[Serusers] NAT with multiple SERs

[Juha Heinanen]

Jan Janak writes:

 > You can redirect the REGISTER request to the 2nd server. SER-1 receives
 > a REGISTER and processes it with save_noreply(). It then redirects the
 > REGISTER method to the 2nd server using sl_send_reply("301", "Moved
 > Permamently"); The 2nd server will detect that the REGISTER has been
 > redirected and will generate 200 OK (a parameter in the request-uri
 > could be used for the detection).

in addition that clients have to support 301 for register request, they
would also need to retain unknown request uri params, which many don't
do.

 > If you set the expires to a short value (using max_expires parameter of
 > registrar module) than the user agent can keep NAT bindins open to both
 > servers.

nat bindings could be kept open by the small udp packets that are
automatically sent to clients behind nats by nathelper/mediaproxy
modules.

-- juha