Fix: Deprecate TCPMSS (#336)

* 修改 DefaultTCPMSS 为 MaxDatagramSize
修改 MaxDatagramSize 的值提高 TUIC 的上传速度
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Larvan2 2023-01-12 00:53:42 +08:00 committed by GitHub
parent be6142aa43
commit 95247154d6
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GPG key ID: 4AEE18F83AFDEB23
2 changed files with 42 additions and 20 deletions

View file

@ -12,12 +12,14 @@ import (
"github.com/metacubex/quic-go/congestion"
)
const DefaultTCPMSS congestion.ByteCount = 1460
const DefaultBBRMaxCongestionWindow congestion.ByteCount = 2000 * DefaultTCPMSS
const InitialCongestionWindow congestion.ByteCount = 32 * DefaultTCPMSS
const MinInitialPacketSize = 1200
const InitialPacketSizeIPv4 = 1252
const InitialPacketSizeIPv6 = 1232
const (
MaxDatagramSize = 1252
DefaultBBRMaxCongestionWindow congestion.ByteCount = 2000 * MaxDatagramSize
InitialCongestionWindow congestion.ByteCount = 10 * MaxDatagramSize
MinInitialPacketSize = 1200
InitialPacketSizeIPv4 = 1252
InitialPacketSizeIPv6 = 1232
)
func GetMaxPacketSize(addr net.Addr) congestion.ByteCount {
maxSize := congestion.ByteCount(MinInitialPacketSize)
@ -33,17 +35,32 @@ func GetMaxPacketSize(addr net.Addr) congestion.ByteCount {
return maxSize
}
func GetMaxOutgoingPacketSize(addr net.Addr) congestion.ByteCount {
maxSize := congestion.ByteCount(MinInitialPacketSize)
// If this is not a UDP address, we don't know anything about the MTU.
// Use the minimum size of an Initial packet as the max packet size.
if udpAddr, ok := addr.(*net.UDPAddr); ok {
if udpAddr.IP.To4() != nil {
//The maximum packet size of any QUIC packet over IPv4. 1500(Ethernet) - 20(IPv4 header) - 8(UDP header) = 1472.
maxSize = congestion.ByteCount(1472)
} else {
// The maximum outgoing packet size allowed.
// The maximum packet size of any QUIC packet over IPv6, based on ethernet's max
// size, minus the IP and UDP headers. IPv6 has a 40 byte header, UDP adds an
// additional 8 bytes. This is a total overhead of 48 bytes. Ethernet's
// max packet size is 1500 bytes, 1500 - 48 = 1452.
maxSize = congestion.ByteCount(1452)
}
}
return maxSize
}
var (
// The maximum outgoing packet size allowed.
// The maximum packet size of any QUIC packet over IPv6, based on ethernet's max
// size, minus the IP and UDP headers. IPv6 has a 40 byte header, UDP adds an
// additional 8 bytes. This is a total overhead of 48 bytes. Ethernet's
// max packet size is 1500 bytes, 1500 - 48 = 1452.
MaxOutgoingPacketSize = congestion.ByteCount(1452)
// Default maximum packet size used in the Linux TCP implementation.
// Used in QUIC for congestion window computations in bytes.
MaxSegmentSize = DefaultTCPMSS
MaxSegmentSize = MaxDatagramSize
// Default initial rtt used before any samples are received.
InitialRtt = 100 * time.Millisecond
@ -51,10 +68,10 @@ var (
// Constants based on TCP defaults.
// The minimum CWND to ensure delayed acks don't reduce bandwidth measurements.
// Does not inflate the pacing rate.
DefaultMinimumCongestionWindow = 4 * DefaultTCPMSS
DefaultMinimumCongestionWindow = 4 * MaxDatagramSize
// The gain used for the STARTUP, equal to 2/ln(2).
DefaultHighGain = 2.885
DefaultHighGain = 2.89
// The gain used in STARTUP after loss has been detected.
// 1.5 is enough to allow for 25% exogenous loss and still observe a 25% growth
@ -249,11 +266,14 @@ type bbrSender struct {
// Latched value of --quic_always_get_bw_sample_when_acked.
alwaysGetBwSampleWhenAcked bool
pacer *pacer
pacer *pacer
maxDatagramSize congestion.ByteCount
MaxOutgoingPacketSize congestion.ByteCount
}
func NewBBRSender(clock Clock, initialMaxDatagramSize, initialCongestionWindow, maxCongestionWindow congestion.ByteCount) *bbrSender {
func NewBBRSender(clock Clock, initialMaxDatagramSize, initialCongestionWindow, initialMaxOutgoingPacketSize, maxCongestionWindow congestion.ByteCount) *bbrSender {
b := &bbrSender{
mode: STARTUP,
clock: clock,
@ -263,7 +283,7 @@ func NewBBRSender(clock Clock, initialMaxDatagramSize, initialCongestionWindow,
congestionWindow: initialCongestionWindow,
initialCongestionWindow: initialCongestionWindow,
maxCongestionWindow: maxCongestionWindow,
minCongestionWindow: DefaultMinimumCongestionWindow,
minCongestionWindow: congestion.ByteCount(DefaultMinimumCongestionWindow),
highGain: DefaultHighGain,
highCwndGain: DefaultHighGain,
drainGain: 1.0 / DefaultHighGain,
@ -274,6 +294,7 @@ func NewBBRSender(clock Clock, initialMaxDatagramSize, initialCongestionWindow,
recoveryState: NOT_IN_RECOVERY,
recoveryWindow: maxCongestionWindow,
minRttSinceLastProbeRtt: InfiniteRTT,
MaxOutgoingPacketSize: initialMaxOutgoingPacketSize,
maxDatagramSize: initialMaxDatagramSize,
}
b.pacer = newPacer(b.BandwidthEstimate)
@ -790,7 +811,7 @@ func (b *bbrSender) MaybeEnterOrExitProbeRtt(now time.Time, isRoundStart, minRtt
// PROBE_RTT. The CWND during PROBE_RTT is kMinimumCongestionWindow, but
// we allow an extra packet since QUIC checks CWND before sending a
// packet.
if b.GetBytesInFlight() < b.ProbeRttCongestionWindow()+MaxOutgoingPacketSize {
if b.GetBytesInFlight() < b.ProbeRttCongestionWindow()+b.MaxOutgoingPacketSize {
b.exitProbeRttAt = now.Add(ProbeRttTime)
b.probeRttRoundPassed = false
}
@ -924,7 +945,7 @@ func (b *bbrSender) CalculateRecoveryWindow(ackedBytes, lostBytes congestion.Byt
if b.recoveryWindow >= lostBytes {
b.recoveryWindow -= lostBytes
} else {
b.recoveryWindow = MaxSegmentSize
b.recoveryWindow = congestion.ByteCount(MaxSegmentSize)
}
// In CONSERVATION mode, just subtracting losses is sufficient. In GROWTH,
// release additional |bytes_acked| to achieve a slow-start-like behavior.

View file

@ -45,6 +45,7 @@ func SetCongestionController(quicConn quic.Connection, cc string) {
congestion.NewBBRSender(
congestion.DefaultClock{},
congestion.GetMaxPacketSize(quicConn.RemoteAddr()),
congestion.GetMaxOutgoingPacketSize(quicConn.RemoteAddr()),
congestion.InitialCongestionWindow,
congestion.DefaultBBRMaxCongestionWindow,
),