidates through signaling, then systematically test pairs to find the best connectable path, preferring direct routes over relayed ones. This negotiation is why WebRTC can connect peers in difficult network conditions where a naive direct connection would fail.
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In the WebRTC handshake, what are the SDP offer and SDP answer?
SDP (Session Description Protocol) messages negotiate the session. The initiating peer creates an offer — codecs it supports, media tracks, encryption parameters, network info — and sends it via signaling. The remote peer responds with an answer selecting compatible options. This offer/answer exchange establishes the agreed media format and parameters before media flows. SDP is a text format; manipulating it directly ("SDP munging") is sometimes done to force codec choices, though it is fragile and discouraged in favor of the proper API.
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Why is WebRTC media described as peer-to-peer, and what is the implication for scaling group calls?
In a 1:1 call, direct peer-to-peer media is ideal: low latency, no server media cost. But in a group call, a full mesh means each participant sends their stream to every other participant — uplink bandwidth and CPU grow with the number of peers (an N-squared problem) and quickly become infeasible. The standard solution is an SFU (Selective Forwarding Unit): each peer sends one upstream to the SFU, which selectively forwards streams to others. This trades pure peer-to-peer for scalability and is how most production video platforms handle multi-party calls.
What does the "WebRTC Signaling" vocabulary exercise cover?
This exercise tests real IT vocabulary related to webrtc signaling through 5 multiple-choice questions, each built from realistic workplace sentences rather than abstract definitions.
Is this vocabulary exercise free to use?
Yes. Every exercise on CoderSlingo, including this one, is completely free — no account, sign-up, or payment required.
How many questions does this exercise have?
This exercise has 5 questions. Each one shows a real-world sentence or scenario with multiple-choice options and an explanation once you answer.
What happens after I answer a question?
You'll see immediate feedback showing whether your answer was correct, along with a short explanation of why — then a button to move to the next question, and a full results screen at the end.
Can I retry the exercise if I get questions wrong?
Yes. Once you reach the results screen, click "Try again" to reset your answers and go through the exercise from the start as many times as you like.
Do I need to create an account to take this exercise?
No account is needed. Your answers are scored in your browser during the session — nothing is saved to a server, so you can jump straight in.
Is my progress saved if I leave the page?
No — progress within an exercise resets if you navigate away or reload. Each exercise is short enough to complete in a few minutes in one sitting.
Are these vocabulary exercises connected to other topics?
Yes — browse the full vocabulary exercises hub to find related modules covering adjacent IT topics and roles.
How is this different from reading a glossary or blog article?
Exercises like this one are active recall drills — you have to choose the correct term or phrasing yourself, which builds retention faster than passively reading a definition.
Where can I find more vocabulary exercises?
Browse the full Vocabulary exercises hub for hundreds of modules covering Agile, DevOps, security, databases, architecture, and more — organised by IT role and skill.