Morning all. I was wonderign if anyone could comment on how deployed is multicast routing in real-world networks. How many of you have enabled multicast routing in your core routers? Do you offer this as a service to your customers? If no, why not? Do you plan to? The problem with IP multicasting is that is not usefull unless everyone is usinging it. I'am wondering when we will start seeing it in use. New products are starting to support multicast (new CUSeeMe, etc) but the infrastructure doesnt seem to be there. Aleph One / aleph1@dfw.net http://underground.org/ KeyID 1024/948FD6B5 Fingerprint EE C9 E8 AA CB AF 09 61 8C 39 EA 47 A8 6A B8 01
On Tue, 6 May 1997, Aleph One wrote:
Morning all. I was wonderign if anyone could comment on how deployed is multicast routing in real-world networks. How many of you have enabled multicast routing in your core routers? Do you offer this as a service to
All the sites that I'm familiar with are still using tunnels. Some of those tunnels might be homed on dedicated routers instead of a Unix/mrouted machine, but I'd be somewhat suprised if anybody ran native multicast in their core routers. People pay for unicast traffic, and its not worth messing up that unicast traffic for a fun multicast experiment that'll crash your router or run it out of memory ever other day. -- Matt Ranney - mjr@ranney.com This is how I sign all my messages.
I think I heard "Matt Ranney" say:
On Tue, 6 May 1997, Aleph One wrote:
Morning all. I was wondering if anyone could comment on how deployed is multicast routing in real-world networks. How many of you have enabled multicast routing in your core routers? Do you offer this as a service to
All the sites that I'm familiar with are still using tunnels. Some of those tunnels might be homed on dedicated routers instead of a Unix/mrouted machine, but I'd be somewhat surprised if anybody ran native multicast in their core routers.
People pay for unicast traffic, and its not worth messing up that unicast traffic for a fun multicast experiment that'll crash your router or run it out of memory ever other day.
I've heard of several ISPs running native multicast on their core routers since it's more efficient than using tunnels, but still using tunnels for inter-domain multicast connectivity. It seems to me that most ISPs would rather use multicast and have traffic traverse their backbone just once than use point-to-point connections for several identical data feeds. I think saying that multicast will "crash your router" might be a harsher statement than is necessary (but I'm not saying that Cisco (and other vendors) haven't had their share of screwups). PIM in later releases of the IOS hasn't inherently unstable, but of course, it must be configured properly. :) -matthew mwhalen@uucom.com Shop as usual...........................and avoid panic buying
In message <Pine.LNX.3.95.970506102317.19519G-100000@wacky.eit.com>, "Matt Rann ey" writes:
On Tue, 6 May 1997, Aleph One wrote:
Morning all. I was wonderign if anyone could comment on how deployed is multicast routing in real-world networks. How many of you have enabled multicast routing in your core routers? Do you offer this as a service to
All the sites that I'm familiar with are still using tunnels. Some of those tunnels might be homed on dedicated routers instead of a Unix/mrouted machine, but I'd be somewhat suprised if anybody ran native multicast in their core routers.
People pay for unicast traffic, and its not worth messing up that unicast traffic for a fun multicast experiment that'll crash your router or run it out of memory ever other day.
The primary reasons people use dedicate mrouters is for reliablity and the fact that that's they way they used to have to do it. (Cisco's didn't always have multicast routers). Its run on lots of real world networks tho, Cisco, Sun, old NSFNet, several of the large nationals will feed you multicast. The main issues with multicast according to nanog, are configuration and policy issues. Current mrouting protocols don't allow for policy based filtering, but there are people working on it. --- Jeremy Porter, Freeside Communications, Inc. jerry@fc.net PO BOX 80315 Austin, Tx 78708 | 1-800-968-8750 | 512-458-9810 http://www.fc.net
On Tue, 6 May 1997, Matt Ranney wrote:
On Tue, 6 May 1997, Aleph One wrote:
Morning all. I was wonderign if anyone could comment on how deployed is multicast routing in real-world networks. How many of you have enabled multicast routing in your core routers? Do you offer this as a service to
All the sites that I'm familiar with are still using tunnels. Some of those tunnels might be homed on dedicated routers instead of a Unix/mrouted machine, but I'd be somewhat suprised if anybody ran native multicast in their core routers.
People pay for unicast traffic, and its not worth messing up that unicast traffic for a fun multicast experiment that'll crash your router or run it out of memory ever other day.
While this statement was true not all that long ago, it doesn't hold water with the more recent code, at least from a particular router vendor that I tend to deal with. There are also more knobs to protect yourself with (and also hang yourself with, but that's as it should be. :)) these days. We run native multicast on our core routers, and the decision to do this was based on scalability. Dozens of tunnels doesn't scale very far. Also, the ability to do sparse mode PIM lessens the load you put on your infrastrucutre. I'm also of the opinion that the congruence between unicast and multicast topology (at least as much as you can do it) is a good thing. As far I know, there are quite a few folks running native multicasting on their routers, even though it's still a minority. -dorian
participants (5)
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Aleph One -
Dorian R. Kim -
Jeremy Porter -
Matt Ranney -
Matthew V. J. Whalen