如果 RTCPeerConnection.createOffer() 只说我的本地 ip,另一端如何理解我的外部 ip?

How does other end understand what is my external ip if RTCPeerConnection.createOffer() says only my local ip?

我愿意:

configuration = {
  iceServers: [
    {
      urls: [
        'stun:stun1.l.google.com:19302',
      ],
    },
  ],
  iceCandidatePoolSize: 10,
};

local_conn = new RTCPeerConnection(configuration);
local_offer = await local_conn.createOffer()
local_conn.setLocalDescription(local_offer)

console.log(local_conn)
{type: "offer", sdp: "v=0 ↵o=- 5782587598134818591 2 IN IP4 127.0.0.1 ↵s=- ↵t=0 0 ↵a=msid-semantic: WMS ↵"}

IN IP4 127.0.0.1 为什么是 127.0.0.1,而不是像 151.101.1.69 这样的外部 IP?

ICE 候选人包括 IP 地址信息。