[Serusers] Rewrite Contact header

[Robert Brown]

Can someone give me some direction as to how I can get SER
to functin as a basic B2BUA?...a document, how-to, etc?

If that is not readily available then I wonder if there is
some way that I can get SER to statefully rewrite the Contact 
header when it relays messages?  The reason for this is that 
I want all of my UAs to interact only with/through SER 
and not directly with each other.  Something like this:

     UA1                     SER                     UA2
    IPaddr1                 IPaddr2                 IPaddr3
      | ---------->           |                       |
      | INVITE                |                       |
      | contact: name at IPaddr1 |                       |
      |                       | ---------->           | 
      |                       | INVITE                |
      |                       | contact: name at IPaddr2 |
    .....                   .....                   .....
      |                       | <----------           | 
      |                       | BYE                   |
      |                       | ruri: name at IPaddr2    |
      | <----------           |                       |
      | BYE                   |                       |
      | ruri: name at IPaddr1    |                       |
      |                       |                       |


Without rewriting the contact header I get the following
which is undesireable:

     UA1                     SER                     UA2
    IPaddr1                 IPaddr2                 IPaddr3
      | ---------->           |                       |
      | INVITE                |                       |
      | contact: name at IPaddr1 |                       |
      |                       | ---------->           | 
      |                       | INVITE                |
      |                       | contact: name at IPaddr1 |
    .....                   .....                   .....
      | <----------------------------------           | 
      |   BYE                                         |
      |   ruri: name at IPaddr1                          |



Thanks to all for contributing to a really nice open source 
system.

Regards,
Robert Brown