Re: [Linphone-developers] Network reachability callback problem in Linphone iPhone

[Albrecht Andrzejewski]

Ivan, are you saying that you manage to have NetworkReachability callbacks 
calls in background mode by using NSStream API instead of the old C socket API ?


Le 5 juil. 2012 à 08:55, IVAN FERNANDEZ a écrit :

> Hi again,
> 
> I've been around this issue for some days, and finally the problem looks to 
> be closely related with the NSStreamNetworkServiceTypeVoIp connection mode,
> 
> Looks like a suspended app only could listen to connectivity changes once it 
> has established an active NSStreamNetworkServiceTypeVoIp connection with the 
> remote server.
> 
> That explains why Reachability sample is not responding to the connectivity 
> changes in background mode (no NSStreamNetworkServiceTypeVoIp connection 
> within the app) and why the voip app neither responds if wifi's off on first 
> launch...
> 
> So, looks like some kind of workaround will be needed for this one...
> 
> 
> 2012/6/28 IVAN FERNANDEZ <address@hidden>
> Hi,
> 
> I've spent several days with this issue but I haven't found a complete 
> solution... for some reason that I can't understand, network changes control 
> for Linphone based on SCNetworkReachability API only works if there is a 
> valid wifi connection when the app is launched (for the moment, I'm only 
> interested in only wifi mode)
> 
> In order to simplificate and avoid some problems on changes between wwan/wifi 
> connection, I've finally replaced the SCNetworkReachability API operations in 
> Linphone code. 
> 
> For my workaround, I used the Reachability class provided by Apple (v2.2), 
> with the following changes on LinphoneManager.m code:
> 
> -(void) setupNetworkReachabilityCallback: (const char*) nodeName 
> withContext:(SCNetworkReachabilityContext*) ctx {
> 
>     //add changes observer    
> 
>    [[NSNotificationCenter defaultCenter] addObserver: self selector: 
> @selector(reachabilityChanged:) name: kReachabilityChangedNotification 
> object: nil];
> 
>     internetReachable = [[Reachability reachabilityForInternetConnection] 
> retain];
> 
>     [internetReachable startNotifier];
> 
>     //launch initial check
> 
>     [self reachabilityChanged: nil];
> 
> }
> 
> 
> - (void)reachabilityChanged:(NSNotification *)notice {
> 
>     // called after network status changes
> 
>     LinphoneProxyConfig* proxy;
> 
>     linphone_core_get_default_proxy([LinphoneManager getLc], &proxy);
> 
>     BOOL isWifiOnly = [[NSUserDefaults standardUserDefaults] 
> boolForKey:@"wifi_only_preference"];
> 
> 
> 
>     NetworkStatus internetStatus = [internetReachable 
> currentReachabilityStatus];
> 
>     if (internetStatus == ReachableViaWiFi) {
> 
>         NSLog(@"Internet accesible via wifi...");
> 
>         linphone_core_set_network_reachable([LinphoneManager getLc],true);
> 
>         if (proxy)  linphone_proxy_config_expires(proxy, DEFAULT_EXPIRES);
> 
>     }
> 
>     else if (internetStatus != NotReachable && !isWifiOnly) {
> 
>         NSLog(@"Internet accesible via wwan...");
> 
>         linphone_core_set_network_reachable([LinphoneManager getLc],true);
> 
>         if (proxy)  linphone_proxy_config_expires(proxy, DEFAULT_EXPIRES);
> 
>     }
> 
>     else
> 
>        [[LinphoneManager instance] kickOffNetworkConnection];
> 
> }
> 
> 
> 
> For the moment, this workaround is working great if wifi is up when you 
> launch the app. But if the app is launched without wifi connection -> then 
> goes background -> then wifi goes up, the app will not register untill it is 
> relaunched or the re-register timer (600s) expires (before that all works as 
> espected). 
> 
> I've tried dozens of solutions, combinations, test... but that's the better 
> approach I could get... Anyone can see a better solution to the problem?
> 
> What do you think about that code replacement? Could it bring some other 
> problems on other scenarios?
> 
> Thanks in advanced,
> 
> IvánF
> 
> 
> 
> 2012/6/23 Jehan Monnier <address@hidden>
> Hi,
> Very interesting indeed. 
> Let us know the outcomes of your further findings.
> Cheers
> 
> Jehan
> www.linphone.org
> 
> 
> 
> 
> 
> 
> Le 20 juin 2012 à 13:48, IVAN FERNANDEZ a écrit :
> 
>> Hi,
>> 
>> I'm facing an strange problem with the callback that detects network changes 
>> in Linphone code.
>> 
>> The problem is that the callback is being called correctly when the wifi 
>> goes off, but it is not called again when the wifi goes on.
>> 
>> I'm running two test (iPhone 4 iOS 5.1.1, Linphone 1.1.2 with TLS enabled):
>> 
>> 1. Wifi set to ON: I run Linphone from xcode ->wait the registration in the 
>> server -> then I go to the settings and switch off wifi -> the callback is 
>> called -> ALL IS GREAT -> then I switch wifi on again... -> the callback is 
>> not called -> ;-/
>> 
>> 2. Wifi set to OFF: I run Linphone from xcode -> no connection so the 
>> registration can not be done -> then I go to the settings and switch on wifi 
>> -> the callback is not called -> ;-/
>> 
>> Let's take a look to the callback:
>> 
>> void networkReachabilityCallBack(SCNetworkReachabilityRef target, 
>> SCNetworkReachabilityFlags flags, void* nilCtx) {
>> 
>>      ms_message("Network connection flag [%x]",flags);
>> 
>>     
>>      LinphoneManager* lLinphoneMgr = [LinphoneManager instance];
>> 
>>      SCNetworkReachabilityFlags 
>> networkDownFlags=kSCNetworkReachabilityFlagsConnectionRequired 
>> |kSCNetworkReachabilityFlagsConnectionOnTraffic;
>> 
>> 
>>      if ([LinphoneManager getLc] != nil) {
>> 
>>           LinphoneProxyConfig* proxy;
>> 
>>           linphone_core_get_default_proxy([LinphoneManager getLc], &proxy);
>> 
>> 
>> 
>>           struct NetworkReachabilityContext* ctx = nilCtx ? ((struct 
>> NetworkReachabilityContext*)nilCtx) : 0;
>> 
>>         
>>           if ((flags == 0) | (flags & networkDownFlags)) {
>> 
>> 
>> 
>>                  [lLinphoneMgr kickOffNetworkConnection];
>> 
>>                  //COMMENTING THE FOLLOWING LINE THE PROBLEM IS PARCIALLY 
>> SOLVED !!!!!!!!!!!!
>> 
>>                  linphone_core_set_network_reachable([LinphoneManager 
>> getLc],false);
>> 
>>                  lLinphoneMgr.connectivity = none;
>> 
>>             
>>      } else {
>> 
>> 
>> 
>>             Connectivity  newConnectivity;
>> 
>>             BOOL isWifiOnly = [[NSUserDefaults standardUserDefaults] 
>> boolForKey:@"wifi_only_preference"];
>> 
>>             if (!ctx || ctx->testWWan)
>> 
>>                 newConnectivity = flags & kSCNetworkReachabilityFlagsIsWWAN 
>> ? wwan:wifi;
>> 
>>             else
>> 
>>                 newConnectivity = wifi;
>> 
>> 
>> 
>>             if (newConnectivity == wwan && proxy && isWifiOnly && 
>> (lLinphoneMgr.connectivity == newConnectivity || lLinphoneMgr.connectivity 
>> == none)) {
>> 
>>                     linphone_proxy_config_expires(proxy, 0);
>> 
>>             } else if (proxy){
>> 
>>                     linphone_proxy_config_expires(proxy, DEFAULT_EXPIRES); 
>> //might be better to save the previous value
>> 
>>             }
>> 
>> 
>>             if (lLinphoneMgr.connectivity == none) {
>> 
>>                       linphone_core_set_network_reachable([LinphoneManager 
>> getLc],true);
>> 
>>             } else if (lLinphoneMgr.connectivity != newConnectivity) {
>> 
>>                       // connectivity has changed
>> 
>>                      linphone_core_set_network_reachable([LinphoneManager 
>> getLc],false);
>> 
>>                      if (newConnectivity == wwan && proxy && isWifiOnly) {
>> 
>>                               linphone_proxy_config_expires(proxy, 0);
>> 
>>                       } 
>> 
>>              linphone_core_set_network_reachable([LinphoneManager 
>> getLc],true);
>> 
>>               }
>> 
>>               lLinphoneMgr.connectivity=newConnectivity;
>> 
>>               ms_message("new network connectivity  of type 
>> [%s]",(newConnectivity==wifi?"wifi":"wwan"));
>> 
>>          }
>> 
>>           if (ctx && ctx->networkStateChanged) {
>> 
>>                   (*ctx->networkStateChanged)(lLinphoneMgr.connectivity);
>> 
>>             }
>> 
>>      }
>> 
>> }
>> 
>> 
>> 
>> The most curious thing is that if I comment the invocation to 
>> "linphone_core_set_network_reachable" that I've pointed in the callback the 
>> first test works great and the callback is called on both on/off wifi 
>> changes (what makes me suspect that the problem can be caused by a silly 
>> issue), but the second test remains failing.
>> 
>> ¿Anyone has that point running? ¿Any ideas about why the callback is not 
>> called any more at some point? 
>> 
>> PD: On Android, the same test with reachability works great on all the cases.
>> 
>> Thanks in advanced..
>> 

--------------------------
Albrecht Andrzejewski