diff --git a/internal/transport/videochannel/transport.go b/internal/transport/videochannel/transport.go
index ed9abcf..2b41a46 100644
--- a/internal/transport/videochannel/transport.go
+++ b/internal/transport/videochannel/transport.go
@@ -23,7 +23,7 @@ import (
 const (
 	defaultMaxPayloadSize = 16 * 1024
 	defaultFragmentSize   = 256
-	defaultAckTimeout     = 1 * time.Second
+	defaultAckTimeout     = 300 * time.Millisecond
 	defaultFrameInterval  = 40 * time.Millisecond
 	defaultConnectTimeout = 30 * time.Second
 	maxSendAttempts       = 20
@@ -301,7 +301,7 @@ func perAttemptAckTimeout(fragments, fps int) time.Duration {
 		fps = 25
 	}
 	frameInterval := time.Second / time.Duration(fps)
-	estimated := time.Duration(fragments) * frameInterval * 3
+	estimated := time.Duration(fragments) * frameInterval * 2
 	if estimated < defaultAckTimeout {
 		return defaultAckTimeout
 	}
diff --git a/internal/transport/videochannel/transport_unit_test.go b/internal/transport/videochannel/transport_unit_test.go
index 25169fc..e1f9003 100644
--- a/internal/transport/videochannel/transport_unit_test.go
+++ b/internal/transport/videochannel/transport_unit_test.go
@@ -262,8 +262,8 @@ func TestPerAttemptAckTimeoutScalesWithFragments(t *testing.T) {
 		t.Fatalf("perAttemptAckTimeout(2,25) = %v, want %v", got, defaultAckTimeout)
 	}
 
-	// 16 fragments @ 25 FPS: 16 * 40ms * 3 = 1920ms.
-	if got, want := perAttemptAckTimeout(16, 25), 1920*time.Millisecond; got != want {
+	// 16 fragments @ 25 FPS: 16 * 40ms * 2 = 1280ms.
+	if got, want := perAttemptAckTimeout(16, 25), 1280*time.Millisecond; got != want {
 		t.Fatalf("perAttemptAckTimeout(16,25) = %v, want %v", got, want)
 	}