diff --git a/Cargo.lock b/Cargo.lock
index 98840e947..902036cb3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -9708,7 +9708,7 @@ dependencies = [
 [[package]]
 name = "webrtc-sctp"
 version = "0.12.0"
-source = "git+https://github.com/rustdesk-org/webrtc?rev=48100bf13e694d7e5bbb49b9a753dbad1c359d0c#48100bf13e694d7e5bbb49b9a753dbad1c359d0c"
+source = "git+https://github.com/rustdesk-org/webrtc?rev=b221f13b1d6f21fbce09f9f63096be27dd392265#b221f13b1d6f21fbce09f9f63096be27dd392265"
 dependencies = [
  "arc-swap",
  "async-trait",
@@ -9748,7 +9748,7 @@ dependencies = [
 [[package]]
 name = "webrtc-util"
 version = "0.11.0"
-source = "git+https://github.com/rustdesk-org/webrtc?rev=48100bf13e694d7e5bbb49b9a753dbad1c359d0c#48100bf13e694d7e5bbb49b9a753dbad1c359d0c"
+source = "git+https://github.com/rustdesk-org/webrtc?rev=b221f13b1d6f21fbce09f9f63096be27dd392265#b221f13b1d6f21fbce09f9f63096be27dd392265"
 dependencies = [
  "async-trait",
  "bitflags 1.3.2",
diff --git a/Cargo.toml b/Cargo.toml
index 980723873..0894163b2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -224,10 +224,13 @@ libxdo-sys = { path = "libs/libxdo-sys-stub" }
 # a congestion window, as KCP does - on by default, `allow-webrtc-congestion-control` opts back in.
 # Sending that way, a reordering window keeps a chunk that is merely late from being resent on a
 # path that jitters, every DATA chunk asks for its SACK at once so a lost tail is back within an
-# RTT at KCP's RTO floors, and bundles of small chunks stay within the MTU.
+# RTT at KCP's RTO floors, and bundles of small chunks stay within the MTU. A T3-rtx resends
+# everything outstanding when it packs into four packets and otherwise probes with one and lets
+# the SACK settle the rest (F-RTO), timed from the latest send, so a stall no longer resends the
+# whole backlog behind itself while a short lost tail still comes back at once.
 # Pinned by rev, not branch: a fork branch can be rewritten out from under the lockfile.
-webrtc-util = { git = "https://github.com/rustdesk-org/webrtc", rev = "48100bf13e694d7e5bbb49b9a753dbad1c359d0c" }
-webrtc-sctp = { git = "https://github.com/rustdesk-org/webrtc", rev = "48100bf13e694d7e5bbb49b9a753dbad1c359d0c" }
+webrtc-util = { git = "https://github.com/rustdesk-org/webrtc", rev = "b221f13b1d6f21fbce09f9f63096be27dd392265" }
+webrtc-sctp = { git = "https://github.com/rustdesk-org/webrtc", rev = "b221f13b1d6f21fbce09f9f63096be27dd392265" }
 
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