can the UPnP media port for gupnp-av-cp be configured?

[Jim Snyder <jhsnyder gmail com>]

Many UPnP devices generate port numbers dynamically on startup.

E.g. rygel's config file defaults the media / SOAP / ??? port to dynamic assignment.

Conventionally UPnP devices seem to use either dynamic ports or a trivnet port (8200-8202) for media transfers.

gupnp-av-cp uses dynamic ports by default.

1) is it possible to configure the gupnp-av-cp dynamic port to a one-time static assignment (er, 8200)? ...

... and if so, how?

I've poked around online for documentation, done the Google thing, and grepped through system files ... no joy.

2) Whether or not gupnp-av-cp can be so configured, how does a network admin configure static firewalls on nodes on a local LAN (no router traversal / IGD) to deal with dynamic ports?

I see that Mac OS X relies on blocking application sockets rather than port blocking, so no problem for Macs.

Dunno about Windows.

Linux, however ...

... I've been looking at packet traces from UPnP sessions with minidlna, rygel-as-UPnP renderers, gupnp-av-cp, etc, and I don't see how conventional iptables port-based firewalls can be compatible with UPnP dynamic ports.

Seems like a local node would have to probe the remote node (eg SSDP or WSDP) to discover the media port, then inject local firewall rules to open/close ports ...

... which is putting a lot of trust in the local discovery agent.

Not sure what I'm missing here... appreciate any explanations / advice.

Thanks, Jim Snyder