[openib-general] IPoIB broadcast MC group membership

[Fabian Tillier]

On 2/21/06, Greg Lindahl <lindahl at pathscale.com> wrote:
> On Tue, Feb 21, 2006 at 08:17:02PM -0800, Fabian Tillier wrote:
>
> > The node joining or creating the multicast group doesn't need to
> > specify the rate - the SA can figure out the rate to use based on the
> > requestor (for creation), or validate that the requestor supports the
> > existing group's rate (for joining).
>
> Um, but that gets back to my point: I want 1X, 4X SDR, and 4X DDR
> nodes running IPoIB to share a multicast group. Are you saying this
> can be done by making the group a 1X group? Or that it's impossible
> to have such a group? Or that everyone would have to drop to 1X to
> make such a group?

You'd have to make the group 1X.  Note that the group being 1X doesn't
limit unicast traffic to 1X rates, since the rate for unicast traffic
would be set based on the rate reported in the path records for the
various endpoints.

So 4X SDR and 4X DDR nodes would have to set their inter-packet delay
for the broadcast group to end up with a 1X packet injection rate.

- Fab