Caller ------------ KamailioVIP(Primary and Secondary Kamailio)------- Callee

    HA provided by Keepalived

    DMQ is used between the Primary and Secondary Kamailio for dialog sync

Suppose the Primary Kamailio has been brought down and the Secondary one is actually active and tied to the VIP.

When a call is fired from the Caller, it traverses through the Secondary Kamailio and lands onto the callee. The dialogs are updated properly. At this point, the Primary Kamailio is brought up, and dialog state is synced due to the DMQ module.

The Keepalived will now attach the VIP to the Primary Instance. If the caller hangs up the phone at this point, the BYE sip message traverses through the Primary Kamailio instance to the callee and the call is cleared, but there are two issues here.

  1.  The Primary Kamailio throws an error in ds_load_remove() saying that it cannot find the load for the specific call id. This is apparently due to the fact that the dispatcher data is not synced between the two modules but dialog data is. So dialog wise, things are fine. Can this be fixed somehow?

  2. The above is still as grave a problem as the dialogs are cleared. BUT, if we check the 'kamcmd dispatcher.list' on the SECONDARY kamailio even well after the call is cleared, the DLGLOAD shows 1. Since we are using the Call Load based distribution for the dispatching, this is effectively one call stuck on the dispatcher, which leads to resource leak.

Is this a known issue, and if so, do we have a way to circumvent this? 

Regards,

Harneet Singh