[zeromq-dev] Publisher side filtering...

[Martin Sustrik]

On 10/26/2010 11:54 AM, Gerard Toonstra wrote:
>
> Conceptually, to some degree, they are similar.
>
> Multicast addressing operates at the level of the IP protocol and is
> implemented in routers.
>
> Publisher forwarding is done at the level of the application/platform.
>
> Differences are that managing subscriptions at the IP level is probably
> much harder than at the level of the application (security concerns
> when/if they apply).
> Multicast routing also requires you to define a specific "ip" group for
> every topic you wish to publish.
>
> Not saying that one is worse/better than the other, it depends on what
> you want to achieve, number of topics, security, etc.
> But clearly, some things you can do with pub forwarding will be
> significantly harder to do with IP multicast, hence my interest.

Aslo, multicast is unlikely to be allowed on WAN. However, you want to 
forward your subscriptions over WAN, say from the trader's desk to the 
exchange -- which can be located at different continent.

Martin