The CDR example does not require that the proxy be dialog stateful - just call stateful.
Here's what I think : Dialog stateful proxy servers are useful for policy enforcement. For example : if you are proxying requests to an intranet you may want to establish a secure dialog state with a caller from the internet side of the firewall ( using tls). On the intranet side of the firewall, you can start another dialog with the Intranet client that is not secure (using UDP). You may want to do this because Dialog state may be sensitive ( ie. route sets to endpoints etc. ) that you may not want to make publicly visible outside the intranet. There's also another pragmatic reason why one sees dialog stateful proxy servers -- dialog stateful API are easier to define and deal with at the programmer level. Now I'd like to know why a proxy server is structured sometimes as transaction stateful ( not necessarily dialog stateful ) sometimes. Can somebody take a shot at that. Thanks Regards Ranga ( not the same Ranga as below :-) ) Ranga wrote: > > Inline comments > > So one again, cause I am really curious for the answer: > > What is the reason a proxy would want to be dialog stateful given > that a > proxy can't send requests (other than CANCEL, and ACK)? > > Why would anyone like to build a dialog stateful proxy? In what way > could a dialog stateful proxy use the information in the dialog > that it > has saved? > > > CDR generation. Proxy would want to be in the path of BYE request to > be able to know the call start and end times. > > > / Christian Jansson > > > -- M. Ranganathan Advanced Networking Technologies Division, National Institute of Standards and Technology (NIST), 100 Bureau Drive, Stop 8920, Gaithersburg, MD 20899. tel:301 975 3664 , fax:301 590 0932 http://w3.antd.nist.gov/ Advanced Networking Technologies For the People! _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
