[zeromq-dev] subports

Martin Sustrik sustrik at 250bpm.com
Wed Jul 27 11:11:31 CEST 2011

On 07/27/2011 10:55 AM, Maciej Gajewski wrote:

> But once again: what is the use case?

I am not a user so I am not really competent to answer. However, at San
Francisco meetup early this year, subports were identified as the most
desired feature to add to 0MQ.

I guess the problem is that opening a port in a firewall is an
administrative and often quite burocratic task. Thus, updating your
application by adding a new feed becomes a costly and time consuming
operation (all the clients have to go through the associated burocratic

> If this feature is designed to
> allow apps to run transparently in environments when available open
> ports are scarce, then the 'well known port' idea does not make sense,
> unless the port is configurable at runtime, say, per zmq::context.

It has to do with the argument above. If there's a fixed VTCP port you
can just ask all the clients to get it open once and then tunnel all the
traffic through that port. Moreover, if they are already using a VTCP
service from a different vendor, the port is already open and no
administrative procedures are required.


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