[Twisted-Python] Mixmaster Architecture

[Mark Evans]

Here's an architecture question for Twisted Matrix gurus.
I need to implement a "mixmaster" scheme, as follows:

                           |--> Remote client A
        UDP            TCP |
Server <---> Mixmaster <---|--> Remote client B
                           |
                           |--> Remote client C
                           |
                           ... (etc.)

Here is the background data:

Server <---> mixmaster is a custom binary protocol
over UDP transport.

Mixmaster <---> clients is custom protocol(s)
over TCP transport.  The most important client type
uses Telnet (raw).

Server and mixmaster script live on the same PC.
Remote clients have individual IPs and MACs.

Server is closed-source Java; I cannot change it.
Server's UDP communications is stock Java from Sun.
Clients are different closed-source systems (not PCs).
Mixmaster script is my Python.  How to architect it?

The Mixmaster script needs to multiplex communications
between clients and server.  The server will think it's
talking to N clients, all of which know its peculiar
protocol.  It's OK for the server to believe they have
the same IP address 127.0.0.1.  There is other identifying
information in the server protocol to distinguish the
clients (including MACs and device name strings).

I have an idea how to proceed, but still would like to
hear your advice, and thank you for it.

Mark