IPv4 stands for Internet Protocol version 4.
IPv4 uses 32-bit addresses (e.g., 192.168.1.1), providing approximately 4.3 billion unique addresses. The exhaustion of IPv4 addresses is one reason NAT exists - multiple devices share a single public IPv4 address.
IPv4 and WebRTC
IPv4 is still the primary protocol for most WebRTC connections. The entire ICE / STUN / TURN infrastructure was largely designed around IPv4's NAT challenges.
Key WebRTC considerations with IPv4:
- NAT traversal: Most IPv4 devices are behind NATs, requiring ICE to establish connectivity
- Address privacy: Local IPv4 addresses from ICE candidates can reveal network information; mDNS addresses help mitigate this
- Dual-stack: Many networks support both IPv4 and IPv6, with ICE gathering candidates for both
As the internet transitions to IPv6, some mobile carriers use IPv6-only networks with DNS64/NAT64 for IPv4 backward compatibility, which can create WebRTC connectivity challenges.
