Dale Worley wrote: > As issue XX-8372 shows, this strategy does not work well in > an HA environment: if the SUBSCRIBE goes to a proxy which is > down, the Registrar's SIP stack takes 2.5 seconds to fail > over to the other proxy. By that time, the Registrar has > given up waiting for NOTIFYs from the SUBSCRIBE, and reports > the pickup as failing. Conversely, if we raise the wait time > to 4.5 seconds, all pickup operations are unduly delayed. >
Are you taking into consideration the fact that dialog subscriptions are challenged by Auth plugin? This potentially adds yet another 2.5 seconds overhead for the resend of subscribe request with challenge response. If both the initial SUBSCRIBE and the SUBSCRIBE after challenge choose the wrong proxy it adds 5 seconds for the failover. Would it make sense to add to the strategy a precalculation of the Proxy-Authorization header. Registrar pickup plugin can create a up-to-date nonce given that it has access to the system-wide shared secret. It can generate well formed Proxy-Authorization header with the nonce and calculate the correct response. The Auth plugin should accept this Proxy-Authorization header and should not challenge the request. This will cut one transaction out of the exchange. The same idea can be used in RLS server for the dialog subscription it generates. Mark. _______________________________________________ sipx-dev mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipx-dev Unsubscribe: http://list.sipfoundry.org/mailman/listinfo/sipx-dev sipXecs IP PBX -- http://www.sipfoundry.org/
