IOS app with SIP concept to connect to server

I am trying to create an iOS application with SIP concept. I need to register on a server and make both incoming and outgoing calls. So I am going through this document . I have completed the Prepare to Build step . Then I started the next step, Building PJSIP . I have already downloaded the PJSIP Source from this.

Downloadable filename: pjproject-2.4

One of the subfolders: pjsip

Pjsip subdirectory list: no dir .

I don't know how to execute this "$ cd / path / to / your / pjsip / dir" statement in a terminal.

What I did in the terminal:

$ cd /Users/abc_123/Downloads/pjproject-2.4

      

        
        
        
      

    

I don't understand what the line is /path/to/your/pjsip/dir

, so just drag and drop the file pjproject-2.4

into the terminal.

Further, if I tried the second operator (for iPhone 5), $ ARCH = '- arch armv7s' ./ configure-iphone && & & make dep && make clean && make from here

The terminal looks like this:

-bash: ./configure-iphone: Permission denied

      

        
        
        
      

    

I don't know how to accomplish this. Please help me.

I have gone through all of the following documents. iOS: Open Source VoIP / SIP Objective-C Code , How to Implement VoIP + SIP in iPhone?

Is there any wise coding tutorial on how to connect Objective C or Swift using SIP and VoIP or SDK or API? I am very new to this concept. Please guide me.