[ih] Why did DCCP fail to gain traction?

[Thomas Fossati]

On Sat, Oct 3, 2026 at 10:22 PM Brian E Carpenter
<brian.e.carpenter at gmail.com> wrote:
>
> On 04-Oct-26 05:46, Thomas Fossati via Internet-history wrote:
> > On Sat, Oct 3, 2026 at 6:26 PM John Kristoff via Internet-history
> > <internet-history at elists.isoc.org> wrote:
> >>
> >> DCCP (IETF RFC 4330) is/was a relatively new transport in Internet
> >> history. I don't think it ever really saw much, if any, deployment or
> >> support in applications. It was removed from the Linux kernel last year.
> >>
> >> Was it too late, too complex, too little, or just deemed unnecessary
> >> given available alternatives such as QUIC?  I don't recall seeing
> >> much discussion about why it failed to gain traction and I'm interested
> >> to hear what the collective wisdom of this group might have to say about
> >> that.
> >
> > It failed because of an abundance of middleboxes and a lack of APIs.
> > Unlike SCTP (which is similarly affected by middleboxes), it never
> > found a niche where it could be safely deployed.
>
> That's certainly true, but I think that in reality there was no operational
> problem that "congestion-controlled unreliable datagrams" would solve more
> cheaply than simply buying extra bandwidth.

Yes, you are right.
Besides, I reckon that ABR may have also helped to solve, for a
significant proportion of Internet traffic, some of the problems that
DCCP was designed to tackle.

> I see that Linux proactively removed DCCP support from Linux 6.16.

For the past ~10 years, the Linux community has been maintaining a
protocol that no one really uses.  It made total sense to drop it.

-- 
Thomas