On SIP Outbound and app composition (Re: Meeting Notes.)
- From: Eric Cheung <
- Subject: On SIP Outbound and app composition (Re: Meeting Notes.)
- Date: Fri, 08 Feb 2013 07:30:23 -0500
I am sorry if I am reiterating on this discussion we had yesterday, but
I don't think my concern about application routing has been adequately
In JSR289 14.2.1 re setOutboundInterface(), "If any application in the
chain acts as UAS (or a B2BUA), then the previous applications setting
(if any) is not relevant anymore". This is not too much of a problem
because the request can still get to the destination using the OS's
normal IP routing.
However, for SIP Outbound case, if the flow is not used then the request
will not get to the destination. It is a serious problem and imposes
restrictions on the deployer on composition.
How about this proposal that preserves the selection of flow across a
B2BUA within the same container JVM:
After an application calls SipSession/Proxy/ProxyBranch.setFlow() and
then proxies or sends a request, if an application downstream acts as a
B2BUA and uses the outgoingReq = createRequest(incomingReq, ...) then
the flow selected by setFlow() previous continues to apply.
(the B2buaHelper class is deprecated but at the F2F we decided to move
the createRequest() methods somewhere else).
If we want consistency, we can consider modifying the specification on
14.2.1. I believe setting outbound interface was considered a corner
case in JSR289. I don't know if anyone relies on this specific behavior
that a B2BUA downstream will remove the setting.
On 2/6/13 11:49 PM, Binod wrote:
- Here is what I think we had consensus on.
- From an application composition perspective, it is similar to 14.2.1
of the spec.
o The settings of the last proxy application in a chain that used the
outbound apis will be used
by the container and that will override any previous settings.
o If the chain contains a UAS, then the previous settings will not be
relevant anymore to the remaining