>It can RR if it wants, but it isn't needed to be transaction stateful. The messages within the transaction are routed based on the Via >headers. Yep responses sent ok through vias. But all mid server INVITE transactions wait ACK, if don't add RR they never get it ? (That means need to add RR for statefull proxy)
But ACK flwo is confusing to me somehow. For example: UA1 statefull-proxy UA2 UA1 sends ACK -> statefull-proxy (it's passed to server transaction, how it reaches UA2. Server transaction processes ACK,looks for Route header, if exists fowards ACK next hop ? ) >They don't "create" dialogs. They maintain awareness of dialogs created by the UAC and UAS. Such case not possible ? http://www.lumisoft.ee/ivx/sip/sip_invite_ringing.gif Probably must skip call statefull stuff now, i just wanted to proxy what support registrar,stateless,statefull,callstatefull .... Paul Kyzivat wrote: > > > Ivar Lumi wrote: >> >> Ok. >> >> Thate means: >> *) Transaction statefull proxy also adds recourd-route header, that >> ensures all messages are passed back through same path. > > It can RR if it wants, but it isn't needed to be transaction stateful. > The messages within the transaction are routed based on the Via > headers. The RR only governs subsequent requests sent within the > dialog (call), and so pertain to dialog statefulness. > >> Transaction statefull proxy don't create dialogs. >> *) Call statefull proxy is like transaction statefull proxy, but >> created dialogs and keeps their state. > > They don't "create" dialogs. They maintain awareness of dialogs > created by the UAC and UAS. > >> Does somebody know place where i can get INVITE flow for: >> UA1 -> call statefull proxy -> UA2 > > It looks like you only sent this response to me, so you won't be > getting any other replies. :-) > > I don't. Call stateful proxies aren't very useful, so there has been > little discussion of them that I am aware of. > > Paul > >> Especially i need UA2 ACK flow to UA1 >> How it's passed through proxy and proxy transaction and dialog, then >> how passed to UA1. >> Also how BYE will go though proxy too. >> >> >> >> >> Paul Kyzivat wrote: >>> A call stateful proxy is a proxy - it follows all the rules for what >>> a proxy can and can't do. It is presumably also transaction >>> stateful, so it follows the rules for that too. Because it is >>> following proxy rules, it must not replace the contact address. >>> >>> Over and above that, it keeps state about calls (dialogs, dialog >>> usages). Presumably, because it keeps such state, it needs to >>> monitor the end of the dialog so that it will no when to abandon the >>> state. To do that, it needs to be on the signaling path for the >>> duration of the dialog. Because it can't rewrite the Contact >>> address, the only way it can ensure this is to record-route. It will >>> then see all the messages in the dialog and can use those to >>> maintain its state, and to know when to abandon its state. However, >>> it won't necessarily know one of he UAs in the call die. It can use >>> Session Timer to request that the UAs signal occasionally, and then, >>> if it fails to see the signaling by the expected time it can presume >>> that one end is broken and it should abandon its state. (If neither >>> UA supports session timer then it is out of luck, and probably >>> should not attempt to be call stateful.) >>> >>> An obvious question is whether there is any value in a call stateful >>> proxy. For the most part I think they have been found to not be very >>> useful. Potentially they could be used for logging and accounting, >>> but they are limited in what can be done, and are dependent on >>> session timer. >>> >>> Paul >>> >>> Ivar Lumi wrote: >>>> >>>> >>>> Can you explain with some words diff of B2BUA and call statefull >>>> proxy ? >>>> >>>> Ok i understand B2BUA, but call statefull then ? >>>> >>>> I'm trying to get best way to implement dialog statefull proxy. >>>> >>>> >>>> Paul Kyzivat wrote: >>>>> >>>>> >>>>> Ivar Lumi wrote: >>>>>> Hi, >>>>>> >>>>>> I'm developing free open source c# SIP stack, all almost well, >>>>>> but now need some help. >>>>>> (I try to make dialog statefull proxy) >>>>>> >>>>>> Is it right if i say: >>>>>> Dialog statefull proxy won't add record-route header field, but >>>>>> adds/updates Contact: field in proxy to point to proxy server. >>>>> >>>>> If you do this, you have built a B2BUA, not a call stateful proxy. >>>>> They are quite different things, though they can be used for some >>>>> of the same things. >>>>> >>>>>> I did some drawing(not finished yet) but shows what i mean: >>>>>> http://www.lumisoft.ee/ivx/sip/sip_invite.gif >>>>>> >>>>>> Any help will be welcome. >>>>>> >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Sip-implementors mailing list >>>>>> [email protected] >>>>>> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors >>>>>> >>>> >> _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
