janus: Tailscale has 1280 MTU actually (#326)

This commit is contained in:
Sergey Radionov
2026-03-10 20:28:13 +07:00
committed by GitHub
parent 88460b72e1
commit fa15d9693f

View File

@@ -27,13 +27,13 @@
// Max RTP size for WebRTC is 1200 bytes: // Max RTP size for WebRTC is 1200 bytes:
// - https://stackoverflow.com/questions/47635545/why-webrtc-chose-rtp-max-packet-size-to-1200-bytes // - https://stackoverflow.com/questions/47635545/why-webrtc-chose-rtp-max-packet-size-to-1200-bytes
// But(!) Tailscale has 1200 MTU. So to fit it required to substract: // But(!) Tailscale has 1280 MTU. So to fit it required to subtract:
// 1. possible RTP extensions (see sdp.c) // 1. possible RTP extensions (see sdp.c)
// 2. additional SRTP fields (>= 10 bytes) // 2. additional SRTP fields (>= 10 bytes)
// 3. UDP header (8 bytes) // 3. UDP header (8 bytes)
// 4. IPv6 header (40 bytes) // 4. IPv6 header (40 bytes)
// Finally it looks like 100 bytes for all above should be enough // Finally it looks like below value should be good enought for all cases
#define US_RTP_TOTAL_SIZE (1200 - 100) #define US_RTP_TOTAL_SIZE 1150
#define US_RTP_HEADER_SIZE 12 #define US_RTP_HEADER_SIZE 12
#define US_RTP_PAYLOAD_SIZE (US_RTP_TOTAL_SIZE - US_RTP_HEADER_SIZE) #define US_RTP_PAYLOAD_SIZE (US_RTP_TOTAL_SIZE - US_RTP_HEADER_SIZE)