TODOs, in random order:
=======================

- siproxd daemonized: looks like clashes between threads
- lost 200 ACK immediately before RTP starts...

- /var/run PID file

- check via loop and private IP addresses
  can comment be used to store a unique ID in there?

- multiple inbound interfaces - do I need to be aware of inbound at all?

- Documentation (yeah, yeah...)

- general security issues
- security tests for received SIP messages (function securitycheck)

- automagically create a proper config file during install

- get_ip_by_host: reduce DNS timeouts (seems to be a more complex problem...)

- via loop detection: send 482 error code

- support Record-Route header

- feature: don't bind to 0.0.0.0 address, but only to inbound/outbound IF's
  (defined by IFNAME)

- support IPTABLES for RTP proxying -> use libiptc

- rtpproxy_masq:
  RACE CONDITIONS! A slot may be timed out, even if the actual
  masquerading tunnel is still active. A following new
  INVITE then tries to use the believed free port -> Buh
  - Can we poll (/proc/something) to figure out if the tunnel
    is still active before deleting? This would require knowledge
    of the text layout in /proc/xxx.
  - are there some other possibilities (netfilter/libiptc)?
  - introduce some kind of connection STATE to the proxy table.
    Timeout based discarding only is active for non-established.
    An INVITE would set the STATE to CONNECTING, the following
    ACK to CONNECTED. A CONNECTED entry can only be deleted by
    a BYE or CANCEL.
  - NETFILTER: during startup (RTP initialization) siproxd should
    clean left over entries that are within the RTP proxy port range
- NETFILTER masquerading: 
  it looks like it is not possible to create an entry in the
  ip_conntrack table from an userspace application. How do we proceed?
  We just might insert/delete DNAT entries in the PREROUTE NAT table.
  This the means that we must implement a connection state into the
  proxy table.