Multicast on a Point-to-Point network?

[Steve Marotta]

Hi again,

I was looking through the example code in ns-3 to try to find examples of multicasting. I found examples for CSMA and WiMax multicasting, but nothing about point-to-point networks. Per the recommendation of others on this forum, as well as the guidance of the example code, I have my p2p network set up such that each link is on its own subnet. Does a multicast have to be performed on a per-subnet basis, or is there a simple way to multicast on a point-to-point network?

The example code that I looked at defines multicast routes manually. Is there any way to simply use built-in shortest-path routing during a multicast?

~ Steve

[Tom Henderson]

On 05/26/2011 02:50 PM, Steve Marotta wrote:
> Hi again,
>
> I was looking through the example code in ns-3 to try to find examples
> of multicasting. I found examples for CSMA and WiMax multicasting, but
> nothing about point-to-point networks. Per the recommendation of others
> on this forum, as well as the guidance of the example code, I have my
> p2p network set up such that each link is on its own subnet. Does a
> multicast have to be performed on a per-subnet basis, or is there a
> simple way to multicast on a point-to-point network?

There should be nothing special in converting the existing CSMA examples
to use point-to-point. Our point-to-point model is multicast capable.
Have you tried?

>
> The example code that I looked at defines multicast routes manually. Is
> there any way to simply use built-in shortest-path routing during a
> multicast?

No, there is no other multicast routing.

- Tom

[Steve Marotta]

Thanks for the response. To answer your question, I haven't tried it yet. I want to make sure I understand how multicasting works in ns-3 first.

I have a point-to-point network. Packets must make multiple hops to get from one end of the network to the other. So I've got a network that's laid out essentially like an X, but with a bunch of nodes where the center point of the X should be. I want to multicast from one corner of the X to the other three. So, correct me if I'm wrong, but from what I can gather, I need to...

1. Create a multicast source
2. Define a multicast group address
3. Set a single interface on my source from which all multicast traffic will originate. (Question: What if I want the sender to use a different interface for each destination in the multicast group?)
4. For each intermediate node in my network that will be forwarding multicast packets, explicitly define which interfaces we want them to forward to.

Does that sound right?

~ Steve