Changes between Version 11 and Version 12 of IPAddressChange

Timestamp:

Apr 22, 2015 10:32:02 AM (9 years ago)

Author:

ming

Comment:

--

IPAddressChange

@@ -124 +124 @@
 TCP is preferred on iPhone because of the background feature, but it has been reported that simply re-registering after an IP address change is detected may not work, presumably because the TCP socket itself is already in bad state and is unable to communicate anymore. The following steps can be used to perform re-registration with a new TCP transport. For a demonstration, please apply attachment:iphone_ip_change_pjsip_1_12.patch at the bottom of this page. The patch is tested on version pjsip-1.12.
 
- 0. You need to implement reachability API (sample is provided in the patch). With this API we can monitor the access point connection status and perform re-registration when necessary.
- 1. We need to keep track of which transport is being used by the registration, by implementing the {{{on_reg_state2()}}} and {{{on_transport_state()}}} callbacks. Add reference counter to it to prevent other from deleting the transport while we're referencing it (it shouldn't happen while the registration is active, but just in case). Sample code:
+ 1. You need to implement reachability API (sample is provided in the patch). With this API we can monitor the access point connection status and perform re-registration when necessary.
+ 2. We need to keep track of which transport is being used by the registration, by implementing the {{{on_reg_state2()}}} and {{{on_transport_state()}}} callbacks. Add reference counter to it to prevent other from deleting the transport while we're referencing it (it shouldn't happen while the registration is active, but just in case). Sample code:
  {{{
 static pjsua_acc_id the_acc_id;
@@ -176 +176 @@
 }
  }}}
-
- 2. When IP address change is detected: a) close the TCP transport that we saved in step 1) above, and b) send unregistration. Sample code:
+ Starting from release 2.4, we have a new callback {{{on_reg_started2()}}} (for more details, please refer to ticket #1825), which allows application to get the transport much earlier, i.e. when the registration process begins. This allows application to close the transport before connecting state. So, you can choose to split the implementation in {{{on_reg_state2()}}} above into two callbacks {{{on_reg_started2()}}} and {{{on_reg_state2()}}}:
+ {{{
+static void on_reg_started2(pjsua_acc_id acc_id, pjsua_reg_info *info)
+{
+   struct pjsip_regc_cbparam *rp = info->cbparam;
+
+ 
+    ...
+    if (acc_id != the_acc_id)
+        return;
+
+    if (the_transport != rp->rdata->tp_info.transport) {
+        /* Registration success */
+        if (the_transport) {
+            PJ_LOG(3,(THIS_FILE, "xxx: Releasing transport.."));
+            pjsip_transport_dec_ref(the_transport);
+            the_transport = NULL;
+        }
+        /* Save transport instance so that we can close it later when
+         * new IP address is detected.
+         */
+        PJ_LOG(3,(THIS_FILE, "xxx: Saving transport.."));
+        the_transport = rp->rdata->tp_info.transport;
+        pjsip_transport_add_ref(the_transport);
+     }
+}
+
+static void on_reg_state2(pjsua_acc_id acc_id, pjsua_reg_info *info)
+{
+   struct pjsip_regc_cbparam *rp = info->cbparam;
+
+ 
+    ...
+    if (acc_id != the_acc_id)
+        return;
+
+    if (rp->code/100 == 2 && rp->expiration > 0 && rp->contact_cnt > 0) {
+        /* We already saved the transport instance */
+    } else {
+        if (the_transport) {
+            PJ_LOG(3,(THIS_FILE, "xxx: Releasing transport.."));
+            pjsip_transport_dec_ref(the_transport);
+            the_transport = NULL;
+        }
+    }
+    ...
+}
+ }}}
+
+ 3. When IP address change is detected: a) close the TCP transport that we saved in step 2) above, and b) send unregistration. Sample code:
  {{{
 static void ip_change()
@@ -199 +247 @@
 }}}
 
- 3. And finally, once unregistration in 2b) above is complete, re-register (with TCP). 
+ 4. And finally, once unregistration in 2b) above is complete, re-register (with TCP).