对Linphone的封装，帮助快速移植
通过cocoapods安装。仓库更新 pod repo update
podfile文件eg:
platform :ios, '9.0'
source "https://gitlab.linphone.org/BC/public/podspec.git"
source "https://github.com/CocoaPods/Specs.git"
target 'linphonedemo2' do
use_frameworks!
pod 'linphone-sdk' , '4.3'
pod 'LinphoneIvna'
end
[[ESSipManager instance]login:@"10020" password:@"123456" displayName:@"10020" domain:@"" port:@"5060" withTransport:@"TCP"];
[[ESSipManager instance]call:@"10019" displayName:@"10019"];
[[ESSipManager instance]hangUpCall];
[NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(callDurationUpdate) userInfo:nil repeats:YES];
- (void)callDurationUpdate { int duration = linphone_core_get_current_call(LC) ? linphone_call_get_duration(linphone_core_get_current_call(LC)) : 0; self.timeLab.text = [LinphoneUtils durationToString:duration]; }