Date: Mon, 25 Feb 2002 14:51:10 +0100 (CET) From: torstenb@vmunix.org (Torsten Blum) To: Ross Finlayson <finlayson@live.com> Cc: multimedia@FreeBSD.ORG Subject: Re: MBONE anyone? Message-ID: <m16fLX4-000ONMC@onizuka.vmunix.org> In-Reply-To: <4.3.1.1.20020224032401.00cab890@localhost>
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Ross Finlayson wrote: > > > Is there anyone with an mbone feed? > >The mbone is obsolete. > > Torsten's use of the term "MBone" is obsolete :-) Nope. Mbone is multicast using DVMRP. It's not my definition. Ask people who do deploy multicast in the internet. > While it's true that *the DVMRP tunneled infrastructure* (the original > "MBone" implementation) is obsolete, the term "MBone" refers to the > *entire* multicast-routed subset of the global Internet. Nope, it does not. > This, of course, is alive and well (now primarily using PIM-SM). Subject to discussion, especially the "well" part ;) There are still (a few) large ISPs not supporting native multicast. But the number is getting smaller every month ;) > ps. One of the nice features of DVMRP is that it allowed someone with a > uncooperative (or clueless) ISP to join the MBone - by tunneling over the > uncooperative ISP. It's a pity that, with the demise of DVMRP, this > ability has been lost... You can still tunnel PIM-SM. But you still don't want that for multiple reasons. Some: the tunnel is multicast and subject to per packet balancing, (creating jitter, out-of-order packets etc), tunnel performance sucks for many router vendors (esp. a well known one ;) and so on. And: If you ask me, the fact that people just did "work around" ISPs not supporting multicast did create the problem we have today that not everybody supports it. Some time ago people just established tunnels to the few ISPs that did support multicast. The majority did not implement it for years as there was not enough (or none at all) demand for multicast from (paying) customers (they all had tunnels to someone else). About DVMRP: it's good that it is dead. It's ok for enterprise networks of limited size or networks with a limited number of multicast sources. For a real multicast enabled internet it does not scale at all. Even any source multicast with PIM-SM has one scability problem: MSDP. Source specific multicast solves that last scalability problem. I'm working on the multicast deployment for my employer. I have heard the argument that "no/only very few customers ever asked for it" many many times. If you want multicast, go to your ISP and tell the sales/account rep. that's responsible for you. -tb Disclaimer: This is my personal opinion and not the one of my employer To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message
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