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Starred by 15 users
Status: Duplicate
Merged: issue 5658
Last visit > 30 days ago
Closed: Nov 2016
NextAction: ----
Pri: 2
Type: Feature

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DSCP support cannot be enabled on iOS
Reported by, Aug 27 2015 Back to list
What steps will reproduce the problem?
1. Create a PeerConnection with the "googDscp" constraint.
2. Observe the debug output and use wireshark to look at the packets

What is the expected result?
DSCP flags should be set, e.g. to DSCP_EF

What do you see instead?
DSCP flags are not set.

What version of the product are you using? On what operating system?
latest git, on iOS (probably windows, too)

Please provide any additional information below.

The method "TranslateOptions" in webrtc/base/ and webrtc/base/ will return -1 for OPT_DSCP, this will prevent DSCP flags to be set.

This is easy to fix (at least for iOS), in

@@ -528,8 +528,9 @@ class PhysicalSocket : public AsyncSocket, public sigslot::has_slots<> {
         *sopt = TCP_NODELAY;
       case OPT_DSCP:
-        LOG(LS_WARNING) << "Socket::OPT_DSCP not supported.";
-        return -1;
+        *slevel = IPPROTO_IP;
+        *sopt = IP_TOS;
+        break;
         return -1;  // No logging is necessary as this not a OS socket option.

Project Member Comment 1 by, Aug 28 2015
Labels: Area-Network
@pthatcher, do you know why we don't support DSCP in socketserver? As I remember we once added DSCP support in Chrome.
Project Member Comment 2 by, Aug 31 2015
I believe it's because of

On older versions of Windows, DSCP was broken.

Should we mark this one a dupe?
Comment 3 by, Aug 31 2015
This issue is about iOS. I only mentioned windows because it caught my eye while i scanned through the sources.
Project Member Comment 4 by, Aug 31 2015
Ah, sorry, I misunderstood.

I don't see a good reason.  If iOS supports DSCP well, I think we should enable it.

Guowei?  Zeke?  Would either of you like to look into this?
Project Member Comment 5 by, Sep 14 2015
Labels: EngTriaged
Project Member Comment 6 by, Sep 15 2015
Labels: OS-iOS
Adding OS-iOS label per #3.
Project Member Comment 7 by, Sep 15 2015
Labels: -Type-Bug Type-Feature
Status: Assigned
Experiencing this same behavior in Windows as well. Same steps to reproduce

Windows 10 Chrome Version 45.0.2454.99 m
Windows 10 Chrome Version 47.0.2517.0 canary
Comment 9 by, Nov 3 2015
We are also experiencing the same behavior. Tested on

Windows 10 Chrome Version 46.0.2490.80 m

Any update on this item? We'd really like to see DSCP working consistently in Windows 10. According to, it looks like it should be working reliably (except possibly in Win7?), but we're not seeing DSCP flags set in our pcaps taken on Win10 tests, even with "googDscp" set. What's the official word on DSCP support in Windows?
Project Member Comment 11 by, Mar 21 2016
CL for IOS/Android/Linux is under review under this issue:

Will look into this. 
Project Member Comment 12 by, Nov 12 2016
Mergedinto: 5658
Status: Duplicate
Summary: DSCP support cannot be enabled on iOS (was: DSCP support cannot be enabled)
This issue was meant to be about iOS (see comment #3), which is covered by

Let's use to track enabling DSCP for Windows.
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