HI, These are response code , what I wanted to know that ,How a proxy tells a ua in advance that it is going down .Also how can it tell ua ,"instead of me contact this proxy", .If this can be done this will help thin cell phone clients to be reconfigured automatically , where it may not have full dns look up capability .
-mahesh -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dale R. Worley Sent: Friday, November 04, 2005 1:07 PM To: Sip-Implementors Subject: Re: [Sip-implementors] Out of service in sip.. On Fri, 2005-11-04 at 09:46 +0900, Mahesh Govind wrote: > What is the mechanism by which a ua can know the proxy is out of service . > Is there any mechanism by which a proxy can tell ua that it is going out of > service and come back after some time or use another proxy as the proxy . Response code 503 looks like what you want: 21.5.4 503 Service Unavailable The server is temporarily unable to process the request due to a temporary overloading or maintenance of the server. The server MAY indicate when the client should retry the request in a Retry-After header field. If no Retry-After is given, the client MUST act as if it had received a 500 (Server Internal Error) response. A client (proxy or UAC) receiving a 503 (Service Unavailable) SHOULD attempt to forward the request to an alternate server. It SHOULD NOT forward any other requests to that server for the duration specified in the Retry-After header field, if present. > If ua uses DNS look up this case will not arise . > But if some thin client is not doing the dns srv how can it know in advance If a UA doesn't do DNS, it must be dependent on some sort of infrastructure (PBX, service provider, etc.) which presumably is responsible for provisioning the UA with an outbound proxy. Dale _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
