Thanks for clearing that up... -----Original Message----- From: Jan Janak [mailto:jan@iptel.org] Sent: Wednesday, April 20, 2005 9:17 AM To: Matt Schulte Cc: serusers(a)lists.iptel.org Subject: Re: [Serusers] failure_route vs. onreply They are quite different. onreply_route is executed for each branch. If your proxy server forks an INVITE to 3 destinations in parallel then onreply_route will be executed 3 times -- for each branch. onreply_route sections process replies (all operations within them will modify replies). After receiving final replies from all the branches, the proxy server decides which of them it should forward upstream. If the selected message is a negative final reply (3xx, 4xx, 5xx, 6xx) then it executes the failure_route section before forwarding it upstream. But -- the failure_route section does not work with the reply being forwarded upstream, but with the original request ! (in this case the original INVITE). That's quite important. There are two reasons why it is this way: 1) The most common operation performed in failure_route sections is serial forking (you take the original message and forward it somewhere else) -- and for that you need the original request. You may also want to change the reply being forwarded upstream and for this the original request will be needed as well. 2) (implementation related) -- it is likely that the reply was received by process A, but will be forwarded upstream by process B (where B is the process which received the reply from the last unfinished branch). To make it possible, the message is stored in shared memory and most functions that can be called from the script cannot handle it. +-----+ (2) 301 301 (1) | |<-------- <---------| SER | (2) 486 | |<-------- +-----+ (1) -- failure_route gets called here (2) -- onreply_route gets called here Jan. On 20-04 07:31, Matt Schulte wrote: