Confirming source-routed multicast is dead on the public Internet

Steve Meuse smeuse at mara.org
Wed Aug 1 13:48:01 UTC 2018


Can your hfc customers do an igmp join?

No? Then it's probably not considered "public".

-Steve

On Wed, Aug 1, 2018 at 5:21 AM Aaron Gould <aaron1 at gvtc.com> wrote:

> As you all have said, to confirm, I use ssm Mcast to distribute TV from
> satellite down links in the headend, out to a few different remote head
> ends.  From there it's converted back to RF video and sent to subscribers
> via cable or hfc plant
>
> Aaron
>
> > On Jul 31, 2018, at 5:15 PM, Job Snijders <job at ntt.net> wrote:
> >
> >> On Tue, 31 Jul 2018 at 23:29, Sean Donelan <sean at donelan.com> wrote:
> >>
> >> Its tought to prove a negative. I'm extremely confident the answer is
> yes,
> >> public internet multicast is not viable. I did all the google searches,
> >> check all the usual CAIDA and ISP sites. IP Multicast is used on private
> >> enterprise networks, and some ISPs use it for some closed services.
> >>
> >> I got sent back with a random comment from a senior official saying "but
> >> I heard different." I bit my tongue, and said I would double (now
> >> quadruple) check.
> >>
> >> If any ISPs have working IP source-routed multicast on the public
> >> Internet that I missed, or what I got wrong.  That's what content
> >> distribution networks (cdn's) are for instead.
> >
> >
> >
> > AS 2914 is working to fully dismantle all its Internet multicast related
> > infrastructure and configs. All MSDP sessions have been turned off, we
> have
> > deny-all filters for the multicast AFI, and the RPs have been shut down.
> >
> > For years we haven’t seen actual legit multicast traffic. Also the
> > multicast “Default-Free Zone” has always been severely partitioned. Not
> all
> > the players were peering with each other, which led to significant
> > complexity for any potential multicast source.
> >
> > Reasoning behind turning it off is that it limits the attack surface
> > (multicast can bring quite some state to the core), reduces the things we
> > need to test and qualify, and by taking this off the RFPs we can perhaps
> > consider more vendors.
> >
> > However, as you noted; multicast within a single administrative domain
> > (such as an access network distributing linear TV), or confined to
> > purpose-built L3VPNs very much is a thing. On the public Internet
> multicast
> > seems dead.
> >
> > Kind regards,
> >
> > Job
>
>


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